Forage-based Livestock Research Articles

Phosphorus Management and Water Quality Problems in Grazingland Ecosystems

Phosphorus management in grazingland ecosystems represents a major challenge of agronomic and environmental importance. Because of the extensive acreage occupied by grazinglands, decisions concerning pasture fertilization and nutrient management in forage-based livestock systems are crucial to both farmers and regulatory agencies. The purpose of this paper is to provide an overview of the literature relevant to pasture P fertilization and the potential impacts on water quality. There continue to be uncertainties regarding interrelationships between pasture management and water quality issues. Despite the extensive body of literature on nutrient transport from grazinglands, limited information is available on the relationships between land use, transport potential, water management, and climatic conditions affecting nutrient losses at a watershed scale. As agriculture continues to modernize and intensify, public concerns about the impacts of plant nutrients on environmental quality will likely increase. Managing water quality protection and profitable agriculture will be a major challenge for the next generations.

Nitrogen and Phosphorus Status of Soils and Trophic State of Lakes Associated with Forage‐Based Beef Cattle Operations in Florida

Forage-based livestock systems have been implicated as major contributors to deteriorating water quality, particularly for phosphorus (P) from commercial fertilizers and manures affecting surface and ground water quality. Little information exists regarding possible magnitudes of nutrient losses from pastures that are managed for both grazing and hay production and how these might impact adjacent bodies of water. We examined the changes that have occurred in soil fertility levels of rhizoma peanut (Arachis glabrata Benth.)-based beef cattle pastures (n = 4) in Florida from 1988 to 2002. These pastures were managed for grazing in spring followed by haying in late summer and were fertilized annually with P (39 kg P2O5 ha(-1)) and K (68 kg K2O ha(-1)). Additionally, we investigated trends in water quality parameters and trophic state index (TSI) of lakes (n = 3) associated with beef cattle operations from 1993 to 2002. Overall, there was no spatial or temporal buildup of soil P and other crop nutrients despite the annual application of fertilizers and daily in-field loading of animal waste. In fact, soil fertility levels showed a declining trend for crop nutrient levels, especially soil P (y = 146.57 - 8.14 x year; r2= 0.75), even though the fields had a history of P fertilization and the cattle were rotated into the legume fields. Our results indicate that when nutrients are not applied in excess, cow-calf systems are slight exporters of P, K, Ca, and Mg through removal of cut hay. Water quality in lakes associated with cattle production was "good" (30-46 TSI) based on the Florida Water Quality Standard. These findings indicate that properly managed livestock operations may not be major contributors to excess loads of nutrients (especially P) in surface water.

Benefits of Re-Integrating Livestock and Forages in Crop Production Systems

SUMMARY Specialization is the foundation of contemporary agriculture, yet until the early decades of the 20th century, enterprise diversity was the norm. As agriculture has become more specialized in the intervening years, yields have increased dramatically, but so too have a range of economic, environmental, and health problems. This contribution presents evidence that specialization is an ecologically dysfunctional design for food production, a thesis which is supported by the predominance of problem-solving research in the contemporary literature. As demonstrated by Louis Bromfield in the 1940s and by organic and sustainable farmers today, the strategic integration of crops and livestock/ forage enterprises avoids many of the problems of specialization, while also capturing economic and ecological synergies denied to specialist producers. In addition to providing human foodstuffs, forage-based livestock production also offers a range of novel opportunities to channel natural processes to the service of humanity, from carbon sequestration and site remediation to non-chemical vegetation management.