Effective Soybean Farming Techniques and High-Yield Varieties

Soybean (Glycine max) is one of the world’s most important oilseed and legume crops. With roughly 40% protein and 20% oil content, it serves as a powerhouse of nutrition for humans and livestock alike. In India, soybean has emerged as a leading kharif oilseed crop, with Madhya Pradesh – often called the “soybean bowl of India” – and Maharashtra together accounting for the bulk of the country’s production. Whether you’re a seasoned farmer looking to improve yields or a student of agriculture exploring crop production, understanding soybean agronomy from soil preparation to harvest is essential.

Why soybean matters in Indian agriculture 🔗

Soybean plays a dual role in India’s farm economy. Its oil is widely used in cooking and food processing, while the de-oiled cake (DOC) is a major export commodity that contributes significantly to foreign exchange earnings. Beyond economics, soybean is a leguminous crop that fixes atmospheric nitrogen, improving soil fertility for subsequent crops. This makes it an ideal component in crop rotation systems – particularly in dryland farming regions where soil health is a constant concern.

India currently produces around 10 million tonnes of soybean annually, representing about 4% of global output. Notably, India grows exclusively non-GMO soybean, which gives Indian farmers a unique advantage in international markets where demand for non-GMO products is rising. However, average national productivity hovers around 1.0-1.2 tonnes per hectare – well below the rainfed potential of about 2.1 tonnes per hectare estimated by research institutes. Bridging this yield gap is one of the biggest opportunities in Indian soybean farming today.

Climate and soil requirements 🔗

Soybean is a warm-season crop that thrives in tropical, subtropical, and temperate climates. For Indian conditions, the optimal temperature range for most varieties is 26°C to 30°C. Growth slows below 18°C and above 35°C. Temperatures above 40°C can be harmful to seed production, and those below 21°C can reduce flowering and pod set.

Soil type matters significantly. Soybean performs best on well-drained sandy loam to clay loam soils with a pH range of 6.0 to 7.5. Waterlogged, saline, or alkaline soils are not suitable. Before sowing, a thorough soil test is recommended to understand nutrient deficiencies and plan fertilizer application accordingly.

The crop needs about 400-500 mm of water through the growing season. The most critical stages for moisture are germination, flowering, and pod formation. However, dry weather is preferred during ripening to avoid seed damage.

Sowing season and field preparation 🔗

Soybean is primarily a kharif season crop in India, sown with the onset of the monsoon in June-July and harvested in September-October. The ideal sowing window is from the third week of June to the first fortnight of July. Sowing should begin only after the area has received at least 100 mm of rainfall to ensure adequate soil moisture for germination.

Land preparation 🔗

Prepare the field by giving two to three ploughings followed by planking to achieve a fine tilth. Form beds and channels for proper drainage – soybean is extremely sensitive to waterlogging. Deep summer ploughing before the season also helps in reducing soilborne pest and disease loads.

Seed rate and spacing 🔗

The recommended seed rate is 70-80 kg per hectare for most varieties, though it can go up to 100-120 kg/ha depending on seed size and germination percentage. Row-to-row spacing of 30-45 cm and plant-to-plant spacing of 4-7 cm is generally followed. Seeds should be sown at a depth of 2.5-5 cm using a seed drill for uniform placement. Always ensure a germination rate of at least 85% before sowing.

Seed treatment 🔗

Seed treatment is a non-negotiable step in soybean farming. Treat seeds with Thiram or Captan at 2-3 g per kg of seed to protect against soilborne diseases. Additionally, inoculate seeds with Rhizobium culture (600 g/ha) and Phosphobacteria to enhance nitrogen fixation and phosphorus availability. Note: treat with fungicides first, then with biofertilizers, as the two are generally incompatible when applied together.

High-yield soybean varieties for India 🔗

Choosing the right variety is one of the most impactful decisions a soybean farmer can make. Variety selection should be based on your agro-climatic zone, maturity duration, disease resistance, and yield potential. The ICAR-Indian Institute of Soybean Research (IISR), Indore has developed and recommended over 100 improved varieties through the All India Coordinated Research Project on Soybean (AICRPS).

