Organic Fertilizer

Background: The post green revolution era witnessed a multiple nutrient deficiency because of higher crop harvest in the intensively cultivated areas where use of organic manure had declined while chemically pure fertilizers like Urea, Di-Ammonium Phosphate, Murate of Potash and other allied items became the major source of plant nutrients. As a result of continued use of chemical fertilizer soil became poorer due to the deficiency of microbial contents of the soil. Agriculture devoid of organic manures / crop residues has resulted in reduction of physicochemical and Biological properties of the soil.

In order to ameliorate the already deteriorated soil conditions and also to reduce dependence on the use of chemical fertilizer and pesticide to arrest the grave ecological damage, Indians took up the program to supplement the national objective. We are implementing a major Biogas program along with implementing Bio-Manure Program throughout the Country. For vermicomposting, pre-digested organic matter is essential (15 to 30 days pre-digestion) as earthworm cannot resist high temperature generated during pre-digestion.
The widely used process in Rural India, is a two step process to convert seed cake into Bio-Fertilizer. In first step the seed cake is fermented in Bio-Gas Plant, along with Cow Dung as seed material, shown below. The cake is mixed with water to form a slurry and slurry is fed into the plant once a day. The processed cake settles to the bottom of plant. The processed cake of earlier days, is automatically driven out in equal quantity. The processed cake, is then carried to Bio-Fertilizer plant. (If you go for single step process, this step is omitted.) The Bio-Gas produced is used for Lighting and Cooking.

Seed cake has C:N ratio of 40. Most of the Carbon is converted to BioGas and C:N ratio is reduced to 10. Large protein molecules in cake are broken down to smaller molecules. The cake coming out of BioGas plant is then further processed in a simple, low cost, BioFertilizer plant as shown below. The smaller protein molecules are further broken down in BioFertilizer plant, which can be absorbed by plants as fertilizer. If first step (Biogas plant) is omitted, the cake is spayed with water to keep the cake moist. Cake is then stacked in over the ground pits made by stacking bricks.

In these sheds the seed cake is eaten by earthworms (shown below) and bacteria to produce Bio-Fertilizer.

Water is sprinkled on the cake heap, which is kept moist at all times. Cake heap is turned upside down once a week. It takes 3 to 4 months to complete the process. After that period, the earthworms are taken away from Bio-fertilizer, by screening cake with the help of screens. Earthworms are sent back to pits, while bio-fertilizer is packed in bags, for sale. It provides employment to a number of tribals. Earthworm requires cold (20-28^oC), humid and shady place to work. Therefore vermicompost units should always be made in shade and kept moist. Earthworms need Protection from predators such as centipedes, snakes, rodents, birds, hens and red ants and therefore requires suitable fencing.
Arranging the pile and making aeration hole: The mixture of the raw materials is arranged into a pile. Piling is made above the air tunnel made from bamboo, in order that the process takes place aerobically. The size of pile is 1.5 meters in height, 1.75 to 2 meters in width and 2 to 4 meters in length.
Observation of temperature and water content: Temperature is measured by inserting a thermometer into the pile. Make a hole, 2/3 pile height deep, put a thermometer in cake and cover the hole. Leave the thermometer in the hole for 1-2 minutes, and then take out the thermometer through its tying rope. The temperature reading in the thermometer is the temperature of the pile.
The observation of water content is done by taking some material from inside of the pile, and then squeezing cake. If no water comes out from among your fingers, it means cake is dry. If a lot of water comes out, it means cake is too wet. The water content required is good, if only a few drops of water come out from among the fingers.
Turn Over: To control the temperature, humidity and aeration of the pile, cake has to be turned over. The temperature of the pile should read 55^oC for at least 15 days. In this condition, it is better to turn over the pile, 5 times.
If the pile is too dry, pour water on cake, to make up optimum water content. But if cake is too wet and anaerobic activity starts, the turn over should be done every day until the water content become normal again.
Maturation: After active composting terminated, maturation is carried out to make the compost reach the final stability, and safe to be used as bio-fertilizer for plant. This process lasts for 14 days. If the temperature is above 45^oC, turn over should be done. If the pile is dry, pour the water on cake. If the temperature is always below 45^oC, it can be concluded that the compost is ripe.

