Fertilizer Recommendations for Vegetable Crops in Michigan

Extension Bulletin E-550B • Cooperative Extension Service • Michigan State University

March 1992 (Revision–destroy all previous editions)$1.25

This bulletin and bulletin E-550A are replacements for E-550, “Fertilizer Recommendations for Vegetableand Field Crops in Michigan.”

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Table of Contents

General Information

Nutrient Management and Water Quality ...........................................................................................3Soil Sampling.............................................................................................................................................4Soil Testing .................................................................................................................................................4Basis for Recommendations ....................................................................................................................5Soil Acidity and Liming...........................................................................................................................6

Major Nutrients ............................................................................................................................................8

Secondary Nutrients ....................................................................................................................................9

Micronutrients for Mineral and Organic Soils ......................................................................................10

Foliar Nutrient Applications......................................................................................................................14

Using Animal Manures and Other Organic Materials .........................................................................14

Suggested Fertilizer Management on Mineral soils .............................................................................16

Asparagus (crown production)...............................................................................................................17Asparagus (new planting) .......................................................................................................................20Asparagus (established planting)...........................................................................................................20Lima Beans, Snap Beans...........................................................................................................................20Carrots, Horseradish, Parsnip.................................................................................................................20Table Beets, Rutabagas .............................................................................................................................20Broccoli, Cabbage, Brussels Sprouts, Cauliflower ...............................................................................20Sweet Corn.................................................................................................................................................20Cucumbers .................................................................................................................................................20Muskmelons, Watermelons .....................................................................................................................21Peas ....................................................................................................................................................21Peppers ....................................................................................................................................................21Radishes, Turnips......................................................................................................................................21Tomatoes ....................................................................................................................................................21Rhubarb ....................................................................................................................................................21Market Gardens.........................................................................................................................................21

Suggested Fertilizer Management on Organic Soils.............................................................................22

Broccoli, Cabbage, Cauliflower...............................................................................................................22Carrots, Parsnips .......................................................................................................................................24Celery ....................................................................................................................................................24Lettuce, Spinach ........................................................................................................................................25Onions ....................................................................................................................................................25Peppermint, Spearmint ............................................................................................................................25Potatoes ....................................................................................................................................................25Sweet Corn.................................................................................................................................................25Table Beets, Swiss Chard, Radishes, Turnips, Rutabagas ...................................................................26Grass Sod....................................................................................................................................................26

Plant Tissue Analysis ..................................................................................................................................26

Reference Bulletins......................................................................................................................................27

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Fertilizer Recommendations for Vegetable Crops in Michigan

D.D. Warncke, D.R. Christenson, L.W. Jacobs, M.L. Vitosh, and B.H. ZandstraDepartments of Crop and Soil Sciences, and Horticulture

The Michigan StateUniversity Soil TestingLaboratory is an essential part ofsoil fertility educational pro-grams of the departments ofCrop and Soil Sciences andHorticulture through theCooperative Extension Service.Soil samples can be submitted tothe MSU Soil Testing Lab direct-ly or through your countyCooperative Extension office.

Information presented in thisbulletin allows Michigan veg-etable growers to develop effec-tive supplemental nutrient useprograms. Nutrient recommen-dations are based on a soil test,soil type, yield and past cropmanagement. Applying the rec-ommended nutrient rates withproper timing and incorporationminimizes the potential that fer-tilizers will be a source of sur-face or groundwater contamina-tion. For example, nutrientsapplied near the time of greatestuptake demand by the crop areused most efficiently.

Many types and grades of fer-tilizer are available, and thenitrogen phosphorus and potas-sium requirements of crops canbe met in a variety of ways.

This bulletin contains recom-mendations for both mineraland organic soils. Any soil con-taining more than 30 percentorganic matter is considered tobe an organic soil. Soils contain-ing less than 20 percent organic

matter are considered mineralsoils. Those with organic mattercontents between 20 and 30 per-cent may fall into either catego-ry, depending on the clay con-tent. The MSU Soil Testing Labuses a bulk density of 0.80g/cm3 to classify soils; thoseabove 0.80 are handled as miner-al soils and those below 0.80 arehandled as organic soils.

Nutrient Managementand Water Quality

Agriculture is coming undercloser scrutiny as a contributorto non-point source pollution.When nutrients are added to thesoil-plant system in great excessof what the crop and soil biolo-gy can use, the risk of losingnutrients to groundwater andsurface waters increases.Climate, soil type, slope of theland, ground cover and soil fer-tility levels, as well as farmingmethods, can influence the fateof nutrients applied to the soil.For instance, on sloping landconservation tillage practicesand fertilizer incorporation orplacement beneath the soil sur-face reduces runoff loss.

Adding excess nutrients tosoil can cause phosphorus toaccumulate in the upper soilprofile and increases the risk ofcontaminating surface waterswith phosphorus where runoffand erosion occur. It also canlead to nitrates being leached

through the soil and intogroundwater, create nutrientimbalances in soils which maycause poor plant growth, andresult in economic loss for theproducer. Avoid adding excessnutrients by soil testing at regu-lar intervals, giving nitrogencredits for previous legumecrops, giving credit for nutrientsfrom additions of manures andorganic materials, establishingrealistic yield goals and follow-ing the fertilizer recommenda-tions discussed in this bulletin.

As phosphorus concentra-tions in soils increase, the risk oflosing phosphorus bound to soilparticles under erosive condi-tions also increases. Therefore,implement adequate soil andwater conservation practiceswhich control runoff and ero-sion. For example, conservationtillage can enhance infiltration ofwater into soils, thereby reduc-ing runoff, soil erosion and asso-ciated phosphorus loadings tosurface waters.

Loss of nitrates to groundwa-ter is a major concern sincewater with a concentration inexcess of 10 parts per millionnitrate-nitrogen may pose ahealth hazard. Since about halfof all Michigan residents obtaindrinking water from groundwa-ter, maintaining good qualitygroundwater is important.Therefore, do not exceed thenitrogen fertilizer recommenda-

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tions given for vegetable cropproduction.

Make an all-out effort toadopt nutrient managementpractices that provide the neces-sary quantities of nutrients toachieve optimum yields withoutadding excessive nutrients thatmay increase the risk of pollut-ing surfacewater and groundwa-ter. Adding quantities of nutri-ents that supply the needs of thecrop without causing excessivenutrient loading achieves twodesirable goals. First, efficientuse of nutrients for crop produc-tion will yield economic benefitsto the crop producer. Second,protecting surface water andgroundwater quality frompotential non-point source con-tamination, due to agricultureactivities, can best be accom-plished when nutrients areapplied at recommended rates.See Extension bulletin WQ-25and NCR Research Publication310 listed in the references sec-tion for additional information.

Soil Sampling Soil samples must be repre-

sentative of the field, otherwisethe soil test results and fertilizerrecommendations are not reli-able or useful. Collect each soilsample with care. Fields onwhich annual vegetables aregrown should be sampled annu-ally, or at least every other year.For perennial vegetable crops,such as asparagus, samplingevery third year is acceptable.

Before sampling a field, checkfor differences in soil character-istics. A soil survey map will behelpful. Consider the produc-tivity, topography, texture,drainage, color of topsoil andpast crop management of thefield to be sampled. If these fea-tures are uniform throughout

the field, collect one compositesample of the topsoil for each 10acres. For non-uniform fields,collect a composite soil samplefor each distinctly different areaof significant economic size. Fora small market garden growerthis may be a quarter acre. For alarge cucumber grower this maybe 2 acres. In most situationssample to a depth of 8 or 9 inch-es. Soil samples are most easilycollected with a soil probe.

Each composite sampleshould consist of at least 20 sub-samples taken at random overthe field or designated area.Avoid sampling close to gravelroads, dead furrows, previouslocations of brush, lime ormanure piles or any unusualareas. Mix the subsamples well,breaking apart the soil cores orchunks, then place a pint of thesoil into a sample box and returnto your County CooperativeExtension Service (CES) office ormail to the MSU Soil TestingLab, Plant and Soil SciencesBuilding, East Lansing, MI48824-1325. Soil sample boxes,soil probes and instructions fortaking soil samples are availablefrom your County CES office.

Mineral Soils: Soil samplesmay be taken at any time duringthe year when the soil tempera-ture and moisture conditionspermit. In fields intensivelyfarmed for a long time, phos-phorus and potassium levelsmay have increased substantial-ly in the subsurface soil. If thesoil tests are in the mediumrange in the subsoil the phos-phorus and/or potassium rec-ommendation may be decreasedby 20 percent, especially fordeep-rooted crops. Collect a soilsample from the 9 to 16 inchdepth every five years to moni-tor subsoil nutrient levels.

Organic Soils: On organicsoils that have been in crop pro-duction for more than threeyears, the time of sampling isimportant. Considerableamounts of potassium mayleach over winter. The potassi-um recommendations given inTable 15 are for samples collect-ed in the fall and assume thepotassium test level willdecrease 25 percent over thewinter and early spring monthsbecause of leaching. For sam-ples collected between Marchand June, decrease these potassi-um recommendations by 25 per-cent. Acid and marl layers occurin some organic soils. As thesesoils subside, existing acid ormarl will eventually occur in therooting zone. Sample the sub-soil every five years to deter-mine the pH and monitor thenutrient status.

Soil TestingSoil testing is vitally impor-

tant to determine which plantnutrients to apply and to assurethat nutrient deficiencies do notoccur or limit plant growth.Applying fertilizers according tosoil test results helps maximizecrop yields, crop quality andeconomic returns. Many otherfactors also must be managedproperly for optimum crop pro-duction, including soil physicalproperties, irrigation, drainage,weeds, insects, diseases, timelyplanting, etc.

The following is a brief dis-cussion of the procedures usedin the Michigan State UniversitySoil Testing Laboratory.

Soil pH is determined on min-eral soils in a l:l soil:water sus-pension. For organic soils a 1:2soil:water suspension is used.

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Lime requirement is deter-mined using the Shoemaker-McLean-Pratt (SMP) buffermethod. See the section on“Acidity and Liming” for moreinformation.

Soil test values do not indicatethe actual level of nutrientsavailable in a soil. Availablenutrient levels as determined bysoil testing extractants providean indication or index of theavailable nutrient status of asoil.

Available soil phosphorus isextracted with the Bray-Kurtz P-l (weak acid) extractant exceptfor “marly organic” soils andcalcareous mineral soils. Forthese soils phosphorus availabil-ity is determined with 0.5 Nsodium bicarbonate (Olsenextractant). Exchangeablepotassium, calcium and magne-sium are extracted with l.0 Nneutral ammonium acetate.Recommendations for phospho-rus and potassium fertilizers arebased on soil test valuesobtained with these extractants.

