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

Abstract

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.

Assessment of Guinea Grass Panicum maximum under Silvopastoral Systems in Combination with Two Management Systems in Orellana Province, Ecuador

“…Panicum maximum is widely used in livestock systems in the tropical region of Ecuador. This guinea grass has high persistence and productivity due to its high photosynthetic and water efficiency, and it has high forage production potential with adequate nutritional value; it is also highly adaptable to different climate conditions and poor soils [6,22].…”

La interfaz suelo-planta en Megathyrsus maximus cv. Mombasa sometida a diferentes dosis de nitrógeno en pastoreo rotacional

“…The PR is directly related to the stocking rate (37) , which was a determining factor in increasing PR in the pastures that received N300 in the post-grazing period. Notably, in the soil's superficial layers (0-10 cm), most grass roots are concentrated (38,39) . A PR greater than 2.5 MPa at these depths can therefore limit the development of roots (37,40) .…”

Morphogenetic, structural and production traits of marandu grass under nitrogen rates in Neo soil

“…The increased availability of N in the soil and, consequently, in the plant cells, enhanced the photosynthetic process. This, in turn, leads to changes in the structural characteristics of the tillers, such as size, weight and appearance rate (Alencar et al, 2010;Gurgel et al, 2020a). These morphogenetic variables directly influence structural variables (Pontes et al, 2003) and promote positive responses in production traits.…”