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Critical for dairy cattle rations
Necessary for phosphorous (P) uptake
Need yield maximized for feed production and maximum
P uptake
Corn Importance in South ID
Examination of 26 different studies showed decrease in yield
Corn yield reduced 5 to 15% for corn following corn compared to the first year corn
www.agecon.purdue.edu/pdf/Crop_Rotation_Lit_Review.pdf
Yield Reduction
Choose the corn seed hybrid most desired for your farm – considering soil, rotations, insect/disease pressures, residues, manure or compost applications, emergence concerns etc.
http://corn.agronomy.wisc.edu/HT/2007/Text.htm has corn hybrid performance for grain and silage in Wisconsin
Carefully Choose Corn Hybrid
Dale Baker has variety trial on corn grain from Kimberly
Then look at cost and necessity of seed treatments included on the seed for insect and disease control.
Carefully Choose Corn Hybrid
We need to minimize insect and disease concerns to maximize corn yield and P uptake
Crop rotation is an effective management tool for reducing hosts for pathogens
Importance of Crop Rotation
Eggs laid in soil during the fall – hatch in spring
Larvae feed on corn roots Adults emerge from soil Adults beetles feed on female flowers (silks) and soft kernels
Western Corn Rootworm
Repeated efforts to control rootworm has led to resistance to methyl parathion and carbaryl
www.areawiderootworm.info/final_report.pdf
Crop rotation is an important option to prevent large rootworm infestations
Consider chemical and transgenic control when it is economically required
Western Corn Rootworm
Disease Triangle
Host Environment
Pathogen
Disease
Risk of disease severity higher with continuous corn, but weather conditions in-season still affect disease severity
Long term buildup of soil born pathogens can reduce corn stands, vigor, yield, plus decrease nutrient uptake potential.
Pathogens survive on corn residues and/or in the soil.
Crop rotation beneficial to break the cycle
Build Up of Pathogens
Increased corn acreage = more stubble, roots, and crowns = potential for increasing Fusarium graminearum, which causes primarily scab (head blight) in wheat and barley, stalk and ear rot of corn
Build Up of Pathogens
Gibberella ear rot is caused by the fungus Gibberella aeae, also known as Fusarium graminearum . It usually appears at the ear tip and is red or pink. A vomitoxin can be produced that causes vomiting in monogastrics.
Gibberella Ear Rot
To stop, look, and carefully evaluate the best corn hybrid and insect/disease control for your farm
Practice good crop rotation to minimize costs and mgmt. intensity for corn production in Idaho, while maximizing P uptake
Keep accurate records when using transgenic seed and chemicals
Remember…
Where do we go with the … Environmental concerns for livestock operations are critical to everyone. *nutrient and waste mgmt.
*water quantity and quality
*air quality and odor mgmt.
Crop Uptake of Soil P
Previous Cereal
An
nu
al P
re
mo
va
l (l
b/A
)
0
10
20
30
40
50
60
70win forage P removalsum corn P removal
Parma, 1999
win
tri
t
sp
r tr
it
win
wh
t
sp
r w
ht
win
ba
r
fall
ow
a
b
c
abab
c
B. Brown, UI Parma
Winter Forage
W F
ora
ge
P
re
mo
va
l (lb
/A
)
0
10
20
30
40
50
60
70 Parma, 1999- 2001
win
trit
sp
r trit
win
w
ht
sp
r w
ht
win
b
ar
100 lb/A
150 lb/A
200 lb/A
Seeding Rate
B. Brown, UI Parma
Previous Cereal
To
tal P
re
mo
val (l
b/A
)
0
20
40
60
80
100
120
140
160
180
200
220 Parma, 1999, 2000, 2001
win
tri
t
sp
r tr
it
win
wh
t
sp
r w
ht
win
ba
r
win
flw
00 WF P00 Si P
01 WF P01 Si P
99 WF P99 Si P
Crop % P % H2O Yieldlb P
Removed
Canola seed
0.44 10 2000 lb/A
8
Peas 0.38 13 2000 lb/A
7
Beans 0.60 40 28 cwt/A 10
Potatoes
0.20 80 500 cwt/A
20
Sugar beets
0.13 77 35 tons/A
21
P Content and Removal with Crops
Information from National Research Council (NRC) with modifications for Idaho where data is available from Dr. Brad Brown, UI in Parma
Crop % P %H2O Yieldlb P
Removed
Wheat grain
0.43 10 120 bu/A 28
Barley grain
0.39 10 120 bu/A 20
Oat grain
0.40 10 160 bu/A 18
Corn grain
0.30 15.5 180 bu/A 25
Corn silage
0.26 67 30 tons/A
51
P Content and Removal with Crops
Information from NRC with modifications for Idaho where data is available from Dr. Brad Brown, UI in Parma
Soil Test P Decline
John Brown's annual corn removes 36 lb P per acre. For his soil, the soil test declines 1 ppm for every 12 lb of P removed each year. His manured field has a soil test P value of 84 ppm.
