Whole farm systems research: An integrated crop and livestock systems comparison study
To examine the long-term productivity, profitability, and ecological interactions associated with whole farming systems, we established an interdisciplinary replicated comparison of a conventional and an experimental alternative crop-livestock farming system in southwest Virginia in 1988. The conventional system uses the best management practices commonly used in the mid-Atlantic region. The alternative system puts more emphasis on crop rotation, grazing and forage management, conservation tillage, cover crops, and integrated pest management. Each is managed as a year-round system, with management decisions based on the system's overall goals. The comparison is planned to run for 10 years, so that only preliminary conclusions can be drawn so far. These include the following: 1) similar total productivity can be achieved with either reduced or full use of herbicides and insecticides; 2) the need for N fertilization can be decreased using grazing management and short-rotation alfalfa; and 3) recycling of manure from cattle fed corn silage provides most nutrients needed for the following corn crop. The comparative profitability of the two systems has fluctuated among years, and it is too early to know which system is more profitable. The process of interdisciplinary systems research has increased our knowledge of total system interactions, challenged prior assumptions, and clarified the methodological problems of integrated systems research.