The soil organic matter content in the topsoil
Increased input of organic materials to EF was made possible by a reduction in the flow of BMS-794833 out of the farming system (mainly through aftermath grazing), and an increase in the flow of biomass into the farming system. An average of 40% of the crop residue produced by OF was exported – to other farms – through aftermath grazing (Fig. 5). In opposition, all the crop residue biomass produced by EF was used on-farm (as feed, fuel or soil amendment) and none of it was exported to other farms (Fig. 5). Aftermath grazing is a major source of nutrient loss for African smallholders, particularly for the poorest ones who own little or no livestock. For example, in north-eastern Zimbabwe, maize residue produced by non-cattle-owning farmers was estimated to represent about 30% of the biomass consumed by livestock during winter (Rufino et al., 2011). As manure is applied exclusively to the fields of the wealthier, cattle-owning farmers (Zingore et al., 2011), aftermath grazing results in an accumulation of nutrients in the fields of wealthier, cattle-owning, farmers and in the depletion of nutrients from poorer, non-cattle-owning farmers. Farmland exclosure may thus improve equity between poorer and wealthier farmers.