腐植酸及其生物降解膜对连作土壤环境及苹果幼苗生长的影响

Effects of humic acid and its biodegradable film on continuous cropping soil environment and growth of Malus hupehensis seedlings

盆栽条件下,以平邑甜茶幼苗为试验材料,设置连作土(对照)、灭菌连作土、连作土添加1.5 g·kg^(-1)腐植酸、连作土添加腐植酸生物降解膜、连作土添加1.5 g·kg^(-1)腐植酸和腐植酸生物降解膜5个处理,通过测定处理后平邑甜茶生物量和植株根系生长状况、土壤微生物数量、土壤酶活性、土壤养分含量等指标,研究腐植酸及其生物降解膜对连作土壤环境及平邑甜茶幼苗生长的影响。8月取样结果表明,与对照相比,腐植酸和腐植酸生物降解膜复合处理使得平邑甜茶幼苗株高、地径、鲜质量、干质量分别提高了72.56%、58.50%、196.20%、250.81%;根表面积、根体积和根系超氧化物歧化酶、过氧化物酶、过氧化氢酶活性较连作土相比分别提高了74.93%、143.75%和63.40%、100.85%、72.57%;腐植酸及其生物降解膜还可以改善土壤环境,施用后土壤中细菌数量明显增加,真菌数量减少,细菌/真菌值增大,细菌、放线菌数量分别比对照提高了115.79%、135.14%,真菌数量降低了87.25%,细菌/真菌值增大了16倍,且土壤有机质及营养元素含量也有所提升,9月变化趋势与8月一致。综上所述,腐植酸及其生物降解膜改善了土壤环境,促进了平邑甜茶幼苗的生长,可有效减轻平邑甜茶的连作障碍。

Under potted conditions,using the seedlings of Malus hupehensis as experimental materials,five treatments were set up,including continuous cropping soil,sterilized continuous cropping soil,continuous cropping soil with 1.5 g·kg^(-1) humic acid,continuous cropping soil with humic acid biodegradable film and continuous cropping soil with 1.5 g·kg^(-1) humic acid and humic acid biodegradable film.The effects of humic acid and its biodegradable film on the continuous cropping soil environment and the growth of Malus hupehensis seedlings were studied by measuring the biomass and root growth status of Malus hupehensis seedlings,the number of soil microorganisms,soil enzyme activity,soil nutrient content and other indicators.The results of the August sampling showed that compared to the control,the combined treatment of humic acid and humic acid biodegradable film significantly increased the height,ground diameter,fresh mass and dry mass of Malus hupehensis seedlings by 72.56%,58.50%,196.20% and 250.81%,respectively,and the root surface area,root volume,and root superoxide dismutase,peroxidase and catalase activities activities were increased by 74.93%,143.75%,63.40%,100.85% and 72.57%,respectively,compared with the continuous cropping soil.Humic acid and its biodegradable film could improve the soil environment,with the application of them,the bacteria in the soil increased significantly,the number of pathogenic fungus decreased significantly,and the bacteria/fungus ratio increased.Compared with the control,the number of bacteria and actinomycetes in continuous cropping soil with 1.5 g·kg^(-1) humic acid and humic acid biodegradable film increased by 115.79% and 135.14%,respectively,the number of fungus decreased by 87.25%,and the bacteria/fungus ratio improved by 16 times.The contents of soil organic matter and nutrients also improved.Moreover,the trend in September was consistent with that in August.In conclusion,the use of humic acid and its biodegradable film improved the soil environment and promoted the growth of Malus hupehensis seedlings while effectively reducing the continuous crop barrier of Malus hupehensis seedlings.