2 results
Nitrogen balance as an indicator of environmental impact: Toward sustainable agricultural production
- G.F. Sassenrath, J.M. Schneider, R. Gaj, W. Grzebisz, J.M. Halloran
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- Journal:
- Renewable Agriculture and Food Systems / Volume 28 / Issue 3 / September 2013
- Published online by Cambridge University Press:
- 02 May 2012, pp. 276-289
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Efficient nutrient use is critical to ensure economical crop production while minimizing the impact of excessive nutrient applications on the environment. Nitrogen (N) is a key component of agricultural production, both as an input to support crop production and as a waste product of livestock production. Increasing concern for future sustainability of agricultural production and preservation of the natural resource base has led to the development of nutrient budgets as indicators and policy instruments for nutrient management. Nutrient budgets for N have been developed by the Organization for Economic Co-operation and Development (OECD) as agri-environmental indicators to compare the evolving conditions in member states, and are also used by the US Department of Agriculture Natural Resource Conservation Service (USDA-NRCS) to develop nutrient management plans. Here, we examine the crop and animal production systems, drivers impacting management choices, and the outcome of those choices to assess the utility of gross annual N balances in tracking the progress of management decisions in minimizing the environmental impact of agricultural production systems. We use as case studies two very different agronomic production systems: Mississippi, USA and Poland. State and country level data from the US Department of Agriculture and OECD databases are used to develop data for the years 1998–2008, and gross annual N balances are computed. Examination of agricultural production practices reveals that the gross annual N balance is a useful tool in identifying differences in the magnitude and trends in N within agricultural systems over large areas. Significant differences in the magnitude of the N budget were observed between the highly diversified, small-scale agriculture common to Poland, and the large-scale, intensive agriculture of Mississippi. It is noted that use of N balance indices can be problematic if the primary intent is to reveal the impact of economic drivers, such as crop prices, or management choices, such as tillage or crop rotation. Changes in cropping systems in response to commodity prices that improve N balance can be masked by detrimental growing conditions, including edaphic, biotic and weather conditions, that are outside of the producers’ control. Moreover, use of large area-scale indices such as country or state-wide balances may mask the severity of localized nutrient imbalances that result from regionalized production systems that overwhelm the nutrient balance, such as confinement livestock production. Development of a policy to address environmental impact and establish sustainable production systems must consider the year-to-year variability of drivers impacting agricultural production, and the spatial heterogeneity of nutrient imbalance.
External economic drivers and US agricultural production systems
- J.M. Halloran, D.W. Archer
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- Journal:
- Renewable Agriculture and Food Systems / Volume 23 / Issue 4 / December 2008
- Published online by Cambridge University Press:
- 30 June 2008, pp. 296-303
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US agriculture operates in a market driven economy, although government policies can have influence on what farmers produce and how they produce it. As with other businesses, agricultural producers respond to economic incentives and disincentives, and make decisions to maximize their welfare; usually measured as net income. We examined how external economic drivers shape the type of agricultural systems that producers adopt. Specifically, we considered the influence of technological advancements, income supports embodied in farm legislation, and changes in market structure and consumer demand. Changes in technology have often favored large-scale and specialized operations. Many of the technological advancements have required large-scale production units to justify the investment. Often the technology has been commodity specific. However, there is some evidence that more diversified production units might be able to achieve economies of both scale and scope. The influence of commodity support programs has been ambiguous. As farm legislation has evolved to decouple production decisions from program benefits, the incentives to specialize in program crops (crops that receive price and/or income benefits under federal legislation, such as corn, other grains and oil seeds) have diminished. However, wealth and risk effects, albeit small, may have promoted or inhibited the adoption of a more integrated system. The ability of producers to adopt more integrated systems has been primarily influenced by their natural resource base and proximity to markets. Changes in market structure, channels and consumer demand in the past five decades have been dramatic with consolidation and specialization in both production and marketing sectors. However, the diversity of consumer demand has also created opportunities for more integrated farm operations. There is an increasing number of consumers who have become concerned about how and where their food has been produced. Markets for organic, locally produced, free range and the like are expected to grow. While price and income supports may have been biased towards specialization (as these programs were targeted to specific commodities), the reduction in risk associated with the programs has enabled producers to expand the number and diversity of their production enterprises. Furthermore, through the use of strategic alliances, cooperation among producers on a regional basis may eventually lead to greater integration and diversification than could be achieved for the individual farm operation.