Effect Of Plastic Film Mulching Duration On Cotton Yield Formation And Soil Environment

Film mulching duration(FMD)not only changed the temperature of farmland,preserved soil,inhibited salt,and prevented grass.It also played a key role in mechanical recovery of residual film and safety evaluation of degraded plastic film.In recent years,with the use of high-strength plastic film and lack of effective recycling measures,residues of farmland plastic film have caused "white pollution" to occur.The barrier effect of the residual membrane changes the water and fertilizer environment of the soil and the water absorption capacity of the root system,resulting in a decline in the quality of the cultivated land and a deterioration of the crop growth environment,which seriously reduces the water use efficiency and production potential of the crop.In order to quantify the effects of plastic film coverage on cotton yield and cotton field environment,40 d(J1),55 d(J2),70 d(J3),85 d(J4),and 100 d were set in typical drip-irrigated cotton fields in Xinjiang Oasis.(J5)Coverage and total growth coverage(approximately 140 days,CK),etc.6 treatments,study of film coverage time on soil temperature,soil water content,cotton field water consumption,water consumption model The effects of number,root morphology,nutrient uptake and utilization,water use efficiency(WUE),and yield composition can provide scientific basis for the scientific and rational use of mulch in oasis cotton and mulching,and also for residual film recovery.The theoretical application of the safety application of degraded plastic film provides theoretical support.The main results as follows:1.Different soil filming time significantly affected the soil temperature.With the extension of the covering time,the soil temperature gradually increased,accelerating the accumulation of soil growth degrees.The results of the two-year trial showed that J1 and J2 treatments had lower soil growth and higher CK during the entire growth period.In the whole growth period,the soil growth degree of CK treatment was 4.9% higher than that of J5.Timely coverage can delay the premature decline of the cotton plant,which is beneficial to the improvement of its yield and its constituent factors.2.With the extension of filming time,the root length density and root weight density showed an increasing trend,but after more than 100 days,a large number of root systems died due to the high soil temperature.J1,J2,J3,and J4 treatments had significant differences compared with CK,and the root length density of 0-15 cm soil layers decreased by 48%,34.3%,51.3%,and 33.2%,respectively,while J5 was5.1% higher than CK..With the development of the growing period,the root activity of cotton with different treatments gradually decreased.Timely coverage improves root growth and improves root vigor.3.With the extension of mulching time,water content of 0～80 cm soil layer gradually increased,ETc continued to decrease,WUE showed an increasing trend,but after more than 100 days,there was no significant effect on ETc and WUE(P<0.05).Compared with CK,the soil water content of J1 ～ J4 decreased by 2.8 ～ 8.2%,and the ETc increased by 6.78 ～ 50.70 mm,while J5 soil water content increased by 4.6%,and ETc decreased by 12.68 mm.The mulching time had a significant effect on WCM.Compared with CK,W1 in the flowering period decreased by 5.0%.Appropriate coverage time can reduce ETc,change WCM,increase WUE and irrigation water use efficiency.4.The nitrate nitrogen and ammonium nitrogen of each treatment were mainly distributed in 0-20 cm soil layer.The content of nitrate nitrogen and ammonium nitrogen decreased with the increase of coating time and depth of soil layer.The content of nitrate nitrogen and ammonium nitrogen in the 0-80 cm treatment in the bell stage J5 was the lowest,which was 7.7% and 9.9% lower than that in the CK 2 years.It can be seen that timely mulching time can promote the use of soil nitrogen and reduce soil inorganic nitrogen residues.J5 treatment of soil temperature and moisture conditions is more suitable for crop growth needs,thereby promoting root growth and development,increase nitrogen and nutrient uptake,and ultimately increase cotton production.In summary,the 100-day coverage is most conducive to cotton growth and yield increase,so the best coverage time for cotton cultivation in Xinjiang Aksu is 100 days.