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United States Department of Agriculture

Agricultural Research Service

Research Project: CONSERVATION SYSTEMS RESEARCH FOR IMPROVING ENVIRONMENTAL QUALITY AND PRODUCER PROFITABILITY Title: Cotton Gas Exchange Response to Standard and Ultra-Narrow Row Systems Under Conventional and No-Tillage

Authors
item Arriaga, Francisco
item Prior, Stephen
item Terra, Jose - INIA-URUGUAY
item Delaney, Dennis - AUBURN UNIVERSITY

Submitted to: Communications in Biometry and Crop Science (CBCS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 8, 2009
Publication Date: July 1, 2009
Citation: Arriaga, F.J., Prior, S.A., Terra, J.F., Delaney, D.P. 2009. Cotton Gas Exchange Response to Standard and Ultra-Narrow Row Systems Under Conventional and No-Tillage. Communications in Biometry and Crop Science. 42(2):42-51.

Interpretive Summary: The availability of soil water to crops is a major limitation to crop production. Use of conservation tillage systems enhances soil residue cover, water infiltration, and reduces evaporative soil water loss. Our objective was to measure cotton (Gossypium hirsutum L.) leaf level photosynthesis and water use during fruit development under different row spacing and tillage conditions on a loamy sand soil in east-central AL. Standard plant row spacing of 102-cm and ultra-narrow row of 20-cm were compared. Also, two tillage systems (conventional and no-tillage) were studied. In 1999, standard row cotton under conventional tillage maintained higher water use rates during early flowering when water was not limiting. However, the opposite pattern occurred during dry cycles. During drought periods, water use rates were higher in no-till systems especially under standard row conditions. In 2000 and 2001, the benefits of no-till were sporadic due to frequent rainfall events. In 2000, ultra-narrow row cotton consistently had lower water use rates compared to standard row cotton; lesser degrees of this occurred in 1999 and 2001. These results suggest that during periods of infrequent rainfall, high rates of photosynthesis can be maintained in no-till systems that conserved soil water needed during critical reproductive stages such as fruit development.

Technical Abstract: The availability of soil water to crops is a major limitation to crop production. Use of conservation tillage systems enhances soil residue cover, water infiltration, and reduces evaporative soil water loss. Our objective was to measure cotton (Gossypium hirsutum L.) leaf level photosynthesis, stomatal conductance, and transpiration during reproductive growth under different row spacing and tillage conditions on a Norfolk loamy sand (Typic Kandiudults) in east-central AL. Gas exchange and soil moisture measurements occurred in the summer of 1999, 2000, and 2001. The study used a split-plot design replicated four times with row spacing [standard 102-cm row (SR) and ultra-narrow row of 20-cm (UNR)] as main plots and tillage systems [conventional (CT) and no-tillage (NT)] as subplots. In 1999, standard row cotton under conventional tillage maintained higher photosynthetic rates during early reproductive growth when soil water was not limiting; the opposite pattern occurred latter during drought cycles. During drought periods, photosynthetic rates were higher in NT systems especially under SR conditions. In 2000 and 2001, the benefits of NT were sporadic due to frequent rainfall events occurring throughout reproductive growth. In 2000, UNR cotton consistently had lower photosynthesis rates compared to SR cotton; lesser degrees of this occurred in 1999 and 2001. In all years, stomatal conductance and transpiration measurements generally mirrored those of photosynthesis. These results suggest that during periods of infrequent rainfall, high rates of photosynthesis can be maintained in NT systems that conserved soil water needed during critical reproductive stages such as boll filling.

Last Modified: 12/27/2014