Cropping management in a livestock-pasture-crop integration modifies microbial communities, activity, and soil health score.

Understanding indicators of soil health is crucial for developing agricultural systems that are sustainable and climate resilient. Labile soil carbon, microbial properties, and nutrient status are all incorporated into the Haney Soil Health Tool with the goal of summarizing several indicators into one index. Monthly soil samples from an integrated crop-livestock system in Central Texas were collected from 2017 to 2019. Fields represented a range of management practices, including cover crops, no-till, rotational grazing, and a native prairie remnant. Soil samples were analyzed for total carbon, water-soluble carbon, macro- and micro- nutrient content and bioavailability, and phospholipid and fatty acids (PLFAs). Microbial activity was determined via a 24-hour CO2 incubation. Soil health score, carbon, and PLFA's were all well correlated with each other. The greatest total PLFA (219.5 nmol g-1 soil) and organic carbon (54.3 g kg-1 soil) were found in the native prairie; and the lowest were found in the unfertilized continuous corn system (60.5 nmol PLFAs g-1 soil and 24.0 g organic carbon kg-1 soil). Of all agroecosystems, the perennial grazing system (soil health score 24.7) was most similar to the native prairie (score 27.4), having high soil carbon and a large microbial community. Of the row cropping systems, the no-till system approached the perennial systems better than the conventional till, and unfertilized conventional till (score 11.1 versus 8.0 and 5.3, respectively). This study highlights the value of perennial grass grazing in agroecosystems and appropriate best management practices. Expanding this analysis to other sites may provide additional insight. This article is protected by copyright. All rights reserved.