Field validation of Nutrient Expert Soybean in China

The objective of this study is to validate Nutrient Expert® (NE)-based fertilizer recommendation for soybean grown in Heilongjiang, Jilin, Liaoning, and Inner Mongolia. Results are directly compared against those obtained with farmer practice (FP) and a soil test-based recommendation.

This study had 11 field validation experiments in each province. Each individual site had a site-specific recommendation, but NE-based plots received an average of 40-55-53 kg N-P₂O₅-K₂O/ha. Plots under FP received an average of 50-68-45 kg/ha and soil test plots received an average of 53-65-59 kg/ha.

Plots receiving NE recommendations produced an average grain yield of 2,850 kg/ha and US$2,200/ha of profit. These yields were 10.1% and 9.7% higher than FP and soil test plots, respectively. Similarly, profits were 13.2% and 10.7% higher under NE when compared against FP and the soil test recommendation, respectively.

Results in 2015 align well with those obtained in 2014 where NE Soybean appears a promising option for making fertilizer recommendations when soil test recommendations are not available or timely. Besides the different fertilizer rates, all NE plots received rhizobia inoculation for enhanced biological N fixation and fertilized with controlled-released urea, while FP and soil test plots received no rhizobia and were fertilized with only regular urea. Therefore the 4R nutrient management strategies here adopted for NE are the right source and the right rate.