Effects Of Straw Deep-Buried On Soil Nutrient Leaching And Crop Growth

As a big agricultural country, straw is abundant in China. Several hundred million tons straw is produced every year. A lot of straw combustion caused a huge waste of resources and environmental pollution Straw concentrate deep-buried can be an effective long-term storage of straw organic matter in the soil, and avoid pollution and waste caused by straw burning.But the study on straw deep-buried has just begun. A pot culture experiment was conducted in Nanjing from2010to2011to study the effects of SDBR on nitrogen leaching, phosphorus leaching, and crop growth. Seven treatments, different buried depth with the5kg/m2buried amount:H1:20cm depth, H2(L1):35cm depth, H3:50cm depth; setting different buried amount with the35cm buried depth:L1:5kg/m2amount, L2:10kg/m2amount, L3:15kg/m2amount and CK:no straw return,were conducted under barreled experiments. In order to improve the straw deep-buried system. Experiments routinely collected by the pelvic floor leakage water seepage water, analysised nutrient concentration, and the analysis production structure in the mature crop test species.The main achievements of this study are as following:1. Effects of straw deep-buried on the impact of soil nitrogen leachingThe first season (rice):Wheat-straw deep-buried returning increased the amount of soil moisture leakage, and the more wheat-straw was buried, the greater leakage was.But treatments of different buried depth with the same buried amount didn’t show difference. The treatment of20and35cm could significantly reduce the leakage of rice, and daily average nitrogen content of the water, was reduced by19.58%and17.20%, and nitrogen retention rate increase by7.35%and10.90%.The second season (wheat):Wheat-straw deep-buried returning increased the amount of soil moisture leakage, and the more wheat-straw was buried, the greater leakage was.But treatments of different buried depth with the same buried amount didn’t show difference.In the whole growth period of wheat, under the conditions of the same depth, the greater the amount straw was buried, the leakage of water daily average nitrogen content was smaller. The treatment of5、10and15kg/m2could significantly reduce the leakage of rice, and daily average nitrogen content of the water, was reduced by20.52%、40.72%and47.25%, and nitrogen retention rate increase by8.61%、14.8%and9.05%. When the amount of the buried-straw is5kg/m2, depth treatments had no affect of the amount of leakage.The third season (rice):Wheat-straw deep-buried returning increased the amount of soil moisture leakage, and the more wheat-straw was buried, the greater leakage was.But treatments of different buried depth with the same buried amount didn’t show difference. The treatment of20and35cm could significantly reduce the leakage of rice, and daily average nitrogen content of the water, was reduced by3.91%and12.47%. Rice nitrogen leaching nitrate based.2. Effects of straw deep-buried return on the impact on phosphorus leachingWheat-straw deep-buried returning increased the amount of soil moisture leakage, and the more wheat-straw was buried, the greater leakage was.But treatments of different buried depth with the same buried amount didn’t show difference. The treatment of20and35cm could significantly reduce the leakage of rice, and daily average phosphorus content of the water, was reduced by19.98and27.74%, and phosphorus retention rate increase by17.24%and6.55%.The second season (wheat):Wheat-straw deep-buried returning increased the amount of soil moisture leakage, and the more wheat-straw was buried, the greater leakage was.But treatments of different buried depth with the same buried amount didn’t show difference. The treatment of20and35cm e was no significant difference with CK on containing phosphorus of leakage water.3. Effects of straw deep-buried return on the impact on crop growthThe first season (rice):The treatment of20and35cm buried depth can significantly improve the rice plant height, and the treatment of35cm increased by9.27%compared with CK; and the relative content of chlorophyll was also increased; tillers of the treatment of35cm was increased by1.13/hole compared with CK, and the yield of the treatment of35cm was increased by9.27%compared with CK. The second season (wheat):Significant difference of plant height was not observed between different treatments. In the depth was35cm, tillering was increased by0.5/hole compared with CK. The treatment of15kg/m2could significantly increase in leaf chlorophyll. Yield of the treatment of35cm was increased by4.5%compared with CK.