Organic Manure in Detail

Organic Manure

Organic Manure , organic material that is used to fertilize land, usually consisting of the feces and urine of domestic livestock, with or without accompanying litter such as straw, hay, or bedding. Farm animals void most of the nitrogen, phosphorus, and potassium that is present in the food they eat, and this constitutes an enormous fertility resource. In some countries, human excrement is also used. Livestock manure is less rich in nitrogen, phosphorus, and potash than synthetic fertilizers and hence must be applied in much greater quantities.

Bulky Organic Manure :

Contain small percentage of nutrients and they are applied in large quantities. FYM, Compost and Green manure are the most impor­tant and widely used bulky organic manures.

I. Farm Yard Manure (FYM):

Decomposed mixture of dung and urine of farm animals along with litter and left over material from roughages or fodder fed to the cattle. FYM contains 0.5%N, 0.2% P₂O₅and 0.5% K₂O. Urine contains 1%N & 1.35%K₂O. N present in urine is mostly in the form of urea which is sub­jected to volatilization losses. Size of trench- 6-7.5m long, 1.5-2.0m wide and 1m deep. Heaped upto height of 45-60 cm above the ground level, dome shaped and plastered with cowdung earth slurry. (Organic Manure)

The manure becomes ready for use in about 4 – 5 months after plastering. Chemical preservatives are used to reduce losses and enrich FYM. e.g. – gypsum, kainite, and superphosphate. Gypsum absorbs urine and prevents volatilization loss of urea and also adds Ca and S. Superphosphate also acts similarly and increases ‘P’ content.

Bacteria and Actinomycetes play active role in decomposition. 60-70% moisture in the initial stage and 30-40% moisture in decomposed manure (ready to use) as well as 50-60° C temperature under the heap are favourable for the activities of these micro- organisms.

Generally 10-20 tonne well decomposed FYM per ha is applied but > 20 tonne FYM /ha in case of fodder grasses and vegetables, at least 15 days before the sowing to avoid immobilisation of N. Entire amount of nutrient is not available immediately.

2. Concentrated Organic Manure:

Concentrated organic manures have higher nutrients than bulky or­ganic manures.

1. Bird guano- The excreta and dead remains of the birds. 7-8% N, 11-14% P₂O₅ & 2-3% K₂O.

2. Fish guano – The refuse left over after the extraction of oil from the fish in factories, is dried in paved yards and used as manure 7% N & 8% P₂O₅.

3. Fish manure – 4-10% N, 3-9% P₂O₅ & 0.3-1.5% K₂O

4. Raw bonemeal – 3-4% N, 20-25% P₂O₅

5. Steamed bone meal – 1-2%N, 25-30% P₂O_s

6. Blood meal – 13-20% N, rich in Iron and its application gives a deep rich colour to the foliage, much appreciated by ornamental gardeners.

7. Meat meal/meat guano/tankage – 8-9% N and 7% P₂O₅.

8. Calcined bone – 37% P₂O₅

9. Oilcakes – Sunflower cake – 7.8% N, Groundnut cake – 7.2% N, Cotton cake – 6.5% N.

Non-edible oilcakes are used as manures especially for horticultural crops (edible fed to cattle). Nutrients present in oilcakes, after mineralisation, are made available to crops 7-10 days after application.

Oilseed cakes need to be well powdered before application for even distribution and quicker decomposition. Neem cake reduces nitrifica­tion means acts as nitrification Inhibitor.

Factors Influencing The Composition of FYM

1) Source of manure: Composition of manures varies with kind of animal producing it. Poultry droppings is the richest followed by sheep manure for nutrient contents. Dung contains phosphate while urine contains N and K2O. Amount of urine soaked in bedding material also decides the composition and vary with kind of animal.

2) Food of the animal: The richer the food in proteins, the richer will be the manure in ‘N’ which comes out in the dung and urine.

3) Age and condition of the animal: Young animals need more proteins to build up their body; hence manure is poorer in N content than old animals. Manure of sick animal is richer than healthy animals.

4) Function of the animals: Milch cantles utilize proteins for milk production; hence manure is poor in N, P & K content than draft purpose animals as they utilize more carbohydrates.

5) Nature & proportion of litter: The composition of litter varies with the kind of straw and hence will affect the quality of manure. Bajara stalks are rich in N, P & K followed by wheat & maize.

6) Preservation: Under ordinary storage, there are losses of N. Potash get lost due to leaching when the manure is too moist.

Green Manure (Green Organic Manure)

Green undecomposed material used as manure is called green manure. It is obtained in two ways: by growing green manure crops or by collecting green leaf (along with twigs) from plants grown in wastelands, field bunds and forest. Green manuring is growing in the field plants usually belonging to leguminous family and incorporating into the soil after sufficient growth. The plants that are grown for green manure known as green manure crops. The most important green manure crops are sunnhemp, dhaincha, pillipesara,clusterbeans and Sesbania rostrata.

