Nitrogen Release Characteristics Of Bag Controlled Release Fertilizer And Its Effect On Phyllostachys Violascens Growth

Bag controlled release fertilizer is a new type of controlled release fertilizer designed according to the demand characteristics of crops.A bag is used to control the release of nutrients by puncturing several micro-holes that is different from the coated fertilizers.Nitrogen release characteristics and the mechanism of nitrogen loss of bag controlled release fertilizer was studied in laboratory.The effect of bag controlled release fertilizer on soil nutrients and physiological and biochemical indicators of Phyllostachys violascens was also studied in field.It is expected that we can provide theoretical and technical support for the use of fertilizer bag controlled-release technology to increase N fertilizer utilization and the sustainable management of Phyllostachys violascens.The main obtain results were listed as follows:Nitrogen release characteristic of bag controlled release fertilizer was evaluated by water extraction method.Nitrogen release rate was determined by the row number of micro-hole,when the mass of nitrogen is equivalent.The more rows of micro-hole the bag have the faster nitrogen release rate is.Smaller amount of nitrogen in bag released faster than the heavy one,with the same rows of micro-hole in bag.Corn starch bag owns better control release performance than waxed kraft paper bag under the same condition.Nitrogen release characteristics of urea fertilizers in bag was investigated by a batch of soil column leaching experiments.In the first time of leaching,the percentage of released nitrogen of urea treatment was 23.38% while corn starch bag puncturing 1,3,5 and 7 rows number hole controlled release fertilizer?B-1,B-3,B-5,B-7?and B-W?kraft paper bag double-sided wax coated controlled release fertilizer?treatments were 0.98%,0.94%,1.07%,1.13% and 2.69%,respectively.For these bag controlled release fertilizer,whose percentage of released nitrogen from the first leach solution are far below the general requirement of slow release fertilizer whose initial dissolution rate is 15%.However,due to the B-W has an excessive amount of nitrogen released in the early stage,corn starch bag puncturing micro-hole controlled release fertilizer has better sustained release performance.Estimated time of turn point of nitrogen accumulation release according to the Logistics equation N=a/(1+e^-k?t-t_c?) was delayed,which showed a significant hysteresis in N release.The results of simulated ammonia volatilization test with the same nitrogen doses showed that the cumulative nitrogen loss from ammonia volatilization of B-1,B-3,B-5,B-7,and B-W5 were lower by 23.78%,18.21%,16.82 %,13.46% and 17.81%,respectively,whose nitrogen loss was significantly less than the urea treatment?P<0.05?.The amount of ammonia volatilization loss from B-W was significantly higher than that of other bag controlled release fertilizers,whose sustained release properties needs to be further improved.A corn starch bag used to control the release of nutrients by puncturing several micro-holes can decrease ammonia volatilization rate,reduce ammonia volatile ization loss,and it is feasible for bag controlled release fertilizer to be applied in practical production.The results of the field experiment showed that when the amount of fertilizer is equivalent,the corn starch bag controlled release fertilizer can maintain a stable nitrogen content in soil.The controlled release fertilizer bags are punctured with 1 and 3 row holes respectively could significantly increase the chlorophyll content of leaves,improve the photosynthetic performance,increase the activity of nitrate reductase glutamine synthetase and promote the nitrogen metabolism.The bag controlled release fertilizer was benefit for the absorption and utilization of nutrients by plants,that leading to a significant increase in nitrogen content and soluble protein content in leaves.Among them,bag puncturing 3 rows micro-hole controlled-release fertilizers own the best performance.According to the study,it can be observed that bag controlled release fertilizer can effectively control the release rate of nutrients,reduce nutrient leaching and ammonia volatilization losses,and can maintain the relative stability of nitrogen content in soil,which is beneficial to the absorption and utilization by plants.Due to the limitation of time,the effect of bag-controlled slow-release fertilizer merits a further study.Moreover,the amount of bag controlled release fertilizer application needs to be further explored as well for meeting the actual production.