- 期刊
割期與收穫季節對白桑作為灌木型芻料作物之影響
Effect of cutting interval and harvest season on mulberry as forage shrub
摘要
白桑（Morus alba）具有生長速度快、環境適應性強及耐刈割等特性，除了高度木質化的枝幹，其葉片與嫩枝對於反芻動物適口性佳且營養價值高，適合作為多年生灌木型芻料。本研究以40、60及80天三種不同割期進行週年性收穫，試驗採完全隨機設計，每種處理三重複，探討白桑在不同割期與季節收穫下芻料產量與品質的變動情形。試驗結果顯示，白桑以80天割期在夏季收穫的株高（168.7 cm）、葉（4.1 t/ha）、莖（5.1 t/ha）及全株乾物產量（9.2 t/ha）、酸洗與中洗纖維含量（葉27.2與40.9%、莖52.3與68.7%、全株41.7與56.9%）最高，但葉／莖比（0.7）與粗蛋白質含量（葉21.0%、莖5.6%、全株12.1%）最低；以40天割期在冬季收穫的株高（58.1 cm）、葉（1.2 t/ha）、莖（0.5 t/ha）及全株乾物產量（1.7 t/ha）、酸洗與中洗纖維含量（葉20.5與30.5%、莖37.3與47.8%、全株25.0與35.1%）最低，但葉／莖比（2.8）與粗蛋白質含量（葉26.9%、莖13.0%、全株23.2%）最高。比較葉與全株之全年總粗蛋白質產量，葉片之產量在三種割期間無顯著差異；全株之產量以80天割期較高（2.7 t/ha），60與40天割期的產量較低（2.5與2.4 t/ha），兩者間無顯著差異。當收穫季節相同，隨著割期愈長，株高與乾物產量愈高，但葉／莖比與芻料品質愈差。在相同割期下，株高與乾物產量均以夏季最高而冬季最低，葉／莖比與芻料品質則均以冬季最高而夏季最低。考量葉／莖比與芻料品質之關係、葉片與全株之全年總粗蛋白質產量，白桑以40天割期作為多年生灌木型芻料具有較高之營養價值。
並列摘要
Mulberry (Morus alba) is characterized by fast growth, strong environmental adaptability and mowing resistance. Except for its highly lignified trunk, leaves and tender branches of mulberry are well-palatable and highly-nutritive to herbivore, which is suitable as perennial shrub forage. To determine the fluctuation of forage yield and quality of mulberry in different harvest seasons and cutting intervals, this study was conducted to harvest mulberry at 40, 60 and 80 days of cutting intervals annually. The experimental design was a completely randomized with three replications. By 80 days cutting interval in summer, plant height (PH, 168.7 cm), dry matter yield (DMY) of leaf (4.1 t/ha), stem (5.1 t/ha), and whole plant (9.2 t/ha), ADF and NDF (leaf, 27.2 and 40.9%; stem, 52.3 and 68.7%; whole plant, 41.7 and 56.9%) were all the highest, but leaf to stem ratio (L/S, 0.7) and CP (leaf, 21.0%; stem, 5.6%; whole plant, 12.1%) were both the lowest. By 40 days cutting interval in winter, PH (58.1 cm), DMY of leaf (1.2 t/ha), stem (0.5 t/ha), and whole plant (1.7 t/ha), ADF and NDF (leaf, 20.5 and 30.5%; stem, 37.3 and 47.8%; whole plant, 25.0 and 35.1%) were all the lowest, but L/S (2.8) and CP (leaf, 26.9%; stem, 13.0%; whole plant, 23.2%) were both the highest. Comparing the annual total CP yield of leaf and whole plant, there was no significant difference in the yield of leaf among the three cutting intervals. The annual total CP yield of whole plant was higher under 80 days of cutting interval (2.7 t/ha), but were lower under 40 and 60 days of cutting intervals (2.5 and 2.4 t/ ha) , which there was no significant difference between each other. In the same harvest season, the longer the cutting interval, the higher the PH and DMY, the worse the L/S and forage quality. Under the same cutting interval, PH and DMY were both highest in summer and lowest in winter, but L/S and forage quality were both highest in winter and lowest in summer. Considering the relationship between L/S and forage quality, and the annual total CP yield of leaf and whole plant, mulberry has higher nutritional value as a perennial shrub forage under 40 days of cutting interval.