The economic opportunities for increasing the use of forage legumes in north European livestock systems under both conventional and organic management

Abstract

Changing from a conventional livestock production system, based on fertilized grass swards, to an organic management system requires the establishment of legume-based swards to replace the purchased fertilizer nitrogen. This paper reviews experimental-based research on both the comparative economics of legume-based systems and grass swards and also the economic advantage that forage legumes confer on organic systems. A methodology to determine the production costs and economic values of a variety of forage legume systems is outlined. The resultant methodology is then applied to experimental results from trials, conducted at a wide range of sites in northern Europe, to determine the comparative profitability of different legume-based systems of silage production under conventional management. The results indicate that potentially red clover (Trifolium pratense L.), and to a lesser extent white clover (Trifolium repens L.), and lucerne (alfalfa) (Medicago sativa L.), can produce higher profits per hectare than grass-based systems using high levels of nitrogen fertilizer. Galega (Galega orientalis Lam) and lotus (Lotus corniculatus L.) can, in certain circumstances, be economically competitive with fertilized grass swards, but would generally not be the forage legumes of first choice. From an economic standpoint, forage legumes are probably best grown in a mixture with grass. As some of the experimental sites involved organic treatments, the analysis has been extended to include an assessment of the comparative economics of organic systems of production based on forage legumes, relative to conventional grass-based systems. Thus, the third part of the paper is concerned with quantifying the economic advantage to organic systems conferred by forage legumes. The results indicate that, under careful management, their use for silage can produce higher profits per hectare for organic dairy systems than those obtained from conventional grass-based systems. While the relative performance of organic systems is strongly influenced by the price premium paid for organic milk, which has declined in recent years, not all the projected economic advantage of legume-based organic dairy systems is eroded by this trend. However, economic advantage is not enough to secure the widespread adoption of forage legumes. This will depend on technological developments and management practices which reduce the risks associated with both more difficult crop establishment and higher nitrate leaching of forage legumes as compared to grass swards.