The ripe compost is characterized by the following:
• The physical form of the pile looks broken, the pile is smaller with loss of 50% of its initial weight.
• The color of the pile is rather black, like soil.
• Processed cake has no odor.
• For several days, its temperature always remains less than 45^oC.
• The organic content of the compost, percentage of carbon or ash content, and C/N decreases.
• No nitrates and ammonia are present.

• Look its physical condition, no odor, no mushroom and other materials, the form is just like soil, and blackish in color.
• Palm of the hand test, to see the water content.
• Germination test, plant the seeds of green bean on the compost. Whether seed grows or not?.
• Put 2 kgs of compost into a plastic bag and pour water to make cake saturated, and then cover up. After several days, if the compost become hot and the plastic swelled, it means that the compost is not ripe yet.
• The lab test to see the nutrient content.

Screening: The screening is done to obtain the size of the compost we want, and to separate the contaminant such as glass and plastic. Ripe compost is divided into 3 groups, namely fine compost: maximum size of 10 mm, medium compost: maximum size 16 mm and coarse compost: maximum size of 25 mm.
Packaging: After screening, compost is packed in a bag. Packaging is performed to protect the product, and help the producer in storing and marketing easier.
Bio-digested Slurry (BDS): To get better results, Biodigested slurry is better. Bio-digested Slurry very good after proper dehydration of 30 to 40% moisture content. Due to bio-digestion bigger protein molecules are broken down to smaller molecules. Bio-digested Slurry can be used as it is, as organic manure. Liquid slurry alongwith 70 to 80% organic matter can be used for composting (In place of fresh cow dung). A combination of 50% green biomass and 50% BDS is very good for vermicomposting. The slurry should be stored in shade as moist fresh slurry contains 20% of anhydrous Nitrogen, which will evaporate in air, due to de-nitrification if exposed to direct sunlight. Unlike Bio-digested Slurry all the prepared compost should be either stored in pits or in shade and 20 to 30% moisture should be maintained in Bio-digested Slurry to retain microbial activity.

Benefits of organic manures:

1. Contains micro and macronutrients, such as Nitrogen Phosphorus and Potassium and a fair amount of Manganese, Zinc, Copper and Iron. These are simultaneously added to the soil. Besides, organic manure increases the microbial activity.

2. Carbon as an energy source and other nutrients are provided to soil microbes, which result in augmentation of their population. They in turn help in decomposition of organic matter, biological nitrogen fixations, solubilization of insoluble phosphates and availability of plant nutrients.

3. There is improvement in Soil structure, water holding capacity, drainage, exchange capacity, seed germination and reduction of soil erosion.

4. Humic substances released as byproducts of soil microbial activity, increase the efficiency of bio and chemical fertilizers.

5. Proliferation of plant parasite, soil nematodes are checked. Resistance of plants to pest attack is increased.

Need for Organic Manure: Some Indian soils being very poor in organic matter and major plant nutrients, addition of regular doses of organic manures in requisite quantities can help restoration of soil health and also compensate the loss of basic nutrients of every year from soil, due to uptake of crops. Therefore, use of organic manure is extremely essential for better productivity of crop and maintaining the fertility of soil to ensure sustainable production.
Methods of composting: There are various methods for the preparation of compost using organic biomass and cow dung / seed cake / biodigested slurry.
Seed cake is converted to Bio-Fertilizer, for using Bio-Fertilizer as fertilizer for crops. If fertilizer is used in plantations, the seed cake can be applied as it is, 3 to 4 months before the timing of actual application. The earthworms in soil, convert these to Bio-fertilizer. But earthworms, may face danger from predaters.

