Nutrient management and balanced fertilization on main crops in Gansu province
IPNI-2006-CHN-GS3
20 Feb 2010
2009 Annual Interpretive Summary
Nutrient Management and Balanced Fertilization in Gansu, 2009
Crop yields in Gansu are mainly limited by water supply, so nutrient management practices must consider the available water regime. Research on nutrient responses and efficiencies to N, P, and K fertilizers were investigated in spring maize, potato, wheat, and soybean in 2009. Plastic mulching is an effective water conservation technique, but in covered crops like wheat and corn, the use of plastic mulch only allows for recommended rates of P and K to be applied in the first season while subsequent crops under the same mulch must rely on residual fertility. Thus, cooperators want to investigate how to appropriately apply nutrients during the first season so that adequate residual P and K fertility can support two or three seasons of crop production under established plastic mulch.
At Dingxi City, spring maize grown with the aid of water conserving plastic mulch and a recommended optimum (OPT) treatment of 225-120-90 kg N-P2O5-K2O/ha produced a high yield of 9 t/ha. This represents a 10.5% increase, valued at US$99/ha, over the mulched version of common farmer practice (FP) of applying 150-105-0 kg N-P2O5-K2O/ha. A similar trial in Zhenyuan County found the OPT to be 225-90-60 kg N-P2O5-K2O/ha. For potato grown at Dingxi City, also under plastic mulch, the OPT of 225-105-90 kg N-P2O5-K2O/ha generated 22% more tuber yield compared to the FP of applying 180-105-0 kg N-P2O5-K2O/ha. The OPT with plastic mulch produced 133% more income (US$611/ha) over the OPT without mulch. A mulched wheat experiment in Dingxi City found the recommended OPT of 150-120-84 kg N-P2O5-K2O/ha could produce 21% more grain than FP using 150-105-0 kg N-P2O5-K2O/ha. The OPT without mulch did not generate a significant grain yield response when compared with each nutrient omission plot or FP. Wheat yield under the OPT with plastic mulch was 42% higher than that of OPT without plastic mulch. In watermelon grown at Xhengyuan County, the OPT of 180-120-90 kg N-P2O5-K2O/ha produced 46% more yield, and US$2,147/ha, compared to the FP of applying 180-90-0 kg N-P2O5-K2O/ha. Soybean grown in Zhenyuan County has shown no response to N, but P and K application have increased yields by 21% and 13%, respectively. Gansu-NMBF