THE EFFECTS OF SOLE AND TRADITIONAL INTERCROPPING OF MILLET AND COWPEA ON SOIL AND CROP PRODUCTIVITY

The after effects of three years' continuous cropping with sole millet , sole cowpea or a traditional millet/cowpea intercrop were compared u sing five levels of nitrogen fertilizer. The continuous sole cowpea sy stem had reduced the carbon to nitrogen ratio more than the continuous sole millet or the traditional intercrop. The test crop millet yielde d much more, and its uptake of nitrogen and phosphorus was greater, wh en it followed sole cowpea than when it followed sole millet or the tr aditional millet/cowpea intercrop. The three years' continuous sole co wpea had an effect equivalent to the application of 205 kg N ha-1 on t he test crop of millet. It also caused the greatest reduction in Strig a infestation in the test crop. It is therefore recommended that cowpe a cultivation be increased in the Sahel.