| This experiment was carried out at the experimental station of Shandong Agricultural University from March 2006 to October 2007. This paper mainly studies preparation method of Humic acid Potassium. The biological effect on Bei Jing 553 is also analyzed, which happens when different Humic acid K are used. Bei Jing 553 is a kind of quality edible sweet potato.The main resultswere as follows:1. The preparation of Humic acid Potassium The humic acid is actived by means of reaction between potassium hydroxide solution and weathered coal. Comprehensive consideration of the crop root's requirements of pH of fertilizer, activation rate of Humic acid Potassium, moisture content of product and so on, the suit reaction conditions of active Humic acid making is determined. The conditions are as follows: :potassium hydroxide solution of 20% concentration, the proportion between weathered coal and potassium hydroxide solution is 3:1.Under the conditions of accession of moderae bentonite , and use of the weathered coal humic acid and granular fertilizer which is producted by weathered coal humic acid and after activation of mixed with potassium sulfate, particle compressive strength have been improved significantly. Sand column leaching tests indicated that the release of K is inhibited by humic acid potassium and active humic acid early in fertilization, meanwhile slow-release effect of active humic acid K is better than that non-active. 2 Physiological basis of high yield and good quality of sweet potato caused by Humic acid Potassium2.1 Effect of humic acid Potassium on yield and quality of tubers Three potassium treatments significantly increased root number and weight per lump, moved up the time for sweet potato and promoted expansion of sweet potato. Comparing with non-fertilizer treatment, the yield of HA-K fertilizer treatment respectively increased yield by 8.04%, the average weight of tubers is also increased significantly. But the quantity of tuber in each sweet potato made no difference. While the yield of active HA-K fertilizer treatment increased the quantity of tuber markedly, respectively increased yield by 9.40% as well, while the the average weight of tubers is similar.Three potassium fertilizer treatment increased the content of soluble sugar notably, decreased the content of starch and protein.Compared with the treatment of equivalent potassium hydroxide, two humic acid potassium treatment significantly increased the soluble sugar content and reduced the starch and protein content. Activated humic acid potassium was better for content of soluble sugar increasing and for content of starch decreasing than non-activated humic acid potassium. But both fertilizers effect the content of protein slightly.2.2 Effect of humic acid potassium on the uptake and partitioning of nitrogen and potassiumCompared with the treatment of equivalent potassium hydroxide, in the middle, sweet root swollen, leaf nitrogen and potassium content is improving in the potassium humate processing (T4, T5), And the nitrogen content is significantly reduced, and the content of potassium increased significantly in the root. Later, in the sweet root swollen with 2 potassium humate leaf nitrogen and potassium content is reduced, and the content of nitrogen and potassium were obviously improved. On the whole, sweet root growth of 2 potassium humate blade and handle root N/K ratios were significantly. 2.3Potassium humate on sweetpotato dry matter accumulation and distributionPotassium sulfate and potassium humate significantly increased dry matter accumulation of sweet potato root and plant, the later is better than the former. But active potassium humate processing and potassium humate made no difference. To analyse sweet root and plant dry matter accumulation by using of Logistic equation. The fitting result indicated that 2 potassium humate increased sweet root and plant dry matter accumulation was caused mainly by high dry matter accumulation rate of tuber and plant, while the duration of active length without close relations. Potassium humate not only can improve both biological yield and the root distribution rate of dry matter, but also can improve the leaf distribution rate of dry matter at harvest, which can prevent premature senility, extended period of blades.2.4 Effect of potassium humate on sweet potato production efficiency and potassium fertilizer utilization ratioHumic acid application can enhance utilization of potassium cooperation with potassium. The dry matter production efficiency and root production efficiency of potassium significantly reduced as result of the total potassium uptake greatly improved. But differences between active potassium humate and potassium humate was not significant. 2.3 Potassium humate on sweetpotato dry matter accumulation and... |
