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Effects of residual mulch film on transport and redistribution of water, salt and nitrogen in silt loam soil |
YU Yonggang1,SUN Chitao1,2*,CHENG Jinjie1,LIU Yueyan3,LYU Pengchao4,ZHANG Mingming1 |
1. College of Water Conservancy and Civil Engineering, Shandong Agricultural University, Taian, Shandong 271000, China; 2. Key Laboratory of Agricultural Film Application, Ministry of Agriculture and Rural Affairs, Taian, Shandong 271018, China; 3. Shandong Provincial Agricultural Ecology and Resources Protection Station, Jinan, Shandong 250000, China; 4. Weihai Agricultural and Rural Affairs Service Center, Weihai, Shandong 264200, China |
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Abstract In order to explore the effects of residual mulch film(hereinafter referred to as ″residual-film″)on the transport and redistribution of soil water, salt and nitrogen, we set up an indoor one-dimensional vertical soil column infiltration-evaporation tests with different residual film contents(0,100,200,400 kg/hm2), and measured the changes of soil moisture content, conductivity, nitrate nitrogen and ammonium nitrogen in each soil layer during the process of water redistribution. The results show that the residual film changes the infiltration performance of the soil, and when the residual film amount in the soil is lower than 200 kg/hm2, the soil wet peak migration distance and the cumulative infiltration rate increases. When the residual film amount is more than 400 kg/hm2, the soil wetting peak migration distance and cumulative infiltration reduces by 4.07 % and 3.59 %, respectively, compared with CK treatment. The leaching effect of water on salt and nitrogen fertilizer gradually decrease with the increase of residual film amount. The residual film hinder the upward transport of salt and nitrate nitrogen, and the upward transport of ammonium nitrogen changes from an obstructing effect to a promoting effect with the decrease of ammonium nitrogen concentration. When the residual film amount is more than 400 kg/hm2, the soil moisture and salt CV values increases by 10.15 % and 6.51 %, res-pectively, compared with CK treatment. With the increase of residual film content, the CV value of nitrate nitrogen concentration decreases significantly, and the CV value of ammonium nitrogen concentration in the same soil layer of different treated soils is quite different, and there is no obvious difference in the variation degree of ammonium nitrogen in the soil profile. At the end of the evaporation experiment, the promotion effect of the residual film on water evaporation changes into a hindering effect as the residual film content increases. This study can explore the transport and redistribution of water, salt and nitrogen in the soil contaminated by residual film, and can provide a theoretical basis for the formulation of a reasonable irrigation system for farmlands containing residual films.
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Received: 26 April 2023
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