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Learn about the SRI system of root intensification and how it promotes soil fertility, nutrient replenishment, and sustainability in the rice-wheat cropping pattern. Discover the implications of nutrient depletion and the solutions of green manure, compost, and balanced nutrient application. Find out the optimal sowing times for wheat cultivation.
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Soil Fertility, SRI and Sustainability KishanRaoParcha
SRI In SRI, the roots of the plant, be it rice or wheat, spread wide and deep and efficiently metabolise nutrients, help tillering and give out strong stems and large leaves. In a non-chemical environment, the roots thrive and proliferate in the presence of ‘humus’ and friendly microbes.
About Depletion of Nutrients It was vividly brought out in the deliberations that the major factor responsible for the low and declining crop response to the fertilizers was the continuous nutrient mining of the Indian soils without adequate replenishment to the desired extent. It is estimated that about 28 Mt of primary plant nutrients are removed annually by crops in India, while only 18 Mt or even less are applied as fertilizer, leaving a net negative balance of about 10 Mt of primary plant nutrients (NPK). http://www.naasindia.org/Policy%20Papers/policy%2035.pdf
About Rice-Wheat Cropping Pattern Of late, concerns have been expressed that the rice-wheat growing areas are developing a so-called “fatigue”, due to continuous uninterrupted cultivation of this very exhaustive cereal-cereal (rice-wheat) cropping system, for now nearly three decades. There is no doubt that rice and wheat, which have similar adventitious rooting systems, are very heavy feeders of plant nutrients.
‘SRI’ results in more depletion!(PSI farm, Dehradun, November 2006) 1 hectare=10,000 m2 1 m2 = 550 gm(Net Weight of Grains)= 5.5 Tonnes/Hectare; 2000 gm = 20 tonnes/hectare
‘swi’, going by the positive outcomes of PSI trials, also results in even more depletion of remaining nutrients in the soil.
The Implications….. In the long run, the soil fertility goes down and along with that, the yields The mineral deficiencies will make the plants/crop weak and disease prone The food grains will be deficient in vital minerals and, in turn, affect the consumers’ health adversely This rice-wheat cropping cycle, year after year, is unsustainable, be it SRI or traditional(organic) or traditional(chemical)
Then, what is the solution? That is... Replenishment Through Green Manure & Compost Or Application of Macro & Micro Nutrients (Chemicals, in a balanced way)
The ‘Replenishment Doctrine’ is * One crop for the Soil and (only then) * One crop for Us
Provided we find enough time and the ‘will’, for a green-manure crop between Rice & Wheat and, then, Wheat &Rice
The Farmers and Scientists know that…. SOWING TIME: Under irrigated conditions, the first fortnight of November is considered to be the optimum time for sowing the medium long-duration wheats, e.g. 'kalyansona' all over India. For short-duration varieties, e.g. 'Sonalika', the second fortnight of November is the optimum time. In eastern India, the sowing of wheat is often delayed owing to the late harvesting of paddy. The sowings in such cases may go up to even the third week of December. http://www.krishiworld.com/html/field_crops2.html
And also….. In north- western India also, wheat sowings get delayed due to late harvesting of paddy or sugarcane or potato. However, wheat sowings beyond the rain fed conditions, the second half of October is the optimum time. The sowing of wheat, when the temperatures are high results in a poor stand, poor tillering, attack by root-infecting fungi and pests and the early onset of flowering. All these factors depress yield. The success of rainfed wheat depends on the amount of conserved moisture in the soil.
Conclusion If sustainable yields and nutritional security are to be achieved on a priority basis, we need to proactively intervene and cultivate green manure crops(preferably, Multi Variety Seed Sowing Technique) in between the two cereal crops, Rice & Wheat. The soils, presently, are on the brink of collapse all over the country. The present and future populations/generations would have some chance of survival only if the soils are restored, made healthy and fertile.
