矿质营养对绿萍生长的影响

本文系通过水培、土培和田间试验,研究了氮、磷、钾和一些微量元素对绿萍生长发育和固氮能力的影响,证明都有明显的效果。磷素对绿萍的生长及其固氮能力均有良好的作用。在红泥田上钙镁磷肥的效果优于过磷酸钙。在有效性氮贫乏的土壤上、在气温较低时,氮素对绿萍的生长也有较好的效果,但其用量必须控制。

EFFECT OF MINERAL NUTRITION ON THE GROWTH OF AZOLLA

Studies related to the main elements, N, P, K as well as the microelemnts, Mn, Mo, B and Zn were conducted with water culture, Pot test and field experiments respectively for Azolla pinnata during winter and spring. By means of the symbiotic association with Anabaena Azollae, phosphorus showed best in increasing both the quantity and the nitrogen fixing capacity of the algae. Nitrogen showed efficiency only during the lower tempetature, while potassium was necessary for balancing the nutrition of this algae. Mn, Mo, and B also showed significant in increasing the nitrogen fixing capacity of Azolla, especially the increasing of ammonium concentration in the medium.