Prominent varieties by region 🔗

For central India (Madhya Pradesh, Maharashtra, Gujarat, Rajasthan), some of the recently recommended varieties include JS 23-03, JS 23-09, NRC 165, NRC 150, NRC 142, MACS 1520, JS 21-72, and MAUS 725 (Maharashtra-specific). For the eastern zone (Chhattisgarh, Jharkhand, Bihar, Odisha), MACS 1407, MACS 1460, NRC 128, and RSC 11-07 are noteworthy. The northern plains can consider Pusa Soybean 21, NRC 149, and SL 1074.

Older established varieties like JS 335, JS 93-05, JS 95-60, and NRC-7 (Ahilya 3) also remain popular in many regions. Varieties such as RKS-24 (developed at ZARS, Kota) are known for traits like larger leaf area and adaptability. When selecting, look for characteristics such as rust tolerance, waterlogging tolerance (e.g., NRC 128), suitability for mechanical harvesting, and high seed longevity.

Nutrient management 🔗

Although soybean fixes its own nitrogen through root nodules, it still needs a balanced supply of nutrients for optimal growth. The general recommended fertilizer dose is 20 kg N, 60-80 kg P₂O₅, and 40 kg K₂O per hectare, applied as a basal dressing at the time of sowing.

Key nutrients to focus on 🔗

Phosphorus is particularly important for soybean as it promotes root development and nodulation. Sulphur (20-40 kg/ha as gypsum) is another critical nutrient that enhances oil content in seeds. Zinc sulphate (25 kg/ha) should be applied where zinc deficiency is identified.

For boosting yield further, foliar sprays of 2% DAP or urea (20 g/litre) at flowering and 15 days after flowering can be beneficial. The use of precision fertilization tools – including soil testing and variable rate technology – helps ensure that nutrients reach the crop at the right time and in the right quantity, reducing waste and environmental impact.

Water management 🔗

Soybean is mostly grown as a rainfed crop in India, but proper water management is still essential. Irrigate immediately after sowing if monsoon rains are delayed, and give life irrigation on the third day. During the season, irrigations at intervals of 7-10 days may be given depending on soil and weather conditions.

The crop is very sensitive to excess moisture. If water stagnates, root health deteriorates rapidly. At the same time, moisture stress during flowering and pod-filling can severely reduce yields. To alleviate mild stress, a foliar spray of Kaolin at 3% or liquid paraffin at 1% can help reduce water loss from leaves. The crop requires roughly 400-500 mm of total water over its 90-110 day duration.

Weed management 🔗

Weed competition during the first 30-40 days after sowing is the most critical period for soybean. Unchecked weeds can reduce yields by 30-70%.

Chemical weed control 🔗

Pre-emergence application of Fluchloralin or Pendimethalin (3.3 litres/ha) within two days of sowing is widely recommended. This can be followed by one hand weeding at 30 days after sowing. For post-emergence control, herbicides like Imazethapyr applied at 20 days after sowing are effective against both grasses and broadleaf weeds.

Cultural and mechanical methods 🔗

If herbicide application is not possible, two hand weedings – the first at 20 days and the second at 35-40 days after sowing – are recommended. Maintaining proper row spacing and using a combination of cultural, mechanical, and chemical methods gives the best results. Crop rotation and inter-cultivation with tools like wheel hoes also help in reducing weed pressure over time.

Pest management 🔗

Soybean is attacked by several insect pests throughout its growth stages. Effective management relies on an integrated pest management (IPM) approach that combines preventive cultural practices with need-based chemical interventions.

Bihar hairy caterpillar (Spilosoma obliqua) 🔗

This is one of the most damaging pests of soybean in India. Young larvae feed gregariously on the undersides of leaves, while older larvae consume leaves from the margins and can completely defoliate plants when populations reach epidemic levels. Management strategies include deep summer ploughing to destroy pupae, collection and destruction of egg masses and early-instar larvae, and installation of light traps to catch adult moths. When the pest reaches economic threshold levels, chemical insecticides such as Chlorantraniliprole 18.5% SC (100 ml/ha), Lambda-Cyhalothrin 4.9% CS (300 ml/ha), or Indoxacarb 15.8% EC (333 ml/ha) can be used. Botanical extracts like neem-based formulations and microbial agents such as Bacillus thuringiensis also offer effective alternatives.

