CHAPTER II

RELATED LITERATURE

I. Fertilizer

Fertilizers and ManuresFertilizers include both natural and artificial substance that increases productiveness of plants. In many countries of the world, including United States and all of the European countries, fertilizers stands in the way if widespread starvation. In areas such as china and India where have been commonplace, extensive use of fertilizers were needed could significantly reduce the incidence of food shortage. It was estimated that by the second half of the 20th century at least 20% of the food produce in the United States was due directly to commercial fertilizers.It had become clean that the rapidly growing population of the world must depend increasingly upon commercial fertilizers for; its food and fibre. (A Society of Gentlemen in Scotland)

Determining Fertilizer needsFertilizers are used primarily to obtain greater yields and secondarily to improve the quality of the crop. Nutrients removed from the soil by harvesting a crop, lost by leaching and erosion, fixed or immobilized, and volatilized must be replaced to obtain optimum growth of the next crop. Next years plant nutrient needs will come from soil mineral that dissolve, from decomposing organic matter, from exchangeable ions absorbed on soil and humus particles, from the atmosphere, and from fertilizer. (Roy L. Donahue et. al,. 1977)

Fertilizers and their useThe worlds greatest emmediate hope for rapid increases in food, feed, and fiber production is the wise use of fertilizers. Ubtil 1974, fertilizer prices were relatively cheap in the United States, and it was common to add fertilizers with a lavish hand; many states doubled their fertilizer consumption between 1960 and 1973.When the energy crisis escalated in 1974, fertilizers prices doubled, then continued to rise. The higher fertilizer costs and current shortages made users re-evaluate the amounts of fertilizer that they had been using. They began again to select the soils and crops on which fertilizers additions would be most successful, and made better use of soil testing.

A. Types of Fertilizer A.1. Organic fertilizer

For hundreds of years, farmers particularly in countries like China, Korea, and Japan have been able to produce sufficiently from their farms to support the needs of their population. How it is possible that productivity of the farm has been maintained even as greater demand for food increases in these countries?Apparently, one of the keys to the agricultural sustainability in these countries and perhaps in others is regular and extensive recycling of a wide array of organic wastes and residues. These include such materials as crop residues, animal manures, green manures and even sewage and urban wastes. These materials were used as either through direct incorporation into the soil or through compostingHowever, through the years, agriculture in the Asia-Pacific region has changed considerably and farmers are now facing rapid soil degradation and loss of productivity. It is clear that alternative agricultural practices and the ultimate goal for a long-term sustainable agriculture depend largely upon regular additions of various organic amendments to soils. The quality and acceptability of many organic wastes, from both on-farm and off-farm sources, can be greatly enhanced through composting. Some wastes that are not suitable for composting because of a wide carbon-nitrogen ratio or excessive moisture content can be blended with other materials to improve their chemical and physical properties, and to optimize rapid aerobic, thermophilic co-composting of the mixture. Today, there is a wide array of composting methods and options for various kinds of organic wastes from the farm and urban centers.

Guide to Soil and Fertilizer Requirements of CropsBasic concepts about organic fertilizers Organic fertilizers are a good prospect as alternative or partial substitute for chemical fertilizers. Estimates have shown that the quantity of organic waste in rural as well as urban areas, when taken together contains enough nutrients for the needs of the crop lands of most developing countries.It is true that chemical fertilizers are more convenient to use because of their high content and greater solubility. However; organic materials, though lower in nutrient composition and are more bulky, can provide long-term benefits. Furthermore, organic fertilizers have multiple effects, affecting not only the chemical nature of the soil but also the Biological and Physical properties.

