集雨补灌春马铃薯收后复种夏蚕豆对土壤养分及细菌群落结构的影响

Effects of Replanting Summer Broad Bean after Spring Potatoe Harvest on Soil Nutrients and Bacterial Community Structure under Rainwater Harvesting and Supplementary Irrigation

[目的]研究集雨补灌条件下,春马铃薯—夏蚕豆复种(薯豆复种)+豆秆还田对土壤养分变化及细菌群落结构的影响。[方法]以薯豆复种+豆秆还田、马铃薯种后空闲以及马铃薯连作土壤为研究对象,测定土壤理化性质;采用Illumina NovaSeq PE250对土壤细菌16S V3~V4区域进行高通量测序。[结果]与常规栽培模式相比,集雨补灌条件下,春作马铃薯提前75~76 d出苗,提前43~74 d收获,避开了晚疫病危害,滇薯23、滇薯47和青薯9号的产量分别增加28953.0、8571.0和28570.5 kg/hm^(2)。与马铃薯连作相比,薯豆复种+豆秆还田的土壤pH值增加0.17,有机质含量增加0.35%,全氮含量增加0.02%,有效氮含量增加43.6 mg/kg,有效钾含量增加51.5 mg/kg。与马铃薯种后空闲相比,薯豆复种+豆秆还田的土壤pH值增加0.14,有机质含量增加0.33%,全氮含量增加0.02%,全磷含量增加0.02%,有效氮含量增加39.8 mg/kg。薯豆复种+豆秆还田模式下,土壤中放线菌门、芽单胞菌门和鞘氨醇单胞菌属相对丰度高于马铃薯种后空闲模式和连作模式,但连作模式下土壤酸杆菌门丰度更高。相关性分析表明:土壤pH以及全磷和全钾含量是驱动细菌门丰度变化的主要环境因子。[结论]薯豆复种+豆秆还田可提高土壤肥力、减缓土壤酸化、增加土壤有益细菌门和属的相对丰度,而马铃薯连作会降低土壤pH和减少有益细菌;集雨补灌春作马铃薯收后复种夏蚕豆可增加复种指数,提高土地利用效率,改善土壤营养状况和细菌群落结构,减轻马铃薯连作障碍。

[Purpose]To study the effects of spring potato-summer broad bean multiple cropping(potato-bean multiple cropping)+bean stalk returning to the field on the changes of soil nutrient and the structure of bacterial community under rainwater harvesting and supplementary irrigation.[Methods]After potato-bean multiple cropping+bean stalk return to field,fallow after potato planting,and potato continuous cropping treatments,taking the soil of three different treatments to measure the soil physical and chemical properties on agrochemical analysis method, and the Illumina NovaSeq PE250 was used to perform high-throughput sequencing of the soil bacteria 16S V3-V4 re-gion. [ Results] On the conditions of rainwater harvesting and supplemental irrigation, spring- cropped potatoes emerged 75-76 days earlier and harvested 43-74 days earlier than conventional cul-tivation mode, avoiding late blight, and the yields of Dianshu23, Dianshu47, and Qingshu No.9 in-creased 28 953.0, 8 571.0, 28 570.5 kg/hm^(2), respectively. To compare with continuous potato crop-ping, the soil pH of potato-bean multiple cropping + bean stalk return to the field increased by 0.17, organic matter content increased by 0.35%, total nitrogen content increased by 0.02%, available nitro-gen content increased by 43.6 mg/kg, and available potassium content increased by 51.5 mg/kg. To compare with fallow after potato planting, the soil pH of potato-bean multiple cropping + bean stalk return to the field increased by 0.14, organic matter content increased by 0.33%, total nitrogen con-tent increased by 0.02%, total phosphorus content increased by 0.02%, and available nitrogen content increased by 39.8 mg/kg. The relative abundance of Actinobacteria, Gemmatimonadetes, and Sphin-gomonas in the soil under the potato-bean multiple cropping + bean stalk return mode was higher than that in the fallow and continuous cropping mode of potato, but the abundance of Acidobacteria in con-tinuous cropping mode was higher. Correlation analysis showed that the soil pH, total phosphorus and total potassium content were the main environmental factors that drive changes in bacterial phyla abundance. [Conclusion]Potato-bean multiple cropping + returning bean stalks to the field can im-prove soil fertility, slowing down soil acidification, and increasing the relative abundance of soil bene-ficial bacteria phyla and genera, while continuous potato cropping will reduce soil pH and decrease the abundant of beneficial bacteria;supplemental irrigation with rainwater harvesting of spring pota-toes can increase the multiple cropping index, improve land used efficiency, improve soil nutrition and bacterial community structure, and reduce the obstacles to continuous potato cropping.