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Phosphorus (P) transformations and associated changes in soil chemistry following lime application in acidic soils are very determinant to enhance P use efficiency. Thus, this study was conducted to evaluate the effects of different rates of lime on soil P fractions and chemical properties in acidic Luvisols of southern Ethiopia. The lime rates were 0 t/ha (0%), 3.75 t/ha (50%), 7.5 t/ha (100%), and 11.25 t/ha (150%), and incubated for a month with three replications. The soil P fractions analyzed includes soluble P (P-sol), P associated with iron (Fe-P), aluminum (Al-P), calcium (Ca-P), organic part (Org-P) and residual (Res-P). The result indicated that liming significantly (p < 0.05) improved the release of P-sol, Ca-P, and Res-P, and reduced Fe-P, Al-P, and Org-P. The changes in soil chemical properties were also significant. For instance, increased rate of lime enhanced soil pH from 5.3 to 6.5, reduced exchangeable acidity from 1.47 to 0.15 cmol(+)/kg, and increased available P from 2.74 to 8.72 cmol(+)/kg. Yet, the amount of P-sol was found low for plant needs even at a 150% rate of lime. Thus, working on external P requirement to equilibrate the need for plants followed by crop response validation are suggested. [ABSTRACT FROM AUTHOR]

The study aimed at investigating effects of lime and mineral P fertilizers on P uptake and growth of maize (Zea mays subsp.) in greenhouse pot experiment. Combination of four P rates and four lime rates were applied to four highly acidic soil samples and the soils were incubated for a total of 112 days after which maize (Zea mays subsp.) was planted. The maize plants were harvested for analysis after 42 days of growth. Control experiments were also included. Available P (Bray I) and pH were significantly increased after incubation. Maximum available P was obtained in the soils that received the highest P rate and optimum lime rate. Levels of exchangeable acidity were significantly decreased in the P and lime treated soils compared to the control experiments. Plant biomasses and P uptake of maize increased significantly (p ≤ 0.001) with application of P and lime compared to the control experiments. [ABSTRACT FROM AUTHOR]