Influence of Different Earthworm Densities on the Growth of Pak Choi(Brassica chinensis L.)and Its Underlying Mechanisms
摘要
蚯蚓作为农业土壤动物区系的重要生物类群,在调节作物生长方面发挥重要作用.本研究通过上海青盆栽试验,设置不同蚯蚓密度添加处理,包括 CK(对照)、LW(低蚯蚓密度)、HW(高蚯蚓密度),探讨蚯蚓添加对上海青生长的影响.结果表明:与 CK 相比,LW 和 HW处理下,上海青总生物量分别提高到 1.2 倍和 1.3 倍,根冠比分别显著降低 8.8%和 27.7%.此外,LW 和 HW 处理下,土壤硝态氮(NO3--N)浓度分别显著提高 0.9 倍和 1.8 倍.然而,LW 和 HW 处理下,土壤铵态氮(NH4+-N)浓度分别降低 32.4%和 63.3%.随机森林分析结果显示,土壤 NO3--N 是决定上海青生物量变化的关键土壤因子,NH4+-N 对上海青根冠比具有显著贡献.土壤蚯蚓主要通过改变土壤理化性质,尤其是土壤养分有效性及其组成,从而促进农作物的生产力.
Earthworms,as an important group of soil fauna in agricultural ecosystems,play a signifi-cant role in regulating crop growth.This study conducted a pot experiment with pak choi(Brassica chinensis L.),with different earthworm density treatments,including CK(control),LW(low earth-worm density),and HW(high earthworm density),to explore the effects of earthworm density on pak choi growth.The results showed that compared with CK,the total biomass of pak choi in LW and HW treatments increased by 1.2 times and 1.3 times,respectively,and the root-shoot ratio decreased sig-nificantly by 8.8%and 27.7%,respectively.Additionally,the soil nitrate nitrogen(NO3--N)con-centration in LW and HW treatments increased significantly by 0.9 times and 1.8 times,respectively.However,the soilammoniumnitrogen(NH4+-N)concentration decreased by32.4%and63.3%,re-spectively.The random forest analysis results indicated that soil NO3--N was the key soil factor deter-mining the biomass change of pak choi,and NH4+-N had a significant contribution to the root-shoot ratio of pak choi.In conclusion,soil earthworms mainly promote the productivity of crops by modifying soil physicochemical properties,especially soil nutrient availability and its composition.
