SOIL-MANAGEMENT FOR CROP PRODUCTION IN THE WEST AFRICAN SAHEL .2. EMERGENCE, ESTABLISHMENT, AND YIELD OF PEARL-MILLET

Crop establishment is an important yield factor for pearl millet in the Sahel. Therefore, we conducted a series of experiments to determine the effects of seed size, depth and method of planting, millet variety, pre-sowing tillage, and soil fertilization upon seedling emergence, crop establishment, and yield. All experiments were conducted on a sandy Psammentic Paleustalf in Niger. For all three millet varieties studied, out of a range of sowing depths from 1 to 7 cm, a sowing depth of 3-5 cm resulted in the highest percentage emergence, the highest above-ground biomass. and most secondary roots. High soil temperatures are common during establishment, typical maximum temperatures at a depth of 1 cm exceed 46-degrees-C. The adverse effects of wind erosion were least when sowing in hills; establishment, crop stand survival, and yield were better under hill planting than drilling seed. Pre-sowing tillage increased initial stands and their survival, the latter also depending on fertility. Thus, improved crop yields result from better stand survival and higher yields per hill. Fertilizer application of 17 kg ha-1 P and 40 kg ha-1 of N tripled grain yields. Ridging without prior tillage and plowing increased grain and stover yields two- to three-fold. In combination with fertilizer application, sixfold yield increases were obtained. If pre-sowing tillage is considered, then, in view of the time limitations, ridging without prior tillage would be preferable to plowing, as it is a much faster operation giving equally good results in terms of crop establishment and yield.