Soil temperature, growth and yield of maize (Zea mays L.) as affected by wheat straw mulch

摘要

Maize crop is grown mostly in tropical/subtropical environments where drought adversely affects its production. A field experiment was conducted on sandy loam soil for four years (1999-2002) to study the effect of wheat straw mulch (0 and 6 t ha~(-1))and planting methods (flat and channel) on maize sown on different dates. Maximum soil temperature without mulch ranged from 32.2-44.4°C in channel and 31.6-46.4°C in flat planting method. Mulching, however, lowered soil temperature by 0.8-7.0°C in channel and 0-9.8°C in flat planting. Mulching, on an average, improved leaf area index by 0.42, plant height by 14 cm, grain yield by 0.24 t ha~(-1) and biomass by 1.57 t ha~(-1), respectively. Mulching improved grain yield only in flat sowing. Interaction between sowing date and planting method was significant. Seasonal variation in biomass were significantly correlated (p = 0.05) with mean air temperature during 0-45 days after planting (DAP) (r= —0.95), pan evaporation during 0-15 DAP (r= 0.79) andnegative correlation with rainfall in entire cropping season (r= —0.89), whereas biomass increase with mulch in different cropping seasons had negative relation (r= —0.74) with amount of rain during 0-15 DAP.