In-field rainwater harvesting: mechanical tillage implements and scope for upscaling. (Special Issue: Rainwater harvesting and conservation techniques for improving household food security.)

摘要

Around the world there is a large difference in crop yields between those obtained by commercial and subsistence farmers. There are many biophysical and socio-economic reasons for this yield gap. With regard to in-field rain water harvesting (IRWH), it is considered that crop yields in smallholder farms could be significantly improved by mechanizing the land as part of an IRWH tillage approach. This paper therefore presents the findings of a study that assessed the implements and procedures for applying IRWH. It involved the development of ridge and puddle ploughs. The subsistence farmers who evaluated the performance of the implements were generally satisfied with them. A five-step procedure was developed for the application of the implements, and valuable lessons were learned with the first large-scale demonstration of IRWH on croplands. Against the background of these positive results, the scope for upscaling was also explored. It was estimated that IRWH can probably be applied on millions of hectares in sub-Saharan Africa, and particularly in the Southern African Development Community. Mechanization of IRWH should potentially contribute towards improving food security in sub-Saharan Africa.