再论土壤条件与桤木结瘤固氮的关系

桤木结瘤固氮与土壤理化因素的关系,可用多元二次回归方程表达.最佳数学模式表明:影响固氮量的主要因素是酸度,其次是有效磷与有效钾、CO₂与有机质、CO₂与有效钼的联合效应.有效磷的不足是固氮的限制因素.共生体的固氮能力在潮土和黄壤(灰岩母质除外)上最强,沙溪庙母质的各种紫色土较高,强钙质土和酸性土则低.

FURTHER STUDY ON INFLUENCE OF SOIL CONDITION ON NODULATION AND NITROGEN FIXATION OF ALNUS CREMASTOGYNE

The fitted multivaliate quadratic regression equation can better express the relation between nodulation and nitrogen fixation of alder and physical-chemical factor of the soils.The best mathematical model indicates that soil pH is the main factor affecting nitroge fixation amount.The associated effect of the available phosphorus with available potassium,the CO₂ with organic matter,or the CO₂ with available molybdenum is the secondary factor.Deficiency of the available phosphorus is the limitation to nitrogen fixation of the alder.The highest N₂-fixing capacify of the symbiont occurs in the alluvial soil and yellow earth (except the calcareous parent material); and higher in the purplish soils on Shaximiao parent material,but low in strongly calcareous and acid purplish soil.