results of a nationwide survey to determine feedstuffs fed to lactating dairy cows.a nationwide survey to determine feedstuffs used in the diets of dairy cows was conducted. this survey was mailed to dairy nutritionists at universities in each state to describe the use of 144 feedstuffs. twenty-eight states responded and were grouped by region as follows: northeast (maine, maryland, new hampshire, new york, ohio, vermont, and west virginia), northwest (idaho, oregon, and washington), midwest (iowa, illinois, michigan, minnesota, missouri, nebraska, north dakota, south dakota, ...199910068966
improving nitrogen efficiency: lessons from malawi and michigan.two case studies are presented here of nitrogen (n) dynamics in potato/maize systems. contrasting systems were investigated from (1) the highland tropics of dedza, malawi in southern africa and (2) the northern temperate great lakes region of michigan. formal surveys were conducted to document grower perceptions and n management strategies. survey data were linked with n budgets conducted by reviewing on-farm data from representative farms in the targeted agroecosystems and simulation modeling t ...200112805780
increasing corn for biofuel production reduces biocontrol services in agricultural landscapes.increased demand for corn grain as an ethanol feedstock is altering u.s. agricultural landscapes and the ecosystem services they provide. from 2006 to 2007, corn acreage increased 19% nationally, resulting in reduced crop diversity in many areas. biological control of insects is an ecosystem service that is strongly influenced by local landscape structure. here, we estimate the value of natural biological control of the soybean aphid, a major pest in agricultural landscapes, and the economic imp ...200819075234
ovarian development and ovipositional preference of the western corn rootworm (coleoptera: chrysomelidae) variant in east central illinois.the rotation of maize, zea mays l., and soybean, glycine max (l.) merr., has been the traditional cultural tactic to manage the western corn rootworm, diabrotica virgifera virgifera leconte, in the corn belt. the reduced effectiveness of this rotation as a pest management tool in east central illinois, northern indiana, and southern michigan can be explained by the shift in the ovipositional behavior of the new variant of western corn rootworm. the objective of this study was to evaluate the inf ...200415154460
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