Maize Yield Response to N, P, K, Population, and Planting Date In Lesotho, Southern Africa.

Conservation agriculture (CA) practices are accepted as a means of increasing soil carbon, and thus productivity, in a variety of climates and geographic locations.  As with any farming practice, it is necessary to adjust fertilizer rates to maximize the benefits for particular soil and climatic regions, and these can only be determined through experimentation.  The study was conducted near Mohale’s Hoek and Roma, Lesotho.  High erosion rates and low soil fertility make the farmlands of Lesotho in sub-Saharan Africa an ideal region to profit from the benefits of CA, particularly the potential to increase the maize yields in a country that is a net importer of its staple food despite the vast areas of land under maize production.  There is currently no scientific data confirming even fertilizer recommendations, plant populations, or date of planting for growing maize in a CA rotation, and without this knowledge farmers cannot maximize their economic yields.  We evaluated N, P, and K fertilizer rates, planting dates, and plant populations and calculated maximimum economic yields for livelihood farmers that use only a hoe, small-scale farmers that use oxen for draft power, and larger-scale farmers that use tractor drawn planters. Decreasing inter- and intra-row spacing, planting as soon as the first October rains appear, applying a pre-plant fertilizer N and P, and side-dressing N are important in maximizing yield and profitability.