Effects Of Different Plastic Film Mulching On Soil Physicochemical Properties And Maize Yield

Insufficient precipitation and seasonal high temperature are important factors restricting maize growth in arid areas.Reducing the negative impact of soil hydrothermal environment on maize growth through drip irrigation coating is a key technical means for increasing maize yield.Therefore,in this study,’ Xianyu 1225 ’,a mid-late maturing maize variety,was used in a single factor randomized block experiment.Four different types of plastic film mulching were set up,namely permeable plastic film(S1),oxidized biological double degradation film(S2),total biodegradable film(S3)and ordinary plastic film(P),and the non-mulching film was used as the control(CK).The effects of different plastic film mulching on maize growth and development,soil moisture,temperature,nutrients,photosynthetic fluorescence characteristics and yield under drip irrigation were systematically studied,so as to screen out the suitable plastic film types for maize growth.The main research results are as follows:(1)There were significant differences in the degradation performance of different types of film.The degradation rate of P treatment was the slowest than that of S1,S2 and S3.The mass loss rate of film after harvest was only 5.84%,and the mass loss rate of biodegradable film(S1,S2 and S3)was 28.03%-41.71%.Each biodegradable film(S1,S2,S3)has entered the induction stage at jointing stage(V6 stage),and 2-3 degradation occurs at wax maturity stage(R5 stage).The common plastic film(P)only reaches 2 degradation at maturity stage(R6 stage).(2)Different plastic film mulching can effectively improve the physical and chemical properties of 0-40 cm soil layer.In the early growth stage,S1,S2 and S3 treatments have better warming and moisture retention performance.In the late growth stage,P treatment has better warming and moisture retention performance.The contents of available phosphorus,available potassium,total nitrogen and organic matter increased with the growth period of maize.In 0-40 cm soil layer,the soil bulk density decreased by 1.55%-8.62%,and the soil porosity increased by 2.23%-10.87%.Compared with CK,the content of available phosphorus increased by 2.17%-24.54%at maturity.Compared with the seedling stage,the total nitrogen content increased by 5.16%-15.19%,and the organic matter content of S1,S2 and S3 treatments was higher than that of P treatment.In the 5-25 cm soil layer,P and S2 treatments had better heat preservation,and the diurnal soil temperature difference gradually decreased with the deepening of soil layer.At 25 cm soil layer,compared with CK,the average daily soil temperature increases of P and S2 treatments were 6.60%and 8.09%,respectively.In0-100cm soil layer,the average soil water content of each film treatment was 23.41%-73.75%higher than CK.Among them,S1 treatment had higher soil water content.(3)Different plastic film mulching can promote maize growth and accelerate maize growth process.Maize plant height increased 6.76%-12.09%under each film treatment.The canopy water content increased by 53.25%-94.05%.The leaf area index reached the peak at the large trumpet stage(V12 stage),which was 42.08%-82.91%higher than that of CK.The dry matter accumulation of maize under different mulching treatments showed a trend of first increase and then decrease in the whole growth period of maize,and the growth rate was the fastest at milk stage,which was 14.17%-37.88%higher than that of CK.In each film treatment,the growth process of maize in P and S1 treatment was faster than that in CK,which was accelerated by 2 d and 3 d,respectively.(4)Different mulching can improve the photosynthetic fluorescence characteristics of maize.The net photosynthetic rate,stomatal conductance,leaf transpiration rate,Fv/Fm,Fv/Fo,PI and ABS/RC of functional leaves at maize growth stage were effectively improved by different film treatments.Except for intercellular CO2 concentration,P and S1 treatments showed better performance.Compared with CK,the net photosynthetic rate of P and S1 treatments increased by 23.20%and 21.07%,respectively.Compared with CK,the fluorescence indexes(Fv/Fm,Fv/Fo,PI,ABS/RC)increased by 0.39%-3.82%,1.63%-32.24%,26.27%-44.23%,4.45%-11.96%,respectively.(5)Plastic film mulching could improve maize yield and water use efficiency.Compared with CK,the yield of maize under S1,S2,S3 and P treatments increased by 64.59%,53.25%,51.69%and 66.54%,respectively.The yield of S1 treatment was higher than that of P treatment.Water use efficiency of S1 treatment was the best,increased by 31.91%compared with CK.To sum up,biodegradable plastic film mulching has multiple effects,such as significantly increasing ground temperature,enhancing photosynthetic fluorescence performance,and water conservation,so that crops can make full and effective use of hydrothermal resources,promote the growth and development of maize,and improve the utilization efficiency of water and fertilizer,so as to obtain good results of early maturity,high yield and high quality.Its farmland application effect is similar to that of common plastic film,but it can obtain better economic benefits than that of common plastic film mulching.Therefore,biodegradable film can be used in agricultural production instead of ordinary film to reduce pollution.