Field validation of Nutrient Expert for middle season rice in China

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


02 Jun 2018

2017 Annual Interpretive Summary

The Nutrient Expert® (NE) field validation study continued for middle season rice in 2017. Field experiments were set up in the Anhui and Hubei Provinces of China to compare the NE-based fertilizer recommendation method to the recommendations based on soil testing (ST) and farmer’s practice (FP).

In Anhui, the average nitrogen, potassium, and phosphorus (N-P2O5-K2O) recommendations were 154-54-105 kg/ha, 195-69-93 kg/ha, and 208-67-67 kg/ha for the NE-based, ST-based, and the FP plots, respectively. Rice grain yield in the NE treatment (8.9 t/ha) was not significantly different from the ST recommendation (8.9 t/ha) and FP treatment (8.2 t/ha). The average agronomic efficiency (AE) and partial factor productivity (PFP) values of N were 14.3 kg/kg and 57.7 kg/kg in the NE treatment. The average AE and PFP in the ST-based and FP treatments were 11.6 kg/kg and 46.0 kg/kg, and 7.5 kg/kg and 39.7 kg/kg, respectively.

In Hubei, the average N-P2O5-K2O recommendation for the NE plots was 159-70-64 kg/ha, for the ST based plots was 158-62-90 kg/ha, while the FP plots received an average of 163-117-117 kg/ha. No significant grain yield difference was observed between the NE-based, ST-based and FP (7.4 t/ha, 7.6 t/ha, and 7.4 t/ha, respectively) nutrient applications. The AE and PFP values also did not show any significant difference among NE, ST, 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 recommendations when the soil test is not available or timely.