Mechanisms Of High Yield Spring Maize For Improving Yield And Efficiency Under Trip Deep Totary Tillage And Different Nitrogen Fertilizer Application Levels

In the high density planting condition, the experiment stdied the effects of two trip deep totary tillage (TX and GTX) on the characteristics of soil structure, root, leaf senescence, nitrogen fertilizer absorption and utilization, so make it clear that the improving yield and efficiency mechanisms of absorption and utilization on the spring maize under the trip deep totary tillage. The main results are as follows,(1)Trip deep totary tillage broke the plough layer effectively, and reduced the soil compaction and unit weight under0-30cm soil layer, and accelerated the moving of soil nitrate nitrogen. Trip deep totary tillage increased the density distribution of root weight, root length, superficial area under15-60cm soil layer, and made the root more slender and longer, so density maximum of root length and superficial area move down the15-30cm soil layer. The leaf area index(LAI), Pn, Fv/Fm and SPAD value of trip deep totary tillage were higher at silking stage. From silking stage to30days after sliking, LAI of trip deep totary tillage reduced more slowly, and Pn, Fv/Fm, SPAD value of trip deep totary tillage maintained higher level at the later stage, so lowerd leaf senescence. GTX than TX is better.(2)Trip deep totary tillage promoted above-ground dry matter accumulation, improved absorption and utilization rate of nitrogen significant increased TKW (Thousand Kernel Weight) and kernels per spike. in addition, TXå’ŒGTX improved yield by19.68%and24.35%. GTX than TX is better.(3)The grain nitrogen content of N30is the highest under trip deep totary tillage of different nitrogen levels. In the same fertilizer application level condition, GTX could incerased the nitrogen content than TX at different stages, but as the increasing nitrogen fertilizer application level, the grain nitrogen content is decreasing, and stem nitrogen content accumulate largely. Nitrogen accumulation amount is the largest between flare opening and silking stage, and the most is N30. Compared with TX-N20, GTX-N20increased the nitrogen content before sliking. GTX-N30and GTX-N40added showed increasing at different stage compared with TX-N30and TX-N40respectively. N uptake efficiency, N fertilizer efficiency and N use efficiency is reducing gradually. N30has highly N utilization efficiency and N harvest index. Compared with TX, Not more than N30GTX is advantageous to the nitrogen absorption and utilization, so made the grain nitrogen content, N utilization efficiency and N harvest index of N20and N30increasing, but if more than N30it will reduced the nitrogen absorption and utilization.(4)Under trip deep totary tillage of different nitrogen levels,. N30has highly TKW, kernels per spike, and yield. Compared with TX, GTX improved TKW, kernels per spike, and yield. N20is outstanding. The yield of GTX-N40is reduced.