B. Advantage of Organic Fertilizer

Importance of Organic MaterialsOrganic materials when added to the soil have numerous beneficial effects, which include increased soil fertility, balanced supply of nutrients, and build up of organic matter (OM). However, these effects are strongly influenced by the nature of the organic materials, their nutrient content, and the process of their decomposition in the soil.There is a diverse array of organic materials, which can be processed and composted for application in the farm. Most of these are called wastes but some are by-products that can be put to good use by simple processes or treatment, e.g. by composting. Such materials are abundant in Philippine farms and urban areas and include plant residues, animal manures, agro-industrial wastes, and garbage.Organic materials are known to improve rhizosphere ecosystem, suppress soil-borne phytopathogens, and promote root growth. Plants treated with farmyard manure have been found to have better root development during the early growing stage. It is believed that among the factors affecting root growth, rhizosphere micro flora, root growth regulators, and behavior of fungi in the may be of particular importance because of their high saprophytic/parasitic activities.Application of organic materials reduced incidence of soil-borne diseases such a rhizoctonia root rot of sugar beet. Pseudomonas spp. is known to be antagonistic to phyto-pathogens of wheat, sugar beet, and potato. The increase in their population may contribute to the reduction of soil-borne disease incidence. Organic materials during decomposition may release various intermediates, which may activate various kinds of microorganisms in soil. In the rhizosphere or root area, microorganisms may proliferate considerably due to an abundant supply of root exudates or root excretions which may contain growth promoting substances or food for microorganisms. This may improve microbial balance, which may suppress multiplication of such specific microorganisms as phyto-pathogens and stimulate root growth.

Role of Soil Organic Matter Organic matter content usually used as an index of soil fertility. It influences soil in three ways, i.e., physical, chemical, and biological. More than 50 % of the carbon exchange capacity of soils is due to OM. As such it is important not only for the retention of nutrients from applied fertilizers but also increasing the buffering capacity of soils, thereby enabling crops to better cope with stresses such as soil acidity and nutrient excess. By itself, OM is also a source of other major and secondary nutrient elements. About 92%-94% of soil nitrogen and 15%-18% of total phosphorus are released from organic matterOrganic matter plays an important role in the environment of soil physical properties. It promotes soil aggregation and improves permeability and aeration of clayer soils. Its high moisture absorbing power and high carbon for growth microbial mycelia may help granulation of sandy soils to improve their nutrient and water-holding capacity.Organic matter is the main source of carbon and energy for soil organisms. Application of OM to soils may be beneficial or injurious to crops depending on the kinds of crops and organic matter applied. Treatment of soil with sawdust, tree leaves, green manure, oil cake and rice bran may increase the population of earth worms to inhibit nematode population. Straw of grasses may reduce wilt and blackleg of potato and roof of common bean, pea and cotton. Soil treatment with OM may increase population of Rhizobia and Mychorrhiza.Organic matter application increased water stable aggregates, porosity, and air permeability while decreasing bulk density and hardness in both sandy loam and silty clay loam.A close relationship was observed between OM content and soil moisture retention of soil. An increase of 1% OM increased field capacity of paddy soil surface by 1.7% and of upland soil by 25% (FAO 1997)Organic matter content of soils is considered as one of the important indicators of good soil quality and a major key to sustainable productivity of croplands. Therefore, one of the good soil management practices that are always advocated is the building up and maintenance of a fairly high level of soil organic matter (SOM). These cropping practices include plowing back crop residues onto the soil or regular application of processed organic materials.The effects of organic matter on the soil properties are summarized as follows:

On physical properties:Promotes granulation of soil particles into water stable aggregates, thus, enhancing balanced distribution of macro and micro pores and giving the soil good aeration porosity, high water-holding capacity, water permeability, and root penetration; Reduces runoff due to high water-holding capacity, which makes the soil less susceptible to erosion. This stable aggregates and the OM as soil cover or much give the soil protection against splashing action of raindrops; and, Gives dark color to soils. The darker the soil the higher is The OM and thus generally the higher the fertility level.

On chemical properties: Increases supply and availability of N, P, K , S and other nutrients. Organic matter contains nearly all the essential elements; Converts chelates metals like Fe, Cu and Zn into organo metal compounds, which enhances their availability to plants; Increases nutrient retention capacity or CEC of soils;Increases buffering capacity or resistance of soils to drastic changes in pH; Reduces Al toxicity in acid soils; and, Absorbs heavy metal pollutants like Pb and Cd.

