3 Main Types of Bulky Organic Manures found in Soil

This article throws light upon the three main types of bulky organic manures found in soil. The types are: 1. Farmyard Manure (F.Y.M.) 2. Compost 3. Green Manuring.

Bulky Organic Manure: Type # 1. Farmyard Manure (F.Y.M.):

Trench Method:

The manure preparation should be carried out in trench of 20-25 ft. long, 5-6 ft. breadth and 3-3 1/2 ft. deep. Dry litter should be spread under each animal in the evening for absorption of urine. Each morning urine-soaked litter and dung should be well-mixed and filled in the one section of 3 ft. length of the trench (lengthwise trench is sub-divided into 7- 8 pits with partitions).

When one section is filled to a height of 1/2 -2 ft. above ground level, the dome-shaped top surface is plastered with a cow dung and soil slurry. After filling the one section (3 ft.) of trench, the next 3 ft. length of the trench is filled. In about 3 months the manure is ready for use.

Heap method of storing manure is recommended. The heaps are prepared on the upland. Each day’s material is arranged, layer by layer in dome-shape. When the heap is about 6 ft. high, it is round on the top and plastered with mud.

Factors Affecting Nutritional Build Up of F.Y.M.:

The following factors affect the composition of F.Y.M.:

1. Age of animal:

Growing animals and cows producing milk retain in their system nitrogen and and phosphorus required for productive purposes like making growth producing milk and the excreta do not contain all the ingredients of plant food given in the food. Old animals on the downgrade waste their body tissues and excrete more than what they do ingest.

2. Feed:

When the feed is rich in plant food ingredients, the excreta produced is correspondingly enriched.

3. Nature of litter used:

Cereal straw and leguminous plant refuse used as litter enriched the manure with nitrogen.

4. Ageing of manure:

The manure gets richer and less bulky with ageing.

5. Manure in making and storage:

In making and storage losses are in various ways (see ‘Losses in F.Y.M.’).

Losses in F.Y.M.:

There are two types of losses in F.Y.M. (a) losses during handling, and (b) losses during making and storage.

(a) Losses during Handling:

(i) Loss of Dung:

A part of the dung is often dried and used as fuel. The dung is valuable as manure and should be used as such

(ii) Loss of Urine:

Urine is not collected by the farmers in this country. Urine containing nitrogen and potash in good quantity is therefore, wasteful. The loss of urine may be minimised by spreading litter under the cattle and by making pucca floor.

(b) Losses during Making and Storage:

(i) Oxidation or Fermentation Loss:

The fermentation being highly aerobic, it is unfavorable for the accumulation of organic acids; due to this the ammonia that is evolved remains unfixed and escapes. The loss increases further with the looseness of the heap and exposure to the atmosphere.

The loss is reduced by compacting the manure and keeping it moist, which results in the reduction of aerobic condition (aerobic bacteria become inactive) and anaerobic bacteria bring about the decomposition of manure. The anaerobic decomposition is comparatively slower, loss of carbonaceous material kept down and humus formation takes place partly in the manure pit and this is the type of fermentation that is desired in manure pits.

(ii) Volatilisation Loss:

Gaseous nitrogen evolved as urea is broken down, to ammonia and carbon dioxide. The volatilisation is increased by an increase in temperature and drying. This loss can be minimised by addition of water to keep down the temperature and by having two or three small storage pits rather than one large one, so that the manure may not lie uncovered for too long a time.

(iii) Leaching Loss. Another source of loss of nutrients is through leaching in the form of liquid that oozes out from the manure heap or pit. This liquid contains not only soluble nitrogen but also phosphorus and potash. The oozing of the liquid is very often due to over watering. Such loss should be prevented by erecting a roof over the pit and further by putting a low bund all round the rim of the pit.

Bulky Organic Manure: Type # 2. Compost:

The process of decomposing organic wastes is called ‘composting’ and the decomposed material is called ‘compost’. The principles involved and the factors operating in the successful preparation of compost are the same as those described under F.Y.M. The final product resembles F.Y.M.

Methods of making Compost:

1. Bangalore or Acharya Method:

The composting of the vegetative waste is done in pits. The size of pit (9 x 2.1 x 0.9 metre) varies with the quantity of material available for composting. A 22 cm thick layer of waste material is first laid in the pit. On each layer is spread a slurry made of dung, urine earth. A sufficient quantity of water is sprinkled over the material in the pit to make it moist but not too wet.

The pit is filled in this way layer by layer, the layer of bedding material alternating with that of slurry and water, till it rises 2 ft. above ground level. At the end dome-shaped heap is plastered over with wet mud. It is left undisturbed. The compost is ready in about 4 to 5 months.

This method overcomes many of disadvantages of the Indore-method like turning etc. After the initial aerobic decomposition during the first eight to ten days (i.e., filling of pit is going on) the material undergoes semi-anaerobic decomposition.

