Effect of Mulches and Bed Configuration. I. Early‐Season Soil Temperature and Emergence of Grain Sorghum and Corn1

Abstract

AbstractClear plastic film, petroleum mulch, and two bed configurations (ridge and 20° south slope) were used on Austin and Houston Black clay to evaluate their effects on soil temperature (7.6‐cm depth) as compared with flat surface (conventional planting).All treatments caused some increase in soil temperature as compared with conventional planting. Mulches had a highly significant effect (1% level) on soil temperature during seedling emergence. Average daily soil temperature (7.6‐cm depth) was increased from 0.6 to 2.2 C by petroleum mulch and from 1.1 to 4.4 C by clear plastic. Bed configuration caused a small (0.3 to 0.6 C) but nonsignificant increase in the average daily temperature of bare soil during emergence.Mulches had more effect on initial emergence than bed configuration. Grain sorghum (Sorghum vulgare) and corn (Zea mays L.) emergence was fastest on clear plastic‐mulched plots and slowest on bare plots. Treatments with earliest emergence also had the densest stand. Both mulches and bed configuration had a highly significant effect (1% level) on seedling emergence. Emergence time for grain sorghum decreased 1 day for each 0.9 C increase in average daily (7.6‐cm depth) soil temperature between 12.8 and 20.6 C (r = −0.94).Results indicate that the soil is too cool at normal planting time for maximum emergence and stand of grain sorghum and corn in the Texas Blackland area.