Abstract

Calcareous soil, comprising more than 15% CaCO₃, which imposes various physical and chemical challenges to plants, is widespread in arid and semi-arid regions. It was against the stated backdrop that an experiment was carried out to compare growth responses of moringa (Moringa oleifera Lam.) seedlings in calcareous, clayey and sandy soils relative to those in loamy soil during autumn (January-March) 2015 and validated in 2016. Treatments comprised loamy, calcareous, clayey and sandy soils, arranged in randomised complete block design, with 15 replications. Each soil type was steam-pasteurised, with hardened-off six-week-old seedlings transplanted in 10 L plastic bags containing 9.8 L soil for each. At 90 days after transplanting, treatments had significantly (p ≤ 0.05) affected growth variables of M. oleifera seedlings. Relative to loam soil, calcareous soil reduced dry shoot mass (33%), chlorophyll content (36%) and dry root mass (47%), but increased root length (28%). In contrast, clay increased dry shoot mass (66%), leaf number (25%) and root length (26%), whereas sandy soil increased dry shoot mass (42%) and reduced dry root mass (51%). In conclusion, relative to loam soil, marginal soils such as calcareous, clayey and sandy soils had effects on growth of M. oleifera seedlings that included physical and chemical attributes of the soil types.

Key words: Calcareous soil, marginal soil, Moringa species, soil pH, soil texture, soil type.