Selecting legume cover crops for hillside environments in Bolivia

The mid-elevation hillsides of the Cochabamba region of Bolivia between 2,5 00 and 4,000 m asl are characterized by a multitude of microclimates for cr op production. Poor productivity of food crops in the Cochabamba region has been associated principally with declining soil fertility. The time for na tural fallow has declined steadily as more land for crop production is requ ired. The use of legume cover crops, therefore, to improve the restoration of soil fertility during the brief natural fallow period offers considerabl e possibilities for improvement. Potential legume cover crops were identifi ed that can germinate, newer, and set seed within the possible growing seas on constrained by temperature, photoperiod, and rainfall patterns. A photot hermal model was calibrated for each of twelve cover crops. Simulations wer e run using the climate records for three hillside sites near Cochabamba. S ix of the more temperate cover crops investigated could mature and provide seed from any sowing date at 2,600 m, and from most sowings at 3,220 m, but few were adapted to 3,490 m. Potential cover crops, not currently grown lo cally, and adapted for this cropping system, were identified and recommende d for further field trials.