Unrevealing the role of consortium soil amendments on growth, physiology, and nutrient use efficiency of citrus rootstock under varied soil moisture regimes

Among the abiotic factors, drought stress, due to climate change, has become the most concerning issue, particularly in arid and semi-arid regions. In citrus, drought conditions restrict growth and nutrient use. The current research was conducted in plastic pots to investigate the impact of integrated nutrient management (INM) on the growth and nutrient uptake of citrus rootstock under various moisture regimes (100%, 75%, and 50% FC). The INM approach was applied singly or in a combined formulation of chemical and organic amendments, at the recommended doses of fertilizer (R), farmyard manure (F), and vermin-compost (VC), following a factorial completely randomized design (CRD). The four treatments were applied as CK (control), R100, R50:F50, and R50:F25:VC25 at each moisture level or field capacity (FC). The growth traits and nutrient use efficiency were recorded and analyzed statistically. Drought stress significantly reduced all measured parameters, with minimum values recorded at 50% FC. However, INM significantly ( p < 0.05 ) improved these growth, physiological, nutrient uptake, and related parameters at all moisture levels. The R50:F25:VC25 treatment combination showed the greatest improvement across all drought stress conditions; the R50:F50 treatment showed moderate increases, while R100 showed comparatively lower improvements. Thus, the integrated application of R50:F25:VC25 proved to be the most effective approach for enhancing growth and nutrient use efficiency by improving plant tolerance mechanisms to drought conditions.