Field validation of Nutrient Expert for middle season rice in China

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


29 Apr 2016

2015 Annual Interpretive Summary

Nutrient Expert® (NE) field validation continued within the middle rice cropping system in Hubei and Anhui Provinces. The objective was to test the NE-based fertilizer recommendation method against traditional soil testing and farmer’s practice (FP). Ten field validation experiments were conducted in both Hubei and Anhui in 2015.

In Hubei, higher grain yield was observed under NE (9.5 t/ha) compared to FP (8.8 t/ha). The NE treatment applied less fertilizer (157-75-72 kg N-P2O5-K2O/ha) compared to FP (182-88-88 kg/ha). Higher recovery efficiency (RE), agronomic efficiency (AE) and partial factor productivity (PFP) of N were calculated from NE (i.e., 36.7 kg/kg, 15.7 kg/kg and 60.5 kg/kg) than in FP (20.5 kg/kg, 9.6 kg/kg and 49.0 kg/kg). The soil test recommendation achieved 9.0 t/ha of grain yield with 176-60-90 kg/ha, which resulted in lower N use efficiency parameters.

In Anhui, the NE treatment produced 8.8 t/ha grain with 157-70-64 kg/ha, which was much higher than FP (8.1 t/ha) with 203-58-56 kg/ha. In contrast to FP, RE, AE and PFP values for N (i.e., 16.6 kg/kg, 9.2 kg/kg, 40.1 kg/kg), were significantly higher under NE (47.1 kg/kg, 16.2 kg/kg, 56.1 kg/kg). Although very similar grain yield (8.7 t/ha) was obtained with soil testing, lower N efficiency was found due to higher fertilizer input (194-72-87 kg/ha).

Results from 2015 demonstrated that NE-Rice is a useful tool to improve N use efficiency while maintaining grain yield. Besides the right rate adopted by NE treatment, all the NE treatments recommended splitting N fertilizer applications at the right time. Therefore, the higher yield and high N efficiency of NE benefited from the implementation of 4R nutrient management, especially applying fertilizer with the right rate and right time.