Field Notes

Modifying SRI to suit coastal salt affected soils of West Bengal

S K Sarangi

In West Bengal, twenty percent of the cultivated area is under rabi paddy. The crop yield during rabi season in the area is usually low due to salinity build up and lack of irrigation water. As the monsoon receedes, the availabilty of freshwater declines, soil starts drying up and the soil salinity builds up gradually.Central Soil Salinity Research Institute, Regional Research Station, Canning Town conduced a field trial in 2010-11 to test the suitability of SRI in increasing productivity and conserving resources for the coastal salt affected soils of West Bengal. However, the experiment conducted at the research station, following the usual set of SRI practices was not successful due to severe mortality of young seedlings.

The Research Institute conducted another trial altering some of the practices in the following rabi season. Salt tolerant varieties like Canning 7, CSR 4, Bidhan 2 were used. Nursery was raised on raised beds, with irrigation facility to wash out salts, and transplanted when the seedlings were 15-18 days old. Azolla was cultivated along with rice and bio inputs like Azospirillum, Phosphate Solubilizing Bacteria and Trichoderma were used. This trial which was demonstrated to 130 farmers of South and North 24 Parganas districts of West Bengal, yielded good results.

There was good survival rate of plants, number of tillers per hill increased from 23 (normal transplanting) to 37. There was higher root growth in terms of root length, volume and weight. The strong tillers with better root systems helped in withstanding hailstorm. The water use efficiency increased, significant amount of precious irrigation water. The grain yield was ofcourse, significantly higher than the conventional method.

For more details, contact Dr. S. K. Sarangi, Senior Scientist (Agronomy) at Central Soil Salinity Research Institute, Regional Research Station, Canning Town, South 24 Parganas, West Bengal-743 329
E-mail: sksarangicanning@gmail.com

Simple tool to maintain spacing in SRI field

G Kathiresan

Maintaining proper spacing is one of the key considerations in SRI to get optimal yield. Farmers have been using several methods like rope marking, iron roller marker etc., to be able to maintain inter row and intra row spacing among plants. But these methods have their own disadvantages like extra labour requirement, difficulty in moving the heavy rollers, markings becoming nonconspicous in puddled fields etc.To overcome these problems, the Tamil Nadu Agricultural University has developed a low weight triangular pointer with three sticks made of bamboo or casuarina or polyvinyl chloride pipes. These three lengthy sticks are tied with small sticks (25 cm length) or 6 mm iron rod fitted with ½ inch GI pipe holder, which is triangular in shape with 600 angles in each corner.

The iron rod with 25 cm length, represents the intra row spacing and the ten feet sticks in which marking is made with 25 cm represents inter row spacing. For assuring the spacing, triangular shape iron rod with 25 cm length is necessarily fitted with the lengthy (10 feet) sticks at every five feet. Six points are marked in the lengthy sticks at the spacing of 25 cm to point the place of planting of paddy seedlings by single labour.

Farmer can use this device by placing it parallel to the horizontal bund. The seedlings are placed inside the triangular lengthy sticks. No extra labour is needed, no drudgery in pulling and no problem of locating the point in which seedlings are to be planted.

Normally for SRI planting, 45 labourers are needed to cover one hectare land. In the case of SRI planting with this new tool, 33 labourers are sufficient to cover the same area. With the new type of tool, proper spacing is maintained between plants in SRI field.

For more details, contact Dr. G. Kathiresan, Director (Planning & Monitoring), Tamil Nadu Agricultural University, Coimbatore – 641 003.

Eco Organic Agriculture and SRI

Thomas Abraham

Sam Higginbottom Institute of Agriculture, Technology and Sciences (Formerly Allahabad Agricultural Institute), Allahabad, conducted a study on the productivity and profitability of SRI using Eco-Organic Agriculture.Eco-Organic Agriculture is a unique production management system, which promotes and enhances healthy agro-ecosystem including biodiversity, natural cycles and soil biological activity.

The trials included use of green manures like crotolaria and sesbania, use of FYM, use of panchgavya and Fish Amino Acid, both in SRI as well as in conventional plots. The agronomic and economic evaluation during three successive years (2009 to 2011) at the Research Farm showed as high as 352% increment due to change of practice from conventional system with transplanted rice to organic practice with adoption of SRI.

Harvest index figures crossed the 40% mark under the green manuring practice both with Crotalaria and Sesbania species, which were buried in the field with tractor drawn disc plough about 55 to 60 days after sowing, during the Zaid (pre-Kharif period). Other practices which were evaluated at the research farm include the use of Bokashi manure and go-mutra (cow urine) culture. Soil application of this formulation at a concentration of 10 to 12.5% (8 to 10 times dilution) had certainly helped in restoring health and soil fertility, concurrently functioning as a prophylactic measure against the attack of termites, root grubs, etc.

The technology and practices under SRI has consistently depicted, both at the research farm and at the farmers’ fields, that the highly expensive, external inputs dependent practices of modern agriculture are fundamentally the most un-fruitful and un-profitable ways to adhere to. Hence this unconventional system, which manages plants, soil, water and nutrients in a diametrically opposite way, enables the enhancement of the abundance and diversity of the soil biota. This wonderful balancing effort can change the agroecosystem to become sustainable and also promote agrobiodiversity catering to several vital needs of the farming community.

For more details, contact Dr. Thomas Abraham, Department of Agronomy, Allahabad School of Agriculture, Sam Higginbottom Institute of Agriculture, Technology and Sciences, Allahabad – 211 007.
E-mail: thomas.abraham@shiats.edu.in