The Regulation Of Yield And Root Formations Through Different Tillage And Density Treatments

Tillage and density are important factors that affect yield of corn.The present experiment was carried out at the Gongzhuling Experimental Station of the Jilin Academy of Agricultural Science.The current main corn variety,Xiangyu 998,was selected,and four kinds of cultivation methods,including traditional rotary tillage（CT）,deep-sown（ST）,no-tillage（NT）and deep-turning（PT）were used.Addtionally two planting densities of 60,000 plants/hm²（D1）and 90,000 plants/hm²（D2）were adopted,for a total of eight treatments.Through the study of maize yield,photosynthetic performance,soil properties and root growth under different tillage and density conditions,the appropriate local farming methods and planting densities were identified.These results indicated that the maximum yield was 12934.26 kg/hm² of no-tillage treatment,when the density was 60,000 plants/hm².When the density was 90,000 plants/hm²,the highest yield was 13105.78 kg/hm² of deep-turning treatment,and no-tillage treatment always showed a high level of yield,which was the least affected by the density factor,and the yield was relatively stable.With the increase of the density,only the deep-turning treatment could increased the yield,and obtained the highest yield in high-density planting.At a density of 60,000 plants/hm²,no-tillage treatment showed that the contribution of dry matter accumulation to the grain at the early stage of silking was significantly higher than that of other tillage methods.At a density of 90,000 plants/hm²,deep-turning treatment showed that the contribution of dry matter accumulation to the grain was significantly higher than that of other tillage methods.With the increase of the density,the dry matter accumulation,dry matter accumulation rate and the contribution of dry matter accumulation to the grain of the four kinds of ploughing methods all reduced,and it was more significant in the early stage of silking.The overall change trend of grain filling rate in maize was consistent with that of single-peak curve changes.The contents of chlorophyll a,chlorophyll b,chlorophyll,and carotenoids in different tillage patterns were as follows:deep turning>no-tillage>rotary tillage>deep-sown.With the increasing of the density,only the chlorophyll content of no-tillage and deep-turn treatment increased.As a result,In addition to the increase in chlorophyll content in no-tillage and deep-turn treatment,the contents of chlorophyll a,chlorophyll b,chlorophyll,and carotenoids in all cultivation practices decreased to varying degrees.Net photosynthetic rate（Pn）,Stomatal conductance（Gs）and Transpiration rate（Tr）showed a decreasing trend from silking stage to late fertility stage,The changes in intercellular CO₂concentration（Ci）and instantaneous moisture utilization efficiency（WUE）were consistent,showing a trend of decreasing first and then increasing.The trend was also consistent,showed a trend of falling first and then rising.Among them,Pn and the Leaf area index of the deep-turn treatment were always at a relatively high level.The POD,CAT,SOD activity and soluble protein content in leaves under no-tillage and deep-rotation treatment were higher.With the increasing of the density,POD,CAT,SOD and soluble protein content in the ear positions of corn under different tillage methods showed increase or decrease trend.At the same density,the Fo and Fv of the deep-rotation treatment were significantly lower than those of the rotary tillage and the deep-sown treatment,followed by the no-tillage treatment,and there was no significant difference in Fv/F0 and Fv/Fm between the four farming methods.Under the same density conditions,the total root dry weight of maize population increased with the progress of fertility in different treatments,and the root length and root surface area showed a trend of increasing first and then decreasing.Under the same tillage method,with the increase of the density,the root weight increased at the filling stage,and the root length and root surface area decreased.The no-tillage treatment had the smallest increase in root weight,and the root length and root surface area had the smallest decrease.The overall performance is that the total root weight,root length,and surface area of the no-tillage maize population are significantly higher than other tillage methods,and their impact on planting density is less than other treatments.