Soil health, microbial communities, and annual ryegrass yield under contrasting management practices

Biological indicators are often used to evaluate the effect of management practices on soil health. However, determining which indicators can detect changes in soil health after implementation of conservation practices and how these indicators relate to plant growth in grass seed production systems remains unclear. The goal of this study was to explore the relationships between management practice history, soil health metrics, plant growth, and soil microbial communities in annual ryegrass grown under greenhouse conditions. Soils were collected from 12 annual ryegrass [Lolium multiflorum (L.) Husnot] fields managed under conventional (till/bale) or conservation (no-till/full straw) management practices, with three silt loams and three silty clay loams collected for each practice. Annual ryegrass was grown for 5 months on each of the 12 soils in a greenhouse. Soils with a history of conservation management improved the majority of the carbon cycling-related metrics for the silt loam soils. Management practices had no effect on seed yield, however, conservation management significantly improved aboveground biomass in silty clay loam soils. Contrasting management practices resulted in distinct microbial communities, making them sensitive indicators of changes in soil conditions. Soil health and plant metrics were positively associated with the microbial communities in soils under conservation management. Total C and organic matter were positively correlated to plant parameters in silt loams, while few indicators were correlated to plant metrics in silty clay loams. These results highlight the complex interplay between microbial communities, soil health, and plant growth and the importance of considering inherent soil properties like texture. The relationship between management practices and soil health and yield outcomes were influenced by soil texture.Biological soil health indicators and yield metrics were positively correlated in silt loam soils.Microbial communities were a sensitive indicator of changes in management practices.Microbial communities in no-till were positively correlated to yield and soil health metrics.