Available manganese and zincare determined by extractionwith 0.l N HCl. Copper avail-ability is determined by l.0 NHCl extraction. Micronutrientlevels are expressed as parts permillion (ppm).

Mineral soil samples submit-ted to the Michigan StateUniversity Soil TestingLaboratory are extracted fromweighed samples. The amountsof nutrients extracted areexpressed as parts per 2 million,or pounds per acre, whichassumes that one acre of loamysoil 6 2/3 inches deep weighs 2million pounds. Organic soilsamples are measured by vol-ume because such materialsusually have much lower densi-

ties than mineral soils. Resultsfor organic soils are expressedon a volume acre furrow slicebasis (volume of one acre 6 2/3inches deep).

Available phosphorus, potas-sium, calcium and magnesiumare expressed as actual poundsof available element (P, K, Ca,Mg) per acre. However, somelaboratories express all nutrientsoil test values as parts per mil-lion. For mineral soils, 2 lb/A =1 ppm. For all soils the exactconversion relation varies withthe bulk density of the soil, butthis is most apparent withorganic soils. For example, foran organic soil with a bulk den-sity of 0.33 g/cm3, 0.5 lb/A = 1ppm. For soils with a bulk den-sity of 0.66 g/cm3, 1 lb/A = 1ppm.

A few laboratories reportphosphorus and potassium testvalues in terms of P2O5 and K2O.The factors to convert between Pand P205 and between K andK20 are: pounds P x 2.3 = pounds P205;or pounds P2O5 x 0.44 = poundsPpounds K x l.2 = pounds K20; orpounds K2O x 0.83 = pounds K.

The fertilizer recommenda-tions are given in pounds ofphosphate (P205) and potash(K20) per acre because fertilizersare expressed and sold in theseterms.

Basis forRecommendations

Field studies conducted overthe years provide the basis forthese nutrient recommenda-tions. Nutrient soil test levelshave been correlated withresponses of crops to appliednutrients. Where insufficientfield data are available, nutrient

recommendations are based onconsiderations of crop removaland soil test levels combinedwith field data from similar soiland crop systems. Phosphorusand potassium recommenda-tions provided by MSU providefor a buildup when soil tests arelow, maintain desirable nutrientlevels when soil tests are medi-um to high, and allow for gradu-al drawdown of available nutri-ent levels when soil tests arevery high. To determine if a rec-ommendation will result inbuildup or maintenance of thepresent soil test level use Table1. A maintenance recommenda-tion is equal to crop removal ofnutrients, whereas buildupoccurs when the recommenda-tion exceeds crop removal.When the soil test levels of phos-phorus and potassium are lowto medium, the total amount ofphosphorus and potassium rec-ommended includes both thebuildup and maintenanceamounts. A gradual buildup toan optimal level occurs in aboutfive years. Applying morenutrients than recommendedresults in a more rapid buildup.

When available phosphorusor potassium levels are high,very little or no fertilizer is rec-ommended, allowing the crop toutilize the nutrients available inthe soil. This causes a gradualdecrease in phosphorus andpotassium levels. The actualrate of decrease depends on thesoil type, the crop grown andthe yield. As the soil test levelapproaches the desirable range(medium to high), the recom-mendation again approachesmaintenance. Soil testing eachfield annually helps monitorchanges in available nutrientlevels. Before adopting a con-servation tillage system of crop

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production, build up availablephosphorus and potassium tomedium or high levels.

Within the limits of a givenmanagement system, the avail-able nutrient level in the soil andthe rate of nutrients appliedaffect the quality and yield ofmany vegetable crops.However, with high availablenutrient levels in the soil, apply-ing more fertilizer will not resultin higher yields. Under this sit-uation higher yields will onlycome with improvements in themanagement system. For exam-ple, a tomato grower produces30 tons per acre with a good fer-tility program, and increasingthe fertilizer application ratedoes not increase the yield. Bygoing to twin rows on raisedbeds, a yield of 40 tons/A is pro-duced. Additional nutrientsneed to be applied to maintainthe level of nutrients in the soil.In this and similar vegetableproduction situations, the yieldaffects the fertilizer rate ratherthan the fertilizer rate affectingthe yield. The phosphorus andpotassium recommendationsgiven in this bulletin are forgood yields (see bulletin E-1565,“Yields of Michigan VegetableCrops”) of the listed vegetables.When higher yields than theseare produced consistently over3-5 years, increase the nutrientrecommendation by the amountnecessary to maintain the nutri-ent status of the soil (see Table 1).

The yield potential of a givenfield must be based on pastexperience and good judgment.Fertilizing to reach a yield thatcannot be attained because ofother limiting factors only incursneedless costs. Nutrients accu-mulated above a level wherecrop response occurs may lead

Table 1. Approximate nutrient removal in the harvested portion ofseveral Michigan vegetable crops.

Crop Yield - - - lb/acre - - - - - - lb/cwt - - -

tons/A N P2O5 K2O N P2O5 K2O

Asparagus 1.5 20 6 15 .67 .20 .50Beans, snap 4.0 40 18 40 1.20 .12 .55Broccoli 5.0 20 5 55 .20 .05 .55Cabbage 20.0 140 32 140 .35 .08 .35Carrots 17.5 70 32 120 .17 .09 .34Cauliflower 8.0 55 21 55 .33 .13 .33Celery 30.0 150 60 480 .25 .10 .80Cucumbers 10.0 20 12 36 .10 .06 .18Lettuce 20.0 100 40 180 .24 .10 .45Muskmelon 9.0 75 18 100 .42 .10 .55Onions 20.0 100 50 95 .25 .13 .24Peas, shelled 1.5 30 7 15 1.00 .23 .50Peppers 12.5 50 18 70 .20 .07 .28Pumpkins 20.0 80 22 135 .20 .06 .34Sweet Corn 9.0 75 25 50 .42 .14 .28Squash 15.0 55 24 100 .18 .08 .33Tomatoes 30.0 120 25 210 .20 .04 .35

1 ton = 20 cwt

to deleterious effects on the soiland the crop. It also mayincrease the potential for envi-ronmental pollution due to ero-sion and/or leaching of nutri-ents into surface water orgroundwater.

Fertilizers are most effectiveon well-drained soils with favor-able structure that promotesdeep rooting. Too much tillagecan cause compaction, destroysoil structure and lower fertilizeruse efficiency.

Soil Acidity and LimingSoil reaction is expressed as

pH. A soil having a pH of 7.0 isneutral—neither acid nor alka-line. A soil having a pH of 6.0 ismildly acid; pH 5.0 is morestrongly acid, while pH 8.0 ismildly alkaline. Most well-drained Michigan soils, in their

natural state, have a pH lowerthan 7.0. This is desirable fromthe standpoint of availability ofmost nutrients.

Do not apply more than 6tons of lime per acre in any oneseason. Applying more maycause localized zones of highalkalinity, reducing the avail-ability of essential nutrients.Retest soil with a lime index of6.4, or below, two years afterlime application to determine ifmore lime is needed. When thelime need is greater than 4 tonsper acre, apply the lime in a splitapplication; i.e., half beforeplowing and half after plowing.This is more effective in neutral-izing the acidity in the plowlayer than one large application.

When growing crops wherescab is a potential problem, suchas potato and radish, maintainthe pH below 6.0. When lime is

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needed do not exceed 2 tons oflime per acre at any one timeand apply it in the fall. For no-till production, base lime needon the pH of the top 3 inches ofsoil and the lime rate will beone-third of that given in Table 2.

Mineral Soils: Plant nutri-ents, particularly phosphorus,are most available in mineralsoils having a pH between 6.0and 7.0. For most vegetablecrops, it is recommended thatacid soils be limed to pH 6.5.

The estimated lime require-ment of acid soil samples sub-mitted to the MSU laboratory isdetermined by measuring thetotal soluble and exchangeablehydrogen and aluminum con-tent. This is determined usingthe SMP buffer method. Thedegree of acidity is reported as

the lime index. This method ofdetermining the lime require-ment is more precise than esti-mates made from soil pH mea-surements alone because itmeasures total acidity instead ofjust the active acidity of the soil.Table 2 shows the amount oflimestone recommended basedupon the lime index value formineral soils.

Applying less than l ton oflime per acre is of questionableeconomic value. When the limerequirement is less than 1 tonper acre, soil pH is usually ade-quate for optimum crop pro-duction. Retest these soilsannually to determine whenliming is necessary.

Organic Soils: Within eachorganic soil series, acidity oralkalinity varies, except thatGreenwood is always quite acid.

Liming most organic soils doesnot benefit the production ofmost crops unless the soil pH isbelow 5.3 (1:2 soil:water suspen-sion). Celery is the exception,requiring a pH of 5.8 or higher.Lime recommendations aregiven in Table 2 for soils with apH below 5.3. In some cases, thetop foot of soil may have a pHaround 5.5 and the second foot apH around 4.5, or it may bealkaline. If the soil is ploweddeeply enough to bring some ofthe subsoil to the surface, theplow layer pH and lime require-ment will change. Therefore, thelime requirement is best basedon a soil sample taken afterplowing. Periodic sampling ofthe subsoil provides a forewarn-ing of potential pH changes.

Table 2. Tons of limestone needed to raise the soil pH of mineral soils to pH 6.0, 6.5, or 6.8 as related toLime Index and tons of limestone needed to raise soil pH of organic soils to 5.2 as related to soil pH.

Mineral Soils Organic Soils Lime Raise Soil pH to: Soil Lime Index 6.0 6.5 6.8 pH Needed

- - - - tons/acre - - - - tons/acre70 0.0 0.0 0.0 5.2 0.068 1.2 1.6 1.8 5.0 1.566 2.7 3.5 3.9 4.8 2.964 4.3 5.3 5.9 4.4 5.862 5.8 7.2 8.0 4.2 7.260 7.4 9.1 10.0 3.8 10.0

Recommendations are based on the following equations and rounded to the nearest tenth of a ton:Mineral Soils:

To pH 6.0 XL = 54.2 - (0.78 x LI)To pH 6.5 XL = 65.5 - (0.94 x LI)To pH 6.8 XL = 71.2 - (1.02 x LI)

Organic Soils:XL = 37.0 - (7.1 x pH)

where: XL = Lime recommendation in tons/acreLI = Lime IndexpH = soil pH

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Major NutrientsNITROGEN (N): A reliable

soil test for determining long-term nitrogen availability hasnot been developed in the GreatLakes states. However, a pre-sidedress soil nitrate test canhelp determine the appropriaterate of nitrogen to apply at thattime. Nitrogen need depends onthe crop to be grown, yield goaland previous management prac-tices. Nitrogen recommenda-tions for vegetables grown onmineral and organic soils aregiven in Table 9 and 13, respec-tively.

