Carbon and Nitrogen Stocks and Soil Quality in an Area Cultivated with Guinea Grass under the Residual Effect of Nitrogen Doses

• Main Authors: Antonio Leandro Chaves Gurgel, Gelson dos Santos Difante, Alexandre Romeiro de Araujo, Denise Baptaglin Montagner, Valeria Pacheco Batista Euclides, Manoel Gustavo Paranhos da Silva
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Sustainability
• Subjects: animal production; <i>Cerrado</i> biome; environmental services; <i>Panicum maximum</i>; pasture fertilization; pasture management
• Online Access: https://www.mdpi.com/2071-1050/12/22/9381

This study examines the residual effect of nitrogen (N) doses on the carbon (C) and N stocks and on soil quality in an area cultivated with guinea grass. The pastures received three annual doses of N (100, 200 and 300 kg ha⁻¹) from 2015 to 2017. In 2018, N fertilization was not applied so the residual effect of the nutrient could be characterized. Soil chemical attributes, C and N stocks, density and penetration resistance and root system characteristics were evaluated at different depths. No difference was observed between the N doses for soil density, which averaged 1.22 and 1.25 g cm⁻³ under and between the tussocks of guinea grass, respectively. Penetration resistance was affected by the N doses post-grazing, with the highest value (1.9 MPa) observed in pastures that received 300 kg ha⁻¹ of N for three consecutive years. Root dry mass was not affected by the N doses. There was no effect of N doses on the average (19.7 mg ha⁻¹) or total (134.3 mg ha⁻¹) C stock in the soil. The total N stock did not change (11.3 mg ha⁻¹) in response to the N doses; however, the average N stock was higher in the soil cultivated with guinea grass under the N dose of 300 kg ha⁻¹ (1.7 mg ha⁻¹). The N doses had little interference with the soil chemical and physical aspects. Regardless of the dose, high C and N stocks were observed in the soil cultivated with guinea grass. Therefore, when properly managed, intensive pasture-based animal production systems become important allies of the environment.