Field validation of Nutrient Expert for single season rice in China

Validation of Nutrient Expert® (NE) for single-season rice continued in 2015 through 10 field experiments in both Heilongjiang and Jilin. The objective was to test the NE-based fertilizer recommendation method against soil test-based recommendations and farmer’s practice (FP).

Each individual site had a site-specific rate applied. In Heilongjiang, the NE-based plots received an average of 168-77-77 kg N-P₂O₅-K₂O/ha, while the FP plots received an average of 142-55-77 kg/ha, and soil test plots received an average of 144-56-94 kg/ha. In Jilin, the NE-based plots received 170-74-72 kg/ha, while FP plots received 188-76-92 kg/ha, and soil test plots received 179-68-88 kg/ha.

Grain yield under NE was higher (9.6 t/ha) than under soil test recommendations (9.1 t/ha) and FP (9.2 t/ha) in Heilongjiang. In Jilin, no differences in grain yield between NE, soil test and FP treatments (i.e., 9.2 t/ha, 9.3 t/ha and 8.9 t/ha). As with yield, agronomic efficiency (AE) and partial factor productivity (PFP) values did not show differences amongst the three treatments The higher yield for NE treatments in Heilongjiang was from the higher and balanced fertilizer rates, while for Jilin the NE with slightly lower fertilizer rate produced comparable yield to FP, and soil test.

Results from the NE recommendation system for single season rice were consistent to those in obtained in 2014. The NE method appears to be promising where soil test recommendations are not available or timely.