Assessing the land equivalent ratio (LER) of maize (Zea mays L.) intercropped with Rhizobium inoculated soybean (Glycine max [L.] Merr.) at various P and K levels

摘要

A 2 years field experiment was carried out in northern Tanzania with the aim of assessing the effects of maize-soybean intercropping systems, Rhizobium inoculation and P and K supplementation on Land Equivalent Ratio. A three replicate experiment was laid out in a split-split plot design with the main plots comprised of Rhizobia inoculation (with and without). The sub plots comprised of three cropping systems and the sub-sub plots having seven fertilizer levels (kg ha-1): Control, 20, 40 K, 26, 52 P, 26 P + 20 K and 52 P + 40 K. The results indicated that compared with pure stand, intercropping maize with soybean was advantageous because all the values of LER were above 1.0. Supplementation of inputs such as Rhizobium inoculants and P and K fertilizers significantly (p0.05) increased the LERs over the control. The rhizobial inoculated plots gave the highest LER of 1.73 and 1.61 grain and biological yield compared with un-inoculated plots which gave the lowest LER of 1.31 and 1.39 grain and biological yield respectively. P and K also significantly increased LER over the control. When compared with the narrower spacing, wider spacing of soybean resulted to a greater LER values suggesting the use of wider spacing for legume-cereals intercropping. Hence, this study suggests that farmers should be advised to intercrop maize with soybean at a recommended spacing, and supplying with the recommended inputs above. However, application of P and K fertilizers will depend on the fertility status of the soil in respective area under consideration.