Livestock Production and Its Impact on Nutrient Pollution and Greenhouse Gas Emissions

Abstract

Abstract The livestock sector provides more than one-third of human protein needs and is a major provider of livelihood in almost all developing countries. While providing such immense benefits to the population, poor livestock management can potentially provide harmful environmental impacts at local, regional, and national levels which have not been adequately addressed in many countries with emerging economies. Twenty-six percent of global land area is used for livestock production and forest lands are continuously being lost to such activities. Land degradation through soil erosion and nutrient depletion is very common across pastures and rangelands. The intensification of livestock production led to large surpluses of on-farm nitrogen and phosphorus inputs that can potentially contribute to nonpoint source pollution of water resources in many parts of the world. The sector is one of the largest sources of greenhouse gases (GHGs) contributing around 14.5% of all human-induced GHG emissions, a major driver of use and pollution of freshwater (accounting 10% anthropogenic water use) and a contributor to the loss of biodiversity. About 60% of global biomass harvested annually to support all human activity is consumed by livestock industry, undermining the sustainability of allocating such large resource to the industry. Despite the negative impacts of livestock production, opportunities exist to balance the competing demands of livestock production and the environment. These include (1) improved technologies and practices that increase livestock productivity with optimal use of land and water, (2) reorienting grazing systems to provide environmental services for water, biodiversity, carbon sequestration, and resource conservation, (3) reducing GHG emission from livestock production, and (4) an effective management strategy for efficient and sustainable use of manure in livestock production. Further research, appropriate policy development, and institutional support are important to ensure the competitiveness of the industry. Integration of crops with livestock production provides opportunities for increasing resource use efficiencies and reducing environmental pollution, making the system resilient to impacts of climate change, reducing GHG emissions from the system, enhancing soil quality and fertility, and improving water quantity and quality. Appropriate techniques for assessing and monitoring impacts of livestock production are necessary for developing strategies and making the system profitable, sustainable, and resilient. Isotopic and nuclear techniques play an important role in such assessment and monitoring.