Effects Of Excessive Nitrogen And Phosphate Fertilizer On The Growth Of The Plant And The Regulating Action Of The Manure

Applying nitrogen and phosphate fertilizers is very important to increase crop yield, however, excessive fertilization also can lead serious problems on yield and quality in facility agriculture. It has been demonstrated that negative impacts of excessive N and P fertilization or the highly enriched soil P on the nutrients uptake and growth of crops occurred. Therefore, in this study, such impacts of manure application under excessive N and P enrichment soils on the nutrients uptake by rape and peanut was investiagated using pot experiment method in order to provide useful information to increase yields, quality and scientific fertilization.1. N and P fertilization can significantly increase the biomass when the P level of soil was not too high. For example, the rape biomass was increased by 11.7-20.6% with N fertilization rate of 100 mg·kg-1; the peanut biomass was increased by 32.9% with P fertilization rate of 200 mg·kg-1; the highest biomass was found when the P and Fe concentrations was 4 mmol·L-1 and 0.14 mmol·L-1 respectively. There is no significant difference on the biomasses of rape and peanut under excessive fertilization conditions. When the N fertilization rate was greater than 400, there was no biomass. In addition, manure or manure+chemical fertilizer application can increase the biomass with 14.5%~40.1%.2. It is also found that the N content of rape was increased by applying N fertilizer, but there were no such impacts on the total P and K; P fertilization increased the P content in peanut. However excessive P uptake by rape was obtained when excessive P fertilization occurred. Meanwhile, reasonable P fertilization also can enhance Fe uptake and transport. For example, the total Fe content of peanut above ground was increased with 44.7% when the P fertilization rate was 200 mg·kg-1. In conclusion, manure application can not only increase the total contents of N, P and K, also enhance the uptake of Fe. In addition, the application of worm dung had a better impact on the Fe uptake, where the Fe content of peanut was 6.26%~39.17% greater than cattle dung application.3. The total soil N and P and available P were significantly increased by N and P fertilization but little effect on phosphatase activities, urease activity in soil and soil organic matter was found. While applying cattle manure, the total soil N, P and available P and urase and phosphatase activities was significantly increased. Furthermore, the soil pH was decreased with 0.15~0.28 due to the cattle manure application, which is very helpful to mobilize the mineral nutrients in soils.