On biological properties:Stimulates activity of soil organisms by providing energy and carbon source; and, Suppresses plant pathogens through the production of antibiotics.The urgency to harness the huge supplies of organic wastes has intensified with the sudden jump of chemical fertilizer cost, the need to properly dispose wastes, the mounting concern for environmental quality, and the need to rehabilitate vast hectares of degraded croplands

TYPES OF FARMYARD MANUREThe amount and composition of farm animal manures will vary depending on the type of animal, size, and weight of the animal, diet, moisture content, percentages, and type of litter or bedding, age of manure and age condition. All manures can become problems for the environment if allowed to accumulate.

POULTRYThe most important manure in the country are broiler litter and egg layer manure. Because poultry excrete liquid and solid waste together, poultry manure is higher in N than manure of other farm animals. This type of manure is assumed to be abundant in Luzon particularly in the regions of Central Luzon and Southern Tagalog.Commercial broilers are reared in houses with rice hulls or wood shavings as litter. Egg layers are reared or layered or low-rise houses. Manure drop to the ground and scrap out more often. In some operations, poultry manures contains feathers, uneaten feed, and broken eggs. As stock of manure cleaned out of this poultry houses may contain materials varying in age from a few weeks to months. Variation in age of the material and the type of the amount of litter in the manure, results in the variation in the nutrient content. In Taiwan. Poultry manure can be composted in channel from fermentor with rotary agitation. Good quality compose is produce in 30-45 days.

BENEFITS FROM USING ORGANIC FERTILIZERSApplication of organic fertilizer as pointed out earlier helps conserve the soil, maintain and sustain crop and quality and productivity, and protect the environment. Organic fertilizer maintains if not increases the organic matter level in the soil; aids in the formation of organo-metallic complexes; increases soil cation exchange capacity. And serves as soil conditioner. The addition of organic matter to the soil increases the soils ability to hold water preventing soil erosion and cracking. It loosen the soil resulting in better soil aeration, root growth, drainage, improved tillage, improved soil property, and increased compaction resistance. Organic fertilizer also improves the biological activities of the soil as it enhances rapid multiplication of fungi, bacteria, actinomycetes, and other soil organism.Many experiments on manures and fertilizers conducted in several countries, however, noted that neither chemical fertilizer alone nor organic sources used exclusively can sustain productivity of the soil under highly intensive cropping system (Singh and Yadav 1992 as cited in Villamor 2002). The experiment made by Capuno (1984) as cited in Villamor (2002) using organic materials including chicken manure alone or in concentration with inorganic fertilizer promoted a more vigorous growth and enhanced productions of more leaves and taller solanaceous crops compared with those treated with inorganic fertilizer alone. The belief is that combined application of organic fertilizer and inorganic fertilizer would result in greater efficiency of fertilizer use. The effect of inorganic fertilizer application is immediate, readily providing nutrients to plants whereas organic fertilizers, although slow-acting, keep intact the physical properties of the soil.

