Effects Of Humic Acid From Different Areas On Nutrition Characteristic Of Chinese Cabbage

Humic Acids are ubiquitous in nature and arise from the decay of plant and animal residues in the environment, and can not be crystallized or separated into pure components, which are complex macromolecules consisting of an array of aromatic and aliphatic structures. Researchers have recognized significant benefits of humic acids to crop productivity. But most of the studies of the effects of humic acids on plant growth were about a single sample, without considering of different areas and different application methods of humic acids, so researchers often came to different conclusions.This article chose four humic acids to inspect the influences of the humic acids on seed germination, the growth, the nutrition characteristics and the stress resistance of Chinese cabbage. We obtained the following conclusions.1. The humic acids from four different areas affected seed germination of Chinese cabbage regularly. Humic acids in concentrations of 50~200 mg/L showed increasing the seed germinationrate, shortening the germination time, increasing the seedling growth and seedling length with increasing humic acid concentration, when the concentration was more than 200 mg/L, the humic acids began to inhibite them, when the concentration reached 400 mg/L, the humic acids decreased the seed germination. In the same humic acids'concentration, the humic acid from Shanxi was much better than the others. Considering of the seed germination, the appropriate concentrations were 100~300 mg/L.2. The humic acids appeared to have positive effects on the dry weight and the quality of Chinese cabbage in the appropriate concentration. Humic acids from different areas showed different influences. Humic acids from Inner Mongolia, Shanxi increased the contents of Vitamin C and Soluble sugar, decreaced the nitrate contents of Chinese cabbage.3. Different effects of different humic acids on the uptake of N, P and K were observed in this test. Humic acid from Inner Mongolia was observed enhancing the uptake of N, P and K in the appropriate concentration. When the concentration of humic acid was 0.16 g/kg soil, the contents of N,P increased 26.05%,11.69%, and the accumulations of N,P,K increased 94.12%,66.67%,41.16% respectively. Humic acid from Sinkiang was observed an increase in the uptake of N, When the concentration of humic acid was 0.16 g/kg soil, the content of N increased 18.61%, the accumulations of N increased 14.70%,14.74% respectively in the concentration of humic acid was 0.08 g/kg soil and 0.16 g/kg soil.4. The humic acids from four different areas decreased pH of the soil , but had no influence on organic matter of soil. The defferent humic acids appeared to have different effects on total N, available P of the soil, and had no influence on available K. Humic acid from Inner Mongolia increased the contents of total N, available P of the soil, the contents of available P increased 27.66%~35.87%. Humic acid from Sinkiang increased the contents of total N of the soil.5. Different methods of humic acid application showed different influences on the growth and the quality of Chinese cabbage, the uptake of N, P and K was observed different too. Using NPK as base fertilizer and pouring humic acids into the soil could increase the dry weight of Chinese cabbage, the contents of Vitamin C and Soluble sugar of Chinese cabbage. By this application method, humic acid from Shanxi enhanced the uptake of N, P and K. Using humic acids as base fertilizer increased the contents of Soluble sugar of Chinese cabbage, decreased the nitrate contents of Chinese cabbage. By this application method, humic acid from Inner Mongolia enhanced the accumulations of N, P and K.6. Under drought conditions, application of humic acid from Sinkiang increased the yield of Chinese cabbage compared with CK, the increase rates were 60.00%, while other humic acids had no effect on the yield of Chinese cabbage under both drought and salt stress conditions. Under drought and salt stress conditions, the contents of malonaldehyde decreased 20.44%~48.89% and 17.56%~51.53% respectively. Compared to other humic acids, humic acid from Inner Mongolia had better effect on the stress resistance of Chinese cabbage under the drought and salt stress conditions.