Soil enrichment: Jatropha curcas cake is rich in nitrogen, phosphorous and potassium and can be used as organic manure after aerobic fermentation. The fertilizer value of different organic fertilizers is as follows

	Moisture	N	P	K
	%	%	%	%
Jatropha Cake	4.58	4.4	2.09	1.68
Cow Dung	9.7	0.97	0.69	1.66
Chicken Manure	10.19	3.04	6.27	2.08
Duck Manure	17.57	2.37	2.1	1.09
Rice Straw Compost		0.891	0.18	0.68
Water Hyacinth Compost		1.43	0.46	0.48
Municipal Waste Compost		1.25	0.25	0.65

Organic Fertilizer increases the organic matter content of the soil, along with the major and minor organic nutrients. The combined interaction of the nutrient ingredients in Organic Fertilizer, integrates the soil with the full range of nutrients within a relatively short time, and their effects last longer for the standing crop to benefit directly. By optimally utilizing these nutrients from the soil, crop productivity in the plots treated with Organic Fertilizer, greatly increases as reflected in the high yields and quality of the crops. Organic Fertilizer is therefore unique in its action in stabilizing and enhancing the nutrient status of the soil, and thereby increasing productivity of crop.
By improving overall physical characteristics of the soil and increasing organic level of soil, Organic Fertilizer prevents physical compaction of soil, improves soil aeration and prevents leaching losses. Organic Fertilizer encourages the microbial activities in the soil, increasing thereby the decomposition of organic matter, leading to improved productivity of soil. Organic Fertilizer not only releases nitrogen, phosphate and potash in a manner easily absorbed by plants, but interacts very positively with inorganic fertilizers as well. This interaction allows better and greater utilization of nutrients, particularly nitrogen by at least 30%.

Method of application: Organic Fertilizer should be applied 30 cm away from plants and well mixed with soil. Application in split dosages is always desirable to avoid excess application. Water should not be applied soon after manuring.

A lot of deficiencies have cropped up in today’s agriculture. In past agriculture was not looked upon as business, but agriculture was art of living. Crops were not grown indiscriminately, again and again. During industrial revolution, agriculture was also commercialized. Tobacco, cotton, and cane sugar were harvested as cash crops, and large patches of land were brought under these crops. By the law of diminishing returns, yield of crops depleted and income fell. The soil starved becoming less fertile. Crops absorb some elements from soil. When these are depleted, yield of crop falls. These elements are Nitrogen, Phosphorous and Potash. Farmers supplemented these with inorganic fertilizers. Plants can not absorb these inorganic fertilizers in efficient way. Some microbes feed on these, in presence of water and convert these into products which the crops can absorb. These fertilizers are used as food by the microbes, and they excrete waste. These waste products are absorbed by crops as nutrients.
These microbes are the real Bio fertilizer plants of nature. The soils where these are more, are considered as fertile lands. There are a number of types of microbes. Some are visible under microscope, while some can be seen by naked eye. Earthworm is one such animal. For the growth of microbes, some organic products are required by these. These should be present in proper proportion. Conversion of these organic products, into fertilizer is the organic fertilizer manufacturing technique.
The microbes can survive till they get fresh supply of organic materials. As the supply depleted, these die and soil becomes less and less fertile. If inorganic fertilizers are added in such a land, these inorganic fertilizers can not be converted into products which crops can absorb. These inorganic fertilizers get accumulated in the soil, and soil becomes infertile. A lot of water is required to wash out these inorganic fertilizers. This leads to fall in income and rise in expenditure.

The advantages of organic fertilizer is as follows:
1. Organic Fertilizer improves the porosity of soil and leads to better air circulation in soil.
2. Organic Fertilizer improves the water level in the soil.
3. Organic Fertilizer helps in drainage of excess water.
4. Absorption of nutrients by roots is better.
5. Number of microbes in soil are increased.