A.2 Inorganic Fertilizer

SYNTHETIC (INORGANIC) FERTILIZERSSynthetic fertilizers, also known as inorganic, chemical mineral or commercial fertilizers, are concentrated minerals or elemental salts. The nutrients they contain (nitrogen, phosphorus, potassium, etc.) are the same as those found in organic fertilizers but synthetics are derived from chemical sources rather than natural sources. For the most part, the nutrients in synthetic fertilizers are rapidly available to plants, although slow-release synthetic fertilizers are available.Synthetic fertilizers are sold in bags or packages that may be labeled with the name of the chemical form of the nutrient and must have a guaranteed analysis- that is the percentage of nitrogen, phosphorus and potassium. The analysis generally consists of three numbers that describe the chemical content of the fertilizer: the first represents the percentage of nitrogen, the second, the percentage of phosphorus as P2O5 and the percentage of potassium as K2O. For example, ammonium nitrate contains 34 percent nitrogen by weight and has no phosphorus or potassium, so it is labeled: 34-0-0. A complete synthetic fertilizer contains some amount of all three nutrients. The term complete does not mean that the fertilizer supplies all of the nutrients needed by a plant nor that they present in the correct relative amounts, only that all three are present. Since complete fertilizers are mixes, they are named after their analysis, such as 16-16-16, instead of being named after the chemicals they contain. A 16-16-16 fertilizer is termed complete, but it certainly does not supply the complete set of nutrients needed by fruit trees: for example, they rarely need phosphorus but the do require zinc.Take special care in the use of synthetic fertilizers. Since synthetic fertilizers are salts, they can increase the salinity of the soil if misapplied and they can burn leaves or fruit if they come in contract with them. Also, when you apply one nutrient you may reduce the trees ability to take up some other nutrients: for example, excess phosphorus can tie up zinc and magnesium may compete with calcium. Too much nitrogen can cause excessive growth, and ammonium sulfate or sulfur may increase the soils acidity to damaging levels.

The Use of Inorganic FertilizersSynthetic inorganic fertilizers were first manufactured on a large scale in the late 1930s; since then, farmers dependence on them to return nutrients to the soil has grown dramatically. Between 1955 and 1975, fertilizer use in the United States more than tripled. The application of massive amounts of synthetic fertilizers has undoubtedly been a major factor in the huge increases in food production that were achieved worldwide in the second half of the 20th century. Unfortunately, however, the use of synthetic fertilizers can cause severe environmental problems.If synthetic inorganic fertilizers repeatedly without the simultaneous addition of sufficient organic materials to sustain the formation of humus, soil becomes compacted and loses its nutrient- and water-holding properties and its ability to fix nitrogen; thus, increasing amounts of the fertilizers must be added to maintain crop yields. Eventually, the soil becomes materialized and increasingly susceptible to erosion. Another problem is the most commonly used fertilizers do not supply the needed micronutrients. (James E. Girard, 2005)

Advantage, Disadvantages and Problems of Organic and Inorganic Fertilizer Considering the rapid increase in the use of inorganic fertilizers and the large quantity of energy needed to produce them, it is beneficial to point out differences between organic and inorganic fertilizes and the advantages and disadvantages of table below:OrganicInorganic

Large non-nutrient contentHigh concentration of nutrients

BulkyEase of transport and handling

Little direct costIncrease cost

Largely renewableMade from finite resources

Imprecise content analysisPrecise content analysis

No direct energy use in manufactureLarge direct energy use in manufacture

Readily availableAvailability depends in production, cost and region

Provides disposal of wastes Creates waste in processing, but can also utilize wastes from other manufacturing process.

Table: 2.0 Advantage, Disadvantages and Problems of Organic and Inorganic Fertilizer

The nutrients content of fertilizers tells that the manures have a considerably lower content of nitrogen, potassium, and phosphorus than manufacture fertilizers do. However, manure, straw the other minerals generally not found in inorganic fertilizers and tend to improve the soils ability to hold water, its crumb structure and its resistance to erosion by water and crusting in being rain.To choice between organic and inorganic fertilizers calls for consideration of some indirect factors as well. Human and animal wastes require safe disposal as they often contain disease-carrying organisms. Using these wastes as a fertilizer can provide a convenient sanitary solution to the disposal problems.Fertilizers are becoming significant environmental problems as regards air and water pollution. The manufacture of phosphate fertilizers results in substantial emission of particulates, fluorides and sulfur oxides. Water pollution can be caused by both organic and inorganic fertilizer. Rain water and run-off leach the nutrients out of the fertilizer and carry them to the water table. Nitrates are greatest pollution treat because they promote algae growth in lakes and streams and contaminate water supplies. Excessive use of fertilizer can cause toxic nitrate levels. Another drawback of inorganic fertilizers is the contribution of the manufacturing process to water pollution.( B.A Stout, 1979)

