Nutrient management and balanced fertilization in Xinjiang
IPNI-2006-CHN-XJ2
23 Jan 2009
2008 Annual Interpretive Summary
Nutrient Management and Balanced Fertilization in Xinjiang, 2008
Cotton and tomato are the main cash crops in Xinjiang. Experiments on nutrient responses, N and P application rate, and methods for improving N use efficiency were investigated for these crops in 2008.
An optimum (OPT) fertilizer rate trial on processing tomato in Ma’nasi County found 300-120-105 kg N-P2O5-K2O/ha to be most effective. The N portion of this treatment was split between a basal application (20% of total N rate), application at fruiting stage (30%), at first irrigation (30%), and at second irrigation after the first harvest (20%). Agronomic efficiency for the OPT was 25 kg fruit/kg N and 97 kg fruit/kg P2O5 higher than farmer practice (FP), which omits K (270-150-0 kg N-P2O5-K2O/ha). The recovery of applied N and P under the OPT was 62% and 26%, respectively. The recoveries for N and P under FP were 57% and 12%, respectively.
In cotton, 75 kg P2O5/ha along with 180 kg N/ha produced the highest lint yield and benefit, 342 kg/ha (18%) more yield, and US$546 more income than the P omission treatment. This OPT rate increased cotton lint yield by 12% (242 kg/ha) and profit US$640/ha compared to the FP of 264-210-20 kg N-P2O5-K2O/ha. Agronomic efficiency of N and P within the OPT was 1.2 kg lint/kg N and 3.7 kg lint/kg P2O5. Under the FP, N and P recovery were 15% and 9%, respectively, and were 40% and 28% under the OPT.
Polymer-coated urea (PCU) applied as a single basal application at 126 kg N/ha and 180 kg N/ha increased lint yield by 18% and 12%, respectively. The high yielding PCU treatment raised income by US$487 compared to the equivalent treatment using conventional urea. At each application rate, PCU increased N recovery efficiency by 45% (low N rate) and 95% (high N rate) compared to the same rate of conventional urea applied in two split applications. The use of slow-release fertilizer would greatly improve nutrient use efficiency in this cotton production system. Xinjiang-NMBF