Normally, 25 tons of organic fertilizer is required per hectare of land. Initially in barren land, twice or thrice the amount of organic fertilizer needs to be added to bring soil back to normal. Till now cow dung, cattle dung, and oil cakes of non-edible oils were used for manufacture of bio fertilizer. The dry leaves and other bio mass can provide good amount of carbonaceous material for the microbes. This is called as farm yield manure (FYM).
Bio fertilizer is a labour intensive business and can provide a lot of employment in poor countries with very small investment on plant and machinery. Bio fertilizer can also be mechanized to reduce labour costs. Due to constant need of biofertilizers, the manufacturing units can do well for a number of years.

These are divided in 3 classes. First class is by way of their Availability. Second one is by way of its Elements. Third class considers Application of the fertilizer.
1. Availability: This is available as number of waste products

1. Excreta of animals and birds
2. Human excreta
3. Dead bodies and slaughtered parts of animals and birds
4. Dry farm materials (FYM)
5. Green farm materials
6. Solid waste from urban area
7. Wastewater from urban area
8. Ash
9. Seed Cake
10. Combination of two or more stated above

1. Humus
2. Nitrogenous fertilizer
3. Phosphatic fertilizer
4. Potash fertilizer
5. Complex organic materials
6. Food for microbes
7. Micro nutrients

1. Direct fertilizer
2. Indirect fertilizer
3. Growth activators

If you consider composted and completely decayed cow dung, Bio fertilizer fits in first category of Availability, all seven categories if Elements, and first two categories of Application. Hence, in India, Bio fertilizer is considered as best Organic Fertilizer and Bio fertilizer is very widely applied in agriculture. No treatment is required for disinfecting Bio fertilizer of bacteria, and other pathogens and toxins.
If you consider Human excreta, Bio fertilizer fits in first category of Availability, all seven categories if Elements, and all three categories of Application. But treatment is required for disinfecting Bio fertilizer of bacteria, and other pathogens and toxins.

Humus: This has the property of holding moisture in the soil. This is very important property for the survival of the crop. When water is applied to soils having less humus, water is not retained in the upper layer of soil, where roots of crop can absorb humus. Water percolates deep in soil, or water evaporates in hot season. Soil cracks in summer, and roots are unable to absorb water, and eventually roots and crops die. Fertile soil should contain at least 40% humus. If humus is not there, application of any amount of fertilizer is of no use. Microbes as well as roots, survive due to humus. These microbes absorb moisture from humus, for their survival. If quantity of humus goes down, it affects the population of microbes and eventually the fertility of soil goes down. These microbes excrete some chemicals from their body, like colloidals and lipids. These help in holding the soil and reducing soil erosion.
Microbes can not grow in soils having very small amount or no humus. Due to this there are no colloidals and lipids in soil. This leads to loosening of soil and desertification. Some parts of crops like cellulose and lignin, provide the humectant properties. This is similar to clay or coal. Coal holds water as coal is porous. Clay holds water and does not release water. Due to this, water is not released, and roots can not absorb the water.
Plants absorb water by osmosis. Hence plants can absorb water better in case of humus, and not so well in clay. Water remains as it is around roots, and the roots rot. Leaves are shed and providing more water also does not help.
Nitrogenous Fertilizer: These are required for nurturing the green parts of the plant. Due to this, more chlorophyll is produced which leads to absorption of more amount of CO₂ and production of carbohydrates. Nitrogenous Fertilizer also helps in absorption of P and K. The growth is better and faster predominantly due to N. Hence, these are very essential for the plants. If N supply falls, leaves turn yellow, and fall off. It also damages roots and absorption of P and K is affected. Fruits and grains, fall of the plants, crop matures early and this affects the income. If N supply is more, the leaves are dark green, and it takes longer for it to mature. Nitrogenous Fertilizer reduces pest resistance, and can get attacked by pests. Proteins are basically, nitrogen compounds, and these are formed with nitrogen from fertilizers.
Phosphatic Fertilizer: N and K help in vertical growth of plant while P assists in lateral growth. Phosphatic Fertilizer improves growth of new cells, hence more food is stored in the plant. Its trunk becomes strong, and branches grow in upward direction. Phosphatic Fertilizer helps in good growth of plants, timely maturity and good growth of fruits and seeds. Phosphatic Fertilizer accelerates growth of legumes and absorption of N is faster.
Deficiency in P leads to shorter growth of plants. Roots do not develop well and red spots are found on branches. The bad effects of excess N are negated by proper dose of P. Excess P can lead to development of toxins in plants.
Potash Fertilizer: Potash Fertilizer is essential for growth of vegetables, paddy, tubers and leguminous plants. Potash Fertilizer increases pest resistance. Plants can stand colder temperature. Plants producing carbohydrates and sugars need more K for growth. N is absorbed better due to K. Plants can store or tolerate more amount of K than required but it delays maturity. It is not significant like that in case of N. If plants are deficient in K, black spots develop on leaves and these dry up.
Complex Organic Materials: These are a number of organic chemicals like colloidals and lipids. These are food for microbes and are indirectly good for plants. These also provide humus materials. Some of these can act as fertilizer. If its concentration exceeds 5%, Complex Organic Materials can create problems of porosity. Complex Organic Materials reduces aeration in soil, and this may lead to deterioration of roots.
Food for Microbes: A number of single cell bacteria grow in soil. These need food, which is provided by some organic materials. These microbes grow and die, and provide nutrients to crops when disintegrated. All indirect fertilizers fall under this category. These have higher concentration of C, compared to N. Hence urea is added for additional N, along with P and K, while feeding these.
Micro Nutrients: These are some types of vitamins, which are required in small doses. Some are created by plants while others need to be fed externally. These are referred as oxins and cycotokinine. Cycotokinine help in healthier growth of trunk. These can be provided by spraying these on leaves, if required. However, Micro Nutrients is better if these are produced by plants themselves.

