Nutrient Status and Horticultural Performance of Orchards Amended with Compost

Commercial peach orchards in the humid southeastern U.S. are typically managed with annual mineral fertilization, raising concerns about nutrient losses and soil degradation. The objective of this study was to determine whether annual food waste compost (FWC) applications can sustain tree nutrition and productivity while improving soil organic matter and fertility in two mature peach orchards (replanted and virgin). Trees received top-dressed annual applications of either (1) 19-19-19 chemical fertilizer at grower-standard rates (Control; mineral fertilizer reference treatment); (2) 11,209 kg ha−1 FWC plus 20% of the chemical fertilizer rate (Compost 1x); or (3) 22,417 kg ha−1 FWC without supplemental chemical fertilizer (Compost 2x). Seasonal changes in soil chemistry at 0–15 cm were monitored, and the impacts of FWC on mid-summer leaf and fruit nutrient status, tree growth parameters, and yield were evaluated. Across orchards, FWC increased soil organic matter and cation exchange capacity and maintained leaf nutrient concentrations. Compost 2x consistently increased soil phosphorus and exchangeable calcium and magnesium (more than 2-fold), and increased trunk cross-sectional area (16–21%) and tree height (7–8%) in the virgin orchard, compared to the control treatment. Annual yields did not differ statistically among treatments in either orchard, although Compost 2x consistently showed numerically higher cumulative yields than other treatments. Overall, annual FWC, particularly Compost 2x, improved soil chemical fertility and maintained tree performance with reduced or eliminated chemical fertilizer inputs, supporting circular nutrient management strategies for peach production in regions with warm, humid climates.