Advantages and Disadvantages of Organic and Inorganic FertilizersIntensive agriculture generally cannot be sustained unless nutrients are applied to the soil to replace those removed through increase production. Nutrients can be added in the form of organic or inorganic fertilizers. Commonly used organic fertilizers include animal manure, household wastes, plant materials (including crop residues), and compost made from one or more of these sources. In addition to providing nutrients, organic fertilizers contribute to soil quality by improving the structure, chemistry and biological activity level of soil. Commonly used inorganic fertilizers include straight fertilizers containing a single nutrient ---usually nitrogen (N), phosphorus (P), or potassium (K)---and compound or mixed fertilizers containing more than one of these so-called macronutrients, plus, in some cases, trace elements such as zinc or boron. For plants, the source of soil nutrients is not important. Plants absorb the nutrient in the same form, regardless of the source, organic or inorganic.Organic and inorganic fertilizers are that they release nutrients gradually and that they raise soil organic matter content. There is a trade-off between these two advantages, however. On one hand, nutrients are released through decomposition of organic material, so more nutrients are available if decomposition is rapid. On the other hand, soil organic matter content is greater when more organic materials is present in the soil, so improvements to soil organic matter content are favored when decomposition is slow. The advantages of organic fertilizer are offset by two main disadvantages. First, because decomposition of organic material is strongly affected by soil moisture and temperature, it cannot be controlled. This means that nutrients may be released when the plant does not need them. Second, only a limited amount of organic material is available in many regions, and because its nutrient content is low, it is generally not possible to meet crop nutrient demands through organic fertilizers alone. The two main advantages of inorganic fertilizers are that their nutrient content is known and that they release nutrients quickly because they do not have to undergo decomposition. This means that the level and timing of nutrient uptake by the crop can be predicted reasonably well. The disadvantages associated with inorganic fertilizers are their high cost, as well as the environmental damage that may result if they are managed poorly.( Michael Morris et. al., 2007)

Organic and Inorganic fertilizersThe two main types of fertilizer materials are organic and inorganic. Which fertilizer you choose really depends on what your values and lifestyle priorities are but also what the soil is like where you live and what plants you are trying to grow in the garden.Inorganic fertilizers are sometimes naturally occurring compounds like limestone and sometimes are lab made. There is a lot of debate whether or not gardeners who are highly experienced and farmers should use organic and inorganic fertilizers. Some gardeners who are highly experienced and compete with other gardens all over the world say that the only way to get the proper soil composition for particular plant is to use highly specialized inorganic fertilizers, but critics of inorganic fertilizers are too high and that organic is way to go.Organic fertilizer can take no longer to break down and e absorbed into the soil and into the plants that inorganic fertilizer, but fans of organic fertilizer say that because all the materials in organic fertilizers are natural and are not chemicals or chemically treated, organic fertilizer is better for the plants, for the environment, and for the gardener too.

Comparing Inorganic Fertilizers and Organic FertilizersThe negatives of using inorganic Fertilizer sometimes seem to outweigh the benefits. Many people list the negative aspects of inorganic fertilizer as reasons that people should switch to using Organic Fertilizer. The most often given reasons to avoid inorganic fertilizer are: Inorganic fertilizer can burn plants- Because of the high phosphorus level of most inorganic fertilizer, if the fertilizer is applied in large quantities or applied to the wrong kind of soil, the inorganic fertilizer can burn or wilt plant instead of helping them grow. Inorganic fertilizer might poison your water- Inorganic fertilizer is more likely to run or get washed away by rain or watering and there is a chance that the fertilizer and its chemical components may get washed into a well or seep into the water. Since some inorganic fertilizer contain chemical compounds and occasionally untreated waste, this can be dangerous at times.Inorganic fertilizer can change the makeup of your soil- Over time, using inorganic fertilizer that gets absorbed into the soil but doesnt break down can change composition of the soil and can make the soil chemically imbalanced or toxic to plants.There are some benefits to using inorganic fertilizer too. Plants that are given inorganic fertilizer receive nutrients almost immediately. Inorganic fertilizer works faster and is better for creating types of soil that are conductive to growing one particular kind of plant. When using inorganic fertilizer, its easy to figure out exactly how much of a certain component, like nitrate, that the soil needs and provide just that component to the soil to make it an ideal soil for growing

