ABSTRACT

To evaluate the forage yield and quality of Berseem and Persian clover cultivars, a two-year experiment was conducted during two growing seasons (2017–2018 and 2018–2019). Irrigation was the main factor, including full irrigation (I₁₀₀), moderately limited (I₇₅), and severely limited irrigation (I₅₀). The sub-factor consisted of ten cultivars of clover, five of which were Persian clover (Pars, Aleshtar, Eghlid, Harat, and Zabol) and five cultivars of Berseem clover (Karaj, Elite, Ekinaton, Vienna, and Alex). The results showed that the highest dry matter (DM) and crude protein (CP) yield under all irrigation levels were obtained from the Berseem clover cultivars. Imposing limited irrigation reduced the DM yield, digestible dry matter (DDM) yield and content, CP yield, dry matter intake (DMI), and relative feed value (RFV) of forage, whereas the content of CP, water-soluble carbohydrates (WSC), neutral detergent fiber (NDF), and acid detergent fiber (ADF) increased. Irrigation water use efficiency (IWUE) for DM, DDM, and CP yield under limited irrigation were also increased. Comparison of two groups of Persian and Berseem clover cultivars also showed that with increasing drought stress intensity, in Berseem cultivars, DM yield, DDM yield and content, and RFV decrease was higher. Increasing IWUE under limited irrigation was higher in Persian cultivars for DM and DDM yield. Overall, Berseem clover had higher forage yield and water use efficiency in all irrigation regimes, and the forage quality of this species showed more sensitivity to drought.

Abbreviations :I₁₀₀, I₇₅, and I₅₀, full, moderately limited, and severely limited irrigation (equivalent to 100, 75, and 50% weekly evaporation and crop water requirement, respectively); DM, dry matter; CP, crude protein; ADF, acid detergent fiber; NDF, neutral detergent fiber; DDM: digestible dry matter; WSC, water-soluble carbohydrates; DMI, dry matter intake; RFV, relative feed value; IWUE, irrigation water use efficiency.

摘要

为了评估 Berseem 和波斯三叶草品种的牧草产量和质量，在两个生长季节（2017-2018 和 2018-2019）进行了为期两年的试验。灌溉是主要因素，包括充分灌溉（I ₁₀₀）、中度限制（I ₇₅）和严重限制灌溉（I ₅₀）。子因子包括十个三叶草品种，其中五个是波斯三叶草（Pars、Aleshtar、Eghlid、Harat 和 Zabol）和五个 Berseem 三叶草品种（Karaj、Elite、Ekinaton、Vienna 和 Alex）。结果表明，在所有灌溉水平下，Berseem 三叶草品种的干物质（DM）和粗蛋白（CP）产量最高。限制灌溉降低了干物质产量、可消化干物质 (DDM) 产量和含量、粗颗粒产量、干物质摄入量 (DMI) 和饲料的相对饲料价值 (RFV)，而粗颗粒含量、水溶性碳水化合物 (WSC) )、中性洗涤纤维 (NDF) 和酸性洗涤纤维 (ADF) 增加。在有限灌溉条件下，DM、DDM 和 CP 产量的灌溉用水效率 (IWUE) 也有所提高。波斯三叶草和 Berseem 三叶草栽培品种两组比较也表明，随着干旱胁迫强度的增加，Berseem 栽培品种的 DM 产量、DDM 产量和含量、RFV 下降幅度更大。对于 DM 和 DDM 产量，波斯品种在有限灌溉下增加 IWUE 更高。总体而言，Berseem 三叶草在所有灌溉制度中均具有较高的牧草产量和水分利用效率，并且该物种的牧草质量对干旱表现出更高的敏感性。

缩写：I ₁₀₀、I ₇₅和 I ₅₀，充分灌溉、适度限制灌溉和严重限制灌溉（分别相当于 100、75 和 50% 的每周蒸发量和作物需水量）；DM，干物质；CP，粗蛋白；ADF，酸性洗涤纤维；NDF，中性洗涤纤维；DDM：可消化干物质；WSC，水溶性碳水化合物；DMI，干物质摄入量；RFV，相对进给值；IWUE，灌溉用水效率。