Author
Baumhardt, Roland | |
LASCANO, R - TEXAS AG EXP STN, LUBBOCK |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/11/1999 Publication Date: N/A Citation: N/A Interpretive Summary: To reduce wind erosion in cotton (Gossypium hirsutum L.) on the Texas South Plains, winter wheat (Triticum aestivum L.) is planted after cotton harvest and then killed with a herbicide in the spring. Fall rains or irrigation is used to produce wheat residues that increase irrigated cotton lint yields over continuous clean-tillage cotton (CCC). There is limited information on the water use and adaptability of a terminated wheat-cotton (TWC) production system for dryland. This study was conducted to compare the CCC and TWC management system effects on: i) infiltration of rain, ii) crop water use, and iii) cotton lint yield under dryland conditions. The water budget of TWC and CCC was measured from May 1992 to December 1995 using micro-watersheds. Residues in the TWC plots reduced runoff and increased crop water use an average of 1 inch annually over CCC. Cotton was hard to establish in the TWC plots due to low seed zone water in 1993 and 1994, but TWC residues protected cotton seedlings from injury during hard spring rains in 1992. Cotton lint yields with the TWC system tended to be greater (not significantly) than with the CCC system in years with above average rain. Planting wheat for residue production during fallow under dryland conditions is high risk and not recommended for use in the Texas High Plains. Technical Abstract: A Texas South Plains cropping system for reducing wind erosion in cotton (Gossypium hirsutum L.), is to plant winter wheat (Triticum aestivum L.) after cotton harvest and then chemically terminate the wheat with a herbicide in the spring. Fall rains, thought to be lost to evaporation, are used for wheat residue production that increase irrigated cotton lint yields over continuous clean-tillage cotton (CCC). There is limited information on the annual water budget and adaptability of a terminated wheat - cotton (TWC) production system for dryland. This study was conducted to compare the CCC and TWC management system effects on: i) runoff and infiltration of rain, ii) the annual water balance, and iii) cotton lint yield and adaptability under dryland conditions. The water budget of TWC and CCC was measured from May 1992 to December 1995 using micro-watersheds. Residues in the TWC plots reduced runoff and increased infiltration an average of 43 mm and evapotranspiration 28 mm annually compared to that in CCC plots. Cotton establishment was problematic primarily due to the lack of seed zone water in 1993 and 1994 with the TWC system and 1993 with the CCC system, but TWC residues protected cotton seedlings from injury due to above average spring rainfall in 1992. Cotton lint yields with the TWC system tended to be greater (not significantly) than with the CCC system, but rain was above average. Planting wheat for residue production during fallow under dryland conditions is a high risk and not recommended for use in the Texas High Plains. |