Give credit for all nitrogensources present in a crop man-agement system. Althoughlegumes are not commonly partof vegetable production sys-tems, they are a source of nitro-gen. When alfalfa or clover isthe previous crop, a nitrogencredit is given based on percentstand according to the equation:pounds of N credit equals 40 +(0.60 times percent stand) where5 to 6 plants per square foot isconsidered to be a 100 percentstand. When soybean is the pre-vious crop, take a nitrogen creditof 40 lb/A. Base nitrogen creditfor animal manures on an analy-ses of the manure since thenitrogen content varies withmanure type and the handlingsystem.

Several nitrogen carriers aresuitable for vegetable crop pro-duction. Studies with a numberof different vegetable cropsshow yields and quality to bebest when nitrogen is present inboth the ammonium and nitrateforms. Under special condi-tions, such as for plants growingin cold soils or on recently fumi-gated land, nitrate-containingfertilizers are preferred. Oncesoils have warmed above 50° F,

the microbial conversion ofnitrogen from ammonium tonitrate occurs quite readily.Hence, for most vegetable pro-duction situations, the variousnitrogen carriers are equallyeffective and can be purchasedon the basis of cost, convenienceof handling and supply. Usingcalcium nitrate on sandy soilslow in exchangeable calcium canhelp alleviate blossom-end-rotand tipburn problems for sensi-tive vegetable crops.Sidedressing celery, which has ahigh potassium requirement,with potassium nitrate can bebeneficial. These are examplesof situations where the moreexpensive double-nutrient nitro-gen carriers can be used effec-tively.

Improve the efficiency of sup-plemental nitrogen and mini-mize nitrate pollution of surfacewater and groundwater byusing recommended nitrogenrates and timely nitrogen appli-cation. Fall nitrogen applicationfor vegetable production is notrecommended. Applying nitro-gen as close as possible to thetime of maximum crop demandincreases the efficiency of useand minimizes the potential forleaching loss. Apply preplantnitrogen as close to plantingtime as possible. Include somenitrogen in the starter fertilizerand sidedress the majority of thenitrogen prior to peak demand.A pre-sidedress soil nitrate testcan help determine the mosteffective nitrogen rate.Supplemental nitrogen also canbe applied through the irrigationsystem. Proper scheduling ofirrigation water to minimizeleaching minimizes nitrogen lossby leaching and denitrificationand maximizes efficiency.

Most nitrogen carriers leave

an acidic residue in the soil. Itrequires about 2 pounds of lime-stone to neutralize the acidifyingeffect of each pound of nitrogenderived from urea, ammoniumnitrate or nitrogen solutions,and 5.5 pounds for each poundof ammonium sulfate. Calciumnitrate and potassium nitratehave a very slight alkalineresidue which has little effect onthe soil pH.

PHOSPHORUS (P):Phosphorus fertilizers providetheir greatest benefit in stimulat-ing the growth of smallseedlings, particularly early inthe spring when the soil is cold.For crops seeded or transplantedwhen the soil is rather cool,below 55° F, band the requiredphosphorus (up to 100 lb P2O5

/A) one inch to the side and oneto two inches below the seed ortransplant. This decreases phos-phorus fixation and stimulatesearly growth. In soils with aphosphorus soil test above 180lb P per acre, including phos-phorus in the starter fertilizerusually does not improvegrowth, quality or yield.Phosphorus recommendationsfor vegetable crops grown onmineral and organic soils aregiven in Tables 10 and 14,respectively.

Phosphorus recommenda-tions provide for phosphorusbuildup in low phosphorus soilsover a five-year period. Studiesshow that 5 to 11 pounds of P2O5

per acre are required to increasethe soil test by 1 pound P peracre in loamy sand and sandyloam soils. In loam and clayloam soils, 12 to 18 pounds ofP2O5 per acre are required. Usethese values to determine theamount of phosphate fertilizerrequired to build up the P soiltest to a desired level.

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Currently, more than 40 per-cent of the soils in Michiganused for vegetable productionhave very high levels of avail-able phosphorus. In these soilssome drawdown can be alloweduntil the soil test P level reachesan optimum level for the cropsbeing grown. At this pointmaintenance rates of phospho-rus can be used. The rate ofdrawdown is about equal to therate of buildup.

The primary phosphorus fer-tilizers are equally effective forvegetable production. Dryphosphate fertilizers marketedtoday are over 90 percent water-soluble, and liquid phosphatefertilizers are nearly 100 percentwater-soluble. When water-sol-uble phosphate, whether from adry or liquid carrier, is added tosoil it immediately reacts withthe soil to form insoluble phos-phorus compounds. Very littlewater-soluble phosphorusremains unless the fertilizer wasbanded in high concentrations.

Concentrated superphosphate(0-46-0) has a low salt index butcan delay seed germinationbecause it readily absorbs soilmoisture. Placement of thismaterial is especially critical indry soil conditions.

Ammonium phosphates havehigh salt effects and must beplaced away from the seeds ortransplants. More caution isrequired with diammoniumphosphate (DAP) than themonoammonium (MAP) formbecause of the possible release ofammonia into the soil system.With adequate soil moisture thishazard is minimal.

POTASSIUM (K): The potas-sium-supplying ability of a soilis related to the types andamounts of clay minerals pre-

sent. Depending on soil texture,2 to 6 pounds of potash (K2O)are required to increase the soiltest by 1 pound K per acre. Thepresent potassium soil test canpredict the potassium-supplyingability of most Michigan soils.However, some soils high in ver-miculite fix potassium in formsthat are not readily available forplant uptake. Routine soil test-ing does not determine the vari-ous types of clay minerals or thefixing capacity of a soil. Soilscontaining vermiculitic claysmay require very high rates ofpotash (K2O) to build up theavailable soil potassium. Oncethese soils have a medium tohigh potassium test level theycontinue to supply potassiumfor some time, even though cropremoval may be high.Potassium fertilizer can bebroadcast in the fall for buildupon fine-textured soils. Fallapplication of potash is not rec-ommended on loamy sand, sandand organic soils due to poten-tially significant leaching loss.

Potassium chloride whichcontains 60 percent K2O is themost common and cheapestsource of potassium. It is effec-tive in producing most veg-etable crops. Potassium sulfate,potassium-magnesium sulfateand potassium nitrate are othereffective potassium carriers thatare used for special cropping sit-uations. These are used to main-tain a low chloride level andprovide one of the other essen-tial elements.

Young developing vegetableseedlings and transplantsrequire less potassium thanphosphorus. However, whenplants reach the rapid growthstage they use large amounts ofpotassium. Crop removal ofpotassium is particularly heavy

when a large proportion of theplant is harvested, especiallywith celery, cabbage and lettuce.

Potassium applied in bandedfertilizer is equally effective orsuperior to broadcast potassium.The amount of potassium thatcan be applied in a band nearthe seed is limited because ofpossible salt injury. For this rea-son broadcast the bulk of thepotassium needed, but includesome (up to 50 lb K2O/A) in thebanded starter fertilizer.

Secondary NutrientsMAGNESIUM (Mg): Apply

magnesium when the exchange-able magnesium level is below75 lb/A; or when potassiumexceeds magnesium as a percentof the total exchangeable bases(calcium + magnesium + potas-sium, expressed in chemicalequivalents); or when the soilmagnesium level as a percent oftotal bases is less than 3 percent.Any one of these three criteriaindicates a potential magnesiumdeficiency. Thus magnesiumdeficiency may be induced byhigh rates of potassium. Onacid soils apply dolomitic lime-stone at the rate needed to raisethe soil pH to near 6.5. On acidsoils not needing pH adjust-ment, broadcast 1000 pounds ofdolomitic lime per acre. Onnon-acid soils needing magne-sium use 70 to 100 pounds ofmagnesium per acre broadcast,or 10 to 20 pounds banded nearthe row. Magnesium sulfate,potash-magnesium sulfate andfinely ground magnesium oxideare satisfactory non-lime sourcesof magnesium.

Magnesium also can beapplied in a foliar spray. Use 10to 20 pounds of magnesium sul-fate (Epsom salts) per acre in at

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least 30 gallons of water. Thissupplies 1 to 2 lb actual magne-sium per acre.

Mineral Soils: Magnesiumdeficiency is most likely to occurin acid soils with sandy loam,loamy sand or sand surface soiltexture and a coarse or coarsersubsoil. Deficiency also occursin similar soils limed with cal-citic limestone or marl. A mag-nesium soil test will indicatewhen a dolomitic (magnesium-containing) limestone is needed.A higher percentage of the soilsin western and southwesternMichigan tend to test low inmagnesium than in other partsof the state. Responsive cropsinclude cauliflower, celery,muskmelons, potatoes, peas andsweet corn.

Organic Soils: High calciumlevels in organic soils contributeto magnesium deficiency inresponsive crops. Apply sup-plemental Mg on soils having aMg soil test less than 150 lb/A.

CALCIUM (Ca): Disorderssuch as blossom-end rot in pep-pers and tomatoes, black heartin celery, and internal tip burn ofcabbage and lettuce are attribut-ed to calcium deficiency. Thesedisorders often occur on soilshigh in calcium. They are morerelated to environmental factorsthat influence calcium uptakeand movement within the plantthan to low calcium levels in thesoil. Calcium deficiency fre-quently is preceded by a periodof moisture stress within theplant. Maintaining a very highsoil potassium level also cancontribute to calcium-relateddisorders. Having all of thenitrogen supplied to the root inthe ammonium form contributesto calcium-related disorders.However this situation rarelyoccurs in a natural soil system.

Because ammonium nitrogen isconverted readily to the nitrateform, the form of nitrogen hasminimal effect on calciumuptake by vegetables in fieldsoils.

Mineral Soils: Well-limedsoils contain high levels of avail-able calcium. Even soils need-ing lime to neutralize excessacidity generally contain suffi-cient soluble calcium for goodplant growth. Poor growth ofplants on acid soils is usuallydue to excess soluble man-ganese, iron or aluminum ratherthan calcium deficiency.Available (exchangeable) calci-um levels are related directly tothe clay content of a soil. Thus,the lowest available calcium lev-els occur in sandy soils.Vegetable crops grown on sandysoils having a calcium soil test ofless than 500 lb/A may benefitfrom applying supplemental cal-cium. Band applications, eitherprior to planting or by side-dressing, or foliar applicationare more effective than broad-cast applications.

Organic Soils: Organic soilscontain high levels of exchange-able and water-soluble calcium.

