干旱区生态环境知识资源中心

On sunny in April, July, October, 2014, the photosynthetic measuring instrument (Lcpro +) in UK was used to study the diurnal variations of forage photosynthesis in Guizhou karst rocky desertification area. Four gramineous forages were selected to test the net photosynthetic rate, transpiration and water use efficiency. The results showed that the highest net photosynthetic rate of gramineous forage is Festuca elata, followed by Bromus catharticus, Lolium perenne and Dactylis glomerata. The highest transpiration rates of four gramineous forages are Festuca elata and Dactylis glomerata, followed by Bromus catharticus and Lolium perenne. The annual water use efficiency of Bromus catharticus and Lolium perenne is the highest, followed by Festuca elata, the lowest is Dactylis glomerata. The net photosynthetic rate of Cichorium intybus is in front of legume forage and gramineous forage, transpiration rate of Cichorium intybus is lower than them, and water use efficiency is the highest in eight kinds of pasture. Planting artificial forage in karst rocky desertification area should consider the net photosynthetic rate, transpiration rate and water use efficiency, take configuration measures of different grasses. It can reduce the transpiration rate to reduce water loss, while improving water use efficiency and easing the arid status in rocky desertification area. Planting mixed pasture, with high photosynthetic rate and transpiration, low photosynthetic rate and transpiration, can improve the biological diversity and productive potential of forage in karst rocky desertification area. It has value to widely promote and good prospects for development.