何振富，贺春贵，魏玉明，刘陇生

(甘肃省农业科学院畜草与绿色农业研究所，甘肃 兰州730070)

光敏型高丹草在陇东旱塬的生物学特性和营养成分比较研究

何振富，贺春贵*，魏玉明，刘陇生

(甘肃省农业科学院畜草与绿色农业研究所，甘肃 兰州730070)

摘要：在陇东旱塬地区研究了海牛、BJ0603和大卡，共3个光敏型高丹草品种的生物学特性、不同生育时期营养成分变化及刈割次数对产量的影响。结果表明：4月下旬播种、10月上旬收获时，各品种都处于抽穗或开花期，不能完成生殖生长。收获前测定表明，品种间在株高、节间数、叶数和茎粗方面差异不显著(P>0.05)，但叶片和单秆重差异显著(P<0.05)；每个品种全年刈割1茬的标准草产量(65%含水量)和干物质产量均高于全年刈割2茬的，但差异不显著(P>0.05)，全年刈割2茬的鲜草产量极显著高于(P<0.01)1茬的。无论全年刈割1茬或2茬，品种间的鲜草、标准草(65%含水量)和干物质产量均差异显著(P<0.05)，产量依次为海牛>BJ0603>大卡；从拔节前期到孕穗期，各品种茎秆中粗蛋白(CP)、粗脂肪(EE)含量呈下降趋势；酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)含量呈上升趋势，粗纤维(CF)、可溶性糖含量呈先升后降的趋势；粗灰分(ASH)含量呈直线下降的趋势；无氮浸出物(NFE)含量呈先下降后上升的趋势。茎秆中CP、ADF、NDF、ASH、NFE及可溶性糖含量在品种间差异显著(P<0.05)，但EE、CF含量差异不显著(P>0.05)。综合考虑产量和养分含量变化，我们认为，在陇东旱塬地区春播光敏型极晚熟高丹草生产模式中，作为青贮利用时，以全年刈割1茬且在霜降前收割最佳；作为干草调制或青饲利用时，以全年刈割2茬且第1茬在拔节后期孕穗前刈割，第2茬在霜降前刈割最佳。

关键词：光敏型；高丹草；陇东旱塬；生物学特性；产量；营养成分

Biological characteristics and nutrients of the photoperiod-sensitive Sorghum×Sudangrass varieties in the arid land of east Gansu

HE Zhen-Fu, HE Chun-Gui*, WEI Yu-Ming, LIU Long-Sheng

AnimalHusbandry-PastureandGreenAgricultureInstitute,GansuAcademyofAgriculturalSciences,Lanzhou730070,China

Abstract:We studied the biological characteristics, the change in nutritional value at different growth stages and the impact of cutting frequency on production with three photoperiod-sensitive Sorghum×Sudangrass varieties: Monster, Big Kahuna and BJ0603 in the arid land of east Gansu. All varieties were sown in late April and were at the heading or flowering stage when harvested in early October. Hence the reproductive growth stage was not completed. At harvest, the differences in plant height, node number, leaf number and stem diameter among varieties were not significant, but the differences in the weight of leaf and single stem (stalk and leaves) were significant. The standardised grass yield (65% moisture content) and the dry matter production under one cut in one year were higher than those under two cuts, but not significantly different, while the fresh grass production under two cuts was significantly higher. The differences in the fresh grass production, the standardised grass yield and the dry matter production were significant among varieties whether under one or two cuts, with the yield ranking: Monster>BJ0603>Big Kahuna. From the early jointing stage to the booting stage, the levels of crude protein (CP) and ether extract (EE) in the stem decreased, while the acid detergent fiber (ADF) and neutral detergent fiber (NDF) values increased. The crude fiber (CF) and soluble sugar levels increased and then decreased, while the crude ash content (ASH) dropped sharply and the nitrogen free extract (NFE) values first decreased and then increased. The contents of CP, ADF, NDF, ASH, NFE and soluble sugar differed significantly among varieties, while no significant difference in EE and CF content was observed. Based on the variation in yield and nutrient content, the best utilisation strategy for photoperiod-sensitive Sorghum×Sudangrass was to cut once per year as silage and to harvest before the first frost. If utilized as hay or green chop, the best strategy in the arid land of east Gansu would be to cut twice yearly with the first cut performed between the late jointing stage and the booting stage, and the second cut before the first frost.

Key words:photoperiod-sensitive; Sorghum×Sudangrass; arid land of east Gansu; biological characteristics; yield; nutrients

高丹草(Sorghum-sudangrasshybrid)是高粱(Sorghumbicolor)与苏丹草(Sorghumsudanense)杂交的一种新型的一年生禾本科饲料作物，具有分蘖力强、再生性强、营养价值高、产量高、适口好、抗旱节水等特点，在畜牧领域有着广阔的开发利用前景[1-4]。因其茎秆……