United States agriculture has become increasingly more efficient over the last two decades, using fewer inputs to produce higher yields, according to the
Environmental Resources indicators report by the Keystone Alliance for Sustainable Agriculture.
The unique and diverse alliance, also known as Field to Market, represents grower organisations, agribusinesses, food companies and conservation groups.
"The report evaluated land use, water use, energy use, soil loss and climate impact in corn, soybeans, cotton and wheat production since 1987," said Sarah Stokes-Alexander, director of sustainability and leadership programs, The Keystone Center.
The Keystone Center is a neutral, non-profit organisation specialising in collaborative decision-making processes for environment, energy and health policy issues.
"Several trends are emerging", says Michael Reuter, The Nature Conservancy.
"Importantly, production agriculture has become increasingly efficient, relying on fewer inputs to produce more.
"However, we recognise there are significant challenges ahead in meeting increased global demand in a sustainable manner."
Kevin Rogers, an Arizona cotton grower, says increased productivity and improved national resource management "will be vitally important as we seek to feed, fuel and clothe our growing world population on the same amount of land in the decades ahead".
"The best opportunity to achieve this goal is for all groups in the food chain to work collaboratively.
"Participation from farmers and the conservation organisations is vitally important."
The report evaluated national-scale metrics since 1987.
The initial index shows soil-loss efficiency trends have improved substantially by 30pc to nearly 70pc for the four crops evaluated.
Energy use per unit of output is down in corn, soybeans and cotton production by nearly 40pc to more than 605.
Irrigated water use per unit of output has also decreased 20pc to nearly 50pc, while carbon emissions per unit of output have dropped by about one-third for these three crops.
"The results are intended to provide meaningful and credible information to shape knowledge-based decisions and to allow tracking of trends over time," explained Stokes-Alexander.
The group plans to provide a similar report on water quality in mid-2009.
In addition to the findings, the report is significant for its direction toward creating a comprehensive methodology that can become the standard for measuring agriculture's sustainability.
"Field to Market conducted a broad-based peer-review process that included 17 experts from universities, government and other institutions to enhance the methodology," noted Stokes-Alexander.
Field to Market members include: American Farm Bureau Federation; American Soybean Association; Bayer CropScience; Bunge; Cargill, Incorporated; ConAgra Foods; Conservation International; Cotton Incorporated; DuPont; Fleishman-Hillard; General Mills; Grocery Manufacturers Association; John Deere; Manomet Center for Conservation Sciences; Mars, Incorporated; Monsanto Company; National Association of Conservation Districts; National Association of Wheat Growers; National Corn Growers Association; National Cotton Council of America; National Potato Council; Syngenta; The Coca-Cola Company; The Fertilizer Institute; Kellogg Company; The Nature Conservancy; United Soybean Board; and World Wildlife Fund.