SULFUR (S): Sulfur is anessential nutrient found inplants in about the same concen-tration as phosphorus. Sulfurdeficiency may be expected inintensive cropping systems,such as vegetable production, asthe result of increased use of fer-tilizers low in sulfur and fromthe cleanup of industrialsmokestacks which were asource of sulfur. However, fieldstudies with a number ofresponsive crops on severalpotentially sulfur-deficient sitesacross Michigan have not shownany benefit from sulfur applica-tion. Even though the surface

soils on these sites tested low,the subsurface soils suppliedmore than adequate quantitiesof sulfur to meet plant needs.

Sulfur deficiency in vegetablecrops is most likely to occur onlight-colored sandy soils.

Micronutrients forMineral and OrganicSoils

Micronutrient recommenda-tions are based on a soil test, soilpH and crop response. Manyvegetables benefit from theapplication of appropriatemicronutrients if conditions anda soil test indicate potentialneed. Table 3 lists many vegeta-bles grown in Michigan andhow they respond to the keyessential micronutrients. Therecommended rates given in therespective tables (Tables 4 to 7)for the various micronutrientsare for the highly responsivecrops. Recommended rates formedium-responsive crops areproportionately lower. A briefdiscussion of each micronutrientfollows.

MANGANESE (Mn):Manganese deficiency is proba-bly the most common micronu-trient deficiency in vegetablecrops grown in Michigan. Cropsmost likely to show signs ofmanganese deficiency includelettuce, onions, potatoes, radish-es, spinach and table beets.

Tables 4 and 5 provide guide-lines for rates of manganese toapply in a band with starter fer-tilizer for responsive crops.Suitable carriers are manganesesulfate, chelated materials (min-eral soils only) and finelyground manganous oxide.Neither granular manganousoxide nor any of the manganicforms are acceptable. Finely

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Table 3. Relative response of selected vegetable crops to micronutrients. The crops listed respond, asindicated, to applications of the listed micronutrient when the soil test for that micronutrient is low.

Crop Mn B Cu Zn Mo Fe

Asparagus low low low low low mediumBean, snap high low low high medium highBroccoli medium high medium high highCabbage medium medium medium low medium mediumCarrot medium medium medium low low Cauliflower medium high medium high highCelery medium high medium low Corn, sweet medium low medium high low mediumLettuce high medium high medium highOnion high low high high highParsnip medium medium medium lowPea high low low low medium Pepper medium low low mediumPotato high low low medium lowRadish high medium medium medium mediumRutabaga medium high medium low lowSpinach high medium high high high highTable beet high high high medium high highTomato medium medium high medium medium highTurnip medium high medium medium

ground manganous oxide thathas been regranulated is reason-ably effective. Broadcast appli-cation of manganese is not rec-ommended due to rapid fixationby soil when exposed to a largesoil surface. Foliar applicationof manganese is effective if bandapplication is not possible ordoes not completely alleviate thedeficiency. Apply 1 to 2 poundsmanganese per acre and reapply7 to 10 days later if new growthshows signs of manganese defi-ciency.

Mineral Soils: Low levels ofmanganese are most likely indark-colored surface soils inlake-bed or glacial outwashareas with a pH above 6.5. Sincemanganese availability decreas-es as soil pH increases, limingcan induce a manganese defi-

ciency on acid soils withmarginal available manganeselevels. Determining precise Mnavailability in soil is difficultbecause its availability changeswith oxidation state.Manganese applied to soil is oxi-dized readily to relativelyunavailable forms, especiallywhen broadcast. Flooding orfumigation of soils temporarilyincreases Mn availability.

Organic Soils: Manganesedeficiency is likely to occur onorganic soils with a pH above6.0. Very acid soils that havebeen limed usually show agreater need for supplementalMn than do soils with a natural-ly high pH. Organic soils quick-ly fix manganese so broadcastapplications are useless. Includemanganese in the planting-time

fertilizer placed near the seed ortransplant. Apply manganeseannually because there is verylittle carryover or residualbuildup of available Mn.Chelated forms of Mn are noteffective in organic soils and insoils high in iron. The chelateincreases the availability of iron,resulting in increased ironuptake which accentuates man-ganese deficiency.

BORON (B): Boron recom-mendations are based on cropresponse and soil pH. Three to 4pounds of boron per acre is sug-gested for broccoli, cauliflower,celery, table beets, turnips andrutabagas. Vegetables with amedium level of responsivenessto boron (see Table 3) generallybenefit from 1 to 2 pounds ofboron per acre.

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Mineral and Organic Soils:Plant-available boron occurs as aneutral compound or a negative-ly charged ion both of which aresubject to leaching. Becauseboron does not accumulate insoils, especially sandy andorganic soils, annual applica-

tions are necessary on these soilswhen growing responsive crops.Boron deficiency is most likelyto occur on sandy loams, loamysands, sand and organic soils.On the fine-textured soils, borondoes not leach as readily, sorequired rates will be lower. The

availability of boron decreasesas soil pH increases. Therefore,the rates recommended arehigher on the high pH soils. Forresponsive vegetable cropsboron is recommended (inpounds per acre) according tothe equation: 0.35 + (0.5 x pH).

Table 4. Manganese recommendations (band applied) for responsive crops grown on mineral soils.

Soil Soil pH Test 6.2 6.4 6.6 6.8 7.0 7.2 7.4 ppm - - - - - - - - - - lb Mn/acre - - - - - - - - - -

2 2 3 4 5 7 8 94 1 2 3 5 6 7 88 0 1 2 3 5 6 7 12 0 0 1 2 3 4 6 16 0 0 0 1 2 3 4 20 0 0 0 0 0 2 324 0 0 0 0 0 0 1

1Recommendations are calculated from the following equation and rounded to the nearest pound: XMn = -36 + (6.2 x pH) - (0.35 x ST)

where: XMn = lb Mn/acrepH = Soil pHST = Mn soil test in ppm

Table 5. Manganese fertilizer recommendations (band applied) for responsive crops grown on organicsoils.Soil Soil pH Test 5.8 6.0 6.2 6.4 6.6 6.8 7.0 ppm - - - - - - - - - - lb Mn/acre - - - - - - - - - -

2 2 4 5 7 9 10 12 4 1 3 5 6 8 10 11 8 0 1 3 5 7 8 10 12 0 0 2 4 6 7 9 16 0 0 1 3 4 6 8 20 0 0 0 1 3 5 6 24 0 0 0 0 2 4 5 28 0 0 0 0 1 2 4 32 0 0 0 0 0 1 336 0 0 0 0 0 0 1

1Recommendations are calculated from the following equation and rounded to the nearest pound: XMn = -46 + (8.38 x pH) - (0.31 x ST)

where: XMn = lb Mn/acrepH = soil pH ST = Mn soil test in ppm

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Table 6. Zinc recommendations (band applied) for responsivecrops grown on mineral and organic soils.1Soil Soil pH Test 6.7 7.0 7.3 7.6

ppm - - - - - - - - - - - - - lb Zn/acre - - - - - - - - - - - - -

1 1 3 4 6 2 1 2 4 54 0 1 3 46 0 0 2 48 0 0 1 310 0 0 0 212 0 0 0 1

1When chelates are used, these rates may be divided by 5.Recommendations are calculated from the following equation androunded to the nearest pound:

XZn = -32 + (5.0 x pH) - (0.4 x ST)

where: XZn = lb Zn/acrepH = Soil pHST = Zn soil test in ppm

For medium and low responsivevegetable crops, the boron rec-ommendation is one-half (0.5)and one-tenth (0.1) of that forhighly responsive crops. Neverapply boron for beans, cucum-bers and peas as they are subjectto boron injury. Applying high-er than recommended ratesleaves the possibility of signifi-cant residual B carryover whichcould injure sensitive crops.This is most likely to occur fol-lowing a dry fall and winter.

ZINC (Zn): Onions and sweetcorn are the vegetable cropsmost responsive to zinc.

Extractable (0.1 N HCl) zinccoupled with soil pH is a verygood indicator of zinc availabili-ty to plants. Zinc availabilitydecreases as pH increases;therefore, more zinc is recom-mended at higher pH levels fora given zinc soil test level.

Recommended rates in Table 6are for inorganic salts of zinc.Organic salts (chelates) are moreeffective and can be used at one-fifth the rates given. Granularforms of zinc oxide are not effec-tive. However, finely groundzinc oxide that has been regran-ulated is effective. Band appli-cations are suggested, butbroadcast applications areacceptable at higher rates.Unlike manganese, zinc remainsavailable in the soil. Annualapplications of zinc will buildup available zinc levels andgradually eliminate the need forsupplemental zinc. Retest thesoil after applying zinc for 3 or 4years. Foliar sprays of 0.5pound zinc per acre as zinc sul-fate effectively correct zinc defi-ciencies of growing plants.

Mineral Soils: Zinc deficien-cy is most common in respon-sive crops grown on the alkaline

lake-bed soils of easternMichigan. Other soils with a pHabove 7.0 also may have lowlevels of available zinc. Zincdeficiency is often seen in cropsgrowing on spoil banks andover tile lines where calcareoussubsoil is exposed, or on soilstesting high in available phos-phorus.

Organic Soils: Zinc deficien-cy is most likely to occur onnearly neutral or alkaline organ-ic soils.

COPPER (Cu): Lettuce,onions, spinach and table beetsare the vegetable crops mostresponsive to copper.Recommended rates of copperfor crops grown on organic soilsare given in Table 7.

Mineral Soils: The mineralsoils of Michigan contain ade-quate copper for growing veg-etables.

Organic Soils: Organic soilsare naturally low in copper.Copper applied to organic soilsis not leached easily and con-tributes to a buildup of availablesoil Cu. Organic soils that havebeen in crop production for 10or more years usually containadequate available copper.Usually no further copper fertil-ization is needed once a total of20 to 25 pounds per acre isapplied for low- or medium-responsive crops, and 40 poundsper acre for highly responsivecrops, or if the soil test exceeds20 ppm. Copper sulfate or oxideare the forms most commonlyused.

MOLYBDENUM (Mo):Molybdenum deficiency hasbeen noted on cauliflowergrown on mineral soils and oncauliflower, lettuce, spinach,cabbage and onions grown onorganic soils. The need for

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molybdenum is most acute insoils with a pH below 5.5. Soilswith a high iron content alsohave a greater potential forneeding supplemental molybde-num.

Foliar application is the mosteffective way to supply molyb-denum to plants. Spray 2ounces of sodium molybdate peracre in at least 30 gallons ofwater. Using a nonionic surfac-tant helps wet the leaves andenhances the absorption ofmolybdenum by the leaves. Forsensitive crops, such ascauliflower, and/or sensitivevarieties, apply every twoweeks. Treating the seed with0.5 ounce of sodium molybdateper acre is suggested forimproving the Mo status of thedeveloping seedling. Even withseed treatment one or morefoliar applications may be necessary.

