Soil fertility and crop management research on cool-season food legumes in the central highlands of Ethiopia
Land degradation and depletion of soil fertility is the critical challenge for sustainable crop production in the highlands of Ethiopia. This paper reviews advances in the major activities and achievements of soil fertility, crop and land management research on the highland pulses, which have been done for the last two decades in the central highlands of Ethiopia. Inappropriate agronomic practices, poor internal drainage, soil acidity and associated low phosphorus (P) availability are major constraints affecting productivity of highland food legumes. Production practices differ across the major highland pulse growing areas of the country. Research findings showed that twice tillage before planting and one properly timed hand weeding resulted in optimum yields of faba bean and field pea. Substantial increments in seed and biomass outputs of faba bean and chickpea were recorded on Vertisols due to the integrated application of improved surface drainage, sowing date and genotypes. At Holetta, the application of lime as calcium carbonate at the rate of 1, 3 and 5 t ha-1 on Nitisols increased mean seed yield of faba bean by 45, 77 and 81%, respectively over non-treated plots. Similarly, application of 23/20-32/30 kg N/P ha-1 on Nitisols resulted in the highest net benefit for faba bean and field pea production. Phosphorus by farmyard manure interaction significantly increased faba bean seed yield. Field pea seed yield also increased at the low and medium soil fertility levels with increasing rates of P application. In conclusion, a concerted effort is necessary to extend the available technologies in order to improve the productivity of highland food legumes.