| With the popularization of mulching technology,especially the large-scale implementation of drip irrigation under mulching technology,the effects of water saving,moisture preservation,temperature increase and production increase have been realized,and the agricultural production increase has also been promoted.However,due to the imperfect recovery mechanism of mulching,a large number of plastic mulching films have remained in the soil for many years,damaging the soil environment,affecting the soil water movement and serious harm to the growth and development of crops.Therefore,it is of great significance to study the residual film for crop growth and water salt transport.In this paper,four residual film levels(CK(0kg/hm2),T1(150kg/hm2),T2(300kg/hm2)and T3(600kg/hm2)were set in Hetao irrigation district for two years to study the effect of different residual film amounts on the growth and development of corn,and three irrigation quotas(20,15,10m3/mu)of high,medium and low were set to study the interaction of soil water and salt transport under different residual film amounts and irrigation quotas The effects of function and yield are to reveal the law of crop growth and water salt transport under different amount of residual film,and to provide theoretical support for the study of the harmfulness of residual film and the rational regulation and irrigation of residual plastic film(RPF)farmland in Hetao irrigation district.The main conclusions are as follows:(1)The RPF had the most significant effect on the soil moisture content of 0?10cm,and the effect gradually decreased with the increase of depth.Generally,the soil moisture content of the RPF treatments(T1,T2,T3)under the high irrigation quota was lower than that of the non-residual film treatment(CK),and the soil moisture content of the RPF treatments under the medium irrigation quota and low irrigation quota was higher than that of the non-residual film treatment.Under the high irrigation quota,Compared with CK treatment,the water content of T1,T2 and T3 decreased by 6.14%,14.01%and 21.50%on average in the two years,respectively;under medium irrigation quota,the water content of T1,T2 and T3 increased by 6.47%,20.09%and 30.22%respectively compared with CK treatment;under low irrigation quota,the water content of T1,T2 and T3 increased by 6.14%,18.10%and 27.41%respectively compared with CK treatment.In addition,the change rule of 10?30cm is consistent with 0?10cm,and the change rule of 30?100cm is opposite to 0?10cm.When the amount of residual film?300kg/hm2,the soil moisture content of different treatments under different irrigation quota was significantly different(P<0.05).(2)Under the high irrigation quota,the EC value of RPF treatments is less than that of non-residual film treatment in 0?30cm soil layer,and greater than that of non-residual film treatment in 30?100cm soil layer,and it was the main saline soil layer;under medium and low irrigation quota,the EC value of RPF treatments is greater than that of non-residual film treatment in the 0?30cm soil layer,and the salt accumulation was higher,while the reverse was observed in the 30?100cm soil layer.(3)RPF affects the growth and development of corn canopy.The plant height,stem diameter and leaf area index decreased with the increase of the amount of residual film.When the amount of residual film was 600kg/hm2(T3),the plant height,stem diameter and leaf area index decreased by 11.28%,13.93%and 15.29%,respectively,compared with CK treatment.At the same time,affected by the RPF,the time of corn entering the rapid growth period under the RPF treatments was later than that non-residual film treatment.(4)The residual film in the soil will reduce the root length density and root weight density of corn,increase the proportion of fine roots,and it also affects the growth of overground plants,resulting in the decrease of overground dry matter mass and corn root shoot ratio with the increase of RPF amount,and the blocking effect of RPF on crop growth is more significant in the pre growth period of corn.The RPF also had a certain effect on the spatial distribution of corn roots in the soil layer.The root volume ratio increased with the increase of RPF amount in the soil layer of 30?60cm and 60?90cm.The root volume ratio of the RPF treatments in the soil layer of 30?60cm and 60?90cm increased by 17.78%and 20.83%,respectively,compared with CK treatment.(5)The yield of RPF treatments was lower than of non-residual film treatment under high,medium and low irrigation quota.Compared with CK treatment,the yield of T1 decreased by 5.62%,5.02%and 6.36%,respectively;T2 decreased by 17.41%,16.54%and 17.39%,respectively;T3 decreased by 25.52%,24.61%and 27.01%,respectively.The yield of corn decreased significantly when the RPF amount was?300kg/hm2(T2).Among the three irrigation quotas,the corn yield and water use efficiency of each treatment under medium irrigation quota is the highest. |
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