Soybean Farming and Production Guide

March 28, 2024 by Lauro Braganza

Soybeans are a powerful agricultural player, boasting exceptional nutritional value and vast industrial applications. This guide delves into everything you need to know about soybean farming and commercial production in the Philippines, ensuring a successful and sustainable harvest.

Soybean Farming Benefits

The benefits of soybean farming are far-reaching:

Food Source: Soybeans are a nutritional powerhouse, providing protein for human consumption through soy milk, tofu, tempeh, and other products.
Versatile Oil: Soybeans are a prime source of high-quality vegetable oil for cooking and industrial applications.
Industrial Uses: Soybeans contribute to various industries, including producing biofuels, plastics, and lubricants.
Soil Enhancement: Soybeans improve soil fertility through nitrogen fixation, a process in which they partner with bacteria to convert atmospheric nitrogen into usable form for plants.
Weed Control: Soybeans help suppress parasitic weeds, reducing reliance on herbicides.
Livestock Feed: Soybean meal, a byproduct of oil extraction, is a valuable source of protein for poultry and livestock.
Animal Forage: Soybean plant residue (haulms) provides nutritious feed for sheep and goats.

Soybean Requirements: Climate and Soil

Favorable Conditions

Areas suited for rice or corn production are generally well-adapted for soybeans.
Crop rotation involving soybeans and wet-season cereals is highly recommended.
Plant soybeans towards the end of the wet season for dry weather harvesting. High humidity during seed maturation can significantly reduce quality.
Soybeans thrive with an ample water supply.

Climate Considerations

Rainfed Production

Climate Types E, F, and G (refer to specific classification systems for your region) are suitable for rainfed production.
Plants are planted in areas like Surigao (Type E) as early as February after the monsoon season.
South Cotabato (Type F) allows planting as early as August after the wet season. However, unexpected rains during harvest can be detrimental.

Irrigated Production

Central Luzon, with distinct wet and dry seasons, requires supplemental irrigation for successful soybean production.
Cagayan Valley (Type D) allows rainfed production after the wet season crop. Plant early to benefit from occasional rains before the dry period typically begins in April.

Soil Preferences

Deep (>1 meter) and well-drained clay or silt loam soils are ideal.
The soil pH range for optimal nitrogen-fixing bacteria activity in soybean root nodules is near neutral (5.5 to 6.5).

Land Preparation and Planting for Peak Performance

Laying the Foundation

Thorough land preparation ensures uniform seed germination and rapid plant establishment and minimizes weed competition.
For upland areas, pulverize the soil thoroughly.
Zero or minimum tillage practices should be considered in fields following rice cultivation.

Planting Techniques

Seeding methods include drilling seeds in shallow furrows spaced 50 to 60 cm apart or dibbling seeds in 20 cm x 20 cm hills at the base of rice stubble.
The ideal planting depth is 3 to 5 cm.
Seed requirements per hectare vary from 25 to 50 kilos, depending on day length and rainfall patterns. Aim for 10 to 20 seeds per linear meter of furrow or two seeds per hill.
Ensure adequate soil moisture for uniform seed germination—flood paddy fields 1 to 2 days before planting for post-rice cultures. In rainfed upland areas, expect rain within seven days after planting.

Water Management

Hydration Throughout the Growing Cycle

Soybeans necessitate ample water availability throughout their growth period (at least 500 mm).
Residual moisture from previous crops and occasional rains often suffice.
Heavier irrigation might be necessary during critical growth stages like flowering, pod formation, and seed filling.
Well-watered and fertile soils can yield over 3 tons of soybeans per hectare.

Nutrient Management: Harnessing Natural Benefits

Symbiotic Power

As legumes, soybeans obtain nitrogen through a symbiotic relationship with nitrogen-fixing bacteria in their root nodules.
To leverage this natural process, inoculate seeds with the bacteria before planting. You can acquire inoculants from reputable sources like BIOTECH, UP Los Baños, or the Department of Agriculture outreach stations.
Avoid applying nitrogen fertilizers, as excess nitrates can hinder nitrogen fixation.

