Publication Date:
1931-01-01
Description:
1. Addition of farmyard manure to soil gives rise, in laboratory experiments, to an abundant development of cellulose-decomposing bacteria of the genus Vibrio in approximately neutral soils (pH 6.5–7.0). In faintly acid soils (pH 5.7–6.2) these organisms develop less abundantly, and are partly replaced by Spirochaeta cytophaga. At lower pH values only the fungi are active in the decomposition of cellulose. Similar results were obtained by adding filter-paper or straw to soils of different reactions. Of the fungi, Trichoderma and Penicillium appear more active in acid soil, whereas other forms, among others Mycogone nigra, Stachybotrys sp., Coccospora agricola (?), and Botryosporium sp. seemed prominent in neutral soil.2. The vibrios, of which four strains were studied in pure culture, are very sensitive to acidity. They fail to develop in the pH interval 6.0–6.4, and have an optimum at p 7.1–7.6. Spirochaeta cytophaga appears to be slightly more resistant to acidity, being able to grow at pH 5.6–6.0.3. The bacteria as well as the fungi are capable of decomposing the lignified cellulose of straw.
Print ISSN:
0021-8596
Electronic ISSN:
1469-5146
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