II. Eggshells A. Chemical CompoundsLocal fertilizer finds; Homemade Plant Food and Dung Data: SoilEggshells. At 93% calcium carbonate, chicken eggshells are a rich source of calcium and an effective alternative to lime for raising the pH of soil. Dry eggshells in a in the oven at the lowest temperature setting. Crumble or pulverized them in a food processor; then sprinkle over acidic soil. Ground clam and oyster shells serve the same purpose.Egg shellEgg shell is brittle and acts as protective membrane to the contents inside. Shells is about 11% of the total egg. Shell is made up of calcium carbonate mainly. The composition of egg shell is a given in Table 2.1(Chintapalli Vidya, 1999)

CaCo392.4

MgCo31.29

P2050.76

Organic matter1.4

Water1.4

Table 2.1 Composition of Eggshell

Eggshell CompositionShell membranes The shell membrane is 95% protein, 2% carbohydrate and 3% fat (Tullet 1987; Palmer and Guillette) an elastic-like protein being the main component (Leach, Rucker and Van Dyke, 1981). The inner surface of the inner shell membrane is covered with a thin (2.7 m) Limiting membrane: an amorphous layer or unknown composition (Tullet, 1987).The True ShellThis part of the shell, which consist of cone and palisade layers as well as the basal caps, is composed of many calcite permeated by and organic network (Sylin-Roberts and sharp 1986) or a matrix, describe as protein-acid mucopolysachharide complex (Simkiss and Tyler, 1957) This matrix, which is variously described as a net formed from cross linked fibrous-sheet (Sylin-Roberts and sharp 1986) or fine fibrils (Tullet, 1987), accounts for circa 2% of the weight of the true shell.

B. Procedure

Formula in producing Calcium PhosphateWe need a rich source of calcium and what could be better than the eggshells we daily collect in our kitchen and toss into our garbage can; once we have collected a sufficient supply of these eggshells, we pound them to smithereens and roast them enough to generate ashes. When the eggshell ashes have cooled down, we add vinegar, which should be in approximately the same amount as the visual volume of the eggshell-ashes. After a couple of weeks, when the ashes have been sufficiently broken down by the vinegar, we remove the remaining eggshell-parts by straining the whole thing through a piece of cloth. We then dilute the liquid part with 20 parts of water. From this concoction, we take half a cup and dilute it further with one gallon of water, which we then use to water our plants.

C. Types of EggshellsQuail EggshellChicken Eggshell

Figure 2.1 and 2.2 (an illustration of Quail and Chicken eggshell).

III. Pechay A. Taxonomic Classification

Kingdom: Plantae

Division:

Class:

Order:

Family: Cruciferae

Genus: Brassica

Species: rapa

Figure 2.3 (An illustration of Brassica rapa)

Oriental Leaf Vegetables, PAK-CHOI Barassica chinensis. This is one of the Chinese cabbages, although it is more nearly related to turnip or turnip rate than to the European cabbages. It evolves at China and its cultivation was recorded in that country in 5th century AD. Pak-choi is widely cultivated in the Far East and South-East Asia, also it is gaining popularity in western countries. It is used in soup and stir-fried dishes but it is seldom eaten raw. The leave are arrange in a spiral and do not form a heart; also the leaf stalks or petioles are not winged. These characters distinguished pak-choi from pe-tsai. The flowers and fruits are typical of the Cruciferae.

