By: Neeraj Rani, School of Organic Farming, PAU, Ludhiana
In Punjab, large amount of paddy straw is available after harvesting and due to narrow window period for wheat sowing, the farmers of Punjab burn the paddy straw in their fields which strongly affects the atmospheric environment quality, resulting in a significant increase in the total amount of suspended particulate matter in the air, and this burning produces a large amount of harmful gases. By using paddy straw along with cow dung, organic manure namely vermicompost can be prepared by using earthworms. Earthworms are known as farmers. best friends because of the multitude of services they provide that improve soil health and consequently plant health. The soil, in addition to being the habitat for crops, also nurtures other organisms, As they move through the soil, earthworms loosen and mix it up, helping to aerate and drain it. This brings nutrients to the surface, making the soil more fertile, and helps prevent flooding and erosion.
Many species of earthworms are available in India, out of all these, Eisenia foetida is considered to be the best. It is surface feeder and can tolerate wide range of temperature and moisture fluctutations. Its approximate length is 3 to 4 inches and weight is one gram. Due to its higher multiplication rate and shorter life cycle, compost can be prepared in shorter period of time.
Method of preparation of vermicompost
Beds need to be prepared to make vermicompost. The bed should be 3 feet wide. Too much width is not good because than it is difficult to lift the compost. Bed lengths can range from 6 to 10 feet depending on the space available. The floor of the bed must be solid. So floor bricks can be tapped. Due to the hardness of the floor, the faeces and urine of the animals do not seep down and the earthworms do not slide down. The height of the bed should be about 2 feet. The bed should first be laid with 2-3 inches layers of straw. Straw should be well moistened but water should not stand on the floor. This keeps the moisture in the pile for a long time. It needs to be covered with two feet of cow dung. Fresh cowpea should not be used as it has high temperature and high amount of gases which can damage the manure. About 4-5 days old cow dung is fine. After application of dung, one kg of earthworms (Eisenia foetida) should be spread per bed (depending on the length).They should then be covered with soaked straw and cow dung. Sheds need to be constructed to protect the earthworms from direct sunlight. The shed protects them from heat and cold and also from heavy rains. Water spraying is necessary to maintain moisture. This spray may need to be applied 2-3 times a day depending on the weather in summer and 2-3 days later in winter. This culture bed takes 2 to 3 months to prepare compost. The vermicompost is environmentally safe and improves the physical, chemical and biological properties of soil. The nutrient content in prepared vermicompost was found to be 1.62% N, 0.98% P and 1.21%K.
Separating the earthworms from compost
The finished vermicompost is uniform, granular, black in color and odorless. The humidity in the bed is reduced to separate compost from the earthworms. This causes the earthworms to slide down a bit. The pile of compost is separated from the top. The compost is allowed to pass through a sieve number 4mm. This sieve is dense and prevents earthworms and cocoons that can be used in new beds. After separation, the prepared vermicompost can be used in different crops.
