Effects Of Controlled-release Fertilizer On Vegetable Yield, Quality And Soil Environment

Based on the actual vegetable production in Zibo City, the effects of controlled-release fertilizer on vegetable yield, quality and soil environment and its using method were studied by means of conventional field experiment. All results in this thesis would provide information and reference for spreading and utilizing controlled-release fertilizers in vegetable cultivation, especially in non-pollution vegetable cultivation. The main results are as follows:1.Controlled-release fertilizer can significantly increase the yield in contrast with the ordinary fertilizer. In condition of similar nutrient inputs, the yield in controlled-release fertilizer is 1.12-1.21 times than that in common fertilizer treatment, the fertilizer productivity is 1.55-3.45 times than that of the common fertilizer. The yield in controlled-release fertilizer treatments was still not less than that in common fertilizer treatments even if the applying quantity of controlled-release fertilizer was half of that of the common fertilizer.2.Controlled-release fertilizer can improve the fertilizer utilization ratio within a growing season. The fertilizer utilization ratio of Controlled-release fertilizer within a growing season is 1.59 -2.40 times than that of the common fertilizer. The utilization ratio of Nitrogen is 28.99%-52.19%, increased 13.53%-26.18%; the utilization ratio of Phosphorus is 12.69%-21.00% , increased 4.69%-8.17%; the utilization ratio of potassium is 54.11%-62.34%, increased 31.6% -33.28%. Nitrogen utilization ratio of controlled-release urea is 28.11% -55.92%, increased 5.91%-19.38% compared with that of ordinary urea.3.Controlled-release fertilizer has obviously improved vegetables' quality, security and commodity properties. Controlled-release fertilizer can significantly improve vegetable quality, increasing Vc of tomatoes by 0.80-1.19 units, increasing reducing- sugar by 0.16-0.24 units, decreasing acidity by 1.48-0.36 units, increasing sugar/acid by 0.05-0.07 units, increasing soluble solids by 0.6-1.1 units; increasing Vc of Leek by 13.22-19.74 units, increasing sugar by 0.34-0.42 units. Vegetables applied controlled-release fertilizers have better appearance, better taste, higher price, and have outstanding advantages in security and commodity properties. 4.Controlled-release fertilizer has less negative effects on soil environment. It is the first choice of the fertilizer used in pollution-free vegetables. Compared with the ordinary fertilizer, the deterioration effects of controlled-release fertilizer on soil environment are much more minor. The controlled-release fertilizer has great advantages in improving nutrient efficiency, cultivating soil fertility, reducing leaching-loss, reducing pollution to underwater. The effect of controlled-release urea on soil urease is less, the contents of the soil urease are always lower than in ordinary fertilizer treatments, this can slow down the decomposition of the amide nitrogen, improve the long-term efficiency and utilization rate of N fertilizer. The effects of controlled-release fertilizers on soil catalase are greater than that of the ordinary fertilizer, it can strengthen the ability of decomposing H2O2 and eliminating its poisonous. After a growing season, the contents of soil organic matter, Alkali released nitrogen, Available phosphorus, are all obviously increased. Under the condition of equal nitrogen, the contents of vegetable nitrate in CRF treatments are significantly lower than in ordinary ferlizer treatments, and meet the demands of pollution-free vegetable.5.Controlled-release fertilizer is easy to use, the fertilizer choosing is mainly based on the economic, environmental values and fertilizer prices. Its physical properties are good. As a kind of environmentally friendly fertilizer, it is very safety. It may be used as basal fertilizer, top dressing, seed manure, nursery fertilizer. The profits in economical crops, flowers and greenhouse vegetables are higher. When applying, the priority should be as basal fertilizer. When used as top dressing , the applying quantity and frenquency should be reduced by 50% compared with the common fertilizer. Developing controlled release fertilizer with low cost, easy manufactory, single-dose application, especially coated fertilizer, is the main direction in the future.