Effects Of Tillage With Mulching On Soil Physical Properties,Potato Yield And Efficient Use Of Water And Heat In Dryland

In order to clarify the effects of tillage with mulching on soil physical properties,potato yield and water and heat use efficiency in the arid regions of southern Ningxia,field positioning experiments were carried out from October 2020 to October 2021,and four tillage depths(ploughing tillage 15 cm(T15 cm)subsoiling 30 cm(T30),subsoiling 40 cm(T40)and subsoiling 50 cm(T50))and four types of mulching materials(no mulching(NM),mulching film(PM),degradable water permeable mulching film mulching(FM)and straw mulching(SM))were set up.Two-factor split-plot experiment with plastic film mulching(FM)and straw mulching(SM)was designed to study the effects of different tillage depths combined with mulching materials on soil bulk density,porosity,aggregate number,soil moisture,temperature,potato yield,water use efficiency and soil accumulated temperature use efficiency,and to provide theoretical basis and technical reference for the increase of dry farming potato yield and the efficient utilization of water and heat.Its main findings were as follows:(1)Tillage with mulching significantly improved soil physical properties during potato harvesting.Tillage mulching can significantly reduce soil bulk density in the 0-60 cm layer,and increase the total porosity and capillary porosity,especially in the 20-40 cm layer.T40×SM treatment has the best effect on improving soil bulk density,total porosity and capillary porosity.Compared with T15×NM treatment,the soil bulk density is significantly reduced by 12.69%,and the total soil porosity and capillary porosity are significantly improved.Degree 12.87%,7.80%.Both T40×SM and T30×SM treatments can significantly increase the number of mechanically and water-stable aggregates in the 0-40 cm layer>0.5 mm,and the interaction between tillage depth and mulching material was treated with T40×SM>0.25 mm.Mechanical and water stability The number of agglomerates is the highest.The interaction of tillage depth and mulching material had a very significant effect on soil compaction in the 0-40 cm layer of potato in the early stage of growth.(2)After fall and winter fallow,tillage and mulching had a significant effect on improving soil moisture in fallow period and growth period.At the end of the fallow period,the average soil water content of the 0-100 cm layer under the T40×SM treatment was the best,which was significantly increased by 26.96%compared with the T15×NM treatment.Under the same mulching material,the precipitation recharge rate was the highest in the T40 treatment,and the SM treatment was the highest under the same tillage depth.The interaction between the two treatments was the highest in the T40×SM treatment,followed by the T40×FM treatment,which were significantly increased by 106.14%and 73.61%compared with the T15×NM treatment,respectively.The effects of tillage depth and mulching material on the soil water storage in the 0-100 cm layer during the key growth period of potato(budding,tuber formation and tuber expansion)were extremely significant.Under the same mulching material,the average soil water storage in the potato growing period was the highest in the T40 treatment,followed by the T30 treatment;under different mulching materials,the SM treatment had the highest soil water storage in the potato growing period,followed by the FM treatment.T40×SM and T40×PM treatments had the best soil water storage effect in the early stage of growth,and the average soil water storage of T40×SM treatment was the highest in the middle and late stages of growth,which was significantly higher than that of T15×NM treatment by 11.49%.The interaction of tillage and mulching on water consumption in the middle and later stages of growth was extremely significant.Under the same mulching material,T15 treatment had higher water consumption in the early stage of growth,while T30 and T40 treatments were higher in the middle and late stage.Under the same tillage depth,the FM treatment in the early stage of potato growth consumes more water,and the SM treatment in the middle and late stage consumes more water.(3)Tillage with mulching can regulate the soil temperature of each layer of 0-25 cm,and the effect of soil temperature is significant in the layer of 0-5 cm.Tillage depth and mulching material have extremely significant effects on the average soil temperature of the 0-25 cm layer during the potato growth period.temperature has a significant effect.The soil temperature in the 0-25 cm layer of potato growth period was higher in the T40×SM treatment.Tillage depth,mulching material and their interaction had significant effects on soil effective accumulated temperature of potato at each growth stage.Under different tillage depths,T30 and T40 treatments had the highest soil effective accumulated temperature in the potato growth stage,and the mulching materials were higher in PM and FM treatments,while SM treatment had dual effects of stabilizing and cooling in the potato growth stage.The soil effective accumulated temperature in the two interactive growth stages was best treated with T40×SM.(4)Tillage depth,mulching material and their interaction had very significant levels on potato yield and number of tubers per plant.Under the same tillage depth,SM and FM treatments had higher potato yields.Under the same mulching material,T30 and T40 treatments had the best yields.In each treatment combination,T40×SM treatments had higher potato yields,number of tubers per plant,and single tuber quality.And the yield per plant was the highest,and the water use efficiency and soil temperature use efficiency were the highest in the T40×SM treatment.Through the correlation analysis of each index,it was concluded that soil moisture,temperature,aggregates and porosity all played an important role in improving potato yield and water and heat utilization efficiency.In conclusion,subsoiling 40 cm with straw mulching was beneficial to improve soil physical properties,increase the number of soil aggregates,reduce soil compaction during the growth period,achieve soil water storage and heat preservation,and significantly improve potato yield and water and heat utilization efficiency.