PE-TSAI Barassica pekinensis. This is another of the Chinese cabbages, a native of china, and it is grown all over the world. It is well-known in western countries, sometimes describes as Chinese leaf. Some forms (2,3,4) form loose rosettes but the form (6) with compact head is best known in western countries. The petioles are winged. Pe-Tsai is used as salad plant, a vegetables, in soups, and in pickles.

Guides to Soil and Fertilizer Requirement of CropsCABBAGE This is one of the most widely consumed leafy vegetables. The two major types oar the one with compact head (Barassica oleraceae L.) and the Chinese cabbage (Barassica pekinensis Rupr.) which resembles lettuce. Cabbage is an ancient crop in China commonly cooked as green and used as ingredients in many recipes. The crop matures in less than 60 days and the yield is nearly 10 tons per hectare or about 1.6 kg/head. This is therefore a very profitable crop to grow.

Evaporative cooling system for short term holding of Chinese cabbage and tomato

In a tropical country like Philippines, temperature is an important factor affecting the quality of agricultural produce such as vegetables kept under hot conditions. Vegetables lose moisture which leads to loss of firmness, turgor, weight, and nutritional content. Keeping these highly perishable commodities at low temperature prevents of excessive loss of moisture. This gives growers, and even traders, leverage in marketing their produce and better prices. (Rudyard R. Roxas, January March, 2011)

Growing healthy, pest-free pak-choiPak-choi is a well-known leafy vegetable commonly served on the dinner table of the average Filipino family. Packed with Vitamins A and C, calcium, iron and riboflavin, pak-choi is also a favorite in other Asian countries. Pak-choi is a short duration crop making cultivation easy to manage easy for backyard farming or for commercial production. Although it is widely-grown in almost all regions in the country, pak-choi is extensively grown in the lowland areas particularly in the provinces of Nueva Ecija, Quezon, Laguna, Batangas, and Rizal.(Rita T. Dela Cruz, January March 2005 )

PechayPechay is planted all-year round in the Philippines. It prefers a cool season; however it will grow in tropics provided there is enough rainfall which is well-distributed. The common varieties grown in the Philippines include: Black Behi, Hongkong, Celestial, and Chinese.

GEOGRAPHICAL DISTRIBUTIONFew places on the Earth can be found where at least some of the five hundred thousand species of plants are not adapted to live. Only the polar zones, highest mountains, the deepest oceans, and the driest deserts are devoid of plants-other than bacteria. Each plant species has a limited distribution, depending on its own particular requirements. Some species are broadly distributed, being tolerant of a wide range f conditions. Narrowly restricted species have limited tolerance to a specific factor, such as soil type.Climate is the major factor affecting the distribution of plants and determining their structural adaptations. The greatest numbers of species are found near the equatorial regions in tropical climates, where moisture and temperature are seldom limiting. The number of species in an area decreases toward the poles.Plants adapt as they occupy drier or colder areas away from the tropics. In drier climates plants develop features, known as xeromorphic (dry form) characteristics, such as smaller, thicker leaves, spines, dense hairiness, and water-storage organs. In colder zones plants grow closer to the ground, with the growing points protected at or just beneath the ground. Because of similar adaptations, plants of a specific climate zone form characteristics vegetation and associated groups of animal species is called a biome. The major biomes of the world include the tropical rain forest, desert, and tundra.

B. Chemical RequirementsSoil requirement for pechay is loam or sandy loam, well drained and rich in organic matter. Soil requirement for the seedbox or seedbeds is the standard combination of 1/3 garden soil, 1/3 sand, and 1/3 organic matter. These materials are thoroughly mixed to acieve uniformity of texture and uniform nutrient effect to seedlings.

Basic NutritionBeing a high yielding crop, cabbage also takes up large amounts of soil nutrients. Like other leafy vegetables, it needs plenty of nitrogen. A crop of one hectare yielding 70,000 kg takes up about 250 kg N, 90 kg P205 and 300 kg K20.Fertilizer requirementThe ranges of fertilizer nutrient requirement are 90 to 250 kg N, 30 to 60 kg K20. The minimum amount of the recommendation, 90-30-30, corresponds to about 4 bags of complete fertilizer plus 1.5 bags ammonium sulfate per hectare at transplanting time and then 2 bags urea a month later.

