Effect of age and cutting frequency on below-ground biomass in grass-clover

Significant amounts of plant biomass and fixed N are incorporated into soil as roots, nodules and root exudates during the growth of grass-clover, which consequently is exposed to soil microbial degradation when the field is ploughed. This has major implications for our understanding of the potential contributions of legumes in the N economics and losses in grass-clover cropping systems. We have studied the effects of grass-clover pasture age and cutting frequency (simulated grazing) on the development of the above ground as well as the below ground plant biomass, with emphasis on below-harvest contribution to the total N2 fixation.