稻草分解促進土壤固氮活性及稻草分解菌與固氮菌共生之研究

Study on the Symbiotic Relationship between Cellulolytic and Nitrogen-Fixing Microorganisms

簡宣裕(S. Y. Jean) ； 林錫錦(C. J. Lin)

《中華農業研究》 34卷1期 (1985/03) Pp. 64-70

https://doi.org/10.29951/JARC.198503.0006

摘要

本試驗在探討固氮菌及纖維分解菌於稻草分解過程中是否有共生現象及稻草施入土中對固氮微生物固氮能力之影響。由試驗分離出3種固氮菌，9種纖維分解菌。試驗結果得知9種纖維分解菌不具固氮能力，但能產生甲烷。固氮菌中有一株於無氮培養基中之固氮活性可達670n mole N2 fixed/hr/20cc. liquid culture medium，其餘二株固氮能力微弱。固氮菌接種於纖維素中，不具固氮能力，但是接種於稻草中則有少量固氮現象，若將纖維分解菌與固氮菌同時接種於稻草及纖維素中，則固氮菌之固氮活性，纖維分解菌之甲烷生成量皆有顯著增加的趨勢，顯示纖維分解菌與固氮菌於稻草分解過程中營共生互利的現象。旱田及水田中稻草的固氮活性分別爲稻草附近土壤的10倍及100倍以上，顯示稻草埋入土中經纖維分解菌分解後產生可供固氮微生物利用的養分擴散範圍不大，而集中於分解中稻草上。土壤水分含量20%及溫度10℃可視爲固氮菌繁殖之臨界條件，低於此則田間土壤固氮活性很小。

並列摘要

The purposes of these experiments were to investigate if there is any symbiotic relationship between cellulolytic and nitrogen-fixing microorganisms and the effect of rice straw buried in soil on the nitrogen-fixing activity of soil systems. Three strains of nitrogen-fixing microorganism which could not produce methane gas and nine strains of cellulose-decomposing microorganism which could not fix nitrogen, but could produce methane gas were isolated and purified from the decaying rice straw.
The results indicated that symbiotic relationship existed between the isolated cellulolytic and nitrogen-fixing microorganisms. The nitrogenase activity of soil systems and the activity of cellulolytic microorganisms were increased when rice straw buried in soils. The nitrogenase activity of decaying rice straw was 10 folds and 100 folds of the soil next to and far from the decaying rice straw, respectively. This indicated that the nitrogenase activity of soil systems were concentrated on the decaying rice straw. When the soil water content lower than 20% and soil temperature below 10℃ inhibited the propagation of nitrogen-fixing microorganisms and their nitrogenase activity. The nitrogenase activity of paddy soil was greater than that of the upland soil.