Several sugarcane cultivars residues quantity and nutrient content of the residue
几种甘蔗品种残体量及其养分含量
Although great advances have been made, they lacked systematic research in both depth and extent, especially study on the litter and residue.
然而，就凤眼莲危害的定量研究以及对水生生态系统的影响，尤其对其凋落物和残体，尚缺乏深入系统的研究。
In the upper reaches of Muyang River valley in the mountainous area of middle part Fujian,there extensively exists several remaining palaeotopograhpic surfaces with altitudes 600 m or so,800 m or so and 1 000～1 200 m above sea level.
在闽中山地的穆阳溪流域上游区域广泛分布着海拔600 m左右、800 m左右和1000~1200 m三级残余古地形面。