Nutrient requirements of ahipa, a tuberous-root crop

Abstract

Ahipa is a legume crop of great potential for the production of raw materials (starch, sugar, oil, and proteins) for industrial use. Its ability to fix atmospheric N2 in association with rhizobia and the tolerance to insects makes it an attractive option for low input agriculture schemes. There is little information available on nutrient requirements of ahipa and none about its behavior in Mediterranean soils. Leaf macro and micronutrient concentration in ahipa field-grown plants was compared with critical levels reported for other legume crops. Low leaf phosphorus (P) and potassium (K) concentration, as well as leaf zinc (Zn) and copper (Cu) might show limiting conditions for growth and productivity in some Mediterranean soils. The evolution of N, P, and K uptake and nutrient distribution in different plant parts was studied in ahipa under field conditions. At harvest, seeds showed high N accumulation whereas roots and pod-shells were the main recipients for P and K. The amount of nutrients removed by harvested roots and seeds was calculated in 67 kg N ha -1, 13.7 kg P ha-1, and 80.2 kg K ha-1.