Abstract:

The effects of Humic acid on nutrient absorption and utilization of sweet potato (Ipomaea batatas LAM.) was investigated by growing sweet potato in field culture in which HA (Humic acid) was used. The changes of mineral elements content in sweet potato plant and soil was studied. The test results indicated that the mineral elements absorption and accumulation of sweet potato was increased significantly with amplitude from 12.87% to 29.84% after application of HA. This was related to the mineral elements rate of absorption increased by HA in sweet potato with different growth durations, the largest increase of the rate was in later growth stage. At harvest, the contents of available P, Ca, Mg and K in soil were increased as well. Through the analysis of mineral elements use efficiency for tuber output which could be found that the use efficiency for tuber output of N, K, Ca, S, B and Cu were enhanced after fertilizing with HA. It could be safely concluded that mineral nutrition was improved, and some kinds of mineral elements’ use efficiency was increased as well by using HA.