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ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #417761
Research Project: Developing Best Management Practices for Poultry Litter to Improve Agronomic Value and Reduce Air, Soil and Water Pollution

Location: Poultry Production and Product Safety Research

Title: Agronomic effectiveness of partially acidified and granulated arraias phosphate rock

Author
item BENITES, VINICIUS - Embrapa
item MOLIN, SULIAN - University Of Santa Catarina
item SITTA, CASSIO - University Of Rio Verde
item SITTA, ERNESTO - University Of Rio Verde
item NASCIMENTO, CARLA - Federal University Of Bahia (UFBA)
item Moore Jr, Philip

Submitted to: Brazilian Journal of Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2024
Publication Date: 6/1/2025
Citation: Benites, V., Molin, S., Sitta, C., Sitta, E., Nascimento, C., Moore Jr, P.A. 2025. Agronomic effectiveness of partially acidified and granulated arraias phosphate rock. Brazilian Journal of Soil Science. https://doi.org.10.36783/18069657rbcs20240154.
DOI: https://doi.org/10.36783/18069657rbcs20240154

Interpretive Summary: Natural rock phosphate typically has low phosphorus (P) solubility in water, so it is not a great phosphorus fertilizer. This rock can be acidified to increase the phosphorus solubility, but that increases the cost. The goal of this study was to evaluate the agronomic efficiency of partially acidified and micro-granulated Arraias phosphate rock. Two greenhouse studies were conducted using corn grown in pots with two kg of oxisol. There were six fertilizer treatments; (1) unfertilized control, (2) triple superphosphate, (3) unacidified Arraias phosphate rock, (4) partially acidified phosphate rock with 5% sulfuric acid (PAPR 5%), (5) PAPR 10%, and (6) PAPR 15%. For the second greenhouse experiment, fertilizer treatments were made with PAPR 15% granulated to average sizes of 0.25, 0.75, 1.50, and 2.4 mm. The agronomic efficiency of all variations of the phosphate rock was lower than the TSP. The PAPR 15% treatment resulted in the highest corn dry mass yield among partially acidulated PR. Granule size did not influence PAPR efficiency with regard to plant biomass, but it did increase phosphorus uptake. Under conditions of this study, partially acidulated and granulated phosphate rock was not an effective alternative to TSP.

Technical Abstract: Natural phosphate rocks (PR) are characterized by low phosphorus (P) solubility in water. Acidification is the normal method to raise P solubility of these materials, however; it increases the cost and causes operational issues. The aim of this study was to evaluate the agronomic efficiency of partially acidified and micro-granulated Arraias phosphate rock. Two experiments were carried out in a greenhouse at the University of Rio Verde, GO, in which corn was grown in pots with two kg of red clayey oxisol. Treatments for first experiment were the natural Arraias phosphate rock; triple superphosphate (TSP) and three partially acidified phosphate rock (PAPR) with 5, 10 and 15 % of H2SO4 relative to PR mass. For the second experiment, treatments were 15% PAPR granulated to average sizes of 0.25, 0.75, 1.50, and 2.4 mm. The agronomic efficiency of all variations of the PR was lower than the TSP. The 15% PAPR treatment resulted in the highest corn dry mass yield among partially acidulated PR. Granule size did not influence PAPR efficiency . Under conditions of this study, partially acidulated and granulated phosphate rock was not an effective alternative to TSP.