Effects of potassium application period on the yield and potassium utilization efficiency of sweet potato

Field trial was conducted to study the effect of different potassium application period on the yield and utilization efficiency of sweet potato Jixu No. 23 as experiment material,and the effect of potassium application period on the accumulation characteristic of dry matter,the distribution of dry matter and potassium utilization efficiency. The results showed that all the different potassium application periods increased storage root yield,applying potassium as basal fertilizer sharpest increased the yield by 26. 09%,followed by as top cover fertilizer,and the lowest was as top-growth peak fertilizer. Compared with the control treatment,applying potassium as basal fertilizer significantly increased the velocity of storage root; significantly reduced T / R ratio of the whole growth period,and the potassium as top cover fertilizer reduced T / R ratio of the later growth period;Three fertilizer treatments significantly improved the dry matter allocation rate at the harvest time. The potassium using efficiency,potassium harvest index,agronomic efficiency of potassium fertilizers and partial factor productivity of potassium of basal treatment were significantly higher than those of other potassium application treatments. In conclusion,applying potassium as basal fertilizer significantly increased the potassium using efficiency,potassium harvest index,agronomic efficiency of potassium fertilizers and partial factor productivity,significantly reduced the T / R ratio,increased velocity of storage root,improved the utilization rate of dry matter distribution at the harvest time and ultimately obtained the greatest increase of sweet potato yield.