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

• Published in: Sustainability 2020-11, Vol.12 (22), p.9381
• Main Authors: Gurgel, Antonio Leandro Chaves, Difante, Gelson dos Santos, Araujo, Alexandre Romeiro de, Montagner, Denise Baptaglin, Euclides, Valeria Pacheco Batista, da Silva, Manoel Gustavo Paranhos
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Animal production; Beef cattle; Cultivation; Experiments; Fertilization; Grasses; Nitrogen; Pasture; Pasture management; Pastures; Penetration resistance; Potassium; Productivity; Soil density; Soil quality; Soils; Sustainability
• ISSN: 2071-1050; 2071-1050
• DOI: 10.3390/su12229381

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.