Acting Research Leader Soybean Research Unit, USDA-Agriculture Reseach Service North Carolina State University Raleigh, North Carolina
The meal protein content derived from most current commercial soybean varieties in the U.S. are below the 47.5% minimum meal protein content needed at the national and international soybean meal markets. This reflects a long-term pattern of slow decline in seed protein content of U.S. soybean. According to the U.S. Soybean Export Council, protein content of U.S. soybean declined to a record low of 34.1 percent in 2017. In November 2016, CME lowered soybean futures meal contracts by 0.5% to 47.5% and allowed for no rejection or penalty to 47.0% to reflect the lower average protein content. This is a major concern for U.S. soybean farmers who want to reverse this trend. The negative correlations of seed protein with seed yield and oil have been major constraints to the development of soybean lines with high meal protein without reduction in yield or oil. Despite the historical negative correlations of seed protein with seed oil and seed yield, recent USB funded research by our group indicates that small but meaningful increases in soybean meal protein are possible with little or no drag on seed yield. We have recently released and are nearing release of new soybean varieties/germplasm which produce high (≥48%) meal protein and have little or no yield drag compared to the elite check varieties. However, significant challenges remain in achieving full success in this area of research, particularly in the area of balanced amino acid profiles. Several amino acids in soybean protein, including the sulfur containing amino acids Methionine and Cysteine are less than optimum in soybean seed. The challenges in improving soybean meal protein, progress being made and way forward will addressed.
Challenges in breaking the negative relation of seed protein with seed yield and seed oil
Advances in simultaneous improvement of soybean seed yield and seed protein
Improvement of amino acid profiles of soybean protein and the challenges therein