Reduced fertilizer rates enhanced yields of vegetables grown on fertilizers overdosed vegetable soils in Yunnan
IPNI-2008-CHN-YN11
04 Jan 2012
2011 Annual Interpretive Summary
Cucumber Yield, Nutrient Use Efficiency, Economic Returns and Soil Phosphorus Forms as Affected by Fertilization and Irrigation Systems in Yunnan, 2011
This ongoing study initiated in 2010 continued to investigate the effects of different fertilizer practices on yield, economic return, and nutrient use efficiency of cucumber, one of the most commonly grown vegetables in Yunnan. The goal was to determine optimal fertilizer rates for cucumber production in the region. The experiment consisted of 26 fertilizer treatments involving different rates of N, P, and K, each receiving two types of irrigation (drip and traditional) and replicated three times. In addition, there were two forms of K (KCl and K2SO4) used in the study to evaluate source differences. Based on the results obtained in 2010, fertilizer rates in 2011 were adjusted to 0, 120, 240, and 360 kg of N, 0, 60, 120, and 180 kg of P2O5, and 0, 195, 390, and 585 kg of K2O per hectare, of which rates of N and P were lowered and K was raised, and applied several times in a 10-day interval starting from seeding.
Results showed that 2011 cucumber yields were higher than those in 2010, especially for drip irrigation. Drip irrigation increased cucumber yield by 7,960 to 11,380 kg/ha (20 to 30%) and saved water by 563 m3/ha (40%) compared to the traditional irrigation. The optimal (OPT) fertilizer treatment tested was 240-120-390 kg N-P2O5-K2O/ha under both irrigation systems in 2011, a reduction of 60 kg N/ha and 30 kg P2O5/ha, but an increase of 30 kg K2O/ha compared to rates used in 2010. The net income of OPT was USD 14,787 for drip irrigation and USD 11,774 for traditional irrigation. The agronomic efficiencies of N, P, and K fertilizers were 45, 53, and 36 kg cucumber/kg nutrient under drip irrigation and 36, 46, and 31 under the traditional irrigation, respectively. Potassium chloride produced higher cucumber yield than K2SO4 at all K rates in 2010, but this was reversed in 2011, possibly due to continued omission of S over for two years. This study revealed that in addition to meeting the proper 4R management of the crop, other agronomic practices such as proper irrigation method were crucial to improving crop yield and fertilizer use efficiency. Yunnan-BFDP-08