Deficit irrigation strategy to sustain available water resources using guar

Authors: SINGH, JAGDEEP - New Mexico State University; ANGADI, SANGU - New Mexico State University; Begna, Sultan; VAN LEEUWEN, DAWN - New Mexico State University; IDOWU, OMOLOLU - New Mexico State University; SINGH, PARAMVEER - New Mexico State University; TROSTLE, CALVIN - Texas A&M Agrilife; Gowda, Prasanna; BREWER, CATHERINE - New Mexico State University

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2024
Publication Date: 2/24/2024
Citation: Singh, J., Angadi, S., Begna, S.H., Van Leeuwen, D., Idowu, O.J., Singh, P., Trostle, C., Gowda, P.H., Brewer, C. 2024. Deficit irrigation strategy to sustain available water resources using guar. Industrial Crops and Products. 211. Article 118272. https://doi.org/10.1016/j.indcrop.2024.118272.
DOI: https://doi.org/10.1016/j.indcrop.2024.118272

Interpretive Summary: The declining Ogallala Aquifer is a major threat to the agriculture economy in the Southern High Plains (SHP). Improved irrigation management practices using drought–tolerant crops may contribute to the sustainability of agriculture in the region. A field experiment was conducted in 2018, 2019 and 2020 to examine the effect of pre–irrigation and in-season irrigation on guar physiology, yield, and yield components. Treatments involved two pre-irrigations (Pre–irrigation: PI, no–pre–irrigation: NPI), four in-season growth stage-based irrigation (full irrigation: FI, no irrigation during reproductive growth stage: Rst, no irrigation during vegetative growth stage: Vst, and no irrigation after crop establishment: RD) and two diverse cultivars (Kinman and Monument). Pre–irrigation (averaged over years, in-season irrigation and cultivars treatments) increased seed yield by 32% compared to without pre-irrigation. When in-season growth stage-based irrigation treatments were compared, FI treatment averaged over years, achieved the greatest seed yield followed by Vst, Rst, and RD. Yield increase was attributed to a higher net photosynthetic assimilation rate, leaf area index, and number of pods per plant. However, seed yield of FI was not significantly different from Vst in all years. Cultivar ‘Kinman' performed better than ‘Monument'. The results suggest that applying pre–irrigation improves overall guar growth and development. Restricted irrigation during Vst resulted in 37% water saving while achieving similar guar seed yield compared to guar with FI, and this is a potential and sustainable irrigation management strategy that growers can use.

Technical Abstract: The declining Ogallala Aquifer is a major threat to the agriculture economy in the Southern High Plains (SHP). Improved irrigation practices using drought–tolerant crops can help sustain agriculture in the region. The objective of this three years experiment conducted from 2018 to 2020 was to analyze the effects of pre–irrigation and in-season irrigation on guar physiology, yield, and yield components of two diverse guar cultivars. A split block design with a split arrangement was used. Pre–irrigation having two levels (pre–irrigation [PI] and no–pre–irrigation [NPI]) as one strip factor and in-season growth stage based irrigation treatment with four levels (full irrigation [FI], no irrigation during reproductive growth stage [Rst], no irrigation during vegetative growth stage [Vst] and no irrigation after crop establishment [RD]) as another strip factor, and cultivar having two levels (Kinman and Monument) as the subfactor with four replications of each treatment was employed. Pre–irrigation improved averaged final seed yield by 32% compared to plots that did not receive pre-irrigation. Comparing different in-season growth stage based irrigation treatments, FI treatment achieved the maximum averaged seed yield over the years followed by Vst, Rst, and RD. It was attributed to a higher net assimilation rate, leaf area index (LAI), and number of pods per plant. Seed yield of FI was not significantly different from Vst in all the tested years. Overall, cultivar ‘Kinman’ performed better than ‘Monument’. We can conclude from this three years study that applying pre–irrigation improves overall guar growth and development. The most sustainable strategy to utilize the available water resources using guar will be to grow guar with restricted irrigation during the vegetative growth stage (Vst) and saving 37% of water, and still obtaining a similar seed yield compared to plots that received irrigation throughout the crop season (FI).