| Yulin sandy area is the suitable area of potato in China,and drip irrigation under film is an important technical measure for efficient water-saving cultivation of potato in this area.However,the long-term extensive use of plastic film has caused problems such as white pollution of farmland,deterioration of soil physical and chemical properties,and decline in crop yield and quality,which seriously restricts the sustainable development of regional potato industry.Degraded plastic film is regarded as a new type of plastic film to reduce white pollution,but its effect on soil characteristics of potato in sandy farmland is not clear.In order to explore the effects of different film mulching types on the physical and chemical properties of farmland soil and potato yield,a field positioning experiment was conducted from 2021 to2022.Five treatments were set up,including no film mulching(T1),degraded white film(T2),degraded black film(T3),polyethylene white film(T4)and polyethylene black film(T5).The effects of different film mulching types on soil water and temperature status,nutrient contents,microbial characteristics,potato growth,yield and quality in sandy farmland were studied,in order to screen out suitable film mulching materials for green and high-yield cultivation of potato in Yulin sandy area.The main conclusions are as follows:(1)There were differences in soil water and temperature status and compactness in 0-20 cm soil layer under different film mulching types.In 2021,the surface soil water content of the four film mulching treatments was 8.93%-77.08% higher than that of T1 treatment,the soil water content of T4 and T5 treatments was 9.38%-25.35% higher than that of T2 and T3 treatments,and the soil water content of T3 treatment was higher than that of T2 treatment.In2022,the change trend of soil water content in the topsoil at the early growth stage(seedling stage to tuber formation stage)was consistent with that in 2021.During the two-year experiment,the surface soil temperature under each film mulching treatment was higher than that of T1 treatment.The surface soil temperature of T4 and T2 treatments was 0.67°C-3.07°C higher than that of other treatments in the early stage of potato growth,and the soil temperature of T4 and T5 treatments was 0.56°C-3.10°C higher than that of other treatments in the middle and late stages of potato growth(tuber expansion stage to maturity stage).The surface soil compactness of T1 treatment was higher than that of each film mulching treatment,and the soil compactness of T3 and T5 treatments was 1.34% and 8.30% lower than that of T2 and T5 treatments,respectively.(2)Different treatments affected the soil chemical properties of 0-20 cm soil layer,and there were differences between years.From 2021 to 2022,the soil p H value of T1,T3 and T5 treatments in the early stage of potato growth was 0.46 %-0.62 % higher than that of T2 and T4 treatments.The soil total nitrogen and available nitrogen contents of T3 treatment in 2021 seedling stage to starch accumulation stage and 2022 starch accumulation to maturity stage were the highest.From 2021 to 2022,the soil available phosphorus content of T3 and T5 treatments was higher than that of other treatments by 5.42%-41.89%.In 2021,the soil available potassium content of T3 treatment in the whole growth period of potato was 3.02%-16.92% higher than that of other treatments.In 2022,the soil available potassium content of T3 and T5 treatments was 2.73%-11.43% higher than that of other treatments.During the potato maturity period during the two-year test period,the soil organic carbon content of T2 and T3 treatments was significantly higher than that of T4 and T5 treatments by 26.20%-31.33%and 42.41%-54.73%(p < 0.05),and the soil organic carbon content of T3 treatment was the highest;in addition,different mulching treatments affected the bacterial community diversity of potato soil in sandy land.In 2021,the soil bacterial OTU abundance of T3 treatment was the highest,and the soil bacterial OTU abundance of T5 treatment was the highest in 2022,followed by T3 treatment.The Shannon and Simpson indexes of soil bacteria in T3 treatment were higher than those in other mulching treatments from 2021 to 2022.At the genus level,T1 and T4 treatments increased the relative abundance of pathogens such as streptomyces scabies,Pseudarthrobacter,Ellin6067 and Gemmatimonas.(3)Different plastic film mulching changed potato growth,yield and quality indicators from 2021 to 2022.The plant height,stem diameter and chlorophyll content(SPAD value)of T3 and T5 treatments in the middle and late stages of potato growth were higher than those of other treatments,and the plant height and SPAD value of T3 treatment were the highest.The yield of T3 treatment was significantly higher than that of other treatments 6.09%-19.43%(p<0.05),followed by T5 treatment and significant difference among treatments(p < 0.05).The commodity potato rate was T3>T5>T2>T4>T1.The starch content of T1 and T3 treatments was higher than that of other treatments.The potato starch content of T3 treatment was significantly higher than that of other film mulching treatments by 10.69%-85.95%(p < 0.05).The reducing sugar content was lower than that of other film mulching treatments,and the ash content of potato under T3 treatment was the lowest.In summary,T3 treatment can improve the physical and chemical properties of potato farmland,promote the growth and development of potato,improve the yield and quality of potato,and the farmland application effects are better than other treatments. |
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