Pearl millet versus gin trash mulches for increasing soil water and cotton yields in a semiarid region

ABSTRACT:

Gin trash and pearl millet stover were used as mulches in the blank rows of a two-planted, two-blank-row (1-m spacing) planting pattern (2×2) for rainfed cotton (Gossypium hirsutum L.) over 4 years. Mulches were applied only one time, April 26, 1982. Gin trash was applied at rates of 7, 23, and 40 Mg/ha (3, 10, and 18 tons/acre), which gave soil coverages of about 30%, 80%, and 95%, respectively. Pearl millet was applied at rates of 10, 20, and 30 Mg/ha (4.5, 9, and 13.4 tons/acre); soil coverages of about 85%, 95%, and 100%, respectively. Check plots were not mulched. Effectiveness of the mulches was ascertained from soil water determinations and lint yields. In 1982, average lint yield on all mulched plots was 53% greater than that on check plots. Insufficient soil water in the planting zone precluded establishment of cotton in 1983 and 1984, but in 1985 cotton was established in the same plots that were used in 1982. Lint yields of mulched plon averaged 13% more than those of check plots. During the 4-year study, plots that had received the greatest amounts of mulch (essentially 100% ground cover initially) consistently had the most soil water. Millet-mulched plots consistently had more stored water than their gin trash counterparts. Producers should be able to significantly increase soil water storage and, hence, increase lint yields and reduce soil erosion losses by the consistent use of mulches of gin trash, millet stover, or comparable organic materials.