Phosphorus Uptake and Partitioning in Maize as Affected by Tillage on Dystric Cambisol and Ferric Acrisol in Ghana

Abstract

Phosphorus deficiency is a major problem confronting crop production in tropical soils. In sub–saharan Africa, the deficiency of the nutrient has caused decline in crop yield over the years. Rele-vant information on phosphorus uptake and partitioning in plants, its use efficiency and the impli-cations on crop yield on different soil types under different management systems will enhance sus-tainability of cropping systems and the environment. Field experiments were conducted at the An-womaso Agricultural Research Station of the Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi located within the semi- deciduous forest zone and Crops Re-search Experimental Station, Ejura within the Forest- Savannah Transition zone of Ghana. The soils of the experimental sites at Anwomaso and Ejura were respectively Ferric Acrisol and Dystric Cambisol. The study aimed at evaluating phosphorus partitioning in maize plants following phos-phorus application under two tillage systems on the two soil types. The field experiments at both locations were split - plots arranged in randomized complete block design with three replications. The main plot factor consisted of two tillage systems namely, conventional tillage (CT) and no – tillage (NT) systems whereas the sub-plot factor consisted of four levels of phosphorus fertilizer: 0, 30, 60 and 90 kg P₂O₅ per ha. Phosphorus uptake and partitioning and, use efficiency (PUE)in different parts of maize (ear, shoot and leaves) were determined at physiological maturity (R6). Phosphorus partitioned into the various plant parts showed significant differences (p < 0.05) among the four levels of phosphorus applied on both soil types. Higher phosphorus concentrations were found in the ears than in the shoots and leaves at physiological maturity. Tillage x phospho-rus interactions influenced phosphorus partitioning in the ears and the leaves on the Dystric Cam-bisol but not on the Ferric Acrisol. PUE in the plant parts were significantly higher under applica-tion of 60 kg/ha P2O5than applications of 30 and 90 kg/ha P₂O₅ on both soils. Though the PUE of maize components on both soils were low, relatively higher values were recorded on the Dystric Cambisol than on the Ferric Acrisol. The study indicated that application of 60 kg/ha P₂O₅ under conventional tillage can lead to higher phosphorus partitioning into the ears at physiological maturity resulting in higher maize grain yield on Ferric Acrisol and Dystric Cambisol in Ghana in the short term.