Researches on Balanced Fertilization Technology of Sweet potato

Sweet potato cultivation is quite extensive in China. But in many sweet potato growing regions, the application rates of fertilizers, especially K, are very low. According to our survey, many farmers applied compound fertilizers, like 15-15-15, to sweet potato instead of other commonly available K fertilizers (like KCl) because of high prices. This has led to a situation where there is under application of K in sweet potato in China. Since K is essential for sweet potato growth, both yield and quality of sweet potato have been steadily decreasing in the past few years.

This project was implemented by the Resource and Environment Institute, Jiangsu Academy of Agricultural Science. In 2012, field trials were conducted to determine the optimum (OPT) application rates of N, P and K fertilizers in sweet potato in Jingmen city of Hubei province, Laiqiao town of Anhui province, Nan'an city of Fujian province, and Liuhe street in Nanjing of Jiangsu province. Results from the trial in Jiangsu province showed that the balanced fertilizer (BF) treatment with application of 112-162-260 kg/ha of N-P₂O₅-K₂O, respectively, obtained significantly higher sweet potato yield of 63 t/ha, which amounted to a yield increase of 8.3 t/ha or 15% and net income increase of RMB 5,851/ha over the CK treatment where no K was applied (i.e. application of 112-162-0 kg/ha of N-P₂O₅-K₂O, respectively). Other provinces also showed similar results. Jiangsu-11