Foliar NutrientApplications

Foliar application can be aneffective way to meet themicronutrient needs of veg-etable crops, especially when afertilizer program or the growthstage of the crop does not allowthe soil application of neededmicronutrients. For responsivecrops foliar sprays of manganeseand molybdenum are essentialsupplements, even when thesenutrients are applied to the soil.Recommended rates for foliarapplication of micronutrientsusing inorganic carriers aregiven in Table 8. Chelate carri-ers can be used, but be sure touse the labeled rate since apply-ing too much can cause foliarinjury. Some fungicides containsufficient amounts of zinc, man-ganese and/or copper to partial-ly or completely meet the need

for these nutrients, especially ifthe deficiency is marginal.Foliar sprays of magnesium andcalcium can benefit responsivecrops under certain soil and/orenvironmental conditions (seethe sections on Magnesium andCalcium for more information).

With a good soil fertility pro-gram, foliar sprays of nitrogen,phosphorus and potassium donot improve crop quality andyields. The amounts of thesenutrients that can be supplied infoliar sprays are small comparedwith the amounts used by thevegetable crops. However, foliarapplication of nitrogen at 4 to 5pounds per acre to vegetablescan help vegetable cropsthrough stress periods, especial-ly saturated soil conditionswhen poor aeration may limitroot activity and nutrientuptake.

Using Animal Manuresand Other OrganicMaterials

Manures, cull vegetable pro-duce and other organic materials(e.g., sewage sludge, septage,food processing wastes, fermen-tation wastes, leaves, etc.) can bea valuable source of essentialplant nutrients and organic mat-ter. The nutrient content ofmany of these materials variesgreatly, depending on thesource. Therefore, the use ofaverage nutrient contents can bevery misleading in calculatingnutrient credits. Have the mate-rial being considered for landapplication analyzed by a reli-able testing laboratory. Theanalyses should at least include:percent dry matter, ammonium-nitrogen, and total nitrogen,phosphorus and potassium.When used together with the

Table 7. Copper recommendations for crops grown on organicsoils.Soil Crop Response Test

Low Medium High

ppm - - - - - - - - lb Cu/acre - - - - - - - -

1 3 4 64 3 4 58 2 3 412 1 2 316 1 2 220 1 1 2 24 0 1 1

Recommendations are calculated from the following equations androunded to the nearest pound:

High Response crops XCu = 6 - (0.22 x ST)Medium Response crops XCu = (6 - (0.22 x ST)) x 0.75 Low Response crops XCu = (6 - (0.22 x ST)) x 0.50

where: XCu = lb Cu/acreST = Cu soil test in ppm

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Table 8. Recommended rates of secondary and micro-nutrients for foliar application.

Nutrient Lb. of element Common Sources1 % Elementper acre

Calcium 1-2 Calcium nitrate 19Magnesium 1-2 Magnesium sulfate 9Boron 0.1-0.3 Soluble sodium borate 20

Boric acid 17Copper 0.5-1.0 Basic copper sulfate 13-25Manganese 1.0-2.0 Soluble manganese sulfate 24Molybdenum 0.06 Sodium molybdate (2 ounces) 39Zinc 0.3-0.7 Zinc sulfate 36Iron 1.0-2.0 Ferrous sulfate 20-31

1 Chelated materials can be used at labeled rates. Use a minimum of 30 gallons of water per acre.

application rate, the analyseswill let you determine theamount of nutrients beingapplied and the nutrient creditsto take. Adjust the amount offertilizer to be applied accord-ingly. Wise use of nutrientresources can provide economicbenefits while maintaining thequality of the soil and waterenvironment.

Recycling nutrients andorganic matter, contained inorganic waste materials, back tocrop land is highly desirable.However, some hazards may beencountered when organicmaterials are applied to the soil-plant system for crop produc-tion if good management prac-tices are not followed. Thesecan include excessive loadingsof nutrients, additions of traceelements and trace organicchemicals, pathogens, soil physi-cal problems, odors and dis-eases. The MSU Department ofCrop and Soil Sciences can helpevaluate the benefits and/orrisks of applying a specificorganic material to crop land orcontact your local countyCooperative Extension Serviceoffice.

A number of managementpractices are suggested for pro-ducers using animal manuresand other organic materials forland application.

First, sample and test everyone to two years those fieldsthat are used for vegetable pro-duction and receiving frequentapplications of manure and/ororganic materials. Use the soiltest results to determine thenutrient needs for the crops tobe grown and to monitor thenutrient status of the soil sys-tem.

Second, have the manure ororganic material being appliedanalyzed for its nutrient content.Subtract the quantity of nutri-ents supplied in the manure ororganic material from the nutri-ent recommendations to deter-mine the need for additional fer-tilizer nutrients.

Third, do not exceed the rec-ommended nitrogen rate withthe amount of available nitrogenin the manure or organic materi-al plus the fertilizer used.

Fourth, follow soil and waterconservation practices to reducethe risk of nutrients entering

surface water. For practicesused to control runoff and ero-sion for a particular site, consid-er factors such as type ofmanure or organic materialbeing applied, surface residue orvegetative conditions, slope, soiltype, and proximity to surfacewater. Incorporate as soon aspossible applied materials tominimize odor problems and toprevent nutrient loss byvolatilization or runoff.

Fifth, keeping records ofmaterial analyses, soil testreports, and rates of manure ororganic material and fertilizerapplication for individual fieldshelps identify land areas neededfor effectively utilizing the nutri-ents from all sources. Goodrecord keeping demonstratesgood management and may behelpful if management practicesare challenged.

Suggested FertilizerManagement andRecommendations forVegetable Crops

Most vegetable crops requirerelatively high levels of fertilityfor good yields and satisfactory

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quality. Recommended nutrientrates are designed to meet theneeds of the growing vegetablecrops and gradually build uplow soil test levels over fiveyears. Once optimum soil testlevels are attained, develop amaintenance fertilization pro-gram by applying the nutrientsremoved by the vegetable crop.Table 1 lists the amounts ofnitrogen (N), phosphate (P2O5)and potash (K2O) removed bytypical yields of some Michiganvegetable crops.

Supplemental nutrients maybe applied for vegetable produc-tion in a combination of meth-ods; broadcast and incorporatedeither before or after plowing,placed in bands near the seed ortransplants, included in trans-plant water, sidedressed or top-dressed, or applied to thefoliage. Cover crops can cyclenutrients effectively. On sandysoils, use cover crops to take up

residual nitrogen and solublepotassium to prevent leachinginto groundwater and to preventwind erosion. Apply onlyenough nutrients to a cover cropto ensure good establishmentand reasonable growth.

Applying nitrogen as close aspossible to the time of maximumcrop demand increases the effi-ciency of use and minimizes thepotential for leaching loss.Apply preplant nitrogen as closeto planting time as possible.Include some nitrogen in thestarter fertilizer and sidedressthe majority of the nitrogenrequired prior to peak demand.Nitrogen recommendations aregiven in Table 9 for vegetablecrops grown on mineral soils.For crops seeded or transplantedwhen the soil is still rather cool,band a high phosphorus fertiliz-er 1 inch to the side and 1 to 2inches below the seed, unless

the P soil test is higher than 180lb/acre. Banding decreasesphosphorus fixation and stimu-lates early growth. For soilstesting higher than 180 lb/acrein available phosphorus, includ-ing phosphorus in the starterfertilizer usually does notimprove growth, quality oryield. Phosphorus recommen-dations are given in Table 10.

Suggested FertilizerManagement on MineralSoils

A good fertilizer programbased on soil test informationcoupled with other good man-agement practices, such as covercrops used for wind erosion con-trol, will provide good yields ofhigh-quality vegetables.General nitrogen recommenda-tions are given in Table 9.Amounts of phosphate (P2O5)and potash (K2O) recommended

Table 9. Nitrogen recommendations for vegetable crops grown on mineral soils.

lb N/A lb N/A lb N/A

Asparagus, old 50 Greens, leafy 100 Radish 50new 80 Horseradish 100 Rhubarb 100crowns 80 Lettuce, head 120 Rutabaga 100

Bean, lima/snap 40 Lettuce, leaf 80 Spinach 100Broccoli 140 Market garden 140 Squash 80Brussels sprout 140 Muskmelon 100 Sweet corn 120Cabbage 140 Onions, dry bulb 180 Sweet potato 60Carrot 100 green 140 Swiss Chard 100Cauliflower 140 Parsley 100 Table Beet 100Celery 180 Parsnip 100 Tomato, fresh 120Cucumber -slicers 80 Pea 40 processing 80-pickling 60 Pepper 100

Eggplant 100 Potato 180 Turnip 80Endive 100 Pumpkin 80 Watermelon 90

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for the various vegetable crops,based on soil tests, are given inTables 10, 11 and 12.

Finding a nutrient recom-mendation in the tables is atwo-step process. First, find thecrop of interest in the upperpart of the table. Second, govertically downward in thatcolumn into the lower part of

the table. In the left hand col-umn of the lower part of thetable find the soil test valuewhich comes closest to yoursoil test value; then follow thisline horizontally across to thecolumn containing the crop ofinterest. The number givenwhere these lines intersect isthe phosphate or potash recom-mendation.

The following are generalsuggestions for fertilizer man-agement programs for variousvegetable crops. The actualamounts of phosphate andpotash to apply depends on soiltest levels.

Asparagus (crown produc-tion): Adjust the pH to 6.8before planting, because aspara-

Table 10. Phosphate (P2O5) recommendations for vegetable crops grown on mineral soils.

Crop Yield Crop Yield Crop Yield Crop Yieldton/A ton/A ton/A ton/A

Asparagus (2) Carrot (15) Asparagus (1) Celery (30)old beds Endive (15) new beds Onions (20)Lima bean (2) Lettuce (20) Broccoli (4) Tomato (30)Pea (3) Parsnip (13) Brussels spt (5) Market garden Snap bean (4) Pumpkins (20) Cabbage (20) .Turnip (15) Radish (4) Cauliflower (8) .Greens (6) Rutabaga (18) Cucumber (15) .

(leafy) Spinach (6) Eggplant (10) .. Sweet corn (10) Horseradish (4) .. Sw potato (10) Muskmelon (9) .. Squash (15) Pepper (10) .. . Rhubarb (15) .. . Swiss chard (8) .. . Table beet (13) .. . Watermelon (11) .

Soil test . Phosphate recommendation, lb P2O5/A .lb P/A . . . .

