The Screening Of Compound Substrate And Its Effect On Growth And Quality Of Watermelon Seedlings

According to the serious environmental pollution on using common fertilizer in vegetable seedlings and lower fertilizer efficiency, the study using watermelon analyzed, and a trial was conducted to evaluate the effects of adding organic fertilizers with various rates in nursing media on growth, sound seedling index, floral bud differentiation and fertilizer use efficiency of watermelon seedlings using no fertilizers and nutrient solution as controls. The findings provided a theoretic support basis for improving the processing techniques, and exploring the intensive utilization of organic fertilizer. The research results were as follows:1. Early in the watermelon seedlings, the growth tendency of treatments of adding organic fertilizer by 25% was the best, with the growth and development and its constant release nutrient, adding organic fertilizer can meet the nutrient demand of later period of vegetable seedlings. Having increased the height and stem diameter, enhanced the root absorption capacity of seedlings. Compared with nutrient solution, The treatment of adding organic fertilizer 25% had the best effects on biomass and sound seedling index: biomass of watermelon seedlings increased by 12.6% respectively; Sound seedling index of watermelon seedlings increased by 3.2% respectively;2. The coated organic fertilizer was meet demand in plant was it supplied by its constant release nutrient. In the course of growth of the plants, especially the later period, had promoted the absorption of the nutrient of plants: the content of chlorophyll, Pn, NR activity, root activity of T7 was higher than the treatment of nutrient solution.3. Organic fertilizer promoted the anti-cold performance of seedlings. when adding organic fertilizer by 25%,electrolyte leakage is the least and the osmoregulation substance is the most. When adding organic fertilizer by 15%,20%, its electrolyte leakage and osmoregulation substance compared with nutrient solution no obvious difference. The treatment of 5% and 10% are the poorest. 4. Organic fertilizer has the function of controlling nutrient release, so basal application controlled-release fertilizer in seedlings could meet the nutrient demand of whole period of watermelon. Seeing from nutrient absorbing of plant organs, accumulation of N, P, K absorption for the treatment of adding 25% organic fertilizer was the highest, when the rate of N, P, K organic fertilizer reduced by 15%, 20%, watermelon still had better growth. Seeing from N utilization, organic fertilizer improved vegetable N absorbing and N use efficiency, quantity of organic fertilizer was applied more fewer and N utilization more higher, Besides, organic fertilizer improved vegetable P and K absorbing and use efficiency, that indicated organic fertilizer play a role on the interaction of N, P, K.