Field validation of Nutrient Expert for early and late rice in China

Field validation of Nutrient Expert® (NE) continued within early and late rice systems in Jiangxi and Hunan Province in 2015. The objective was to test the NE-based fertilizer recommendation method against soil testing and farmer’s practice (FP). In Jiangxi, 14 field validation experiments on early (7 sites) and late rice (7 sites) were studied. In Hunan, 20 field validation experiments on early (10 sites) and late rice (10 sites) were studied.

In Jiangxi, the NE treatment produced a significantly higher grain yield for both early rice (9.6 t/ha) and late rice (9.1 t/ha) using 151-63-63 kg N-P₂O₅-K₂O/ha and 155-68-62 kg/ha, respectively. In comparison, soil testing produced 7.9 t/ha with 150-66-109 kg/ha for early rice, and 8.2 t/ha with 178-69-128 kg/ha for late rice; while FP produced 7.1 t/ha with 150-68-88 kg/ha for early rice, and 7.6 t/ha with 197-93-181 kg/ha for late rice.

In Hunan, NE improved grain yield for both early rice (7.6 t/ha) and late rice (7.7 t/ha) with 148-54-65 kg/ha and 150-54-44 kg/ha, respectively. No yield differences were observed between soil testing (7.5 t/ha with 145-58-75 kg/ha) and FP (7.4 t/ha with 128-49-62 kg/ha) in early rice; however, in late rice soil testing produced a higher grain yield (7.6 t/ha) with 171-39-83 kg/ha than FP (6.9 t/ha) with 121-41-66 kg/ha.

Results from Jiangxi and Hunan agree that NE can maintain grain yields with less N or less K fertilizer input, and more balanced fertilizer application. The key points that NE advocate are to apply fertilizer at the right rate and time since NE recommends a second N application at a later stage than FP for both early and late rice cropping systems.