Effects of Rhizobium inoculation and cropping systems on macronutrients uptake and partitioning in two legumes (Common bean and Lablab)

The study to investigate the effect of Rhizobium inoculation and cropping systems on the uptake of macronutrients in shoot, root and whole plant of Phaseolus vulgaris and Lablab purpureus was conducted at Selian Agricultural Research Institute (SARI) for two cropping seasons. A randomized complete block design was used in a 3-factorial arrangement with two levels of Rhizobium (with and without rhizobia), two legumes (P. vulgaris and L. purpureus) and five cropping systems (sole maize or sole legumes, 1 row maize to 1 row legumes (1: 1) i.e. 0 m or 0.45 m of legume from maize row, 1 row maize to 2 rows of legumes (1: 2) i.e. 0.1 m or 0.2 m of legumes from maize rows). The result showed that Rhizobium inoculation significantly (P<0.001) increased the uptake of N, P, K, Ca and Mg in the plant parts and whole plant. Similarly, cropping systems significantly (P<0.001) increased the uptake of N, K and Mg in shoots and whole plant of P. vulgaris and L. purpureus but decreased the P and Ca content in roots. Legumes significantly increased the uptake of the macronutrients in shoots and roots but more nutrients concentration in shoots than roots for both cropping seasons. There were significant (P<0.001) interaction between; Rhizobium x legumes x cropping systems on whole plant uptake of N in cropping season 1 and 2. Regardless of the type of interaction, inoculated legumes maximized the uptake of macronutrients in shoots, roots and whole plant.