GREEN LEAF MANURE

Application of green leaves and twigs of trees, shrubs and herbs collected from elsewhere is known as green leaf manuring. Forest tree leaves are the main sources for green leaf manure. Plants growing in wastelands, field bunds etc., are another source of green leaf manure. The important plant species useful for green leaf manure are neem, mahua, wild indigo, Glyricidia, Karanji (Pongamia glabra) calotropis, avise(Sesbania grandiflora), subabul and other shrubs.

Types of green manuring: 

There are two types of green manuring:

1. Green manuring in-situ: When green manure crops are grown in the field itself either as a pure crop or as intercrop with the main crop and buried in the same field, it is known as Green manuring In-situ. E.g.: Sannhemp, Dhaicha, Pillipesara, Shervi, Urd, Mung, Cowpea, Berseem, Senji, etc.

These crops are sown as: 
i) Main crop,
ii) Inter row sown crop, 
iii) On bare fallow, depending upon the soil and climatic conditions of the region.

2. Green leaf manuring: It refers to turning into the soil green leaves and tender green twigs collected from shrubs and tress grown on bunds, waste lands and nearby forest area. E.g.: Glyricidia, wild Dhaicha, Karanj.

Characteristics of a good manuring:

1. Yield a large quantity of green material within a short period.
2. Be quick growing especially in the beginning, so as to suppress weeds.
3. Be succulent and have more leafy growth than woody growth, so that its decomposition will be rapid.
4. Preferably is a legume, so that atm. ‘N’ will be fixed.
5. Have deep and fibrous root system so that it will absorb nutrients from lower zone and add them to the surface soil and also improve soil structure.
6. Be able to grow even on poor soils.

Stage of green manuring: 

A green manuring crop may be turned in at the flowering stage or just before the flowering. The majority of the G.M. crops require 6 to 8 weeks after sowing at which there is maximum green matter production and most succulent.

Advantages of green manuring:

i) It adds organic matter to the soil and simulates activity of soil micro-organisms.
ii) It improves the structure of the soil thereby improving the WHC, decreasing run-off and erosion caused by rain.
iii) The G.M. takes nutrients from lower layers of the soil and adds to the upper layer in which it is incorporated.
iv) It is a leguminous crop, it fixes ‘N’ from the atmosphere and adds to the soil for being used by succeeding crop. Generally, about 2/3 of the N is derived from the atmosphere and the rest from the soil.
v) It increases the availability of certain plant nutrients like P2O5, Ca, Mg and Fe.

Disadvantages of green manuring:

i)  Under rain fed conditions, the germination and growth of succeeding crop may be affected due to depletion of moisture for the growth and decomposition of G.M.
ii) G.M. crop inclusive of decomposition period occupies the field least 75-80 days which means a loss of one crop.
iii) Incidence of pests and diseases may increases if the G.M. is not kept free from them.
Application of phosphatic fertilizers to G.M. crops (leguminous) helps to increase the yield, for rapid growth of Rhizobia and increase the ‘P’ availability to succeeding crop.

Compost:

Composting is the process of reducing vegetable and animal refuse (rural or urban) except dung to a quickly utilisable condition for improving and maintaining soil fertility and decomposed material is called compost. Compost is like well- decomposed cattle manure in general appearance, more powdery and lighter in colour. (Organic Manure)

Ordinary compost can be enriched with N and P through Azotobacter and superphosphate respectively. When superphosphate is used during compost making it is called super compost and compost prepared by using N-fixing bacteria is called Azo compost. Azo compost is the cheapest source of N among all organic manures (N → 1.5%).

Superphosphate or rock- Phosphate @ 10-15kg/tonne of raw material is applied at the initial stage of filling the compost pit. Size of pit is about the same of FYM.

The compost made from farm waste like sugarcane trash, paddy straw, weeds and other plants and other waste is called Farm-Compost (0.5% N, 0.15% P₂O₅, 0.5% K₂O). Farm compost prepared by Bangalore method contains 0.80 -1.24% N, 0.40-0.59% P₂O₅ and 2.0-3.3% K₂O.

The compost made from town refuses like night soil, street sweep­ings and dustbin refuse is called Town compost (1.4%N, 1% P₂O₅, 1.4% K₂O).

Night Soil (or Poudrette):

Night soil is human excreta, both solid and liquid. It contains 5.5% N, 4.0% P₂O₅ 2.0%. K₂O)

The dehydration of night soil, as such or after admixture with absorb­ing materials e.g. soil, ash, charcoal & sawdust produces a poudrette that can be used easily as manure. Poudrette contains 1.32% N, 2.8% P₂O₅ & 4.1% K₂O.

Sewage and Sludge:

The solid portion in the sewage is called sludge and liquid portion is sewage water. Both the components are separated and are given a pre­liminary fermentation and oxidation treatments to reduce bacterial con­tamination and offensive smell, otherwise soil quickly becomes ‘sewage sick’ owing to the mechanical clogging by colloidal matter in the sewage and the development of anaerobic organisms which not only reduce the nitrates already present in the soil but also produce alkalinity.

These de­fects can be removed by thoroughly aerating the sewage in the settling – tank by blowing air through it. The sludge that settles at the bottom in this process is called activated sludge’ (3-6% N, 2% P₂O₅ & 1% K₂O).

