Humic substances in a soil treated with household compost under two tillage practices

Abstract

Household-derived compost at the rate of 0, 20, 40, 60 t/ha, 30 t/ha + 20 t/ha ash, and NPK fertilizer at 112kg/ha were applied to tilled and untilled soils at Awka, South-East Nigeria in 2001 and 2002. The soil was grown to cowpea. At the end of 2002 the relative proportions of humic carbon, humic acid and fulvic acid were determined. Tillage (hoeing) significantly enhanced the formation of humic substances (HS) in the soil. Formation of humic substance (HS) was not favoured by fertilizer application which gave lower % HS than the control. Fulvic acid fraction was higher in compost amended soil.

Nigerian Journal of Soil Science Vol. 15 2005: 86-89