Cultivation practices of Soybean under Manipur condition

K Nandini Devi and Mukul Kumar
Soybean is an environment friendly grain legume and has now become a major source of protein, oil and health promoting phyto-chemicals for human nutrition and livestock feed around the globe, Soybean cultivation also improves soil health because of its atmospheric nitrogen fixing ability and deep root system. Manipur has a great potential for production and domestic utilization of soybean and its derivatives for health and economic benefits of the people of the State. It is essential to select a variety of the people of the State. It is essential to select a variety suitable for a particular region. A multilocational trial have been conducted under All India Co-ordinated Research Project on Soybean and found that Soybean variety JS 335 was found to be the best suited under Manipur condition. The recommended package of practices for Soybean variety JS 335 is given below.
Varietal Characteristics:
Duration    110-115 days
Plant height     45-60cm
Yield potential  1200-1800 kg/ha
Oil content    20%
Protein content 40%
Resistance to pod shattering and yellow mosaic virus (YMV).
Well drained and fertile loam soils are most suitable for the cultivation of soybean. Water-logging is injurious to crop. Soybean grows well in warm and moist climate. A temperature of 26.5 to 30 C appears to be the optimum.
Land preparation
One cross ploughing with tractor just after the harvest of rabi crop followed by two cross harrowing or ploughing with cultivator are sufficient. Land should be well-levelled.
Seed Rate:  60 kg/ha
Seed Treatment : Seed should be treated before sowing with Thiram+Carbendazim (2:1) @3g/kg of seed to check seed borne diseases.
Seed inoculation : The treated seeds should be inoculated with Bradyrhizobium japonicum @3g/kg seed at least half an hour before sowing.
Time of sowing : The optimum time of sowing for soybean is June to first week of July. It can be extended upto last week of July.
Spacing : The seeds should be sown in lines at a spacing of 45cm from row to row and 10cm from plant to plant. The seeds should be placed at a depth of 2-3cm. The seeds should be covered well with soil.
Manures and fertilizers : About 5 tones/ha of Farm Yard Manure (FYM) or compost should be applied before 15 days of sowing. The recommended dose of N:P:K:S for Manipur condition is 20:60:40:40 kg/ha. Tractor operated seed-cum fertilizer drill have been found to give good results. Fertilizer should be placed 5-7 cm below the seed. If not possible, it should be evenly broadcast and then plough/harrowed to mix it with the soil.
Weed Management : Effective weed control during the first 30-40 days of crop growth is essential for achieving higher productivity. Early post emergence herbicide Quizalofop ethyl 15% EC should be applied @ 1ml/litre of water at 15 days after sowing. It should be followed by one hand weeding at 40 days after sowing.
(I)    Major pests : Bihar hairy caterpillar, tobacco caterpillar and leaf roller are the major insect pests of soybean in Manipur. These insect pests can be effectively controlled by spraying Quinalphos 25EC @ 1.5ml/litre of water. In order to part with sole dependence on chemical insecticides, an integrated pest management (IPM) approach consisting of deep summer ploughing, appropriate sowing time, balanced fertilizer dose, mechanical and or biological controls, pheromone/light traps etc. is suggested.
(ii)    Disease : No occurrence of serious diseases in Manipur condition. But proper seed treatment with fungicide before sowing is a must.
Soybean matures in about 110-115 days after sowing. When the plants are mature, the leaves turn yellow and drop. The soybean pods dry out quickly. Such plants should be cut above the ground and kept 3-4 days in the sun for drying. Delayed harvesting leading to pod-shattering is one of the major cause of poor yield of soybean. Timely harvesting also minimizes field deterioration of seed /grain quality.
Threshing should be done carefully and any kind of severe beating or trampling may damage the seed coat and thus reduce the seed quality and viability. Threshing by running the tractor on the harvested crop should be avoided as it leads to seed coat cracking, breakage and splitting of seeds.
Post-harvest technology is an integral and important component of soybean production and utilization systems and it plays a key role in minimizing post production losses of soybean and its transformation into consumable products like oil, meal and other soybean food and feed products. After threshing the seeds should be cleaned, graded and dried in the sun for 5-6 days. The optimum moisture content of seed for safe storage is 8-10%.

The writers are from Central Agricultural University, Imphal
For more details contact: Public Relation & Media Management Cell, CAU, Imphal