Abstract:

Common bean (Phaseolus vulgaris L.) is one of the most important grain legumes in East Africa, but its yield has
remained below the genetic potential. Declining soil fertility is among the primary constraints to bean production
in most East African bean producing regions. Often existing recommendations are generic and inept to guide farm
level decision making on nutrient replenishment. A greenhouse nutrient omission study was conducted to determine
the limiting nutrients in three soils of Masaka District, commonly cropped to beans: “Liddugavu” a Phaeozem,
“Limyufumyufu” a Cambisol and “Luyinjayinga” an Umbrisol soil. Nine treatments; (i) complete nutrient
treatment, (ii) N omitted, (iii) P omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca omitted, (viii)
Micronutrients omitted and (ix) control without nutrients. Each treatment was randomly assigned to the three
soils and replicated three times using a completely randomised design. Nitrogen, phosphorus and potassium were
limiting nutrients for bean production in Umbrisol (Luyinjayinja) while in Cambisol (‘Limyufumyufu), common
bean production was most limited by soil acidity. The performance varied with soil types, with beans grown on
the Phaeozem registering greater leaf number and growth, confirming both scientist’s and local farmer’s knowledge
that this soil has greater potential than the other two soils