Soil Attributes and Productivity of Sorghum as a Function of Gypsum and Potassium Doses

ABSTRACT

This study aimed to evaluate the influence of gypsum application in association with potassium doses in the cerrado soil chemical attributes and sorghum grain yield. The experiment was conducted in a Latosol of a Cerrado biome in a 5 × 5 factorial scheme, being five doses of gypsum (0, 500, 1,000, 2,000, 4,000 kg ha⁻¹) and five doses of potassium (0, 100, 180, 240, 360 kg ha⁻¹ of potassium dioxide – K₂O) as potassium chloride in a complete block design, with four replications. Sorghum yield and soil chemical modifications after crop cultivation in the 0–0.2 and 0.2–0.4 m layers were evaluated. Sorghum yield was not influenced by the factors assessed. The highest dose of gypsum increased the concentration of calcium and sulfur and raised the sum of bases and base saturation in both soil layers evaluated. In the 0.2–0.4 m layer, the highest dose of gypsum increased the availability of phosphorus and sulfur by 32.5% and 681%, respectively. The gypsum shifted the K⁺ from the 0–0.2 to the 0.2–0.4 m soil layer, demonstrating the importance of performing combined gypsum and potassium chloride applications in soils with low potassium (K) content in order to avoid the K⁺ depletion in the superficial soil layer of cerrado.

KEYWORDS:

• Calcium sulfate
• grain yield
• potassium chloride
• soil chemistry
• Sorghum bicolor

Acknowledgments

The authors acknowledge the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) for financial support for the research (RDP Processes 00202-10 and PPM 00623-11); the VALE for the partnership signed in the public call for research projects – Notice 1/2010; and the Coordination for the Improvement to Higher Education Personnel (CAPES).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado de Minas Gerais [RDP Processes 00202-10].