Other major pests 🔗

Tobacco caterpillar (Spodoptera litura) damages leaves and pods, especially from August through September. Gram pod borer (Helicoverpa armigera) feeds on flowers and pods. Aphids and whiteflies are sucking pests that can transmit viral diseases. For all these pests, regular scouting, use of pheromone traps (5 per hectare), bird perches (50 per hectare), and timely insecticide application based on economic threshold levels form the core of an effective IPM programme.

Disease management 🔗

Soybean is susceptible to a range of fungal, bacterial, and viral diseases. Prevention through resistant varieties, seed treatment, and good field hygiene is always more cost-effective than curative measures.

Charcoal rot 🔗

Caused by the soilborne fungus Macrophomina phaseolina, charcoal rot is a serious disease that develops when plants face heat and drought stress during the mid to late summer. Symptoms typically appear from the R5 (beginning seed) to R7 (beginning maturity) stages and include wilting, premature leaf death, and a grey or silver discoloration on the lower stem and roots – giving the disease its name. The fungus can survive in soil for at least two years. Management involves reducing drought stress through proper irrigation scheduling, reduced tillage (which keeps soils cooler), crop rotation with cereals, and avoiding excessively high plant populations.

Other important diseases 🔗

Yellow mosaic virus (YMV) is transmitted by whiteflies and causes yellowing and mottling of leaves. Grow resistant varieties like SL 525 and SL 958. Soybean rust is another concern; varieties like PS 1024 and Indira Soya 9 offer tolerance. Bacterial blight and Rhizoctonia root rot can be managed through seed treatment with Trichoderma viride at 4 g/kg seed or Pseudomonas fluorescens at 10 g/kg seed, combined with proper crop rotation.

Harvesting and post-harvest handling 🔗

Soybean matures in approximately 90 to 110 days, depending on the variety and climatic conditions. The crop is ready for harvest when most of the leaves have yellowed and shed, and the pods have turned brown. Harvest should be timed carefully – too early and the seeds will have high moisture content; too late and the pods begin to shatter, leading to significant field losses.

Cut the plants at ground level and thresh them after drying in the sun for a few days. Mechanical threshers can speed up the process for larger holdings. After threshing, dry the seeds to a moisture content of about 10-12% for safe storage. Store in clean, dry conditions to prevent fungal growth and insect damage. The Indian government supports soybean farmers through Minimum Support Price (MSP) mechanisms, and farmers are encouraged to explore value addition options like oil extraction, soy milk, and tofu production for better returns.

Tips to bridge the yield gap 🔗

Indian soybean yields can be substantially improved by adopting a few evidence-based practices. First, always use certified seeds of recommended varieties for your region. Second, follow a disciplined nutrient and water management schedule. Third, adopt integrated pest and disease management rather than relying solely on chemical sprays. Fourth, practice crop rotation – particularly with cereals – to break disease cycles and improve soil health. Finally, timely sowing within the recommended window (late June to early July) has a major impact on final yields.

What do you think? If India’s average soybean yield is only about half of its rainfed potential, what role can better variety selection and precision farming play in bridging this gap? And how important is it for Indian farmers to leverage the non-GMO advantage in global markets?

References

1. https://link.springer.com/article/10.1007/s40003-013-0088-0
2. https://www.sopa.org/soybean-program/
3. https://agritech.tnau.ac.in/agriculture/CropProduction/Pulses/pulses_soybean.html
4. https://naclind.com/maximizing-soybean-yields-expert-tips-for-the-best-crop-production/
5. https://iisrindore.icar.gov.in/varieties.html
6. https://www.global-agriculture.com/seed-industry/latest-recommended-high-yielding-soybean-varieties-in-india-2025/
7. https://www.agrifarming.in/soybean-farming-information
8. https://link.springer.com/chapter/10.1007/978-981-97-8104-1_3
9. https://extension.umn.edu/soybean-pest-management/charcoal-rot-soybean