WIND EROSION CONTROL USING CROP RESIDUE .2. EFFECTS ON MILLET ESTABLISHMENT AND YIELDS

Effects of three levels of millet stover residue (0, 500, and 2000 kg ha-1) on establishment and growth of pearl millet (Pennisetum glaucum (L.) R.Br) were determined in a wind-erosion-affected area in Niger, West Africa, during 1991 and 1992. The extent of millet seedlings buried by blown soil in plots with 500 kg ha-1 residues was similar to that of control plots. A residue amount of 2000 kg ha-1 reduced the extent of covered millet, but did not provide complete protection during severe sand storms. Partial covering of millet seedlings by blown soil decreased biomass yields compared to uncovered millet. Grain production, averaged over two years, was about 500 kg ha-1 for the control, 570 kg ha-1 with 500 kg ha-1 residue, and 730 kg ha-1 with 2000 kg ha-1 residue. Increased yields were caused by both wind erosion protection and direct growth stimulating effects of residue. Stover yields for all treatments in both years were less than 2000 kg ha-1 and thus insufficient to sustain the levels required for protection of crops against wind erosion damages. An increase in dry matter left in the field or the implementation of alternative wind erosion control measures is needed for sustainable crop production in wind-erosion-affected areas.