Does minimum tillage with planting basins or ripping raise maize yields? Meso-panel data evidence from Zambia

Despite nearly two decades of promoting minimum tillage (MT) in Zambia, there is little empirical evidence on its maize yield effects under typical smallholder conditions. We use nationally representative survey data from nearly 48,000 smallholder maize plots for the period 2008-2011 to estimate the maize yield effects of planting basins and ripping. After controlling for unobserved heterogeneity at the enumeration area level, yields were significantly higher on ripped plots compared to conventionally plowed plots if tillage is done before the rains. The gains average 577 kg/ha nation-wide and 821 kg/ha in low rainfall agro-ecological zones. The gains from planting basins relative to hand hoe tillage average 191 kg/ha when tillage is done before the onset of the rains. Thus, MT with early land preparation can raise smallholder maize yields in Zambia; however, further research would determine whether these yield benefits are large enough to offset the higher costs of MT