Effects Of Different Mulching Methods And Fertilization On The Growth Of Spring Wheat And Change Of Inorganic Nitrogen In Dryland

The cultivation of full-membrane-covered soil in dryland is another major new dryland farming technology following the full-membrane double-furrow planting technology.This technology can effectively improve soil water and heat conditions because of its ability to collect rain and suppress steam,conserve water,increase temperature and security,reducing the damage of crops caused by low temperature and drought in spring,significantly increasing crop yields.So it is being widely promoted.Although there are a lot of relevant research reports on this technology in recent years,it is more common in its cultivation techniques and yield increase effects.There is still a lack of systematic research on its specific mechanism for increasing production,especially Changes for the soil hydrothermal environment caused by full-film mulching,impacts on soil organic nitrogen mineralization and changes in dry matter accumulation laws.There are two trials in this study.Experiment I:Positioning test of wheat with three cover types:full-membrane-covered soil?M2?,conventional plastic film cover?M1?and open field?M0?,organic fertilizer plus fertilizer application?F3?,and pure organic fertilizer?F2?The four fertilization treatments for pure chemical fertilizer?F1?and no fertilization?F0?were performed with completely randomized block settings.There were a total of 12 treatments,namely F0M0,F0M1,F0M2,F1M0,F1M1,F1M2,F2M0,and F2M1.F2M2,F3M0,F3M1 and F3M2.They were used to determine the soil moisture content,water use efficiency,wheat yield and inorganic nitrogen content in the soil after harvest.In the second experiment,based on the wheat location test,three types of covering methods?F2?,M2,M1 and M0.F1M0,F1M1,and F1M2 were selected under the application of chemical fertilizer?F1?to survey soil temperature,moisture,and soil nitrogen mineralization.Effects of soil moisture and soil environment on nitrogen mineralization in soil moisture content,soil inorganic nitrogen residual wheat yield,water use efficiency,wheat yield components,and soil erosion by full-membrane cover soil sowing Impact.The result is as follows:1.Coverage treatment significantly increased the average soil temperature in the 0²0cm soil layers during the early and late wheat growth period,and showed a“U”pattern during the entire growth period of wheat growth.Compared with open field,The average soil temperature increased by 1.7°C and 1.1°C during the entire growth period for both the full-film soil and the conventional plastic film.Different coverage methods have different effects on soil temperature in different wheat growth stages.Wheat in the early growth stage showed full-film soil cover>conventional plastic film cover>open soil,and the filling stage and maturity stage showed traditional plastic film cover>full-film soil cover>open field;The temperature increase effect of the whole membrane cover soil and the traditional plastic film cover is the most obvious.The accumulated soil temperature in the 0²5cm soil layer increased by 7.6°C and 8.6°C,respectively;and the cover treatment has the effect of varying degrees of stable ground temperature,mainly manifested in 8:00 am and20:00 pm Positive temperature rise and fall phase is conducive to warming and warming of farmland soil.2.Soil nitrogen in the 0¹5cm soil layer of the dry-cultivated wheat under different coverage conditions during the entire growth period showed net mineralization.But,the performance of soil nitrogen mineralization varies at different time periods.Fertilization only affected the soil nitrogen mineralization in the first stage?0¹5 days?after wheat sowing.The overall performance is that the net mineralization is from 0¹5 days after sowing,and the net retention is mainly from16⁶2 days,and the net mineralization is mainly from 63¹16 days.During the whole growth period of wheat growth,the total mineralization of the film,traditional plastic film and open land was 27.52mg/kg,26.55mg/kg and 14.70mg/kg,respectively,the net retention was 27.02mg/kg,14.25 mg/kg and 12.27 mg/kg;the rate of net mineralization of the whole membrane soil cover,conventional plastic film cover and open soil was 1.83 mg/kg·d^-1,1.77 mg/kg·d^-1 and 0.98 mg/kg.d^-1.The net retention rates were 1.80 mg/kg·d^-1,0.95 mg/kg·d^-1and 0.85 mg/kg·d^-1,respectively.Coverage treatment significantly increased soil mineralization and mineralization rates in the0-15 soil layer.3.Plastic film coverage and fertilization have significant effects on the inorganic inorganic nitrogen content in the vertical section from 0²00 cm.At the same fertilization level,the covering treatment significantly increased the inorganic nitrogen content in the shallow layer?0⁶0 cm?,reduced the inorganic nitrogen content in the deep layer?80²00 cm?,and was consistent with the variation of NO₃-N content.The total film soil cover and conventional film cover significantly increased soil inorganic nitrogen content in soil layers from 0⁶0 cm,which increased 17.81 mg/kg and 4.47 mg/kg,respectively,compared to exposed land.Soil inorganic nitrogen content at 80¹00 cm decreased by 63.56 mg/kg and 60.24mg/kg compared with exposed land.Under the same covering pattern,the soil inorganic nitrogen content in organic fertilizer+chemical fertilizer treatment and chemical fertilizer treatment 0⁶0cm soil layer was much higher than organic fertilizer and no fertilizer treatment,which increased by 45.07¹25.61mg/kg and 44.41⁸7.18respectively compared with no fertilizer application.There was no significant difference between different fertilization treatments in mg/kg and 80²00cm,and the inorganic nitrogen content in 0²00cm soil layer had no regular change among treatments.4.Plastic film coverage and fertilization all had significant effects on wheat yield and grain water use efficiency.The average yield and water use efficiency of the whole membrane soil cover under the three cover patterns were the highest,being3875 kg/?mm·hm²?and 15.14 kg/?mm·hm²?.Compared with the non-film treatment?exposed areas?,it increased by 65.26%and 46.46%,respectively.Under the four fertilization methods,wheat yield and grain water use efficiency were the highest,which were 3498 kg/?mm·hm²?and 14.92 kg/?mm·hm²?,respectively,which were increased by 20.97%and 29.10%respectively compared to the non-fertilization treatment?exposed land?.Under the interaction of covering and fertilizing,the total film-covered soil cultivation methods and organic fertilizer plus chemical fertilizer treatments significantly increased wheat yield and grain water use efficiency compared with other treatments,with the lowest exposure to open soil and no fertilizer application.5.Both plastic mulching and fertilization could optimize wheat whole plant weight,plant height,panicle length,panicle weight,number of spikelets,number of panicles and agronomic traits of panicle weight.