Crop rotation and soya beans.

As mentioned in the previous blog Soya Manufacturing in South Africa: An Overview the demand for soybeans is estimated to grow to 2,3 million tons by 2020. To be able to match capacity soya manufacturers need to consider precision soy strategies. They need to arm themselves with research and data to dial into the right plant population. It’s a financial decision that can boost the return on their investments. A strategy that soya manufacturers should look at is crop rotation.

Some manufacturers are still growing soybeans on soybeans, while it’s becoming less common, it is a practice that is still out there. Whilst rotation crops do not entirely affect the yield amounts of soybeans it has been found that if soya manufacturers don’t rotate soya crops with other crops, the soybean crops have issues with Phytophthora root rot. Another concern is if soybean cyst nematode moves into the area it will impact the soybean yields. Both Phytophthora root rot and soybean cyst nematode are long-term disease problems, once they’ve moved in – they’ll be in the crops for a long time. Many soya manufacturers are now choosing to grow other crops (wheat/corn/oats) both before and after their soybean crops. Soybean and cereals both yield well in soybean-cereal-soybean-cereal sequences. A soybean-cereal rotation is a good risk management strategy for both crops. Soybeans in the rotation crop let manufacturers have a better control over pest management, it reduces tillage, saves on nitrogen (as soybeans put nitrogen into the soil), and diversifies weed control chemistry as well as cutting down the resistance risks.

Many soya manufacturers are now choosing to grow other crops (wheat/corn/oats) both before and after their soybean crops. Soybean and cereals both yield well in soybean-cereal-soybean-cereal sequences. A soybean-cereal rotation is a good risk management strategy for both crops. Soybeans in the rotation crop let manufacturers have a better control over pest management, it reduces tillage, saves on nitrogen (as soybeans put nitrogen into the soil), and diversifies weed control chemistry as well as cutting down the resistance risks.

However, to get the most out of a rotation, manufacturers need to treat soybeans like first class citizens. In order to do this, the best genetics need to be selected, narrow rows of soybeans need to be planted, fertilising of the crops needs to be done (at the right time), preemergence herbicides need to be applied and seed treatments need to be implemented. Soil nutrient levels also need to be monitored to ensure that the soil has adequate fertility. The soybeans need fertile soil because they are high phosphate and potassium users.

Despite results showing that the soybean-cereal/corn rotation means in higher yields for the other crops but not soybean yields, crop rotation is still, as mentioned above, beneficial in preventing diseases and should be a soya strategy that is employed by all soya manufacturers.