Crop modeling application to improve irrigation efficiency in year-round vegetable production in the Texas Winter Garden Region

Authors: KIM, SUMIN - Dankook University; MEKI, MANYOWA - Texas Agrilife Research; KIM, SOJUNG - Dongguk University; Kiniry, James

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2020
Publication Date: 10/7/2020
Citation: Kim, S., Meki, M.N., Kim, S., Kiniry, J.R. 2020. Crop modeling application to improve irrigation efficiency in year-round vegetable production in the Texas Winter Garden Region. Agronomy. 10(10). Article 1525. https://doi.org/10.3390/agronomy10101525.
DOI: https://doi.org/10.3390/agronomy10101525

Interpretive Summary: Supplemental irrigation plays an important role to ensure the viability and profitability of vegetable crops from unpredictable changes in weather. With drought, however, irrigation for agriculture is often given low priority for water allocation. This reduced water availability calls for greater irrigation efficiency while not not compromising crop quality and yield, and provide economic benefit for producers. This study developed vegetable growing models for 8 different vegetable crops (bush bean, green bean, cabbage, peppermint, spearmint, yellow straight neck squash, zucchini, and bell pepper) based on data from several years of field research. The ALMANAC model accurately simulated yields and water use efficiency (WUE) of all 8 vegetables. The developed vegetable models were used to evaluate various irrigation regimes on vegetable growth and production in several locations in the Winter Garden Region of TX under variable weather. Based on our simulation results from 960 scenarios, optimal irrigation amounts that produce high yield as well as reasonable economic profit to producers were determined for each vegetable crop. Overall, yields for all vegetables increased as irrigation amount increased. However, irrigation amount did not have a sustainable impact on vegetable yield at high irrigation treatments, and the WUEs of most vegetables were not significantly different among various irrigation regimes. When vegetable yields were compared with water cost, the rate decreased as irrigation amount increased. Thus, producers will not receive economic benefits when vegetable irrigation water demand is too high.

Technical Abstract: Given a rising demand for quality assurance, rather than solely yield, supplemental irrigation plays an important role to ensure the viability and profitability of vegetable crops from unpredictable changes in weather. However, under drought conditions, agricultural irrigation is often given low priority for water allocation. This reduced water availability for agriculture calls for techniques with greater irrigation efficiency that do not compromise crop quality and yield, and provide economic benefit for producers. This study developed vegetable growing models for 8 different vegetable crops (bush bean, green bean, cabbage, peppermint, spearmint, yellow straight neck squash, zucchini, and bell pepper) based on data from several years of field research. The ALMANAC model accurately simulated yields and water use efficiency (WUE) of all 8 vegetables. The developed vegetable models were used to evaluate the effects of various irrigation regimes on vegetable growth and production in several locations in the Winter Garden Region of TX under variable weather conditions. Based on our simulation results from 960 scenarios, optimal irrigation amounts that produce high yield as well as reasonable economic profit to producers were determined for each vegetable crop. Overall, yields for all vegetables increased as irrigation amount increased. However, irrigation amount did not have a sustainable impact on vegetable yield at high irrigation treatments, and the WUEs of most vegetables were not significantly different among various irrigation regimes. When vegetable yields were compared with water cost, the rate decreased as irrigation amount increased. Thus, producers will not receive economic benefits when vegetable irrigation water demand is too high.