| Dry farming(rainfed)agricultural areas are the most important grain production bases in my country.Ensuring the high efficiency and stability of corn production in this area is of great significance to ensure food security in my country.The traditional plowing measures adopted for a long time in this area will damage the soil structure,which will lead to the decline of farmland soil quality,soil erosion and other problems.Conservation tillage represented by no-tillage and deep loosening can improve soil structure,improve soil quality,and ensure the stability of grain production.However,under rain-fed conditions,the effects of long-term straw returning conservation tillage measures on soil structure and maize growth and development need further study.Therefore,this study was based on a long-term tillage trial(Northwest Agriculture and Forestry University,North Campus West)that started in 2009,with summer maize in two production years 2021-2022,to investigate the effects of conservation tillage practices(chisel plow tillage: CPT;zero tillage: ZT)and traditional tillage practices(plow tillage: PT)on soil structure,moisture and nutrients and summer maize physiology and growth.The study investigates the effects of long-term conservation tillage on the soil structure and physiology and growth of summer maize,and provides a theoretical basis for the promotion of conservation tillage in dry agricultural areas.The main findings of this paper are as follows:(1)Long-term conservation tillage improved the physical structure and nutrient status of the soil.Compared to PT,CPT and ZT significantly(P<0.05)enhanced the proportion of large aggregates(28.18%-140.36% and 46.72%-53.42%),water stability of aggregates(40.41%-46.72% and 46.72%-53.42%)and physical Stress resistance(46.31%-83.04% and 74.22%-79.79%),and the proportion of large agglomerates and soil structural stability decreased with increasing soil depth;soil organic carbon content and soil total nitrogen content significantly increased by33.69%-51.79% and 18.99%-60.01% under CPT and ZT treatments,respectively,compared to PT,and their contents were significantly and positively correlated with soil structural stability were significantly positively correlated(P<0.05).(2)Long-term conservation tillage alters soil moisture and nutrient status during summer maize growth.Compared to PT,CPT and ZT treatments significantly(P<0.05)elevated increased soil moisture content in 0-20 cm soil(7.09%-16.81% and7.30%-15.34%),increased water infiltration capacity,increased soil water storage in0-200 cm soil during late summer maize growth(R1-R3)(4.13%-4.14% and 2.75%-5.63%)and significantly increased the inter-root soil nitrate-ammonium nitrogen content(17.62%-89.48%)in different fertility periods of summer maize.(3)Long-term conservation tillage improved the physiological growth of summer maize in different rainfall years,increased the photosynthetic leaf area(9.12%-15.90%),improved the resistance of summer maize to drought stress,and increased the dry matter accumulation(10.24 %-127.98%).At the same time,conservation tillage enhanced the stability of summer maize yields and economic benefits.Yield under normal weather conditions(2021 growing season)did not differ significantly from tillage relative to PT,but significantly increased crop seed yield(CPT: 15.78%;ZT: 10.59%)and harvest index(CPT: 40.23%;ZT: 28.58%)under relatively dry weather(2022 growing season);in addition,conservation tillage has higher and more stable net returns,with CPT and ZT increasing by 25.49% and 25.21%respectively compared to PT.Considering the sustainability and stability of agricultural production,conservation tillage may be an excellent alternative to traditional tillage practices in the dry farming areas of northern China.In summary,in dryland agricultural areas,conservation tillage can effectively improve soil structure,improve soil structure stability,increase soil moisture and nutrient content and optimize their distribution;at the same time,conservation tillage can increase maize yield in dry climates And harvest index,improve economic benefits.Therefore,conservation tillage has a positive impact on the stability and sustainable development of summer maize production in dryland agricultural areas.In this area,conservation tillage can be considered to partially replace traditional plowing,improve soil quality,and ensure stable agricultural production. |
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