NSLS-II Friday Lunchtime Seminar

Integrating two years of bahiagrass (Paspalum notatum) into conventional peanut (Arachis hypogea L.) and cotton (Gossypium hirsutum L.) cropping systems (bahiagrass-bahiagrass- peanut-cotton) improves soil quality and crop production compared with the conventional peanut-cotton-cotton rotation (CR). However, it is unclear if this system, known as a sod-based rotation (SBR), affects interactions within soil biota and if such interactions affect nutrient cycling and soil fertility. In this study, we collected soils from long-term plots under CR and SBR (located in Quincy, FL), before cotton planting. Our results showed that the metabolic activities of relative low trophic groups (i.e., bacterivores and herbivores) were positively correlated with r-strategists irrespective of cropping systems, but negatively with k-strategists only under CR. These demonstrated that microbial communities under higher rotational diversity contributed larger to C, energy, and nutrient flows in soil food webs relative to CR. Compared with SBR, one or more functional nematodes groups were entirely missing or showed few abundances, and less evenness of the microbial community was exhibited under CR in spite of no significant differences between these twoKo systems. These results imply that SBR with greater rotational diversity induced higher soil community diversity and consequently sustains the distribution of soil biological community, with positive effects on soil nutrient availability and the control of plant parasites.