Advantages of compost in crops farming
Posted by Unknown in Fertilizer, Manure and Composting, Organic Farming on Monday, 10 September 2012
The use of inorganic fertilizer has considerably increased with the cultivation of exhaustive crops in the backdrop of green revolution. Despite that, hundred of thousand of cultivated fields have become unproductive due to depletion of nutrients essential for plant growth and development. Not to speak of macro-nutrient deficiency even micro nutrients has been reported in different fields of Punjab and Sindh.
Off-take of fertilizer has increased from 18.9 million nutrients in 1990-91 to 29.8 million nutrient tons in 2005-06 while cropped area has also been increased from 21 million hectares to 23 million hectares during the same period. Fertilizer requirements are met partly from domestic production and partly from imports. Though off-take of fertilizers is on increase yet domestic fertilizer production is on decline. Domestic production has decreased from 2.28 million nutrient tons in 2001-02 to 2.13 million nutrient tons in 2005-06. On the other, import has increased from 0.62 million nutrient tons to around one million nutrient tons during the same period.
With the increase in off-take of fertilizer, the crop productivity has also increased significantly but excessive use of fertilizer has augmented the cost of production and incidence of insect, pest and disease attacks. Excessive use of DAP is destroying the under soil of the farm land, increasing compaction of soils and enhancing level of acidity of cultivated soils. Moreover, fertilizer use efficiency is low in the backdrop of huge nutrient losses in the form of leaching, de-nitrification, volatilisation, immobilisation and fixation of nutrients with soil complex and hence contributing to soil, water and air pollution.
Therefore, it is appropriate to look forward to those techniques that on one hand add nutrients into soil and improve soil texture, structure, organic matter and water holding capacity on the other. To achieve the desired objectives, the agricultural scientists are pressing hard of switching to compost farming.
Application of compost is very useful as it utilizes the farm garbage and wastes in an effective way. Moreover, 100 kg compost contains 1.34 kg nitrogen, 1.3 kg phosphorous, 1.04kg potash and 0.89kg calcium respectively. Therefore, the growers should give due importance to the production and use of compost.
Preparation of compost is easier and raw material comes from agricultural farms not from the market. Different type of crop residues such as wheat straw, rice straw, leaves, cattle dung & urine, and other household garbage could be effectively used for preparing compost. Simply, these are put into a trench with adequate moisture. Trench is 3-3.5 feet deep and length and width depends upon the availability of organic matter. A trench of 25 feet long, 3-3.5 feet deep and four feet wide is recommended for small farm containing 5-6 animals. However a trench 35-40 feet long, seven feet deep and 3-3.5 feet wide is recommended for big farms. The microbes like bacteria and fungi convert the organic matter into compost. The microbes utilize 10 parts carbon and only one part of nitrogen for their growth. However, action of fungi is more efficient than bacteria. In this process, gases like methane, ammonia, carbon dioxide hydrogen are produced that could be effectively utilized for energy purposes. Only draw back in producing compost is that it is slow process and completes in 3-5 months.
Size and mixing of crop residues also influence timing of compost formation. Microbes thrive better on particles having size 5cm or less. Maintaining the C:N ratio is crucial. It could be done by mixing legume crop residues, water hyacinth, butcher-house waste, sewerage sludge, biogas slurry. In the case of high C:N ratio, we can mix soil to produce a good compost. Best moisture for compost formation ranges between 50-60 per cent. High temperature is inevitable for the activity of the microbes because it kills disease causing micro-organisms and weed seeds. In case moisture is less than 40 per cent, the process of compost formation will be extremely slow. To speed up the process, it is important to invert the organic matter frequently.
Inoculation is important to enhance the activity of nitrogen-fixing fungi like penicellium and aspergillus and bacteria such as azotobactor. Inoculation is effective when temperature of the medium ranges between 30-35 centigrade. Inoculation is done to reduce the period of compost formation from 3-4 months to 4-6 weeks. This also enhances amount of nitrogen up to 10-30per cent.
Use of calcium phosphate reduces time of compost formation as well as enhances nitrogen uptake. During compost formation, it is essential to destroy the disease causing agents especially when sewerage sludge is mixed in the organic matter.
Well-pulverised compost adds more nutrients to the soil and within a short span of time. It improves soil texture, structure, oxygen diffusion ratio, pore space, water holding capacity and plant resistance against lodging and microbial activity.
Compost is suitable for all kinds of crops including cereals, vegetable, oilseeds, fruits and flowers. About 15-20 carts per acre in irrigated and 5-10 carts per acre in rain-fed areas are recommended. Compost enhances uptake of inorganic fertilizer by crop plants.
It is advisable for the farmers to assemble animal dung and wasted straw for compost preparation. Addition of compost into soil will cut the use of artificial fertilizer, conserve soil and water, improve physical health of soil, enhance fertilizer use efficiency, improve soil fertility and ultimately enhance crop yields.
The Dawn
