Phosphorus (P) availability is a critical factor influencing plant growth, particularly in highly weathered tropical and subtropical soils where mineral and organic P sources often exhibit low absorption efficiency. In response to soil low P availability, plants typically undergo physiological and biochemical adaptation, including reduced photosynthetic rates, increased root/shoot ratio, and alterations in the root system. This study aimed to assess changes in the maize root system and their relationship with P absorption and utilization efficiency under field conditions. The experimental design comprised three treatments: pig slurry, mineral fertilizer, and a control with no fertilizer, arranged in a randomized block design with four replications. Key morphological parameters were analyzed at the vegetative (V8) and flowering (R1) phenological stages, alongside physiological and chemical assessments of the aboveground plant parts. Plants grown in soil with a history of pig slurry application had the lowest morphological root parameters, yet demonstrated higher P absorption efficiency, grain yield, and dry matter production. The application of pig slurry and mineral fertilizers increased P and potassium (K) levels in the soil, photosynthetic rates, and dry matter production. These findings underscore the complex interplay between root morphology and nutrient absorption, offering insights into optimizing fertilizer strategies for maize cultivation in low-P availability soils.
Marchezan et al. (2026) studied this question.