CHANGES IN SOIL PROPERTIES AND NUTRIENT ACCUMULATION IN NEEM UNDER THE CANOPY OFACACIA TORTILIS

Abstract

ABSTRACT Investigations were made on the growth of young neem (Azadirachta indica A. Juss) seedlings, planted among mature Acacia tortilis trees, and associated soil properties, to determine whether seedlings could be successfully introduced among old tree stands in the arid environment. Size measures of 52 mo-old neem seedlings planted along the mature and unlopped trees of Acacia tortilis (mean height 8.3 m, crown diameter 12.6 m and diameter at breast height 24.7 cm), indicated that A. tortilis significantly affected the growth of neem seedlings planted under the canopy. Maximum size reduction was observed in the plants found under the inner crown (IC) compared to the plants in the outer crown (OC) and outside crown (OS) zone. Soil parameters (0 to 75 cm depth) of pH, electrical conductivity, and P, Ca and Mg concentrations, were higher in the soil of the OC (6 to 9 m) zone of A. tortilis compared to the IC zone (1 to 4 m) and OS zone (15 to 24 m). The concentration of K, NH4-N and NO3-N were highest u...