Huo Na, Huang Jing-Hua, Geng De-Zhou, Wang Nan, Yang Pan-Pan, Zhao Shi-Wei
College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, China.
State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling 712100, Shaanxi China.
Ying Yong Sheng Tai Xue Bao. 2021 May;32(5):1825-1834. doi: 10.13287/j.1001-9332.202105.033.
Soil nematode communities play an important role in ecosystem material cycling and energy flow. In this study, soil samples were collected from three rotation systems in southern Ningxia mountainous region, including alfalfa continuous cropping (A-A), alfalfa-corn rotation (A-C), alfalfa-potato rotation (A-P). Soil physicochemical properties, nematode community composition and their metabolic footprints were measured. Compared with the A-A plot, the concentrations of soil organic carbon (SOC) and total nitrogen (TN) were significantly increased by 4.6% and 7.4% for SOC, 4.0% and 5.2% for TN in the A-C and A-P plots, respectively. Soil microbial biomass carbon and nitrogen were significantly higher in the A-C and A-P plots when compared with the A-A plot. The total abundance of soil nematodes in the A-C and A-P plots was higher by 49.5% and 93.7% than that in the A-A plot, respectively, with the dominant trophic group being changed to omnivores-predators from plant parasite. Compared to the A-A plot, the plant parasite index (PPI) was decreased significantly in the A-C and A-P plots, indicating that the harm of plant-parasites was reduced in soil food web. The nematode channel ratio (NCR) in the A-C and A-P plots were higher than that in the A-A plot, indicating that the role of bacterial decomposition was enhanced in soil organic matter decomposition. The maturity index (MI), the total nematode metabolic footprint, enrichment footprint, structure footprint in the A-C and A-P plots were all significantly higher than those in the A-A plot, suggesting that the structure and function of soil food web were more mature and stable, and the productivity and metabolic activity of nematodes were significantly enhanced. In general, the alfalfa-crop rotations improved soil nutrient status and reduced the disturbance degree of soil food web. Furthermore, soil ecosystem developed in the stable and healthy direction, which would be beneficial to the sustainable development of agriculture.
土壤线虫群落对生态系统的物质循环和能量流动起着重要作用。本研究采集了宁夏南部山区三种轮作系统的土壤样本，包括苜蓿连作（A-A）、苜蓿-玉米轮作（A-C）、苜蓿-马铃薯轮作（A-P）。测定了土壤理化性质、线虫群落组成及其代谢足迹。与A-A小区相比，A-C和A-P小区土壤有机碳（SOC）浓度分别显著提高了4.6%和7.4%，全氮（TN）浓度分别显著提高了4.0%和5.2%。与A-A小区相比，A-C和A-P小区土壤微生物生物量碳和氮显著更高。A-C和A-P小区土壤线虫的总丰度分别比A-A小区高49.5%和93.7%，优势营养类群从植物寄生性转变为杂食-捕食性。与A-A小区相比，A-C和A-P小区的植物寄生指数（PPI）显著降低，表明土壤食物网中植物寄生性线虫的危害降低。A-C和A-P小区的线虫通道比（NCR）高于A-A小区，表明细菌分解作用在土壤有机质分解中得到增强。A-C和A-P小区的成熟度指数（MI）、线虫总代谢足迹、富集足迹、结构足迹均显著高于A-A小区，表明土壤食物网的结构和功能更加成熟稳定，线虫的生产力和代谢活性显著增强。总体而言，苜蓿与作物轮作改善了土壤养分状况，降低了土壤食物网的干扰程度。此外，土壤生态系统朝着稳定健康的方向发展，这将有利于农业的可持续发展。
