Responses of rice to different fertilizer treatments under different soil fertility in Guizhou province

IPNI-2008-CHN-GZ10

09 Jan 2009

2008 Annual Interpretive Summary

Response of Rice to Fertilizer under Varying Soil Fertility Status in Guizhou, 2008

This project studied the specific response of rice cultivar Jinyou527 to different fertilizer treatments on yellow-earth soil with varying soil fertility levels. Optimal (OPT) fertilizer rates for rice production were also verified for the province. Fertilizer treatments included OPT- N, - P, and - K treatments, a series of nutrient omission treatments, and an unfertilized check (CK). The OPT treatments were designed as 180-120-150, 150-105-120, and 120-90-90 kg N-P2O5-K2O/ha for the high, medium, and low fertility soils, respectively.

On the high fertility soil, rice yield was most limited by K, followed by P, and then N. Compared to the OPT, yields on high fertility soil were reduced by 823 to 1,043 kg/ha (9 to 11%) with individual omission of N, P, or K. The case of a less N responsive site is unusual, but with the low fertility soil, rice responded more commonly as N became the largest yield-limiting factor, followed by P and then K. In this case, rice yields were 697 to 898 kg/ha (7 to 9%) lower than the OPT with omission of N, P, or K. The rice response in the medium fertility soil was intermediate if compared to results obtained for the high and low fertility soils.

The results suggest that a better approach to nutrient management is possible with an assessment of various nutrient blends. Adoption would lead to more balanced fertilizer input and enhanced fertilizer efficiency for areas in China where soil testing is currently unavailable. Guizhou-BFDP-2008