Effect of Vegetation Cover and Height on Soil and Plant Properties Across Managed and Unmanaged Agricultural Land in a Temperate Climate

The aim of the study was to investigate the effect of vegetation cover and height on soil and plant nutrients across managed and unmanaged agricultural land in a temperate climate. Fresh soil and vegetation samples were collected during the years 2023 and 2024 from 125 different land parcels in the southwest of the UK. Land was either managed for grazing and/or feed production or not managed for agricultural use, and had a range of grass, crop, legume, herb, and flower species. A linear mixed model was used to assess the effect of vegetation height (in cm) and cover (tonnes of dry matter per hectare) on soil and plant nutrients. The results showed plant dry matter (DM) digestibility, acid detergent fibre (ADF), water-soluble carbohydrate, and oil contents increased with vegetation height, and soil DM and neutral detergent fibre (NDF) decreased with vegetation height. The ratio of soil-to-plant OM reduced and ADF increased with increasing vegetation cover. Interactions between vegetation height and cover (i.e., density) were found for the ratio of soil-to-plant OM, ADF, NDF, DM, DM digestibility, oil, water-soluble carbohydrate, and crude protein nutrients. Measuring the interaction between soil and plant properties showed soil OM stocks increased and soil pH decreased with increased vegetation cover across agricultural land.