Effect Of Intercropping Radix Isatidis On Winter Wheat Growth And CH₄ Flux

With the increasing demand for food and dietary food structure change, it is expected that the greenhouse gas emissions in global agricultural fields will show an increasing trend in future; therefore, active measures taken to curb emissions are of great importance for the development of ecological agriculture, the reduction of agricultural pollution and greenhouse gas emissions.In the investigation, reducing CH4 by winter wheat intercropping with Radix Isatidis, was carried out at the agrometeorological experiment station of Nanjing University of Information Science and Technology, using a static box (black box)-gas chromatography to regularly sample and analyze of CH4 flux in the duration of the wheat field. Meanwhile, the related parameters of wheat plant under different treatments were determined. The lab static-culture experiments were conducted based on gradient temperatures, moistures and root secretions of Radix Isatidis, so as to investigate the effect of environmental factors and root exudations on CH4 flux. The key conclusions were listed as follows:(1) Compared with NPKW (compound fertilizer+wheat), the yield, thousand-grain weight, ear length, ear weight, total grain number and plump grain number of wheat under NPKWR(compound fertilizer+wheat+Radix Isatidis,) were respectively increased by 9%,1%,13%,39%,29.2% and 28.6%. The CH4 flux of winter wheat field indicated soil absorption, tendency was NPKWR> N0P0K0W(no compound fertilizer+wheat)> NPKW. The soil CH4 absorption in the treatment NPKWR was cumulatively increased by 34% compared with that in the treatment NPKW, this intercropping type of wheat and Radix Isatidis brought a 5% increase in their integrated production, which increased by 2017.25 RMB·hm-2 in economic income.(2) The CH4 flux of static culture-flask soil under different environmental factors were demonstrated as follows:the CH4 emissions with the increasing temperatures of 10℃,20℃,30℃,40℃ and 50℃ showed a decreasing trend after the first increase, and it was the maximal content of CH4 at the temperature of 40℃; the best moisture condition of CH4 emission in this study was in the range of 60%-80% soil moisture content; Adding 0.2ml,0.4ml,0.8ml and 1.6ml root exudates of Radix Isatidis in 1000g soil can reduce 64.6%,105.7%,124.3% and 180.6% for CH4 emissions.This work showed that the winter wheat intercropping with Radix Isatidis was economical and environment-friendly. It increased economic benefits and absorption promotion of CH4 in fields, and thus relatively decreasing CH4 emissions, economically and environmentally, which was significant for the utilization of land resource, the economic increasing and the development of low carbon agriculture.