|Roth, G - PENN STATE UNIVERSITY|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2002
Publication Date: August 20, 2002
Citation: ROTZ, C.A., ROTH, G.W., STOUT, W.L. ECONOMIC AND ENVIRONMENTAL IMPLICATIONS OF SMALL GRAIN PRODUCTION AND USE ON PENNSYLVANIA DAIRY FARMS. Applied Engineering in Agriculture. 2002. Interpretive Summary: Wheat, barley, and rye crops can potentially provide supplemental grain or forage on dairy farms in Pennsylvania and other Mid-Atlantic states. These small grain crops can be grown over the fall and winter months. With an early harvest in mid May, a double crop of corn harvested for silage can follow the small grain crop. Use of small grain crops in the cropping system may provide several advantages. These include yields that are less prone to drought than corn and more diversity in the crop sequence, both of which reduce production risk. Use of small grain crops can also provide a cover crop over the winter, reducing soil erosion and nitrate leaching to ground water. There are also disadvantages though including lower corn yields following a small grain crop and greater production costs. Because the performance of cropping strategies is highly dependent on weather and soil conditions, it is difficult to evaluate their impact on farms using experimental procedures. Long-term computer simulations of dairy farms using various cropping systems determined that the use of small grain crops reduced nitrogen leaching loss, reduced soil phosphorus accumulation, and improved farm profit. Thus, use of small grain crops on dairy farms should be encouraged in this region for their environmental and economic benefits, particularly when double cropped with corn.
Technical Abstract: Two challenges facing dairy producers are low profit and environmental concerns related to nutrient management. Whole farm simulation was used to determine if adding small grain crops to traditional corn (Zea mays L.) and alfalfa (Medicago sativa L.) rotations could provide long-term environmental and economic benefits. Small grain cropping strategies included: 1) corn double cropped with barley (Hordeum spp.) harvested as cash crop grain and straw bedding, 2) corn double cropped with barley harvested as feed grain and straw, 3) corn double cropped with barley harvested as silage, 4) corn double cropped with rye (Secale spp.) harvested as silage, and 5) corn replaced with cash crop wheat (Triticum spp.) and straw. Nitrogen leaching loss over the farm was reduced by 10 kg ha-1 when 40% of the corn was double cropped with a small grain, and soil P accumulation was reduced by 2 to 3 kg ha-1. Farm net return or profit was increased by up to $111 cow-1 when barley or wheat was harvested as grain and straw, by $15 cow-1 for double-cropped barley silage, and $36 cow-1 for double-cropped rye silage. Use of small grains generally reduced the risk or year-to-year variation in net return. The economic benefit of using small grains was not sensitive to farm size, herd milk production level, the amount of forage used in animal rations, and grain prices. Less economic benefit was obtained for using small grains when the farm was moved to a more northern climate or straw was not harvested and used for bedding. Use of small grain crops on Pennsylvania dairy farms should be encouraged, particularly when double cropped with corn, to reduce N leaching loss, reduce soil P accumulation, and improve farm profit.