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Calcium deficiency identified as an important factor limiting maize growth in acid ultisols of eastern Nigeria

Research paper by B. O. Njoku, W. O. Enwezor, B. I. Onyenakwe

Indexed on: 01 Jun '87Published on: 01 Jun '87Published in: Nutrient Cycling in Agroecosystems



Abstract

Poor maize growth in unlimed acid soils of eastern Nigeria was investigated with a view to identify the main factors responsible for infertility in such soils. Surface soils collected from 4 sites in the region were amended with (i) CaSO4 (ii) Ca(OH)2 and (iii) MgCO3. Maize was grown in each soil, including an untreated check, in the greenhouse for 4 weeks and tops and roots dry matter were measured.Although CaSO4 depressed the pH of the soil, it caused a highly significant increase (p = 0.01) in the yield of dry matter of tops and roots and a non-significant increase in the uptake of P and Ca. Exchangeable Al was virtually eliminated when the soil was amended with MgCO3 but maize growth in this soil was drastically inhibited and symptoms of severe calcium deficiency were observed. Higher yield increases, arising from soil amendment with Ca(OH)2 relative to CaSO4 were ascribed to better Ca nutrition rather than reduction in the level of exchangeable Al. Uptake of P and Ca was significantly increased (p = 0.05) by liming with Ca(OH)2.The results suggest that Ca deficiency is a more serious growth-limiting factor than Al toxicity in the soils tested. The implication of this finding is that much money can be saved by using industrial wastes of relatively low neutralizing value, like cement fluke dust and basic slag, as soil amendments rather than the costly ocnventional liming materials.