When any organic matter from plant or animal origin, is thoroughly decomposed, it is called Bio-Fertilizer. Decomposition is achieved by feeding these to anaerobic and aerobic bacteria. The resulting product is good for absorption by microbes in the soil. Since the conditions required for anaerobic and aerobic decomposition, are opposite to each other, these can not be performed together. Two different systems need to be designed for these. Aerobic process is called as composting while Anaerobic process is called bio composting. Apart from this bigger size organisms like earth worms are used for conversion of these organic compounds. Earth worms do the same job with the help of microbes at a very fast rate. This is called as vermi culture.
Aerobic: The microbes required for this are normally found in soil. Some of these are algae, and they need NPK for their growth. These can grow well in a temperature range of 28 to 38^oC and pH range of 5 to 8. If these conditions are not met, these become dormant and the decomposition process slows down. When these organic fertilizers are applied to soil, these are consumed by microbes in soil, releasing CO₂ in the process. These also release some nutrients and vitamins. These microbes form compounds of metals like calcium, potassium, zinc, copper, manganese and molybdenum, which can be easily absorbed by crops as micro nutrients.

Why the organic matter is not used as it is:

1. The organic material that is not decomposed has a C:N ratio of 40:1. If organic matter is applied as it is, the process of decomposition takes place in soil, over a longer period. Microbe growth is very high due to high carbon in organic matter. Microbes in soil need C:N ratio of 5:1. Soon soil has deficiency of N, and these microbes start grabbing N that is required for crops.

2. A lot of heat is generated due to growth of microbes, which heats up the roots of crops. This reduces osmotic pressure, and roots can not absorb water. This leads to damage to crops.

3. A lot of pests and insects are also attracted to the organic matter. These consume the organic matter at a very high rate, and then consume the crop itself.

