An analysis of environmental and economic implications of nil and restricted grazing systems designed to reduce nitrate leaching from New Zealand dairy farms. II. Pasture production and cost/benefit analysis

摘要

Abstract Nitrate leaching from animal urine is perceived to be a serious consequence of dairy farming. Previous results suggested that nil and restricted grazing systems could reduce nitrate leaching by up to 50%. It is likely that such systems may also increase pasture production. However, potential disadvantages include reduction in the clover content of pastures and increase in capital and/or operating costs. This paper examines the economic implications of nil and restricted grazing systems based on data from an average New Zealand dairy farm and from a long‐term farmlet study. The analyses suggested that pasture production increased by about 20% and 2–8%, respectively, compared with a conventional grazing system. Based on the average New Zealand dairy farm, the costs/benefit analysis of the nil grazing system suggested a negative return on capital of about ‐10%. For the restricted grazing system, the average return on capital was about 9% (range: ‐4 to 25%) and depended largely on the efficiency of a...