D3053: Long-term effects of alternative agroecosystem management practices on soil arthropod communities

Soil arthropod abundance and functional diversity are important indicators of soil health and fertility, as many soil arthropods play key roles in decomposing crop residues and nutrient cycling. It is likely that these communities are impacted by management practices that alter the physical, chemical, or biological properties of the soil. To test this, we conducted a longitudinal study at a long-term agricultural research site located in North Dakota with a corn-soybean-spring wheat crop rotation that differed in agricultural management practices: 1) the traditional management practices for the three crops (Business as Usual), 2) management practices involving no-till, residue retention, and cover cropping (Alternative Practice 1), and 3) intercropping of intermediate wheatgrass and alfalfa as perennials (Alternative Practice 2). Subterranean arthropod communities were assessed during the first and fifth year of the experiment.  Three soil cores from each plot were sampled, homogenized, and a 1000 mL subsample taken just after planting in May, during peak growth in July, and in September. Arthropods were extracted using Berlese funnels and key taxa identified and quantified. In the first year of the study, mesostigmatid, astigmatid, and oribatid soil mites, Collembola, and Psocodea populations peaked with the growth of the crops in July and dropped off sharply in October. We expect that after five years of treatment, the differences in arthropod diversity will become more apparent. Our findings provide insight into how sustainable agricultural practices can enhance soil biodiversity and ecosystem function, contributing to the productivity of agroecosystems in the face of environmental challenges.