Effect of Mulching on Soil Temperature and Moisture Regime on Emergence, Growth and Yield of White Yam in a Tropical Wet-and-Dry Climate

Abstract

An on-farm yam experiment was conducted to study the effect of mulching on soil temperature and moisture regime on white yam (Dioscorea rotundata) growth and yield in Abeokuta, South-western Nigeria. Three mulching options (grass mulched, polythene mulched and unmulched) was selected and related to crop growth and yield. Grass mulch sig- nificantly (P < 0.05) lowered maximum soil temperature by 1-2℃ at 15cm depth during the thermal critical period (Janu- ary - March). This led to higher rate of emergence which accounted for 28 and 46% to the polythene mulch and the un- mulched plots respectively. Furthermore, grass mulch had tuber yield of about 4-6 tonnes ha-1 season-1 greater than the polythene mulch and the unmulched plots. Irrespective of mulching materials, it was found that mulching significantly (P< 0.05) increased tuber yield by about 6-8 tonnes ha-1 season-1 than the unmulched. The effect of grass mulch over nylon mulch on yam performance in the study was also discussed.