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Effects Of Water And Nitrogen Application On Resources Utilization Of Wheat After No-till Plastic Film Mulching Maize

Posted on:2019-06-03Degree:MasterType:Thesis
Country:ChinaCandidate:Y GuoFull Text:PDF
GTID:2333330563455542Subject:Crop Cultivation and Farming System
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There is lack of academic and technical basis on water-nitrogen coupling in crop production,it has led to a great short slab on water-fertilizer saving technology through the integrated application of crop rotation,no-tillage and two-year of plastic mulching.A field experiment was conducted to investigate the dynamics on water and nitrogen use during the entire growth stage under two kinds tillage practices on maize stubble managements(NT: no tillage with two-year plastic film mulching of previous maize stubble;CT: conventional tillage),two irrigation levels(I2: conventional irrigation level;I1: conventional irrigation is reduced 20%)and three nitrogen levels(N3: conventional nitrogen level;N2: conventional nitrogen is reduced 20%;N1: conventional nitrogen is reduced 40%).The purpose of the study focused on providing academic and practical evidence for high-efficient use of water and nitrogen through optimizing managements of previous stubble.The purpose of this study is to reveal the mechanism of water and nitrogen utilization in response to the two-year of plastic mulching combined to water-nitrogen coupling and crop rotation techniques.It also provided theoretical and technical basis for the efficient utilization technology of water and nitrogen for wheat production under the integrated techniques on no-tillage,crop rotation and plastic mulching.The main results are follows:1.No tillage with plastic mulching of previous maize stubble(NT practice)significantly enhanced grain yield of wheat,and water-nitrogen coupling pattern further improved grain yield of wheat with NT practice,compared to conventional tillage(CT practice).Grain yield of wheat with NT practice was boosted by 10.4% over CT practice.The decreasing of 20% irrigation level(I1)boosted grain yield by 2.4% over the traditional high irrigation level(I2).Similarly,traditional high level(N1)and the decreasing of 20% nitrogen level(N2)increased grain yield of wheat by 12.9% and 15.8% over the decreasing of 40% nitrogen level(N2)level,respectively.NT practice integrated with the decreasing of 20% irrigation and 20% nitrogen techniques(NTI1N2 treatment)had greater grain yield by 15.2% than conventional tillage with high irrigation and nitrogen application levels(CTI2N3 treatment).2.No tillage with plastic mulching of previous maize stubble(NT practice)reduced soil evaporation(E),evapotranspiration(ET),and the ratio of evaporation to evapotranspiration(E/ET)of wheat field,and water-nitrogen coupling pattern further strengthened the effect of saving water for wheat field under NT practice.Although NT practice had no significant effect on decreasing evapotranspiration in comparison to CT practice,NT practice integrated with the reduction of irrigation and nitrogen application have the significant effect on reducing evapotranspiration,compared to CTI2N3 treatment,NTI1N2 and treatments reduced evapotranspiration by 4.3% and 11.3%,respectively.NT practice reduced soil evaporation(E)by 16.2% over CT practice.The I1 level reduced soil evaporation by 10.6% over the I2 level.Similarly,the N2 supply level reduced soil evaporation by 6.2% over the N1.Compared to CTI2N3 treatment,NTI1N2 and NTI1N1 treatments reduced E by 28.4% and 35.6%,respectively.Meanwhile,NT practice reduced the ratio of evaporation to evapotranspiration(E/ET)by 14.9% of the following wheat field over CT practice.Similarly,the I2 level reduced E/ET ratio by 6.7% over the I1 level,N2 application level reduced E/ET ratio by 5.6% over the N1 level.Compared to CTI2N3 treatment,NTI1N2 and NTI1N1 treatment reduced E/ET ratio by 25.1% and 27.4%,respectively.The above results indicated that no-tillage with two-year plastic mulching of previous maize stubble had the potential of water-saving,and water-nitrogen coupling pattern further strengthened the effect of watersaving for wheat field under NT practice.3.No tillage with plastic mulching of previous maize stubble(NT practice)had the obvious saving nitrogen effect,and water-nitrogen coupling pattern further strengthened the effect of saving nitrogen for wheat field under NT practice via reducing nitrogen leaching in the deep soil and ammonia volatilization of surface soil,thus,it can promote the uptake and accumulation of nitrogen for wheat plants.Although tillage practice,irrigation and nitrogen levels had no significant effect on soil total nitrogen,NT practice significantly decreased soil nitrate nitrogen content in the deep soil depth by 14.4% over CT practice.I1 level decreased soil nitrate nitrogen and ammonium nitrogen content in the deep soil depth by 7.2% and 12.5%,respectively,compared to I2 level.Similarly,N1 and N2 application levels reduced soil nitrate nitrogen by 45.6% and 26.1%,and reduced ammonium nitrogen content by 21.1% and 10.1% over the N3 level,respectively.Compared to CTI2N3 treatment,NTI1N2 treatment reduced nitrate nitrogen and ammonium nitrogen leaching content of 80 to 100 cm soil depth by 43.2% and 17.5%,respectively.NT practice reduced ammonia volatilization amount by 17.8% over CT practice.N2 level decreased ammonia volatilization amount by 29.1% over N3 level,but it increased by 49.0% over N1 supply level,respectively.The ammonia volatilization amount of NTI1N2 and NTI1N1 treatments was lower 42.0% and 61.0% than CTI2N3,respectively.NT practice increased nitrogen accumulation of wheat plant by 15.6% over CT practice,NTI1N2 treatment increased nitrogen accumulation and nitrogen harvest index by 16.0% and 10.0%,respectively,compared to CTI2N3 treatment.The results indicated that no-tillage with two-year plastic mulching of previous maize stubble had the potential of saving nitrogen,and water-nitrogen coupling pattern further strengthened the effect of saving nitrogen for wheat field under NT practice.4.No tillage with plastic mulching of previous maize stubble(NT)significantly enhanced water use efficiency and nitrogen partial productivity,and water-nitrogen coupling pattern further strengthened the effect of improving water and nitrogen use efficiency for wheat field under NT practice,compared to CT practice.NT practice increased water use efficiency(WUE)and nitrogen use efficiency(NUE)by 12.3% and 5.3%,over CT practice,respectively.I2 level had greater WUE by 9.7% than N1,and greater NUE by 5.8% than N3 level,respectively.NTI1N2 treatment had greater WUE and NUE by 20.4% and 8.4%,respectively,than those of CTI2N3 treatment.Overall,the integrated technique on no tillage with two-year of plastic mulching were application of reduced 20% irrigation and nitrogen levels is one of the efficient cropping systems of saving water and fertilizer for wheat production in the Oasis Irrigation regions,because the increasing-yield potential,higher economic and environmental benefits.
Keywords/Search Tags:Whole plastic-film mulching maize, No tillage, Water-nitrogen coupling, Crop rotation, Crop productivity, Water and nitrogen use efficiency
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