Irrigation Management Strategies to Enhance Forage Yield, Feed Value, and Water-Use Efficiency of Sorghum Cultivars

Amir Ghalkhani; Farid Golzardi; Azim Khazaei; Ali Mahrokh; Árpád Illés; Csaba Bojtor; Seyed Mohammad Nasir Mousavi; Adrienn Széles

doi:10.3390/plants12112154

Irrigation Management Strategies to Enhance Forage Yield, Feed Value, and Water-Use Efficiency of Sorghum Cultivars

Plants (Basel). 2023 May 30;12(11):2154. doi: 10.3390/plants12112154.

Authors

Amir Ghalkhani^{1

2}, Farid Golzardi², Azim Khazaei², Ali Mahrokh², Árpád Illés³, Csaba Bojtor³, Seyed Mohammad Nasir Mousavi^{3

4}, Adrienn Széles³

Affiliations

¹ Department of Agronomy and Plant Breeding, Karaj Branch, Islamic Azad University, Karaj P.O. Box 31485-313, Iran.
² Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj P.O. Box 31585-4119, Iran.
³ Institute of Land Use, Engineering and Precision Farming Technology, University of Debrecen, 138 Böszörményi St., 4032 Debrecen, Hungary.
⁴ Department of Plant, Food and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada.

Abstract

Water scarcity is a major obstacle to forage crop production in arid and semi-arid regions. In order to improve food security in these areas, it is imperative to employ suitable irrigation management techniques and identify drought-tolerant cultivars. A 2-year field experiment (2019-2020) was conducted in a semi-arid region of Iran to assess the impact of different irrigation methods and water deficit stress on forage sorghum cultivars' yield, quality, and irrigation water-use efficiency (IWUE). The experiment involved two irrigation methods, i.e., drip (DRIP) and furrow (FURW), and three irrigation regimes supplied 100% (I₁₀₀), 75% (I₇₅), and 50% (I₅₀) of the soil moisture deficit. In addition, two forage sorghum cultivars (hybrid Speedfeed and open-pollinated cultivar Pegah) were evaluated. This study revealed that the highest dry matter yield (27.24 Mg ha^-1) was obtained under I₁₀₀ × DRIP, whereas the maximum relative feed value (98.63%) was achieved under I₅₀ × FURW. Using DRIP resulted in higher forage yield and IWUE compared to FURW, and the superiority of DRIP over FURW increased with the severity of the water deficit. The principal component analysis indicated that, as drought stress severity increased across all irrigation methods and cultivars, forage yield decreased, while quality increased. Plant height and leaf-to-stem ratio were found to be suitable indicators for comparing forage yield and quality, respectively, and they showed a negative correlation between the quality and quantity of forage. DRIP improved forage quality under I₁₀₀ and I₇₅, while FURW exhibited a better feed value under the I₅₀ regime. Altogether, in order to achieve the best possible forage yield and quality while minimizing water usage, it is recommended to grow the Pegah cultivar and compensate for 75% of soil moisture deficiency using drip irrigation.

Keywords: deficit irrigation; drip irrigation; dry matter yield; forage quality; furrow irrigation; metabolizable energy; water saving.

Grants and funding

Project no. TKP2021-NKTA-32 has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.