4. Rats also feed on organic matter, and these even destroy roots of plants.

5. Also organic matter leads to formation of some toxins, which can destroy the crops.

The microbes consume the organic material in proportion of their surface. Hence, the rate of production of organic fertilizer depends on the surface area of the microbes. Organic matter should be as finely ground as possible. If it is less or more, growth of microbes get affected. Some microbes double or triple within hour, but some take very long time. Even if the feed is finely ground, it takes certain amount of time, that is absolutely necessary. The microbes are generally present in soil, and their concentration is few thousand to billions per cubic meter. In the process of decomposition some soil having good concentration of microbes is added as seeding material.

Most important points for decomposition are:
1. Rate of decomposition depends on surface area of microbes and fineness of feed material. It also depends on the number of microbes present.
2. Time required for complete decomposition depends on particular microbe.
3. A temperature range of 28 to 38^oC is ideal for growth. However temperature should not drop below 10^oC.
4. The pH of the medium should be controlled in the range of 5 to 8.
5. Humidity should be 90 to 100%.

1. Useful: These are algae, single cell bacteria, fungus and actinomycetes. These help in decomposition. These can be aerobic as well as anaerobic.
2. Harmful: These are protozoa, nematodes, viruses and pests. These spread diseases in the field. These are mostly aerobic.

Small scale Production by Composting (Aerobic): This is used for small facilities, to produce bio fertilizer from cattle waste, oil seed cakes etc. Compost should be produced at a place away from locality, as Compost produces gases having foul smell. Composting should be set up under the shade of a large tree, or in a covered shed. If exposed to sunlight, Compost dries up the mass and process can slow down. Land should also be elevated to avoid water logging. Fresh material is spread in layers and some old compost is spread on cake as seeding material. Compost is then covered with thin layer of soil. Layers are added till the heap is about 500 mm in height, 2,000 mm wide and 6,000 to 8,000 mm long. Once one heap is ready, second one is set up. During dry season, water is sprinkled on cake to maintain humidity, once in 15 days. After a week, heap is turned upside down and set up as 1,000 mm wide and 1,000 mm tall. As cake gets decomposed, Compost will fall in height. Compost should be turned around every 15 days for first two months. Compost is then left as it is for two more months, when Compost is ready for use. 3 batches can be produced in a year. Darkness is very important for the process of decomposition.
Large scale Industrial Production by Composting (Aerobic) : A covered permanent shed is set up as production area. Some machines like hammer mill, cutting machine, weigh scale, mixer and homogenizer are required. Some of batch sizes are as follows:
Cattle waste and seed cake: 300 parts
Dry waste from farm: 100 parts
Ash: 15 parts
Soil: 50 parts
Old manure as seeding material: 10 parts
Urea: 8 parts
Super phosphate: 4 parts
The raw materials are first preprocessed. Dry waste is ground in hammer mill, and a stock is maintained. Cattle waste and seed cake is mixed in mixer (like a concrete mixer) and mixed with soil, urea and super phosphate. This is then homogenized in a homogenizer by sprinkling water on cake. Homogenizer has cutting blades in it. Blades cut, grind and make a wet pulp like solid material. The prepared meal is then placed in composting area. Cake is ready for use in 20 to 50 days. When cake reduces in size to 1/4^th of its original size, Compost is then ready for use. In this process, turn around of pile is not required, but keeping cake moist is very important.
Large scale Industrial Production by Composting (Anaerobic) : This is done in a bio gas digester. The solid material coming out of bio gas digester, is organic fertilizer. Continuous process is the commonly used process. The processed material available after second or third step is organic fertilizer.
The process is carried in a tank having 5 compartments. These are rectangular concrete tanks. There are up to 12 steps for complete decomposition.

1. Feed section: In this section, finely ground and mixed feed material is added. Its size should be 1/6^th to 1/4^th of total volume.

2. Primary decomposition section: The material from first section enters in this section and moves on. The entrance for the material from feed section to this is at the bottom of the wall between the two sections. Primary decomposition takes place in this section. Its size should be 1/4^th to 1/3^rd of total volume.

