Field validation of Nutrient Expert for middle season rice in China

response and agronomic efficiency as compared with soil testing and farmer's practice


22 May 2017

2016 Annual Interpretive Summary

Nutrient Expert® (NE) field validation continued for middle season rice in 2016. Field experiments were set up in Anhui and Hubei provinces of China to compare the NE-based fertilizer recommendation method to the recommendations based on soil testing, and the farmer’s practice (FP).

In Anhui, the average N-P2O5-K2O recommendations were 169-58-95 kg/ha, 194-68-92 kg/ha, and 212-72-59 kg/ha for the NE-based, the soil test-based, and the FP plots, respectively. Rice grain yield in the NE-based treatment (8.8 t/ha) was not significantly different from the soil test-based recommendation (8.7 t/ha), but both were higher than FP treatment (8.1 t/ha). The average agronomic efficiency (AE) and partial factor productivity (PFP) values of N were 14.3 kg/kg and 52.2 kg/kg in the NE-based treatment. The average AE and PFP in the soil test-based and FP treatments were 12.1 kg/kg and 45.1 kg/kg, and 8.1 kg/kg and 38.4 kg/kg, respectively.

In Hubei, the average recommendations for the NE-based plots was 155-60-52 kg/ha, for the soil test-based plots was 177-60-90 kg/ha, while the FP plots received an average of 182-88-88 kg/ha. No significant grain yield difference was observed between NE-based, soil test-based and FP (8.6 t/ha, 8.3 t/ha and 8.8 t/ha, respectively) of nutrient application. The AE and PFP values also did not show significant difference among NE, soil test and FP treatments.

The on-farm trials suggest that the NE could be used as an effective tool for providing 4R-based site-specific fertilizer recommendation when a soil test is not available or timely.