Effects Of Organic Fertilizer On Vegetable Output And Soil Physical-chemical Properties

Increasing awareness of the ecological environment protection has caused a fast development of pollution-free agriculture and green agriculture, which has the potential to meet the requirements to environment protection and human health. However, during the vegetable production, techniques for the recommendation of fertilization are still inefficient. Under this condition, excessive fertilization is very common due to achieving higher yields. This has led to a strong declination of vegetable quality and a high risk of nonpoint soil pollution. Researches have demonstrated that such soil over-loading issues can be reduced with manure application.In this study, the impacts of various application rates of organic fertilizers on the yield response, soil P forms, soil organic mater and enzyme activities were investigated using soil culture, medium culture and in situ field experiment methods, which is very important to reduce fertilization rates, improve vegetable quality and fulfill rational fertilization under the conditions of excessive P and N fertilization and the resulted high soil P enrichment. The main results are shown in below:In contrast to CK, the biomasses of oilseed rape and color pepper were both increased by applying cow manure, wormcast and biogas residue. For example, the biomass of oilseed rape and pepper were increased by 26.1% and 107.4% for single application of cow manure, 53.6% and 216.4% for single wormcast application, and 13.1% and 66% for single biogas residue application. It demonstrates that the yield responses to cow manure, wormcast and biogas residue were in an order of wormcast > cow manure > biogas residue.Total P contents of rape and color pepper were increased by applying cow manure, wormcast or biogas residue and the order was wormcast > cow dropping > biogas residue. All forms of phosphorus in soil, organic matter and enzyme activities were increased with three types of manures applied and the soil pH value was adjusted to an appropriate range for vegetable production. The impacts of these three manures are in an order of wormcast > cow dropping > biogas residue.It has been indicated that the rape biomass was increased with a P application rate of 180~360 mg/kg, while it was reduced when the P fertilization rate was greater than 720 mg/kg. However, there was no significant difference on rape biomass when the P fertilizer was mixed with manure. To some extent, it demonstrates that the application of manure can reduce the inhibitive impacts of excessive P fertilization on rape biomass.