4R nitrogen management produced more yield and benefit on rice in Ningxia, China

Research focused on effect of N recommendation by Nutrient Expert integrated with CRU and placement on rice yield and benefit as well as N use efficiency.


22 May 2017

2016 Annual Interpretive Summary

Imbalanced use of nitrogen (N) in rice production is common in the northwestern province Ningxia, leading to possibilities of N losses to the environment. The objective of this project was to use the Nutrient Expert® (NE) tool to make site-specific fertilizer recommendations for rice, based on the 4R Nutrient Stewardship Principles, to help improve N use efficiency and farmers' income.

The present study had four treatments with three replicates: 1) no N (control); 2) farmer practice (FP) of 270-90-60 kg N-P2O5-K2O/ha, with broadcasting of 60% N, all P and K before transplanting, and the rest 40% N applied in two equal splits, after translation and at tillering; 3) NE recommendation of 195-66-112 kg/ha, with broadcasting of 1/3 N and all P basally, rest of the N applied in two equal splits at tillering and at panicle differentiation, while 50% K is applied before transplanting and the rest at panicle differentiation; and 4) NE recommendation with full N (60% through controlled-release urea (CRU) and 40% through regular urea), P and K were banded at 3 to 5 cm depth and 5 cm away from the seedlings during transplanting by machine.

The results indicated that N application produced 3,400 to 3,590 kg/ha or 90 to 95% more rice grain than the control. NE recommendation with regular urea and broadcasting produced similar yield and benefit to FP, but improved the agronomic efficiency (AE) by 4.4 kg grain/kg N and saved 75 kg N/ha. NE recommendation integrated with CRU and banding resulted in 196 kg/ha of extra grain yield, US$48/ha of extra income, and improved the AE by 1 kg grain/kg N over the NE treatment where regular urea was broadcasted; and produced 59 kg/ha of extra yield, US$30/ha extra benefit, and higher AE (5.3 kg grain/kg N) than the FP treatment. Therefore, 4R N management in rice production in Ningxia could improve yield, farmers' income, and the N use efficiency.