How many years will it take with his current cropping system to lower soil test P to 40 ppm based just on the crop P removal with no additional P applied?
Soil Test P Decline Question
STP change in one year36 lb P a year / (12 lb P/ppm) = 3 ppm P
Difference in ppm P 84 ppm - 40 ppm = 44 ppm
Years to change STP 44 ppm44 ppm / 3 ppm = 14.6 years
Predicted Soil Test P IncreaseA new dairy wants to apply composted manure at the rate of 10 tons per acre annually to a field. The compost is 70% dry matter and 0.92% P (dwt basis). Initial soil test P for the field is 20 ppm. He can remove 37 lb P annually with corn silage but is wondering about a double cropping system that would remove 55 lb P per acre annually. Assume soil test P changes 1 ppm for every 12 lb P applied per acre. How many years for STP to reach 40 ppm P?
Predicted Soil Test P Increase Question
Net P added per acre?10 tons x 2000 lb per ton = 20,000 lb 20,000 lb x 0.70 = 14,000 lb dry matter14,000 lb x 0.0092 = 128.8 lb compost P per acre
128.8 lb P added - 37 lb P removed = 91.8 lb P = net P gained annually with single crop corn
128.8 lb P added - 55 lb P removed = 73.8 lb P gained annually with double cropping
Predicted Soil Test P Increase Question
Soil test P change?40 ppm P - 20 ppm P = 20 ppm P
Annual soil test change91.8 lb net P added/ (12 lb P/ppm) = 7.65 ppm73.5 lb net P added/ (12 lb P/ppm) = 6.125 ppm
Time required? 20 ppm P change / 7.65 = 2.6 yrs with SC 20 ppm P change / 6.125 = 3.26 yrs with DC
Hauling hay from east Idaho here and exporting compost back
High fertilizer prices making the export farther away more economical
High quality compost marketed for organic producers
Lime, struvite cystalization, anaerobic digesters, nursery industry – continue the quest for ways to export P!
Crop Import and Manure Export?
Produced by mold fungi – Aspergillus falvus and Aspergillus parasiticus
Aflatoxins are harmful or fatal to livestock and are considered carcinogenic
No aflatoxins allowed for milk from dairies
See Aflatoxins in Corn, PM1800 Iowa State University, for sampling procedures and control methods
Aflatoxins in Corn
Highly effective compounds like the triazoles and Qol fungicides (e.g. strobilurins) with specific modes of action developed
These affect one specific site in one metabolic pathway of fungus
Fungi only have one barrier to overcome
Fungicide Resistance
FRAC = Fungicide Resistance Action Committee
Goal is to provide fungicide resistance mgmt guidelines to prolong effectiveness of “at risk” fungicides.
FRAC Code
Look on label for group number-easier to alternate chemistry
M is when a fungicide acts onmultiple sites and resistance is low
FRAC Code
Product Rate (fl oz/acre)
REI (hours) PHI (days)
Headline 6-12 12a 7
Quadris 6-15.5 4a 7
Quilt 7-14 24a After brown silk
Statego 7-12 24a After silking
Tilt 2-4 24a After silking
Restrictions for Corn Fungicides
aREI is 7 days for bare-hand detasseling activity
*Headline and Quadris are strobilurin fungicides*Considered “high risk” for fungicide resistance*May result in yield increases, even in supposed absence of any disease pressure, in short term *Exercise caution-use only when required to minimize selection of fungicide-resistant strains of fungal pathogens. *http://www.ipm.iastate.edu/ipm/icm/node/2529/print
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