Mohsin Tanveer, Shahbaz Atta Tung, Haseeb Zahid
Nature has sanctified us with biological entity and life is not possible without it. And that biological entity is SOIL. Soil is layer of upper earth crust and a source of mineral nutrients, containing a vast array of organic, inorganic nutrients and gases in different proportions. Plant takes up 16 elements from soil and makes its food. Unfortunately, we are not taking care of it and under the scenario of current agriculture problems; soil health is of burning issue right now. Agriculture is modified and transformed into industry and now the only aim of farmer is to get high yield even though he has to deteriorate its soil. Farmers have increased their cropping intensity in greed of more earning without taking into consideration of soil health. As a result, nutrient status of soil is diminishing rapidly day by day.
Although the nutrient requirement could be done with synthetic fertilizer application, but fertilizer prices and their quality is still a question. However, total avoidance of synthetic fertiliser is not possible, so there is need of sustainability oriented approach that reduces artificial fertilizer application and improves soil fitness. The basic concept behind adoption of that technology is just to increase organic matter in soil. Soil fertility depends on the availability of organic matter. This organic matter not only improves water holding capacity, nutrient retention capacity but also enhances microbial activity in soil by providing them food. It is primitive for better productivity that our soil should contain enough nutrients. Plant stores nutrient in grains, leaves, stem and roots. It is rule for successful and progressive farming that, after removing economical part of plant, remaining should be incorporated in soil.
Using combine harvesters, lot of wheat stubbles remained on soil and that is marvellous source of organic matter. Usually farmers burn these stubbles and putting stubbles on fire causes environmental issues and loss of nutrients and sometimes it takes shape of massive accidents. Burning also affects soil microbes and reduces soil health. Burning of stubbles is crime, then why does our farmer do this? The reason is, he does not have any idea how to get rid of that and what to do with that. Department of Agronomy, University of Agriculture Faisalabad has devised a system that not only improves soil health but also provide an additional source of income. Main benefit of this technology is that being leguminous crop and addition of organic matter in soil, fertiliser requirement dips to half amount and by burning, 80% nitrogen, 25% phosphorous and 21 % potassium is lost. On the other hand these nutrients can be returned back by putting them in soil. Dr. Ehsan Ullah and his team introduced three methods:
Sowing of Sesbania in standing wheat: Sesbania is leguminous crop that has potential to produce excess biomass in short time with low input requirement. It has capability to fix nitrogen in soil and increase nitrogen concentration in soil. At the end of March/ start of April and when last irrigation of wheat is done then broadcast sesbania at rate of 10 kg per acre in standing wheat. Soak the seed for 10-15 hours before surface steeping that increase germination speed. Then at harvesting time of Wheat, Sesbania grows up to height of 1 foot and at that time it is not ploughed in soil by using simple cultivator. At this stage, upper grown parts can be harvested and fed to animals as fodder. And below ground parts may be act as organic matter in soil. 2) Sowing of Sesbania after wheat harvesting: Sometimes, farmers do not able to sow seed, might be due to unavailability of seed. Then they can sow seed even after harvesting. Seeds may be sown by giving irrigation heavily after harvesting and broadcast primed seed in field. In this method, Sesbania get little height at time of land preparation for rice. But that little biomass of Sesbania improves sol health a lot.
Sowing at field capacity level of soil after wheat harvesting: In this method, seeds are broadcasted at field capacity level (optimum soil moisture level) of soil after harvest of wheat. Weeds may also be growing in this way that can be removed easily. Incorporate the Sesbania when, land preparation is required. Under all these methods, our aim is to introduce a leguminous crop and utilize nutrients and time between wheat harvesting and sowing of next crop. There are two methods, employed to incorporate them in soil. Through rotavator: Rotavator is best option for Sesbania incorporation. Give light irrigation to field, then at optimum moisture level, rotavate the field, in this way stubbles of wheat and Sesbania may be cut down and can be easily incorporated. By puddling method: At the core areas of rice belt, it is started raining and at that time Sesbannia may be deposited in soil in that standing water of rain. This method yield two benefits, firstly the rovator cut down plants in to small pieces which will start decomposing abruptly and secondly, there will be no need of land preparation further. Soil becomes soft and fertile after this method and that helps in transplanting of rice nursery.
Questions regarding the adoption of this method:
· Some farmers feel reluctant to spend money on purchasing Sesbania seed. They do not want to increase the expense but they do not know, if they use this technique, they will not only sustain their soil but also get high yield and price of Sesbania seed is very low.
· Some farmers ask how this will increase our yield. The answer is Sesbania is leguminous crop. It will fix environmental nitrogen in soil and boost up the availability of nitrogen in soil. This will reduce fertiliser requirement.
· Some farmers inquired about the feasibility of adoption of this method. This method is feasible under all agro-ecological zones and can be adapted at all kind of soil series.