Under these conditions, the decomposition is more gradual and slow. Under this process, there is less loss of organic matter and nitrogen and hence there is a greater production of compost. Therefore, this method is called developed or superior method.

Requirements of Composting:

For making good compost the following conditions should exist:

1. Moisture:

Decomposition is due to the activity of microorganism. For the proper development of microorganism there should be sufficient moisture.

2. Temperature:

Optimum temperature is conducive for the growth and activities of microorganism.

3. Nutrients:

Straw material such as wheat stubble, cotton stalks etc., are the source of nutrients.

4. Starter material:

To hasten decomposition, dung, urine, nitrogenous fertilizer is added.

Bulky Organic Manure: Type # 3. Green Manuring:

Green manuring is the practice of applying as manure large quantities of green material such as leaves and twigs of plants or crops grown for this purpose. Growing of a crop or applying of leaves and twigs of plant and incorporating it with the soil is called ‘green manuring’.

Methods of Green Manuring:

There are two methods:

(A) Green manuring in situ and

(B) Green leaf manuring.

(A) Green manuring in Situ:

Growing a crop and incorporating (ploughing) it in the same field with the soil is called situ method of manuring.

Green Manure Crops:

Leguminous (Pulse) Crops used for Green Manuring:

(1) Sannhemp(Crotalaria juncea). Adapted to well-drained soil, suitable for upland condition, quick growing, relatively resistant to pest and disease, have deep root system.

(2) Dhaincha (Sesbaniaaculeata). Resistant to drought, salt and water-logging, ideal for rice soil (clay), generally grown in lowland, suitable for saline and alkaline soil, have deep root system.

(3) Dhaincha (Sesbaniarostrata). A newly introduced green manure crop which can also grow in water-logged condition. In this crop nodules formation is on the roots and also in large number on the stem. So that it fixes more nitrogen than Sesbaniaaculeata.

(4) Mung (Phaseolusaureusmung). It is quick growing, drought resistant.

(5) Indigo (Indigoferatinctoria). Suited to heavy soil (clay), slow growing.

(6) Khesari (Lathyrussativus). Winter season crop (see table 16.2).

Non-Leguminous Green Manure Crop:

1. Bhang (Cannabis sativa)

2. Kodogira (Vernoniacenerea)

(B) Green Leaf Manuring:

When green leafy material is collected from other places and ploughed in the field it is known as green leaf manuring.

Green Leaf Manuring Crop:

1. Glyricida (Glyricidiamaculata)

2. Karanj (Pongamiaglabra)

3. Ipomoea (Ipomoea carnea)

Decomposition of Green Manure:

A host of microorganisms affect the complete disintegration of organic matter leading up to ammonification and, finally nitrate production. The factors for complete decomposition are the varying moisture conditions of the soil.

The denied results would follow if moisture contents are high in the beginning, leading to semi-anaerobic fermentation of resistant material and low (moisture) afterwards for inducing aerobic condition under which nitrification can take place. Decomposition also depends on other factors such as composition of green matter (crop) and presence of available inorganic nutrients.

Varmicompost:

Nutrient recycling is becoming an increasingly important element of environmentally sound sustainable agriculture. This involves return to the soil of essential elements that are taken up by plants and then find their way into animal, domestic, and industrial products. Such recycling not only reduces the need for additional fertilizer elements but simultaneously provides organic matter and soil cover that are essential for sustainable agriculture.

There are three major sources of nutrients to be returned to the soil are:

(i) Crop residues

(ii) Animal manures, and

(iii) Domestic and industrial wastes.

Varmiculture is a handy solution to garbage management.

Varmicompost can be prepared in the garden/field pit. In the lack of space in the garden, it can be stored in containers like, earthen pot, metal containers, plastic tub. Domestic waste and crop residues are to be stored in pit/container. Cow dung and red earthworms are added into the collected waste.

Factors affecting Earthworm Activities:

Earthworms prefer a well- aerated but moist habitat. Earthworm must have organic matter as a source of food. It is necessary to maintain the pH level of the collected garbage within the range of 6.5 to 7.5 as it is the suitable level for the sustainability of the earthworms. The pit (or container) is covered by jute sack and humid atmosphere is maintained by sprinkling of water.

After every week, stirring of garbage mixture is necessary to promote the growth of earthworms and speed up manure production. At the end of 3 months, the garbage would convert into manure. Sprinkling of water is stopped for 2-3 days so that the earthworms go deep in the soil. This would facilitate the collection of manures.

Problem in Varmicompost Preparation:

(a) Problem of stinking of garbage due to over watering.

(b) Development of other worms due to lack of proper air circulation in the container.

(c) Problem of dogs/cats/rats due to collected waste in the container.

(d) Influx of mango flies if the garbage is left uncovered.