Evaluation of N and P Contribution to Improve Soil Fertility Potentials of the (Vicia faba L. and Glycine max L.) to Subsequent Cereal Crops

Abstract

Decline in soil fertility has become a serious problem in the Sub Saharan Africa region. Among the countries in SSA, Ethiopia has the highest rates of nutrient (N and P) depletions mainly due to the low nutrient input. However, the net contribution of legumes to soil nutrient balance is determined by the extent to which crop residue is removed from the field. Therefore, we assessed two possible selected grain legumes (Vicia faba L. and Glycine max L.). Soil samples were collected on a transect walk from Dedo and Tiro-Afeta districts. Six composite soil samples from each transect based on elevation were collected at the depth of (0-30cm). The soil samples were collected from fields that are known to grow continuous cereal-cereal at least for the last three years. A pot experiment was therefore conducted under screen house a condition in a RCBD with three replications on soils obtained from transects. Soil physic-chemical properties were studied before and after sowing. All plants related data from crops were recorded at 75% flowering stage. The effect of different elevation levels showed that soil properties before planting were significantly (P<0.05) for all studied parameters. The effect was observed by measuring soil and plant biomass (N and P) for each Vicia faba L. and Glycine max L. The study showed a significant (P<0.05) difference and positive correlation between treatments with soil available P before planting for both crops. Vicia faba L. recorded higher value for the N and P under Dedo soils than Glycine max L. for the same parameter.  Similarly, Glycine max L. recorded higher value under Tiro-Afeta soils than Vicia faba L for the N and P. Thus, this study concludes that firstly growing Vicia faba L. crop on the Dedo soils and the Glycine max L. crop on the Tiro-Afeta soils would improve N and P quickly and inexpensively thereby crop productivity can be enhanced.

Keywords: Vicia faba L., Glycine max L., N and P.