Rainwater use by irrigated cotton measured with stable isotopes of water

T.S. Goebel, R.J. Lascano, P.R. Paxton and J.R. Mahan

Agricultural Water Management, 2015, vol. 158, issue C, 17-25

Abstract: The natural rate of recharge for some groundwater systems, such as the Southern Ogallala Aquifer in the central United States, is smaller than the rate of annual withdrawals for irrigation. As aquifer depletion continues, efficient management of the water budget gains importance. Of interest is the use of rainwater by irrigated crops during the course of the growing season, as rain can account for an important amount of the water input in the semi-arid climate of the Texas High Plains. We tested the suitability of stable isotopes of water as a method to determine the source of water in the transpiration of field-grown cotton (Gossypium hirsutum L.) plants from either rain or irrigation-water. We selected this method because irrigation water from the Ogallala Aquifer has a stable isotopic signature that can either be enriched or depleted when compared to the isotopic signature of water from any rain event. Cotton petioles were sampled before two rain events of 33mm, and after every 2h for two days. The water in the cotton petioles was extracted using cryogenic vacuum distillation and was analyzed for its isotopic signature. The results showed a shift of 29% from −7 (‰) to −5 δ18O (‰), which is similar to the isotopic signature of the rainwater (−4.2 δ18O (‰)). These results suggest that it is possible to use water stable isotopes to differentiate between rainwater and irrigation transpired by cotton under field conditions.

Keywords: Semiarid; Evapotranspiration; Irrigation; Drip irrigation; Water balance; Field-grown (search for similar items in EconPapers)
Date: 2015
References: View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377415001304
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:158:y:2015:i:c:p:17-25

DOI: 10.1016/j.agwat.2015.04.005

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().