3. Secondary decomposition section: The main reaction takes place in this section. In this section anaerobic microbes hydrolyze the feed material. Its viscosity reduces and the material flows freely. A large quantity of methane and CO₂ is released in this section. CO₂ bubbles out and churn all the feed inside this section. Its size should be 1/3^rd to 1/2 of total volume.

4. Tertiary decomposition section: In this all the gas is given out completely as small bubbles and the decomposition is complete. Its size should be 1/3^rd to 1/4^th of total volume.

5. Exhaust section: This is just next to tertiary decomposition section, and the ready materials ejects into Exhaust section. cake is then dewatered by percolation into soil and allowed to dry in sunlight.

1. Daily production: 20 tons, or 40 cubic meters. (Volume of 1 ton material: 2 cubic meter).

2. 40 cubic meters of material will be fed in feed section and same will be ejected in exhaust section. Cake will be loaded only once in day in about 3 hours.

3. Size of feed section tank = 40 x 30 = 1,200 cubic meters. The maximum and minimum volume is thus, 1,200/4 = 300 cubic meters and 1,200/6 = 200 cubic meters.

4. Size of primary decomposition section tank = 40 x 30 = 1,200 cubic meters. The maximum and minimum volume is thus, 1,200/3 = 400 cubic meters and 1,200/4 = 300 cubic meters.

5. Size of secondary decomposition section tank = 40 x 30 = 1,200 cubic meters. The maximum and minimum volume is thus, 1,200/2 = 600 cubic meters and 1,200/3 = 400 cubic meters.

6. Size of tertiary decomposition section tank = 40 x 30 = 1,200 cubic meters. The maximum and minimum volume is thus, 1,200/3 = 400 cubic meters and 1,200/4 = 300 cubic meters.

The height of different sections is as follows:

• Feed section should be 4 meters (200 cubic meters, area of 50 square meters),
• Primary decomposition section should be 3.8 meters (300 cubic meters, area of 80 square meters),
• Secondary decomposition section should be 3.5 meters (400 cubic meters, area of 115 square meters),
• Tertiary decomposition section should be 3.4 meters (300 cubic meters, area of 88 square meters)

1. The width of primary decomposition section should not be more than 10 meters and less than 5 meters. If the width for all these sections is maintained at 10 meters, the length of feed section will be 5 meters. The length of primary decomposition section will be 8 meters. The length of secondary decomposition section will be 11.5 meters. The length of tertiary decomposition section will be 8.8 meters. Total length is 33.2 meters. The length of exhaust section will be 60 meters. The tanks should be 2.8 meters below ground level and rest above the ground.

2. The cake height in exhaust section should be 50 mm, for faster drying. Hence the area of drying pit should be 600 square meters. Cake dries up in 1 day. Cake is then dried in a heap for one more day, and sold off. The dry material removed every morning and then fresh material is added to the feed section.

The feed processing machinery like mixer, cutter, homogenizer etc. are placed 3 to 4 meters upstream of feed section. Office and other facilities can be set up upstream of feed processing machinery. The waste water from toilets of the office, can be sent to primary decomposition section tank. There should be a good road on one side of plant. A mixer is placed downstream of exhaust section to produced mixed fertilizer.
Seed Cakes: Most of the non edible oil cakes are used in the manufacture of organic fertilizer. Most of the seed cakes are rich in NPK content. They also have Micro nutrients, which are very important for crops. Seed cakes of Jatropha, Karanj, Castor and Neem have pesticide materials, which saves the crops from pests. NPK content of some of seed cakes is as follows:

Seed cake	N	P	K
Castor	4.2	2.0	1.3
Cotton seed	7.0	3.0	1.6
Groundnut	7.0	1.3	1.5
Coconut	3.5	1.5	2.0
Neem	5.5	1.0	1.5
Rapeseed	4.6	11.8	1.2
Safflower	7.9	2.1	2.0
Karanj	4.0	1.8	1.3
sesame	5.8	2.0	1.3
Jatropha	6.0	2.75	1.68