Farid Golzardi

Clover is recognized as one of the most distinguished forage crops within the leguminous family, particularly suited for temperate and humid regions. Given clover's sensitivity to drought stress, its yield and quality in semi-arid and arid regions heavily depend on the irrigation regimen. Revising irrigation and irrigation strategies due to global climate change is vital in semi-arid ecologies. To determine forage crops and varieties with high water use efficiency will have a key role in animal production in the future. The plants include Berseem clover and Persian clover species that can be grown in semi-arid ecologies. A two-year experiment was carried out in a semi-arid area (Karaj) of Iran, to investigate the impact of shortages of irrigation on production, forage values, efficiency of water use, and drought stress indices across five Berseem and five Persian clover genotypes. There were two levels of irrigation considered: full irrigation (100% moisture requirement) and deficit irrigation (50% water requirement). Among the genotypes studied, Berseem-Win exhibited the highest fresh forage yield (104.48 Mg ha–1) and dry matter yield (17.20 Mg ha–1), Berseem-Ekinaton displayed the greatest plant height (69.63 cm) and leaf area index (2.17), Berseem-Karaj recorded the highest energy content (2.76 Mcal kg–1) and digestible protein (13.69%), and Berseem-Alex showed superior energy efficiency in water use (4.88 Mcal m–3) and digestible protein production (0.246 kg m–3). The Berseem-Alex displayed the greatest drought tolerance. Persian clover genotypes exhibited lower drought tolerance compared to the Berseem genotypes, with the Harat emerging as the most tolerant among the Persian clovers. Overall, the findings suggest that Berseem clover genotypes possess greater potential for forage cultivation within semi-arid and arid areas than Persian clover.

Objective: This study aimed to evaluate transpiration and its effects on grain quality in some maize hybrids under drought stress conditions. Material and Methods: The experiment was conducted using three irrigation levels-60 mm (control), 90 mm (moderate drought stress), and 120 mm (severe drought stress) of evaporation from a class A pan-applied to four maize hybrids: KSC 703, KSC 704, KSC 705, and KSC 706. This study was set up with three replications, carried out at Seed and Plant Improvement Institute (SPII), Karaj, Iran during 2015 and 2016 growing seasons. Results: The results indicated that under drought stress conditions, the levels of crude fiber and ash increased, while starch content decreased. The KSC 706 hybrid exhibited the lowest stomatal resistance and canopy temperature, and the highest grain starch content, averaging 64.84%. These findings suggest that increased stomatal opening and transpiration are associated with improved maize grain quality. Conclusion: Based on the findings, in regions where irrigation water is available and a higher starch content in grain is a priority, the KSC 706 hybrid is recommended.

Addressing water scarcity and the need for high-quality forage in arid regions necessitates the development of efficient irrigation techniques. This study assesses the impact of various irrigation methods on the performance and irrigation water-use efficiency (IWUE) of sorghum cultivars under water-deficit conditions in a semi-arid region of Iran during the 2019 and 2020 cropping seasons. Three irrigation methods—variable alternate furrow irrigation (AFI), fixed alternate furrow irrigation (FFI), and conventional furrow irrigation (CFI)—were evaluated alongside three levels of drought stress (severe stress: I₅₀, moderate stress: I₇₅, and full irrigation: I₁₀₀) and two sorghum cultivars. The results indicated that increasing drought stress, as well as the transition from CFI to AFI and FFI, led to reductions in metabolizable energy yield (MEY), plant height, cellulose, hemicellulose, and lignin. Conversely, there were increases in leaf-to-stem ratio, digestible organic matter, metabolizable energy content, crude protein content, and IWUE for metabolizable energy production (IWUE_ME). The highest MEY (211.68 GJ ha^-1) was recorded under CFI×I₁₀₀, albeit at the expense of maximum water consumption (7261 m³ ha^-1). Meanwhile, the AFI×I₅₀ and FFI×I₅₀ treatments exhibited the highest IWUE_ME (44.46 MJ m^-3) and metabolizable energy content (8.736 MJ kg^-1), respectively, while conserving over 60% of water. Hybrid Speedfeed outperformed in forage yield and IWUE_ME, while cultivar Pegah excelled in forage quality. Transitioning from CFI to AFI or FFI resulted in decreased forage yield but improved forage quality and IWUE_ME. Principal component analysis revealed that leaf-to-stem ratio and plant height serve as effective indicators for assessing the nutritive value and forage yield of sorghum, respectively. Considering the overall results, cultivating the hybrid Speedfeed under AFI×I₇₅ conditions is recommended for optimal water utilization, achieving satisfactory forage yield and quality, and enhancing IWUE.

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.

BACKGROUND: Strategies to enhance the efficient use of irrigation water require a major shift in irrigation and cropping systems. It was hypothesized that (i) replacing water‐demanding crops such as corn silage with more drought‐tolerant forages species, (ii) adoption of intercropping instead of monoculture, and (iii) use of alternative irrigation methods, may alleviate the water shortage in semi‐arid regions, while producing high‐quality forage.RESULTS: Adoption of drip irrigation (DRIP) and alternate furrow irrigation (AFI) reduced water consumption by 43% and 20%, respectively. Additionally, DRIP produced 11% more biomass than the conventional furrow irrigation. The intercropped ratio of 50% sorghum and 50% amaranth under DRIP maximized forage production and improved irrigation water‐use efficiency (IWUE). Principal component analysis indicated that the DRIP increased the dry matter yield and IWUE, whereas the AFI improved the forage quality. The intercropped ratio of 75% sorghum and 25% amaranth demonstrated the highest yield stability and was considered superior cropping system regardless of the irrigation strategies.CONCLUSIONS: DRIP and AFI strategies were effective in reducing water consumption, with DRIP being the most water‐efficient method. Intercropping sorghum and amaranth at a ratio of 50:50 under DRIP resulted in the highest forage yield and IWUE. While sole amaranth had the highest forage quality, intercropping sorghum and amaranth increased dry matter production with better forage quality than sorghum monoculture. Overall, the combination of DRIP and intercropping sorghum and amaranth at a ratio of 50:50 considered as a suitable strategy for improving forage yield and quality, as well as IWUE. © 2023 Society of Chemical Industry.