School of Earth, Environmental, & Marine Sciences Faculty Publications and Presentations

Mineral amendments benefit soil moisture but not nutrient cycling or crop productivity in a Florida organic vegetable system established on a sandy soil

Document Type

Article

Publication Date

7-10-2025

Abstract

Coastal plain soils of the southeastern United States are primarily coarse-textured, resulting in limited water and nutrient-holding capacity. Given their low clay content, incorporating high-clay mineral amendments could improve water and nutrient dynamics. We established a field experiment in North Central Florida to evaluate the effect of two different mineral amendments incorporated into the top soil of an organic farm. For 16 months following amendment application, we measured productivity (cover crops and cabbage [Brassica oleracea L.]), plant and soil nutrient concentrations, soil water content, soil carbon indicators, and weed and nematode abundance. We also conducted a partial budget analysis. In a parallel greenhouse experiment, five amendment levels were compared in controlled conditions to determine their effect on soil moisture and sorghum sudangrass (Sorghum bicolor × S. bicolor var. sudanense) biomass. While the addition of mineral amendments significantly increased soil moisture at 15 cm (by 5%, with mineral amendment 2) and 30 cm (by 11%, with mineral amendment 1) under field conditions, there were few significant effects of amendments on other variables in this organic vegetable production system. In contrast, the highest mineral amendment level had the highest soil water content (16% greater than the control, p <  0.001) and plant biomass (p = 0.012) in the greenhouse experiment, although biomass was not significantly greater than the control. By improving water retention, mineral amendments could help reduce irrigation costs and benefit organic vegetable systems, although the magnitude of these effects will depend on individual amendments, systems, and soil conditions.

Comments

Student publication. Original published version available at https://doi.org/10.1007/s13165-025-00510-y

Publication Title

Organic Agriculture

DOI

10.1007/s13165-025-00510-y

Link to Full Text

Share

COinS