30 110 150 190 23050 90 130 160 20070 60 100 140 18090 40 80 110 150

110 10 50 90 130130 0 30 60 100150 0 0 40 80170 0 0 10 50190 0 0 0 30 210 0 0 0 0

Recommendations are calculated from the following equations and rounded to the nearest 10 pounds:XP1 = 150 - 1.25 x ST where: XP1 = lb P2O5 /acre in column 1XP2 = 188 - 1.25 x ST XP2 = lb P2O5 /acre in column 2XP3 = 225 - 1.25 x ST XP3 = lb P2O5 /acre in column 3XP4 = 263 - 1.25 x ST XP4 = lb P2O5 /acre in column 4

ST = soil test in lb P/acre

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Table 11. Potash recommendations for vegetable crops grown on sandy loam and loamy sand soils.

Crop Yield Crop Yield Crop Yield Crop Yield ton/A ton/A ton/A ton/A

Asparagus (2) Asparagus (1) Cabbage,fr. (20) Broccoli (4)old beds new beds Cabbage,pr. (35) Brussels spt. (5)

Bean, lima (2) Carrot,fr. (15) Cucumber,hand (15) Cauliflower (8)Bean, snap (4) Carrot,pr. (35) Cucumber,mech (9) Celery (30)Pea (3) Endive (15) Eggplant (10) Tomato (30)Pumpkin (20) Lettuce,head (20) Horseradish (4) Market gardenRadish (4) Lettuce,leaf (13) Muskmelon (9) .Squash (15) Onion, green (10) Onion, bulb (20) .Turnip (15) Sweet corn (10) Parsnip (13) .Greens (6) . Pepper (10) .

(leafy) . Rhubarb (15) .. . Rutabaga (18) .. . Spinach (6) .. . Sweet potato (10) .. . Swiss Chard (8) .. . Table beets (13) .. . Watermelon (11) .

Soil Test . Potash recommendation, lb K2O/acre .lb K/A . . . .

75 160 200 250 290100 130 180 220 270125 110 160 200 250150 90 130 180 220175 70 110 160 200200 40 90 130 180225 20 70 110 160250 0 40 90 130275 0 20 70 110300 0 40 90325 20 70350 0 40375 20400 0

Recommendations are calculated from the following equations and rounded to the nearest 10 pounds:

XK1 = 225 - .90 x ST where: XK1 = lb K2O/acre for column 1XK2 = 270 - .90 x ST XK2 = lb K2O/acre for column 2XK3 = 315 - .90 x ST XK3 = lb K2O/acre for column 3XK4 = 360 - .90 x ST XK4 = lb K2O/acre for column 4

ST = soil test in lb K/acre

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Table 12. Potash recommendations for vegetable crops grown on loam, clay loam, clay and similar typesoils.

Crop Yield Crop Yield Crop Yield Crop Yieldton/A ton/A ton/A ton/A

Asparagus (2) Asparagus (1) Cabbage, fr. (20) Broccoli (4)old beds new beds Cabbage, pr. (35) Brussels Spt. (5)

Bean, lima (2) Carrot, fr. (15) Cucumber,hand (15) Cauliflower (8)Bean, snap (4) Carrot, pr. (35) Cucumber,mech (9) Celery (30)Pea (3) Endive (15) Eggplant (10) Tomato (30)Pumpkin (20) Lettuce,head (20) Horseradish (4) Market gardenRadish (4) Lettuce,leaf (13) Muskmelon (9) .Squash (15) Sweet corn (10) Onion, bulb (20) .Turnip (15) Onion, green (10) Parsnip (13) .Greens (6) . Pepper (10) .

(leafy) . Rhubarb (15) .. . Rutabaga (18) .. . Spinach (6) . . . Sweet potato (10) .. . Swiss Chard (8) .. . Table beets (13) .. . Watermelon (11) .

Soil Test . Potash recommendation, lb K2O/acre .lb K/A . . . .

75 150 200 250 300100 120 170 220 270125 100 150 200 250150 70 120 170 220175 50 100 150 200200 20 70 120 170225 0 50 100 150250 0 20 70 120275 0 0 50 100300 0 20 70325 0 50350 0 20375 0

Recommendations are calculated from the following equations and rounded to the nearest 10 pounds:

XK1 = 225 - 1.0 x ST where: XK1 = lb K2O/acre for column 1XK2 = 275 - 1.0 x ST XK2 = lb K2O/acre for column 2XK3 = 325 - 1.0 x ST XK3 = lb K2O/acre for column 3 XK4 = 375 - 1.0 x ST XK4 = lb K2O/acre for column 4

ST = soil test in lb K/acre

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gus does not grow well on soilsbelow pH 6.0. Before seeding,disc in 50 pounds of nitrogenand the recommended amountsof phosphate and potash. Whenasparagus plants are about 6inches high, sidedress with 50pounds of nitrogen per acre.

Asparagus (new planting):The year before planting, test thesoil and apply lime to attain apH of 6.8. In the spring broad-cast 50 pounds of nitrogen peracre and the recommendedamounts of phosphate andpotash and plow 12 inches deep.It is important to get adequatephosphorus below the crownsbefore planting. Apply 30pounds of phosphate per acre inthe furrow at the time of settingcrowns. After the fern is 6 inch-es high, sidedress with 50pounds of nitrogen per acre.

Asparagus (established plant-ings): Annual applications ofnitrogen should be split betweenpre- and postharvest. The totalamount of nitrogen should notexceed 80 pounds per acre.Every second year, apply potas-sium at 60 pounds of K2O peracre or the rate indicated by asoil test. Applying phosphorusafter establishment is not benefi-cial.

Lima Beans, Snap Beans:Row fertilizer, placed 2 inches tothe side and 2 inches below theseed, may include 30 pounds ofnitrogen, all the required phos-phate and 40 pounds of potash.Most of the required potash isbest plowed down or broadcastand incorporated prior to plant-ing. Apply manganese eitherwith the row fertilizer or as afoliar spray if a soil test or pastcropping history indicates apotential manganese deficiency.

Carrots, Horseradish,Parsnip: Plow down 50 poundsof nitrogen and the requiredphosphate and potash andinclude 1 pound of boron peracre. Four to six weeks afterseedling emergence topdresswith 50 pounds of nitrogen peracre. On soils with a pH above6.5, carrots may benefit fromfoliar application of 2 pounds ofmanganese per acre.

Table Beets, Rutabagas: Atseeding, band 2 inches to theside and 2 inches below the seed30 pounds of nitrogen, all thephosphate and 40 pounds ofpotash. Before planting, broad-cast and incorporate the potashrequired above this amount. Onsandy soils and on soils with apH above 6.5, include 3 to 4pounds of boron per acre in thefertilizer program. Topdresswith 50 pounds of nitrogen peracre after the plants are wellestablished.

Broccoli, Cabbage, BrusselsSprouts, Cauliflower:Incorporate after plowing 50pounds of nitrogen per acre plusthe potash indicated by a soiltest. Include in the broadcastfertilizer the phosphate requiredin excess of that included in thestarter solution. Include suffi-cient boron in the broadcast fer-tilizer to supply 3 to 4 poundsper acre. Use a high phosphorusstarter solution when setting thetransplants. For cauliflower,include 2 to 4 ounces of sodiummolybdate per acre in the startersolution. Sidedress 40 poundsof nitrogen three weeks aftertransplanting and again (exceptcabbage) three weeks later.Foliar application of sodiummolybdate (2 ounces per acre)on a two-week schedule isessential for some cauliflowervarieties.

Sweet Corn: Plow down orincorporate after plowing 50pounds of nitrogen per acre andmost of the required potash. Atseeding, band 30 pounds ofnitrogen, all the required phos-phate and 40 pounds of potashper acre placed 2 inches to theside and 2 inches below theseed. Sidedress 40 to 50 poundsof nitrogen when the corn is 6 to12 inches high.

Cucumbers: For slicingcucumbers and hand-pickedpickling cucumbers, band astarter fertilizer 2 inches to theside and 2 inches below the seedthat contains 30 pounds of nitro-gen, all the required phosphorusand up to 40 pounds of potassi-um per acre. If the soil pH isabove 6.7 and/or a soil testshows a need for manganese,include in the starter fertilizersufficient manganese to supply 4pounds per acre or the amountindicated by a soil test.Broadcast and incorporate mostof the potash before planting.Topdress 30 to 40 pounds ofnitrogen per acre just before tip-over. Nitrogen also can beapplied effectively through theirrigation system (10 to 15pounds of nitrogen per acre perapplication).

For pickling cucumbers withplant populations exceeding50,000 plants per acre in 10- to28-inch rows and intended formechanical harvest, broadcastand incorporate 30 pounds ofnitrogen and all the requiredphosphate and potash fertilizerbefore planting, unless planting-time fertilizer will be applied.Topdress 30 pounds of nitrogenper acre just before tip-over andirrigate in, if possible.Broadcasting and incorporatingall the nitrogen in a slow-releaseform before seeding is effective.

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If a soil test or past history indi-cates a need for manganese,make a foliar application of 2pounds of manganese per acre.

Muskmelons, Watermelons:Nearly all melons are grown onplastic mulch, so apply requirednutrients to the soil before lay-ing the plastic. Broadcast andincorporate or apply in bands,under where the plastic will belaid, all of the required nitrogen,phosphate and potash. Thetotal suggested nitrogen rate is75 to 90 pounds per acre.Nitrogen applied through trickleirrigation is used quite efficient-ly, so the preplant nitrogen ratecan be reduced. Melonsrespond quite well to magne-sium. If the soil-test magnesiumlevel is marginal (below 100pounds per acre) broadcast andincorporate 50 pounds of actualmagnesium per acre or applymagnesium (2 pounds per acre)to the foliage every two to threeweeks.

Peas: Broadcast and incorpo-rate 40 pounds of nitrogen peracre plus the amounts of phos-phate and potash recommendedbased on a soil test.

Peppers: Broadcast andincorporate 40 pounds of nitro-gen per acre, and all therequired phosphate and potashminus that applied in the trans-planting solution. Use a high-phosphorus starter solutionwhen setting the transplants.Sidedress with 30 to 40 poundsof nitrogen three to four weeksafter transplanting and againafter another four weeks or afterthe first harvest. A nitrate soiltest can help determine whetheror not to sidedress with addi-tional nitrogen. Supplementalnitrogen can be effectively sup-plied through the irrigation (10to 15 pounds per application).

This is a very efficient way tosupply nitrogen on very sandysoils.

