Environmental impacts and nutrient recycling on pastures grazed by cattle

Abstract

Grasslands are being replaced by urbanization and more profitable agricultural activities around the world. Producers may be faced with land constraints and need to consider intensification of the remaining grasslands as a means of maintaining overall production on a decreasing land resource. However, intensification of the grazing system is usually associated with greater nutrient inputs, including those from commercial fertilizers and supplement fed to animals. Excessive loading of nutrients in intensive grazing systems via fertilizer and animal wastes can cause nutrient buildup in the soil and subsequent water quality problems. Surface runoff and leaching of nutrients are the two major process affecting water quality. Nitrogen and P represent major nutrient concerns as related to water quality. Increased nitrate concentrations render groundwater unsuitable for drinking and can cause serious health issues for humans. Excessive N and P concentrations may contribute to eutrophication of streams and lakes. Maximizing efficiency of nutrient recycling through the soil-forage-animal system minimizes off-site nutrient transport and decreases production costs by reducing the quantity of commercial fertilizer needed. Management strategies to reduce soil and water contamination include refining the balance of nutrient inputs from feeds and fertilizers as well as accounting for the nutrients recycled through the decomposition of plant litter and animal wastes. Current interest in the development and adoption of efficient and sustainable agriculture systems has led forage researchers to amplify the scope of grasslands research by increasing multidisciplinary efforts. There is an increased interest in quantifying the impacts of forage-animal management strategies on the environment, with the goal of developing economically viable best management practices that result in optimum forage production and profitability, while protecting the environment. Furthermore, these best management practices will supply reliable information for future environmental policies that may be adopted by governmental agencies

Temperature and Moisture Controls of C Fluxes in Grazed Subalpine Grasslands

“…Since there were no significant differences in either soil temperature and moisture or soil C or nutrient status between cattle-and sheep-grazed areas, we speculate that the increased GEP, R e , and R s in cattle-grazed areas may be driven by changes in the nutrient cycling resulting from the shift in herbivore type driven by (i) changes in the species composition and their decomposition rate and hence nutrient availability, and/or (ii) greater input of feces and trampling caused by cattle (Bardgett, 1998;Güsewell et al, 2003;Olofsson et al, 2004;Vendramini et al, 2007). Alternatively, the greater C turnover found in the cattlegrazed area might also be driven by the shifts in plant species composition resulting from the change from sheep to cattle grazing (Sebastià et al, 2008a).…”

Infestação de Tetranychus ogmophallos Ferreira & Flechtmann (Acari: Tetranychidae) em Amendoim Forrageiro (Arachis pintoi Krapov. & Greg.) nos Estados do Acre e Minas Gerais

“…intensificação dos sistemas de produção de pecuária bovina a pasto geralmente está associada com o aporte de nutrientes, incluindo fertilizantes químicos e suplementos para os animais (Vendramini et al 2007). Entre as diversas espécies de leguminosas forrageiras, espécies silvestres do gênero Arachis (Fabaceae), conhecidas popularmente por "amendoim forrageiro", vêm despertando interesse de muitos produtores e pesquisadores ao redor do mundo (Cook et al 2005;radoViCh et al 2009).…”

Evaluation and comparison of soil under integrated crop‐livestock-forest system in the southeast of Gois, Brazil

“…Partitioning of nutrients between feces and urine also reduces the uniformity of nutrient return through excreta. Cattle grazing a given patch consume forage containing different nutrients; however, the return does not occur uniformly at a given site (Vendramini et al, 2007).…”