Section
Biological Sciences
Abstract
A field study was initiated towards the end of the 1973 rain season to assess some residual effects of lime, N and P applications to a moderately acid Oxisol (initial pH 5.6; LR 10 tons/ha) on grain yield in navy beans, Phaseolus vulgaris L., grown soon following maize silage. The Oxisol was a sandy clay loam (35:13:52). The design was a split-plot, confounded factorial with 4 levels of lime at 0, 7.5, 10.0 and 12.5 tons agricultural lime/ha; N at 0, 100, 200 and 300 kg N/ha as ammonium sulphate; and P at 0, 40, 80 and 120 kg P/ha as triple superphosphate. Lime was applied in November, 1970 and N and P rates repeated annually during 1971-73 with previous maize crops. Grain yield increased linearly and significantly with lime up to mean pH of 6.7 along with increases in residual Ca2+, electrolyte, base content, AI-P, Fe-P, and with reduction in extractable Mn and exchangeable Al. Yields at low N and P fertility were, however, drastically reduced as the optimum mean pH was exceeded. Yield increased linearly and highly significantly with N and P fertilization. Yields were low where lime, N and P were not applied together. The data indicate that for the Oxisol, which had less than 0.2 me/100 g of exchangeable Al in the absence of applied lime and N, liming to reduce exchangeable Al cannot be taken as a criterion for liming but that optimum pH, adequate balance of ion ratios and adequate conservation of soil nutrients would be appropriate.
Recommended Citation
Mongi, H. O. and Uriyo, A. P.
(1975)
"Influence of Previous Liming, N and P Fertilization of an Oxisol on Grain Yield in Navy Beans,"
Tanzania Journal of Science: Vol. 1:
Iss.
2, Article 1.
Available at:https://doi.org/10.65085/2507-7961.2116