Soybean cultivation

Dear farmers,

                         Soybean is cheapest, easiest and richest source of best quality proteins and fats with multipurpose uses as food and industrial product. It is therefore called as wonder crop. It is considered as highly nutritive crop containing 40% high quality protein and 20%  oil. Soybean protein is rich in amino acid and lycine (5%); which is deficient in most of the cereals.

Climatic requirements for soybean cultivation

Soybean is a warm season crop. Its cultivation is now extended to subtropics and temperate climates. It can grow well in areas receiving annual rainfall from 600 to 1000 mm. Soil temperature of 15.5°C or above favour rapid germination and vigorous seedling growth. The minimum temperature for effective growth is about 10°C. Lower temperature delays the flowering. Temperature of 26.5 to 30°C appears to be optimum for most of the varieties. Soybean is basically a short day plant. Day length is the key factor. They are sensitive to photoperiod. this critical photoperiod for bud initiation is around 14 hours.

Soil requirements for soybean cultivation

Soybean papers natural soil having pH between 6.5 and 7.5. It grows on variety of soils ranging from light to black cotton. Well drained and fertile loam soils are best waterlogged soils, inhibit germination of seeds. Acidic soils liming has to be done to raise the pH to 7.0. Water logging is harmful to crop.

Land preparation for soybean cultivation

Soybean requires fine seed bed with least clods. One deep plough with mould board plough followed by two harrowings are enough to obtain good seed bed. For better seedling establishment there should be sufficient moisture at the time of sowing.

Seed rate and spacing for soybean cultivation

Seed rate depends upon size of seed, test weight, spacing and method of sowing. Optimum seed rate for soybean with 80% germination is 75 kg/ha. An optimum plant population of 4,44,444 plants/ha must be maintained for higher yield. For late planting and for spring crop, seed rate should be 100-200 kg/ha.

Seed treatment for soybean cultivation

The seed should be treated with Thiram @4.5 g/ka of seed or with a mixture of Thiram + Bavistin 1:1 @ 3 g/kg of seed to reduce fungal attack.

       For efficient biological nitrogen fixation the seed is also treated with Rhizobium japonicum @ 25g/kg of seed. Moist the seed with water and mix the culture uniformly in shade just before sowing. Always fresh culture should be used. In case of virgin field the rate of culture should be 5 to 10 times then the normal dose.

Method of sowing for soybean cultivation

Sowing is done by drilling the seeds in the soil with the help of seed drill or behind the plough. The depth of sowing should not be more than 2-3 cm in heavy and 4-5 cm in light soil. If seed is sown deeper or if there is crust formation just after sowing, the germination is delayed and crop stand is poor. Planting should be done after sowing to cover the seed and provide better soil contact.

Nutrient management for soybean cultivation

The nutrient requirement of the crop vary with climate, yield potential, cropping system and management practices. Soyabean crop yielding 10 q/ha removes about 80 N, 13 P2O5, 40 K2O, 15 Ca, 12 mg and 2 S kg/ha. For obtaining good yield of soybean 15-20 tonnes of FYM or compost should be added before the last harrowing. Being a legume soybean is able to meet its nitrogen requirement from atmosphere through Rhizobium. Application of 30 kg N as a starter dose is sufficient to fulfill nitrogen requirement of the crop in the initial stage in soils which are poor in organic matter.

                 Phosphorus requirement of crop is relatively higher than other crops. The demand of phosphorus is more during pod formation to seed development. The crop should be fertilized with 70-80 kg P2O5 per hectare. Phosphorus application stimulates nodulation and bacteria becomes more mobile.

                 Potassium requirement of the crop is also more than other crops. The rate of potassium uptake is peak during vegetative growth and slows down when the pod begins to form. 50-60 kg K2O/ha should be applied.

                 All the fertilizers should be applied at the time of sowing fertiliser should be placed 5-7 cm away from the seed at a depth of 5-7 cm.

                 In zn and sulphur deficient soils, application of ZnSO4 @ 20 kg and sulphur @ 10kg/ha is necessary. Zinc deficiency can also be corrected with spraying 5 kg zinc+ 2.5 kg lime in 1000 L of water. 

Water management for soybean cultivation

Being a deep tap rooted crop it can draw moisture from about 1.8 m soil depth. Flowering and pod development are the most critical stages for moisture stress. Moisture stress at these stages results in flower and pod dropping scheduling irrigation at 50% DASM or at IW/CPE ratio of 0.6 is optimum. Generally kharif crop does not require any irrigation. However if there is long dry spell at above stages irrigation may be given. Spring crop needs about 5-6 irrigations.

Weed management for soybean cultivation

Soybean crop is sensitive to weed competition particularly in early growth stages. The most common weeds infesting the crop are grassy weeds (Echinochloa colonum, Sorghum halepense, Cyprus rotundus, Cynodon dactylon, etc). and broad leaf (Celosia argentia, Phylanthus nirun, Digitaria sp, etc.). If the weeds are not properly controlled there is reduction in the in  the yield to the extent of 40-45%. The most critical period for crop weed interference is initial 15 to 45 days. Weeds emerge after this period are suppressed by smothering action of crop. Hoeings and weedings one at 20-22 DAS and other at 40-45 DAS keeps the weed under control

Cropping system

Intercropping

Intercropping with soybean which is more for production stability than yield advantage under rainfed condition. Soybean is ideal remunerative inter crop.

1. Soyabean+ Maize (2:1,2:1)

2. Soyabean+ Finger millet (2:2)

3. Soyabean+ Groundnut (1:4,1:6)

4. Soyabean+ Pearl millet (2:4,2:6)

5. Soyabean+ Pigeonpea (2:2,4:2)

6. Soyabean+ Cotton (1:3,2:1)

7. Soyabean+ Sorghum (1:2,2:2)

          Paired row technique is the simplest way of accommodating optimum plant population of both the component crops. Case of maize+soyabean system paired rows of maize (30/90 cm) and soybean in 2:2 and paired maize (45/90 cm) and soybean in 2:2 appears ideal.

Sequence cropping

Sequence cropping on stored soil moisture is possible in deep black cotton soil.

1. Soybean-Wheat

2. Soybean-Safflower

3. Soybean-Chickpea

Yield in soybean cultivation

A good crop of soybean yields 20 to 25 quintal grains per hectare.