Sheep and Goat Manure:

It contains 3% N, 1% P₂O₅ & 2% K₂O.

It is applied to the field in two ways:

(i) Sweeping of sheep and goat sheds are placed in pits for decompo­sition and it is applied later to the field.

(ii) Sheep penning, wherein sheep and goats are allowed to stay overnight in the field and urine and faecal matter is added to soil.

Poultry Manure:

3.03% N, 2.63% P₂O₅ & 1.4% K₂O, Litter is the straw, peat, sawdust, dry leaves etc. are used as bedding material for farm animals and birds. It absorbs urine and faeces voided by animals and birds.

Vermicompost

Vermicompost is an organic manure (bio-fertilizer) produced as the vermicast by earth worm feeding on biological waste material; plant residues. This compost is an odorless, clean, organic material containing adequate quantities of N, P, K and several micronutrients essential for plant growth. Vermicompost is a preferred nutrient source for organic farming. It is eco-friendly, non-toxic, consumes low energy input for composting and is a recycled biological product.

Nutrient Analysis of Vermicompost
Parameters Content
pH 6.8
OC% 11.88
OM% 20.46
C/N ration 11.64
Total Nitrogen (%) 1.02
Available N (%) 0.50
Available P (%) 0.30
Available K (%) 0.24
Ca (%) 0.17
Mg (%) 0.06

Process of vermicomposting

Following steps are followed for vermicompost preparation
• Vermicomposting unit should be in a cool, moist and shady site
• Cow dung and chopped dried leafy materials are mixed in the proportion of 3: 1
and are kept for partial decomposition for 15 – 20 days.
• A layer of 15-20cm of chopped dried leaves/grasses should be kept as bedding
material at the bottom of the bed.
• Beds of partially decomposed material of size 6x2x2 feet should be made (fig.3).
• Each bed should contain 1.5-2.0q of raw material and the number of beds can be
increased as per raw material availability and requirement.
• Red earthworm (1500-2000) should be released on the upper layer of bed (fig.4).
• Water should be sprinkled with can immediately after the release of worms (fig.5)
• Beds should be kept moist by sprinkling of water (daily) and by covering with
gunny bags/polythene (fig.6)
• Bed should be turned once after 30 days for maintaining aeration and for proper
decomposition.
• Compost gets ready in 45-50 days (fig.7).
• The finished product is 3/4th of the raw materials used.

Harvesting of Vermicompost

Common methods (or techniques or procedure) of harvesting vermicompost or vermicast from a  heap or pile are briefly described below. Any method may be adopted exclusively by preference, subject to some limitations. Otherwise, two or more methods may be applied on the same pile. Except for the first method, the rest is intended for harvesting in bulk at one time.

1. Gradual, manual harvesting of vermicast

 This method is practiced where a gardener wishes to collect small amounts of vermicast just a few days after the compost pile is stocked with composting worms. This becomes a resort when, for example, the gardener finds need of organic soil amendment as ingredient in preparing a fertile potting mix. In this case the pile has not been fully decomposed but the top is covered with a layer of vermicast. 

2. Bulk harvesting by pyramidal heap

The vermicompost is first gathered to form a pyramid- or cone-like heap within the composting enclosure provided that the heap is exposed to light. Otherwise, the vermicompost is transferred on to a flat surface elsewhere in open sun over which a plastic sheet or sack or some other substitute is spread. 

This method of harvesting vermicompost takes advantage of the earthworms’ sensitivity to light (and heat). If the pyramid is exposed to bright light, the earthworms will tend to move deep into the pyramid.

3. Screening or Sieving

This method of harvesting vermicompost can be applied anytime of the day or even at night. It also has the advantage of ease in separating the vermicompost, undecomposed substrates, and earthworms from each other.

This  can be done manually using the same fabricated tool used in screening out rough sand for masonry work. This tool consists of mesh wire nailed on wood.

4. Harvesting by inducing first the migration of eathworms

This method of harvesting vermicompost is based on earthworms’ ability to detect sources of food. They also have the habit of abandoning the pile exhausted of food and moving towards more palatable source. 

Advantages of Vermicomposting

• Organic wastes can be broken down and fragmented rapidly by earthworms, resulting in a stable nontoxic material with good structure, which has a potentially high economic value and also act as soil conditioner for plant growth.
• Vermicompost supplies a suitable mineral balance, improves nutrient availability and could act as complex-fertilizer granules.
• Vermicomposting involves great reduction in populations of pathogenic microorganisms, thus not differing from composting from this point of view.
• Vermicomposting also leads to decrease the environmental problems arising from their disposal, without needing in many cases to complete the process.
• It should be realized that vermicomposting can be a useful cottage industry for the underprivileged and the economically weak as it can provide them with a supplementary income.
• If every village can formulate a cooperative society of unemployed youth/women group, it could be a wise venture for them to produce vermicompost and sell it back to the village at a recommended price. The youth will not only earn money, but also aid society by providing excellent quality organic manure for sustainable agro-practices.