10 Jan 2014
Liming acid soil and balanced fertilizers boosted potato yield
Potato is a common crop in the hilly areas of the southwest China. However, most of this crop is grown on acid soil with soil pHs below 5.5, which seriously limits potato yield and quality. Field experiments were conducted by the IPNI collaborator - Chongqing General Station of Ag-Tech Extension to investigate optimum rates of phosphorus and potassium fertilizers with addition of lime for potato grown in acid soil in the hilly area. The optimal fertilizer rate (OPT) was designed as 180-90-150 kg N- P2O5- K2O/ha plus lime at 1500 kg/ha in a soil of pH 4.1. Results showed addition of lime increased potato yield from 15028 kg/ha to 25790 kg/ha, or 42% of yield increase. The potato yield decreased as the fertilizer rate was either above or below the OPT rate, proving the OPT optimal in the area. Further analysis showed that due to the antagonistic relationship between K and Ca, additional K should be considered to meet demand of potato for K when using lime to neutralize soil acidity. Addition of K could enhance the number of large-sized potato tubers, synthesis of protein and starch and improve both commercial and nutritional traits of potato.
