Dr. Parveen Kumar,
Dr. Anil Kumar
Keeping in mind the importance of good soil health in promoting crop growth, December 5 every year is to be celebrated as world Soil Day. It reaffirms our commitment to healthy soils all over the world for increasing yield of crops and for a hunger free world.
Green revolution holds an important position in the agricultural development of India. The so-called green revolution transformed agriculture with fertilizers and pesticides, improved seeds and modernized farm management which led to huge jumps in production and yields. But, it also contributed to environmental degradation. One of the impacts of the environmental degradation was that the soils in many parts of the world, such as South Asia suffered badly. They suffer from excessive tillage, leading to erosion and nutrient mining. With the increased reliance on chemical fertilizers and pesticides, such biological amendments as manure and compost have not been added back to the soil. The result was that soils become deficient in many plant nutrients. All this went on despite that soil contains the essential sixteen nutrients required for plant growth. Of these sixteen some like the Nitrogen, Phosphorous, and Potassium are macro nutrients needed by the plants in large quantities and some are micronutrients like Zinc, Manganese, Magnesium needed by the plants in small quantities. It is still a business as usual and that will not get the job done.
Soil health ultimately determines how well crops grow and whether the planet can feed a population of 9 billion by 2050. The next revolution therefore in agriculture must be brown, not green. The time is for brown revolution based on soil health. Healthy and productive soil is the key to meet the world’s growing demand for food in the face of limited available cropland water and other resources. No amount of improved seed or synthetic fertilizer can revive dead soil. One teaspoonful of spoon has more micro organisms than there are human on earth. As such soil deserves to be celebrated for its fundamental role in creating the food both crops and animals that make peoples healthy. The importance of a brown revolution can be gauged from the fact that scientists claim that the solution to climate change mitigation and global food security could lie in the soil beneath our feet. In fact “Brown revolution” promotes conservation agriculture, which involves minimal soil disturbance and the use of cover crops and crop rotations to naturally control weeds, pests and diseases. He hopes to improve soil health and reverse such land degradation by incorporating conservation agriculture. Healthy soils are essential for future productivity, Hobbs said. They have structure, aeration and water retention, fewer pathogens and better biological activity resulting in improved nutrient recycling needed by plants.
Intercropping: intercropping with legumes that produce an edible food such as Pigeon pea or Lablab bean have helped put up to 500 pounds of nitrogen back into the soils. They also provide an additional source of food and income. Cover crops have helped to reduce soil temperature by 20 degrees F. It helps build the ecology of the soil, and enhance soil’s ability to keep its nutrition levels high.
Cover crops: Soil erosion deprives fields of the most fertile portion that contains the highest percentage of organic matter and nutrients. A raindrop falling at high speed can dislodge soil particles and cause them to move as far as six feet. Once the soil particles get loose they become more vulnerable to being carried away by running water. Any aboveground soil cover can take some of the punch out of a heavy rainfall simply by acting as a cushion for raindrops. Here is where cover crops play an important role in fighting soil erosion. These are the crops planted by farmers to enrich soil when it is not being used. For example clover can be grown after soybean harvest rather than to keep the land fallow. Cover crops interact with the soil, exchanging nutrients through the roots and building richer soils. A cover crop also slows down the action of moving water, thus reducing its soil-carrying capacity, by creating an obstacle course of leaves, stems and roots through which the water must maneuver on its way downhill Increase the soil’s ability to absorb and hold water, through improvement in pore structure, thereby preventing large quantities of water from moving across the soil surface and help stabilize soil particles in the cover crop root system. The Revised Universal Soil Loss Equation developed by the Natural Resources Conservation Service predicts that a soil cover of just 40 percent when winter arrives can reduce erosion substantially until spring. Also a fewer pesticides are needed to keep the land free of weeds. Even some cover crops are also delicious like buckwheat. Even pastures also improve the soil health as they blanket the land that enhances the soil nutrients. More cover crops and pastures mean more plants and roots to transfer carbon dioxide out of the air and into our soil.