THE WOODY NITROGEN FIXATION RESOURCE AND ITS EXPLOITIVE AVENUES IN THE SICHUAN RED BASIN
四川盆地木本固氮资源和利用途径

The resource of 41 local N-fixing woody plants is reported in this paper. Among them 10 species belong to those newly recorded. Some of them are characteristic species of our country and some are rare or nearly extinguished ones. According to a preliminary investigation, at least 25 species have nitrogen-fixing function and good cultural prospects in the region. The characteristics and ecological properties of nodulation and nitrogen fixation of the woody plants are studied. The difference in nodulation and N-fixing ability of each species and the relativity of the ability under different soil conditions are demonstrated. The experience in exploiting the nitrogen fixation resource effectively is summarized. The main avenues of exploitation of the resource include the following: (1) It can be used as member of mixed plantation; (2) It is a pioneer plant for reclaiming wasteland; (3) It should be rationally arranged in an agriculture-forest combination system and in a protection forest; and (4) It has used in economic forest. Exploitation of this resource is significant to establishing a forest nitrogen fixation system, improving soil fertility, and increasing forest productivity.