Soil Fertility and Plant Nutrient Status During the First Half-Life of Peach Orchards in Central Portugal

Peach production is economically important in Portugal’s Beira Interior region, which holds roughly half the country’s peach area. Orchard management can affect soil fertility, but the changes develop slowly and are rarely studied. We hypothesised that soil organic matter would increase after orchard establishment, that high soil K, P, and Cu levels would be reflected in leaf nutrients and tree growth, and that soil changes would be greater in tree rows than in inter-rows. To test these hypotheses, we tracked soil fertility, leaf nutrients, and trunk sectional area from orchard establishment (2018) to half-life (2024). Of the initial 31 orchards, only 16 remained by 2024, mainly because of bacterial canker (Pseudomonas syringae). Soil nutrients were generally high, suggesting overfertilisation, while leaf nutrients were mostly within the reference ranges, although K and Zn were low in several orchards. Although soil Cu content was high (ranging from 25 mg/kg to 49 mg/kg), no phytotoxic effects were observed. Soil changes were more frequent in the rows, where organic matter rose, though not significantly, from 2.65% to 3.45%–3.46%, a promising result given the region’s coarse-textured soils and hot summers. The results indicate that fertilisation should be guided by soil and leaf analysis.