C. Cultivation

Calcium PhosphateAs mentioned before, our pre plants are composed of different parts and go through different stages. Needless to say, they have different nutritional needs during each of these stages. Actually, we ourselves are not much different ; we need protein for our brains, amino acids for our muscles, carbohydrates for energy, calcium for our bones, etc. but we need these different nutrients in different quantities at different stages of our life.We can distinguish three major stages in the life of our Plants:The first is the vegetative stage during which our plants start life and form all their important parts( something like our childhood) and for which they need plenty of Nitrogen. The second is the change-over stage (something like our adolescence), which is a very critical stage between the vegetative stage, and the third stage, which we call reproductive stage. In this stage, our plants need appropriate nutrient, very crucial of which is calcium phosphate, as this enhances the general health of our plants; increases their productivity and determines the quality of their final reproductive stage. In the reproductive stage (something like our adulthood), our plants develop flowers and fruits to ensure their survival as a species. At this stage, our plants are in critical need of K potassium.

Common NameVarietyPlant FamilyTransplant AbilityPounds per 100 FeetDays to HarvestComments

Chinese CabbageMicihili, Wong Bok, Bok Coy, Napa

Cruciferae (Mustard)

I

100

70-90Bok Choy is open-leaf type; Michihili and Napa form round heads.

Table 2.3 Vegetable Varieties, Families, and Characteristics

HARVESTINGVegetables should be harvested when they are at the peak f maturity. At this point the produce has reached its optimal size: the flavor is fully developed: texture is just right: it keeps best and produces as quality processed product. The best harvesting time varies with each vegetable crop. Some vegetables hold their quality for only a few days, and others can hold their quality over a period of several weeks (see Figure 20-4). Table 20-5 provides guidelines for harvesting some of the vegetables crops.When harvesting produce from some vegetables plants like peas, beans, and cucumber, growers take care not to damage plant. Injured plants may be killed and stop producing fruit. Also, growers should never harvest vegetables when foliage is wet, because this practice may spread plant diseases.Depending on the type of operation and the type of crop, harvesting is done by hand r by mechanical harvesters. Mechanical harvesters for larger commercial operation are designed to prevent injury to the crop.

VegetableWhen to Harvest

CabbageWhen heads are solid and before they split. Splitting can be prevented by cutting or breaking off roots on one side with a spade after a rain

Table 2.4 Some Guidelines for Harvesting Vegetables

RELATED STUDIES

The Eggshell That Makes The Best Fertilizer

Background of the StudyIn addition to the calcium, the eggshells contain about 1% nitrogen, about a half-percent phosphoric acid, and other trace elements that make them a practical fertilizer. Calcium is an essential plant nutrient which plays a fundamental part in cell manufacture and growth. Most roots must have some calcium at the growing tips. Plant growth removes large quantities of calcium from the soil, and calcium must be replenished, so this is an ideal way torecycle your eggshells.

Eggshells as soil neutralizer

AbstractA study was conducted to utilize eggshell in offsetting soil acidity. Acidity soil resulted from series application of inorganic fertilizer. Farmers and gardeners then treat lime in their farms and gardens to revive and neutralize the soil. Calcium carbonate, which is essential in soil neutralizing, comprises the lime. Calcium carbonated eggshell can be used as a substitute for lime. The researchers prepared six different set-ups with varied amount of eggshells and soil. The effect of the eggshells in acidic soil was observed in ten days, showing changes in pH range of the soil. There is also a change in the growth of plants, particularly the height of the seedlings, number of leaves and duration of sprouting. Eggshells can definitely be a substitute for lime. The use of eggshells can greatly help farmers and gardeners in the increase of crop production.