African Journal of Biotechnology Vol. 6 (17), pp. 2004-2008, 5 September 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Mulching an Arenic hapludult at Umudike: Effects on saturated hydraulic conductivity and rhizome yield of turmeric

Nwokocha, C. C.^1*, Olojede, A. O.¹, Ano, A. O.¹ and Mbagwu, J. S. C.²

¹National Root Crops Research Institute Umudike, Abia State, Nigeria.

²Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, Enugu State, Nigeria.

*Corresponding author. E-mail: chystova@yahoo.co.uk. Tel: +234 805 5846 329.

Accepted 27 April, 2007

A study was carried out over two cropping seasons on an Arenic Hapludult at Umudike, southeastern Nigeria, to investigate and determine the quantity and type of mulch material that would optimize the rhizome yield of turmeric (Curcuma longa Linn) and improve the saturated hydraulic conductivity of the soil. The turmeric was planted at two depths; 5 and 10 cm. Two types of mulch, straw (elephant grass) and wood shavings were evaluated at 3 rates (0, 4 and 8 t/ha). Results showed that the effect of mulching on rhizome yield was significant. Yields increased significantly with the rate of mulch. Rhizome yield of turmeric was significantly influenced by the depth of planting and mulch type used. The 10 cm planting depth out-yielded 5 cm depth, and straw mulch out-yielded wood shavings. Optimum values of Ksat occurred at the 4 t/ha mulch rate. Bulk density, macro porosity and micro porosity were the most important physical properties influencing K_sat of the soil. Total porosity (P_t), and void ratio (V_e) were not good indicators of K_sat even though they positively explained between 98 and 96% of its variations, respectively.

Key words: Turmeric, mulching, saturated hydraulic conductivity, bulk density, porosity, Arenic Hapludult.