Phosphorus and Potassium Management

Apply phosphorus and potassium only if soil tests reveal deficiencies.
A soybean crop yielding 2-3 tons per hectare typically removes around 40 kg P2O5 and 60 kg K2O from the soil.

Fertilizer Options

If readily available, use solophos or muriate of potash. However, more common formulations like 14-14-14 can also be used.
Crucially, the amount of nitrogen supplied shouldn’t exceed 30 kg/ha.

Strategic Application

Consider applying fertilizers during the preceding rice or corn crop. The cereal crop will utilize the nitrogen, while residual phosphates will remain available for the subsequent soybean crop.

Micronutrients

Apply micronutrients only when necessary, prioritizing organic fertilizers whenever possible.

Crop Protection: Safeguarding Your Soybean Harvest

Potential Threats

Soybeans can be susceptible to various insect pests, diseases, and weeds. Here’s how to manage these challenges:

Insect Pests

Bean Fly: This is the most destructive pest during the early vegetative stage. Once established, infestations are difficult to control with insecticides. However, soybeans can recover from some initial damage. Focus on optimal cultural practices to promote rapid vegetative growth.
Aphids: These pests harm young plants and can transmit harmful viruses. Thankfully, they are readily controlled with insecticides applied directly to aphid colonies.
Lepidopteran Larvae: Various caterpillars can defoliate the crop during the vegetative stage. In most cases, natural predators can keep them in check. However, if intervention is necessary, opt for Bt (Bacillus thuringiensis) formulations or highly specific insecticides. This approach also helps manage pod borers later in the growth cycle.
Pod Borers: Widespread infestations of pod borers can be highly destructive and challenging to control. Planting earlier in the season can help avoid peak pest populations.

Diseases

Soybean Rust: This fungal disease thrives during cool and dry seasons. Severe infections during pod development can significantly reduce seed size.
Purple Seed Stain: This fungal disease prevails during periods of frequent rain. Severe infections during seed formation result in purple discolorations on the seed coat.

Management Strategies

Resistant Varieties: Select soybean varieties with partial resistance to common diseases.
Fungicides: Utilize fungicides only when disease pressure is severe.

Weeds

Critical Control Period: Soybeans grow slowly in the initial 2-3 weeks after emergence, making weed control crucial.
Prevention Techniques
- Implement thorough land preparation before planting.
- Cultivate the spaces between rows as soon as possible after planting.
- Practice hand weeding for targeted control.

Chemical Control Options

- For zero or minimum tillage practices, apply a broad-spectrum herbicide before planting.
- In well-prepared land, use a pre-emergence herbicide.
- If necessary, follow up with post-emergence herbicides suited to the specific weed types present.

Harvesting and Processing

Signs of Maturity

As soybeans reach maturity, their pods turn brown and lose moisture.

Harvesting Tips

Begin harvesting when most leaves have dropped and the pods are dry.
Harvest early in the morning to minimize pod shattering.
The harvesting process resembles rice harvesting. Cut the stalks at the plant base.
Threshing can be done manually or with a rice thresher, but adjust the speed to avoid damaging the seeds.

Post-Harvest Handling

Clean and dry the seeds thoroughly.
For seeds intended for future planting, dry them to 9% moisture content. To preserve seed quality, avoid exceeding 43°C during drying.
Store dried seeds in airtight containers in a cool, dry place protected from rodents.
Maintain good sanitation practices to prevent storage pest infestations.

Conclusion: Cultivating Success with Soybeans

Soybean farming offers a rewarding opportunity to contribute to food security, industrial development, and sustainable agricultural practices. Following the comprehensive guidelines outlined in this guide, you can establish a thriving soybean production system and reap the benefits of this versatile and valuable crop. Remember, consulting with local agricultural experts and staying informed about the latest advancements in soybean cultivation can further optimize your soybean farming endeavors.