氮素和刈割对桂牧1号杂交象草光合作用、产量和品质的影响  

Effects of nitrogen fertilization and cutting on the photosynthesis,yield,and quality of Pennisetum purpureum cv. Guimu-1

作　　者：梁志霞[1,2,3] 宋同清[2,3] 曾馥平[1,2,3] 彭晚霞[2,3] 杨钙仁[1] 谭秋锦[1,2,3] 

机构地区：[1]广西大学林学院,南宁530004 [2]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [3]中国科学院环江喀斯特生态系统观测研究站,广西环江547100

出　　处：《生态学杂志》2013年第8期2008-2014,共7页Chinese Journal of Ecology

基　　金：中国科学院西部行动计划项目(KZCX2-XB3-10);中国科学院战略性先导科技专项(XDA05050205;XDA05070404);国家科技支撑计划项目(2011BAC09B02);国家自然科学基金项目(31000224;31070425和U1033004);中国科学院"西部之光"人才培养计划和广西"特聘专家"项目资助

摘　　要：采用L16(45)正交试验设计,研究了喀斯特地区桂牧1号杂交象草光合生理特性、产量和品质对不同施氮水平、刈割次数、刈割强度的响应。结果表明,施用氮肥显著增加了桂牧1号杂交象草的叶绿素a、b和叶绿素总含量、净光合速率、产量及营养成分含量,肥效最佳水平是1000kg·hm-2·a-1。刈割次数显著影响桂牧1号杂交象草的净光合速率、叶绿素含量和牧草营养成分含量,刈割过2～3次,桂牧1号光合作用能力显著提高,而每年刈割3～4次,牧草的营养品质最优。刈割强度对粗蛋白含量影响显著,对其他营养成分含量和产量均无显著影响,以5或20cm刈割强度为最优。综合各指标结果,提出了喀斯特地区栽培桂牧1号杂交象草获得高产优质的最优方案,即施氮1000kg·hm-2·a-1,刈割牧草3次,刈割强度为5或20cm。A L16 （45） orthogonal experiment was conducted to study the photosynthesis, yield, and quality of Pennisetum purpureum cv. Guimu-1 in a karst region of Southwest China under effects of different nitrogen fertilization rates and cutting times and intensities. Nitrogen fertilization increased the chlorophyll a and b and total chlorophyll contents, net photosynthetic rate, yield, and plant nutrient contents significantly, with the best effect of 1000 kg＆middot;hm-2＆middot;a-1. Cutting times had significant effects on the net photosynthetic rate, chlorophyll content, and plant nutrient contents. After 2 or 3 times cutting, the photosynthesis improved significantly; after cutting 3 or 4 times per year, the nutritional quality of Guimu-1 was the best. Cutting intensity had significant effects on the crude protein content, but minor effects on the other nutrient contents and yield. The best effects were obtained when the cutting intensity was at the distance 5 cm or 20 cm from the roots. Based on the comprehensive analysis of the indices, the optimum scheme for high yield and good quality of Guimu-1 in the karst region was proposed as nitrogen application rate 1000 kg＆middot;hm-2＆middot;a-1, 3 times cutting per year, and cutting at the distance 5 cm or 20 cm from the roots.

关 键 词：氮素 刈割 光合作用 产量 品质 桂牧1号杂交象草 正交试验 

分 类 号：S543.9[农业科学—作物学]