Effects Of Tillage Methods On The Soil Properties And Maize Growth

The soil quality influences on the crop yield and agricultural sustainable development.Meanwhile,the tillage layer of crop field was improved by agricultural machine and equipment to adjust the relationship of soil water content,temperature,air and nutrients.With the innovation of agricultural production and popularization of agricultural machine,the rational tillage system was unknown for constructing the optimal tillage layer structure,adjusting the soil three-phrase,enhancing the maize growth and improving maize yield.So,the research area was part of a testing site of the Jilin Academy of Agricultural Sciences in Gongzhuling,in Jinlin Province of China（43°45′N,125°01′E）and the experiment began in1983 and involved four methods of tillage–MP,ST,and CT,with NT as a control–laid out in randomized block design with three replications.The study would be completed by combination of field experiment and laboratory test analysis to ascertain the effects different tillage systems on soil properties and maize growth from aspect of soil and crop and offer the optimal tillage system for enhancing the sustainable development of northeast agricultural production in China.The main results were drawn as follows:Spacing tillage declined the field soil hardness and improved the soil tillage layer environment.In addition,the alternative change of freeze and thaw also enhanced the decline of soil compaction.The soil bulk density of different tillage systems changed with the seasonal change and increase with depth of soil,the change trend was very obvious from 0cm to 30cm,however,the change was disappear under 30cm of soil layer.Moreover,seasonal freeze and thaw declined soil bulk density and soil bulk density after freeze and thaw was less than before.Soil total porosity changed with change of season and soil total porosity earlier stage was lower than later.Meanwhile,Soil total porosity of different tillage systems decreased with depth of soil layer.The change of soil total porosity was very obvious from0cm to 30cm;however,it was not obvious under 30cm.Furthermore,seasonal freeze and thaw could increases soil porosity and soil porosity after freeze and thaw were more than earlier stage under different tillage systems.Specially,spacing tillage not only enhanced the increase of total porosity of upper field soil but also did lower.Soil temperature of different tillage systems declined with depth of soil layer and it was higher upper than lower significantly.Although soil temperature was lower at earlier,soil temperature escalated with the progress of growth and then soil temperature starts to decline slowly with growth.Moreover,soil temperature of on tillage is lower than other tillage systems;difference of other tillage systems is not significant.The liquid of different tillage systems is higher than solid in spring,however,soil solid declines and soil gas increases.Furthermore,soil three-phrase very stable from seeding stage to jointing stage,the trend is solid>liquid>gas.Soil solid is increased and soil liquid decreased,however,soil gas significant is increased at flowering.In addition,the freeze-thaw enhances solid less and make liquid and air increase.However,it is not significant under tillage layer.No-tillage and spacing tillage enhanced the accumulation of soil total N and increasing from 18.7%to 32.0%than other plow tillage and conventional tillage.Moreover,spacing tillage increased the content of soil total P and the trend was higher than other treatments.The total K increased with release of year under spacing and no tillage.However,the total K of plow tillage and conventional tillage declined at earlier stage and then increases at later.The available N content increased from 99.24 mg/kg to 131.51 mg/kg under plow and no tillage.The available P of spacing tillage and no tillage were higher than plow and conventional tillage and increase with land use.Furth more,spacing and no tillage improved the content of available K and the soil available K are recovered by tillage systems.Soil NH₄⁺-N content increased with depth of soil layer and there are different at different stage.The increase of spacing tillage was from 46.87%to 173.47%than other tillage in 0-60cm soil profile.Meanwhile,the content of NO₃^--N was improved under spacing tillage.The relationship was very significant between yield and nutrient traits.Moreover,it was at P≤0.05 significantly between yield and total K and there were at P≤0.01 significantly between yield and SOC,available N and NH₄⁺-N.So,these traits were key factors that effects on maize yield.Spacing tillage and no tillage increased soil bacteria,fungi and actinomycetes,meanwhile,decreased soil respiration rate significantly.Moreover,there was significant relationship between soil temperature and respiration rate.So,conservative tillage could increase the number of soil microorganism.Furthermore,soil microorganism enhanced to transfer organic carbon in straw to soil organic matter in order to improve soil fertility and enhance the agricultural sustainable development.Soil water content of different tillage systems decreased with depth of soil layer and the trend was obvious under 40cm.Moreover,seasonal change of soil water content was impacted by precipitation significantly.In addition,soil freeze-thaw declines the soil water content and soil water content increased from 0.93%to 2.23%with comparison with other tillage.Soil water storage increased at earlier stage and then decreases with development of maize growth.Furthermore,soil water storage at earlier stage was higher than later significantly.Field water consumption and water consumption coefficient were not different among tillage systems.However,spacing tillage improved the water use efficiency.In addition,although there was not significant correlation between yield and water use efficiency,there was significant negative correlation between water use efficiency and soil water storage before planting field water consumption,water consumption coefficient and precipitation during maize growth.Spacing tillage and no tillage improved the soil structure and enhance the water aggregation stability.Furthermore,these tillage systems increased aggregation carbon content and storage.However,plow tillage and conventional broke water stable macro-aggregation and increased the number of micro-aggregation.Long term conservative tillage could improve the content of water stable macro-aggregation and mean weight diameter（MWD）and improve the macro-aggregation organic carbon content and storage.Moreover,spacing tillage increased the soil aggregation in deep soil layer and improves water stable macro-aggregation.Meanwhile,spacing tillage increases soil organic carbon content and enhances new soil carbon accumulation in the macro-aggregation.There was significant relationship between different particle aggregations and soil organic carbon and there are lots of soil organic carbon in1-2mm and 0.25-1mm aggregation.The emergency rate was improved from 11.3%to 14.6%by spacing tillage and significantly maize leaf area.Meanwhile,spacing tillage enhanced the seeding growth and improved the stem characters.In addition,spacing tillage enhanced the growth of maize root and increased 16.8 with comparison of other tillage.Moreover,aerial root under spacing tillage were increased 0.8 layers.Spacing tillage significantly improved maize dry matter weight that was increased from 4.96%to 19.27%with comparison of other tillage.Besides,root dry weight of spacing tillage was increased from 2.88%to 90.13%with comparison of other tillage.There was the highest photosynthetic rate at top 5 and 9 leaves and SPAD was increased by10.53%under spacing tillage.Moreover,maize under spacing tillage could be able to utilize the PPFD and CO2.Meanwhile,spacing tillage could improve maize physiological characters and specific leaf weight and increase the content soluble sugar and protein.In addition,spacing tillage could decline the content of MDA and delay the aging process of maize leaf.So,spacing tillage can make maize yield improve from 11.79%to12.28%with comparison of other tillage.