Radishes, Turnips: Broadcastand incorporate 50 pounds ofnitrogen per acre plus the rec-ommended amounts of phos-phorus and potassium. If thesoil pH is above 6.7, include 1pound of boron per acre forradishes and 2 pounds forturnips. Radishes are highlyresponsive to manganese. If asoil test or past cropping historyshows manganese is needed,apply 2 pounds of manganeseper acre (8 pounds of man-ganese sulfate) in a foliar spray 1to 2 weeks after emergence.

Tomatoes: The appropriateamount of total nitrogen toapply for tomatoes depends onmany factors. Direct-seededtomatoes generally require lessnitrogen (about 25 pounds peracre less) than transplantedtomatoes. When tomatoes fol-low soybeans, reduce the nitro-gen rate by 30 pounds per acre.Avoid large single nitrogenapplications on sandy soils tominimize the potential for leach-ing loss. Tomato yields dependon many management factors.When yields over 30 tons peracre are expected, increase thephosphate (P2O5) and potash(K2O) rates by 5 and 30 poundsper acre, respectively, for eachadditional 5 tons of expectedyield. Set realistic yield goals forthe management system (theaverage of the three highestyields achieved over the last fiveyears) to prevent unnecessaryexpenditures.

Processing: For machine-har-vest processing tomatoes, 75pounds of nitrogen per acre isusually adequate. However, anadditional 25 pounds may be

beneficial when anticipatinghigh yields or when adverseweather conditions result in theloss of nitrogen by leaching ordenitrification. Broadcast andincorporate 50 pounds of nitro-gen plus the recommendedamounts of phosphate (minusthat in the transplant solution)and potash. Apply a solutionhigh in phosphorus when set-ting transplants. Sidedress 25pounds of nitrogen four weeksafter transplanting. Additionalnitrogen can be applied throughthe irrigation system (10 to 15pounds nitrogen per applica-tion).

Fresh Market: Fresh markettomatoes may require up to 120pounds of nitrogen per acre.Broadcast and incorporate 60pounds of nitrogen plus therequired phosphate and potash.Sidedress 30 pounds of nitrogenthree weeks after transplantingand again three weeks later.Determinant tomato varietiesproduce good yields in responseto high nitrogen rates withoutproducing excessive vegetativegrowth. With indeterminatevarieties, high nitrogen ratestend to stimulate vegetativegrowth and delay fruit set andmaturity. For the indeterminanttypes, use two to three sidedressapplications of 25 pounds ofnitrogen per acre.

Rhubarb: In early springapply 50 pounds of nitrogenplus the recommended amountsof phosphorus and potassium.Sidedress with an additional 50pounds of nitrogen per acre twoweeks after new growth begins.

Market Gardens (mixture ofcrops): Plow down or incorpo-rate 50 pounds of nitrogen peracre plus the recommendedamounts of phosphate and

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potash according to a soil test. Ifa starter fertilizer is placed 2inches to the side and 2 inchesbelow the seed at planting, itmay include all of the phospho-rus plus 30 pounds of nitrogenand 40 pounds of potassium.Make one or two sidedressapplications of 30 to 40 poundsnitrogen during the growingseason, depending on the veg-etable crop being grown.Suggested total nitrogen ratesare given in Table 9. For vegeta-bles not listed, topdress addi-tional nitrogen when the cropbegins to look light green. Morenitrogen generally is needed forthe green leafy vegetables, toma-toes, peppers, sweet corn andrhubarb than for beans, peas,cucumbers, melons, root cropsor asparagus. Avoid overusingnitrogen to minimize the accu-mulation of nitrates in the veg-etables and to minimize thepotential of leaching loss.

Use a high-phosphorus startersolution when setting vegetabletransplants, unless the phospho-rus soil test is above 180 lb/acre.Starter solutions tend to stimu-late growth of leafy vegetable

crops when soils are cold and airtemperatures are low. Avoidoverfertilizing; it may cause saltinjury.

Suggested FertilizerManagement on OrganicSoils

Organic soils are classified asmucks and peats. The mostimportant organic soil series inMichigan are Carlisle,Carbonadale, Greenwood,Houghton, Kerston, Lupton andRifle. Soils must have more than20 percent organic matter to becharacterized as organic. In theMSU Soil Testing Lab, soils witha bulk density below 0.8 gramper cubic centimeter are handledas organic soils.

Many of the warm-seasonvegetable crops will grow onorganic soils, but they are notrecommended for commercialproduction on organic soilsbecause of potential problems.Organic soils generally occur inlow areas and are more subjectto late spring and early fallfrosts. The release of nitrogenfrom the organic matter and

warm soil temperatures stimu-late vegetative growth whichmay delay fruit set and maturity.

Nitrogen rates and fertilizerplacement guidelines are givenfor each crop. Recommendednitrogen rates for vegetablecrops grown on organic soils aregiven in Table 13. Apply phos-phorus and potassium at ratesgiven in Tables 14 and 15. Usesoil test data and crop responsesto determine micronutrientneeds.

Broccoli, Cabbage, Cauli-flower: Broadcast and incorpo-rate 50 pounds of nitrogen andall of the phosphate and potashbefore planting. Use a high-phosphorus starter solutionwhen setting transplants. Forcauliflower include 2 to 4 ouncesof sodium molybdate per acre inthe starter solution. Sidedressthe plants with 30 to 40 poundsof nitrogen per acre after trans-planting and again (except cab-bage) four weeks later. Somevarieties of cauliflower benefitfrom foliar sprays of sodiummolybdate (2 to 4 ounces peracre) on a two-week schedule.

Table 13. Nitrogen recommendations for vegetable crops grown on organic soils.

lb N/acre lb N/acre lb N/acre

Beans 40 Endive 80 Parsnip 80Broccoli 120 Greens, leafy 80 Potato 100Brussels sprout 120 Horseradish 80 Radish 40Cabbage 90 Lettuce, head 100 Carrot 60 Lettuce, leaf 70 Rhubarb 80 Rutabaga 40Cauliflower 120 Mint 80 Spinach 80Celery 150 Onion, bulb 150 Table Beets 40Chard,Swiss 40 Onion, green 110 Turnip 40Corn, sweet 80 Parsley 80

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Table 14. Phosphate (P2O5) recommendations for vegetable crops grown on organic soils.

Crop Yield Crop Yield Crop Yield ton/A ton/A ton/A

Mint Brussels sprout (5) Broccoli (4)Snap bean (4) Cabbage, fr. (20) Cauliflower (8)Radish (4) Carrot, fr. (15) Celery (30)Sweet corn (10) Cucumber, hand (15) Market gardenRutabaga (18) Endive (15) Onions (20)Turnip (15) Horseradish (4) Potato (20)Greens (6) Lettuce, head (20) .

(leafy) Parsnip (13) .. Spinach (6) .. Swiss Chard (8) .. Table beet (13) .. Grass Sod .

.Soil test . Phosphate recommendation, lb P2O5/acre . lb P/A . . .

30 120 190 230 50 100 160 20070 70 140 18090 50 110 150

110 20 90 130130 0 60 100150 0 40 80170 0 10 50190 0 0 30210 0 0 0

Recommendations are calculated from the following equations and rounded to the nearest 10 pounds:

XP1 = 160 - 1.25 x ST XP1 = lb P2O5 /acre for column 1 XP2 = 225 - 1.25 x ST XP2 = lb P2O5 /acre for column 2XP3 = 263 - 1.25 x ST XP3 = lb P2O5 /acre for column 3

ST = soil test in lb P/acre

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Table 15. Potash (K2O) recommendations for vegetable crops grown on organic soils.

Crop Yield Crop Yield Crop Yield ton/A ton/A ton/A

Snap bean (4) Asparagus (2) Broccoli (4)Sweet corn (10) Cabbage, fr. (20) Brussels Spt. (5)Turnip (15) Carrot, fr. (15) Cauliflower (8)Radish (4) Cucumber (15) Market garden Grass sod Endive (15) Onion, bulb (20)Greens (6) Horseradish (4) Onion, green (10)

(leafy) Lettuce,head (20) Potato (20). Mint Rutabaga (18). Parsnip (13) Spinach (6). . Swiss Chard (8). . Table beet (13)

Soil Test . Potash Recommendation, lb K2O /acre .lb K/A . . .150 200 260 360225 140 200 300300 80 140 240375 20 80 180 450 0 20 120 525 0 0 60600 0 0

Recommendation are calculated from the following equations and rounded to the nearest 10 pounds:

XK1 = 320 - 0.8 x ST where: XK1 = lb K2O /acre for column 1XK2 = 380 - 0.8 x ST XK2 = lb K2O /acre for column 2XK3 = 480 - 0.8 x ST XK3 = lb K2O /acre for column 3XK4 = 570 - 0.8 x ST XK4 = lb K2O /acre for Celery

ST = soil test in lb K/acre

Carrots, Parsnips: Plowdown or incorporate at least 6inches deep 60 pounds of nitro-gen per acre and all the recom-mended phosphate and potash.Include sufficient boron in thebroadcast fertilizer to supply 1pound per acre. If a soil testindicates the need for copper,include sufficient copper sulfateto supply 3 to 4 pounds copperper acre.

An alternative program is toplow down a fertilizer high inpotash that contains the neededboron and copper. Band the

nitrogen and phosphate 3 inchesto the side and 3 inches belowthe seed at seeding, but do notexceed 300 pounds of fertilizerper acre in rows 21 inches ormore apart. Sidedress addition-al nitrogen if plant growth andcolor indicate a need. On well-drained, high-organic soils, usea total of 60 pounds of nitrogenper acre. On sandy mucks andmarly muck soils, use a total of80 to 100 pounds of nitrogen.

Additional manganese maybe needed periodically duringthe growing season, especially if

the soil pH is above 6.5. Foliarapply 2 pounds of actual man-ganese per acre as manganesesulfate. If boron is not includedin the broadcast fertilizer, one ortwo foliar sprays of 0.3 pound ofboron per acre is beneficial.

Celery: Broadcast and incor-porate 50 pounds of nitrogenper acre plus the recommendedamounts of phosphate (minusthe amount to be band near thetransplant row) and potash.Banding a high phosphorus fer-tilizer near the transplant rowwhen the soil is cool (average

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soil temperature at 4 inches isbelow 55° F) stimulates rootdevelopment and plant growth.If the phosphorus soil test isabove 180 lb/acre, bandingadditional phosphate usually isnot beneficial. Once the soilwarms to 60° F, usually by May15 to June 1, banding a high-phosphorus fertilizer is not ben-eficial unless the soil tests low tomedium in phosphorus. Includesufficient boron in the broadcast,or band fertilizer to supply 3 to 4pounds per acre.

Spray the foliage periodicallywith manganese (2 pounds peracre) if the soil pH is above 6.2and/or past history or a soil testindicates a need for manganese.

