Effect Of Release Characteristics Of Humic Fertilizer And Its Efficiency

Fertilizer is very important in agriculture. But now, low N use efficiency and high environmental risk of chemical N fertilizer are worldwide concern, which may be overcomed by using new slow-release fertilizers. So, the study on slow release fertilizer has very important practice meanings to the production in agriculture and forestry, etc. The brown coal is a kind of important raw material of the fertilizer and its reserves in our country are up to more than 130 billion tons. The effects of slow-release nitrogen fertilizer(SRNF) on corn yield was studied with pot experiment. Moreover,humic acid fertilizer was manufactured through the adsorption characteristic. At the same time, we studied the N,P,K release characteristic and regularity and the effect of this humic acid fertilizer on the quality and output of spinach. Purpose of this research was offering basic data for the production of humic acid slow-release fertilizers, the main result are as follows:1. The effects of slow-release nitrogen fertilizer(SRNF) on corn yield was studied with pot experiment. The results showed that: SRNF supplies the available nitrogen in soil with a higher level throughout the whole growing season of corn to meet there quirement for nitrogen uptake by the plants, compared with common urea. The transportations of N into grains are speeded up,the nitrogen contents in the plant and grain are increased by application of SRNF, which result in higher biological and economic yields. Moreover,because the slow-release nitrogen fertilizer have obviously function of slows release, it provides the effective technical way to raised nitrogen use efficiency. After 24 hours,the release rate of SRNF are 15.28%,22.95%and 11.58%.2. Laboratory incubation experiments in constant temperature were implemented to study the influence of humic–acid on fixation and release of potassium in soil. The results indicate that application of humic acid accelerated potassium release from the soil, showing a tendency of the rate of K release increasing with the rate of humic acid addition. After incubating at 25℃for 30days, K release increased by 15% in the soil treated with 20g·kg-1 humic acids. Application of humic acids may reduce the rate of the soil fixing extraneous K. After application of 600 mg?kg-1 K,the soils treated with humic acids differed significantly from the soil in the control in K fixation. In the treatments where humic acids-treated soils were incubated in constant temperature for 10days before application of potassium,the K fixation rates were lower than that in the treatment of applying potassium and humic acids at the same time. The effect of humic acids on fixation and release of potassium in soil was possibly accomplished by dissolving K-bearing minerals or blocking interlayer and adsorbing K.3. With equal-nutritrional quantity, the release of chemistry feryilizer is mainly in the first and second time, which is significantly higher than humic acid fertilizer. However, the release of the humic acid fertilizer is higher than the chemical fertilize in the succeed time. NH4+-N was the dominate in ealier stage, while NO3--N was the main form latter.4. All fertilizer treatment were notably out-weighted the CK and the treatment of HA-NPK purely was the highest but didn't notably all. With equal-nutritrional quantity, humic acid fertilizer apparently decreased the NO3--N content and increase VC ,soluble sogur and chlorophyll content.5.Based on the effects of HA compound fertilizer on the quality and physiological mechanism of rape under the soil culture condition , the conversion of soil nutrient and activities of soil enzyme were studied in this paper. The results showed: compared within organic fertilizer , HA pound fertilizer increased the fresh and dry weights of rape and Nutilization ; HA compound fertilizer increased the contents of available N and P and the consumption of K in soil ; HA pound fertilizer reduced the pH ,improved the activities of alkaline phosphatase and hydrogen peroxidase in soil; but it decreased the activity of urease that indicated HA could be used as inhibitor for urease.