By Mohsin Tanveer, Dr. Ehsan Ullah and Dr. Shakeel Ahamd Anjum
BOURGEONING POPULATION and inclination in food demand has modified agriculture into an industry liked prototype. Under such situation, farmers are growing more and more crops per unit area in hunger of more earning. Soil is the gift of nature; life is not possible without it. Soil is the source of mineral nutrients, containing a vast array of organic, inorganic nutrients and gases indifferent proportion. Plant takes up 16 elements from soil and makes its food. However, under the scenario of current agriculture problems, soil health is of burning issue right now. Farmers are intensively growing cash crops which are exhaustive in nature without taking into consideration of soil health. As a result, nutrient status of soil is decreasing abruptly day by day.
Although the need of these nutrients can be fulfilled by application of synthetic fertilizer, but fertilizers prices and their quality is still a question. Furthermore, 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.
Now a day, wheat is harvested using combine harvester and by employing that, enough amount of dry matter in form of stubbles remain on soil. Usually farmers burn these stubbles. Burning of stubble 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. 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. At the end of March/start of April and when the 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 cannot be ploughed in soil by using simple cultivator. Incorporation methods of sesbania are discussed later.
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 of wheat and broadcast primed seed in field. In this method, Sesbania gets little height at time of land preparation for rice. But that little biomass of Sesbania improves soil health a lot.
Sowing at field capacity level of soil after wheat harvesting:
In this method, seeds are broadcast at field capacity level (optimum soil moisture level) of soil after harvest of wheat. Weeds may also be grown in this way that can be removed easily. Incorporate the Sesbania when land preparation is required.
Methods to incorporate sesbania:
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.
Benefits of employing this technique:
l With passage of time, fertiliser requirement dips to half amount.
l There are some allelochemicals in wheat stubbles, on incorporation in soil they improve soil health.
l By burning of wheat stubbles, 80% nitrogen, 25 per cent phosphorous and 21 per cent potassium is lost. On the other hand these nutrients can be returned back by putting them in soil.
l This will increase soil fertility
l If farmers are not intended to incorporate sesbania in soil they can harvest the plants and use them as fodder.
Questions regarding the adoption of this method:
l 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.
l 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.
l 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.
This technology is very much useful in current scenario, where farmers only intention is to increase the yield, does not matter what is happening to soil. They are totally dependent on synthetic fertiliser that not only increase cost of production but also reduce soil health, which (soil) is main biological entity in agriculture production.
Dr. Ehsan Ullah and his team worked on this and arranged many field trials at farmers field level to convince farmers to adopt this to sustain their soil.