Sidedress two to three timesduring the growing season with40 to 50 pounds of nitrogen peracre per application. The num-ber of applications depends onthe season, drainage and type ofmuck. The color of the plantand plant tissue tests help deter-mine the need for supplementalnitrogen. The highest rate ofnitrogen uptake in celery occursfrom six weeks after transplant-ing to harvest.

Certain celery varieties needmagnesium applied as a foliarspray to prevent deficiency signsfrom appearing. Use magne-sium sulfate (Epsom salts) at therate of 10 pounds per acre every10 days to two weeks. If thisrate does not correct the magne-sium-yellowing, increase therate to 20 pounds. Foliar appli-cation of calcium frequently isneeded to prevent black heart.Apply calcium nitrate at the rateof 15 pounds per acre, or calci-um chloride at 10 pounds peracre. Directing the spray intothe heart is most effective. Ifthis is not possible, apply morefrequently. Black heart is most

likely to occur after environmen-tal stress; such as high tempera-tures, or saturated soil (oxygenstress).

Lettuce (leaf and head),Spinach: Broadcast and incor-porate after plowing the recom-mended rate of potash. Apply40 pounds of nitrogen, all therequired phosphate and 0.5pound of boron in a band 1 inchto the side and 2 to 3 inchesbelow the seed at planting time.If transplanting, place the fertil-izer 2 inches to the side and 3inches below the soil surface.Include manganese and copperin the banded fertilizer if a soiltest indicates a need. On acidfibrous peats apply a foliarspray of 2 ounces of sodiummolybdate after thinning or 2 to3 weeks after transplanting.Sidedress with 60 pounds ofnitrogen after thinning or 3weeks after transplanting.

Onions, bulb: Broadcast andincorporate 60 pounds of nitro-gen per acre and the recom-mended amount of potash. Atseeding band 2 to 3 inchesdirectly below the seed the fertil-izer containing all the recom-mended phosphate plus somenitrogen and potash, andenough manganese to supply 4pounds per acre or the amountindicated by a soil test.Depending on soil tests, copperand zinc may also need to beincluded in the banded fertilizer.Sidedress 80 to 90 pounds ofnitrogen per acre in mid-June.Use a soil nitrate test as a guidein determining the appropriaterate of nitrogen to sidedress. Onsoils with a pH above 6.5, foliarapplication of 2 pounds of man-ganese per acre in early to mid-June and again two weeks laterwill be beneficial.

Peppermint, Spearmint: Forrow-mint, broadcast and incor-porate 40 pounds of nitrogenper acre plus the recommendedamounts of phosphate andpotash before planting. In earlyJune, topdress with 40 poundsof nitrogen. For meadow-mint,in the early spring before thecrop emerges, drill in or broad-cast the recommended amountsof phosphate and potash plus 30pounds of nitrogen per acre. Inearly June topdress with 50pounds of nitrogen per acre.Use a pelleted form and applywhen the foliage is dry. Irrigatein the nitrogen if rain is not like-ly to occur during the next 5 to 7days.

If the pH is above 6.5, a foliarapplication of manganese maybe required, depending on thesoil test or past cropping history.

Potatoes: Plow down the rec-ommended amount of potash.Include in the planting-time fer-tilizer, all the required phos-phate plus 40 pounds of nitro-gen and some potash, placed 2inches to the side of the seed-piece. If a soil test indicates theneed, include sufficient man-ganese to supply 4 pounds peracre or the recommendedamount. Sidedress prior to or athilling with 40 to 70 pounds ofnitrogen. Use the lower rate onhighly organic soils and thehigher rate on sandy muck soils.Applying supplemental nitro-gen through the irrigation sys-tem is effective (10 to 15 poundsper acre per application).

Foliar application of man-ganese (2 pounds per acre perapplication) may be beneficialduring the growing season,especially if the pH is above 6.0.

Sweet Corn: Plant popula-tion goals should be 20,000 to

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22,000 plants per acre.Broadcast and plow down therecommended amount ofpotash. At planting, band fertil-izer containing all of the recom-mended phosphate plus 30pounds of nitrogen and 40pounds of potash per acre, 2inches to the side and 2 inchesbelow the seed. Include suffi-cient manganese and zinc tosupply 4 and 2 pounds per acre,respectively, or the amountsindicated by a soil test.Sidedress with 50 pounds ofnitrogen per acre when the cornis 6 to 12 inches high. On sandymuck soils increase the sidedressnitrogen rate by 20 pounds peracre.

Table Beets, Swiss Chard,Radishes, Turnips, Rutabagas:Broadcast and incorporate,before seeding, the recommend-ed amounts of nitrogen, phos-phate and potash. Include in thefertilizer: 1 pound of boron peracre for radishes, 2 pounds forturnips, rutabagas and Swisschard, and 4 pounds for tablebeets. Use a soil test or pastcropping history to determinethe need for manganese. Foliar

application of manganese is themost effective way to supplymanganese to these crops.Spray 2 pounds of manganeseper acre. More than one applica-tion may be needed when thepH is above 6.5, especially forradishes.

Grass Sod: Before seeding,broadcast and incorporate 30pounds of nitrogen per acre plusthe required amounts of phos-phate and potash. After thegrass is well established, top-dress with 30 pounds of nitro-gen per acre. The need for addi-tional topdressings withnitrogen depends on the organicmatter content of the soil andthe amount of rain. Less nitro-gen is required on high organicmatter muck soils than on sandyor marginally organic soils. Ingeneral, apply 20 to 30 poundsof nitrogen per acre topdressedevery 4 to 5 weeks during thegrowing season for a vigorousgrass sod. Using frequent nitro-gen applications at low ratesminimizes the potential fornitrogen loss by leaching or den-itrification.

Plant Tissue Analysis

Nutrient analysis of appropri-ate plant parts for each crop canhelp diagnose a plant growthproblem during the season or infine tuning long-term soil fertili-ty management. Plants are thebest indicator of whether or notthey are able to take up ade-quate quantities of the essentialnutrients. However, a low nutri-ent level in the plant does notalways mean that there is aninsufficient amount available inthe soil. Other conditions, suchas compact soil or poordrainage, may limit the rootgrowth and nutrient uptake ofplants.

Table 16 indicates the criticalnutrient levels in the appropri-ate plant part of some vegetablecrops. The appropriate plantpart to sample varies with thecrop and stage of growth. Amore complete sampling guideis available from the MichiganState University Soil TestingLab.

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Table 16. General guidelines for sufficient nutrient levels in sampled plant tissue of some vegetablecrops. (Adapted from Plant Analysis Handbook by Jones, Wolf and Mills, Micro-Macro Publishing,Inc.)1

Vegetable Crop N P K Ca Mg S B Cu Fe Mn Zn

- - - - - - - - - - - - - - % - - - - - - - - - - - - - - - - - - - - - - - - ppm - - - - - - - - - Asparagus 2.5 .25 1.5 .60 .25 40 5 40 25 20Bean, snap 5.0 .35 2.3 1.50 .30 20 7 50 50 20Broccoli 3.2 .30 2.0 1.00 .25 .30 30 5 70 25 35Cabbage 3.6 .33 3.0 1.10 .40 .30 25 5 30 25 20Carrot 2.1 .20 2.8 1.40 .30 30 5 50 60 25Cauliflower 3.3 .33 2.6 2.00 .27 30 4 30 25 20Celery 1.6 .30 7.5 2.20 .25 25 5 30 10 25Cucumber 4.5 .34 3.9 1.40 .30 .40 25 4 30 50 25Lettuce 3.8 .45 6.0 1.50 .36 25 7 50 25 25Muskmelon 4.5 .30 4.0 2.3 .35 .25 25 7 50 50 20Onion 4.5 .30 3.5 1.50 .25 .50 25 15 60 50 25Pea 4.0 .30 2.0 1.20 .30 25 7 50 30 25Pepper 4.0 .35 4.0 1.00 .30 25 6 60 50 20Potato 3.0 .25 6.0 1.5 .70 40 7 40 30 30Squash 4.0 .30 3.0 1.2 .30 25 10 50 50 20Sweet corn 4.0 .60 3.5 0.5 . 20 .21 8 5 50 30 20Tomato 4.0 .25 2.9 1.0 .40 .40 25 5 40 40 20

1Guidelines are for the youngest mature leaves, except celery which is for the youngest mature petioles.The values given are generally the critical values separating sufficient and deficient nutrient concentra-tions. The critical value may vary depending on the stage of growth when a sample is taken.

Reference BulletinsFor more information about

fertilizing and testing soils, thefollowing bulletins are availablefrom county CooperativeExtension Service offices or fromthe Michigan State UniversityBulletin Office, 10 B AgricultureHall, East Lansing, MI 48824-1039.

E-471 “Lime for MichiganSoils.”

E-498 “Soil Sampling forFertilizer and LimeRecommendations.”

E-550A “FertilizerRecommendations for FieldCrops in Michigan.”

E-896 “N-P-K Fertilizers.”

E-933 “Fluid Fertilizers:Liquids and Suspensions.”

E-1262 “Soil ManagementUnits and Land Use Planning.”

E-1566 “Facts About Lime:Answers to CommonQuestions.”

E-1616 “Soil Sampling for No-Till and Conservation TillageCrops.”

E-2058 “Understanding MSUSoil Test Report: Results andRecommendations.”

E-2220 “Best ManagementPractices for Potatoes: PotatoFertilizer Recommendations.”

NCH-02 “The Philosophy ofSoil Testing (Corn).”

NCH-12 “Managing AnimalManure as a Source of PlantNutrients.”

WQ-03 “Managing OrganicSoils to Reduce NonpointPollution.”

WQ-12 “Livestock ManureManagement for Efficient CropProduction and Water QualityPreservation.”

WQ-25 “Nutrient Managementto Protect Water Quality.”

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MSU is an affirmative-action equal-opportunity institution. Cooperative Extension Service programs and materials are available to all withoutregard to race, color, national origin, sex, handicap, age or religion.

Issued in furtherance of Cooperative Extension work in agriculture and home economics, acts of May 8 and June 30, 1914, in cooperation withthe U.S. Department of Agriculture. Gail L. Imig, Director, Cooperative Extension Service, Michigan State University, E. Lansing, MI 48824.

This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by theCooperative Extension Service or bias against those not mentioned. This bulletin becomes public property upon publication and may be printedverbatim with credit to MSU. Reprinting cannot be used to endorse or advertise a commercial product or company.

Revised 3:92 (Replaces Extension Bulletin E - 550) 5M - TCM - MP - Price $1.25, For sale only.

File 22.04 (Fertilizers)