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本工作就我国华东、华中地区一些主要类型水稻土进行土壤微生物区系(细菌,放线菌,真菌,嫌气性细菌,好气性非共生性固氮菌,硝化细菌,反硝化细菌,反硫化细菌和好气纤维分解菌等)分析,并测土壤氨化强度和呼吸作用强度,获得以下主要结果:1.水稻土中微生物区系数量分布与其他土壤一样,无论是细菌和放线菌,或者是真菌,都是主要集中于耕作层,犁底层数量突降,一般均为耕作层数量20—50%,心土中微生物更少。好气性细菌和嫌气性细菌之间的比值,随土层深度增加而增加。2.各主要类型水稻土耕作层中,每克土壤中细菌数量在300万—2,000万之间,放线菌处于10万—300万的范围内,真菌为0.7万—12万。3.好气性非共生固氮菌在江苏省内分布较广,数量也较多,除无锡的黄泥土(母质为湖积物)外,平均每克土壤数量为1000—10000以上。而江西省,除乐平的污泥土由于大量使用石灰,土壤已呈微碱性(pH7.5—8.0),合有较多固氮菌细胞(6000/1克土),其他土壤中固氮菌时有时无。湖北孝感的土壤中,固氮菌数量平均每克土中不足200个细胞。4.无论是什么地区,何种母质上发育形成的水稻土,在其肥力水平高的土壤中,细菌、放线菌和真菌数量均比肥力低者为多;生理类羣中的硝化细菌、氨化细菌、好气性非共生固氮菌和好气性纤维分解细菌也有同样的趋势,而反硝化细菌却适得其反。5.不同肥力的同一类型水稻土,肥力高者其氨化强度和呼吸强度较肥力低者为大,但是,土壤中生化作用强度的大小与其相适应的微生物类羣数量并不是简单的比例关系。6.深耕土壤,增施肥料,特别是有机肥料的施用,直接促使了水稻土中各类羣微生物数量增加,大大加强了土壤微生物的活动性。
In this work, the soil microbial flora (bacteria, actinomycetes, fungi, anaerobic bacteria, aerobic non-symbiotic azotobacter, nitrifying bacteria, denitrifying bacteria, anti-sulfur bacteria And good gas-fiber decomposing bacteria, etc.) were analyzed, and the soil ammonification intensity and respiration intensity were measured to obtain the following main results: 1. The distribution of microbial flora in paddy soil was the same as that of other soils, whether bacteria and actinomycetes, or Fungi, are mainly concentrated in the tillage layer, plow the number of sudden drop, are generally 20-50% of the tillage layer, heart soil less microorganisms. The ratio between aerobic bacteria and anaerobic bacteria increases with soil depth. 2. The main types of paddy soil tillage, the soil per gram of bacteria in the number of 3 million -2,000 million actinomycetes in the range of 100000 -300 million, the fungus is 70000 -120000. 3. Aerobic non-symbiotic Azotobacter widely distributed in Jiangsu Province, the number is also more, in addition to the Wuxi yellow soil (parent material for the lake sediment), the average number of soil per gram is 1000-10000 above. However, due to the large amount of lime in the leachate in Leping, Jiangxi Province, the soil was slightly alkaline (pH7.5-8.0), and there were more Azotobacter cells (6000/1 g soil) and other nitrogen-fixing bacteria Sometimes no Xiaogan in Hubei soil, the number of nitrogen-fixing bacteria per gram of soil less than 200 cells. 4 no matter what region, what kind of parent material on the formation of paddy soil, in its high fertility levels of soil, the number of bacteria, actinomycetes and fungi are less than those with low fertility; physiological groups of nitrifying bacteria, Ammonia bacteria, aerobic non-symbiotic Azotobacter and aerobic fiber decomposition bacteria have the same trend, and denitrifying bacteria are counterproductive. The same types of paddy soils with different fertility, the higher the fertility of its higher amylase and respiration intensity than the lower fertility is large, but the size of the biochemical interaction in the soil and adapt to the number of microbial groups is not a simple proportional relationship . 6. Deep plowing the soil, increasing the application of fertilizers, especially organic fertilizers, directly led to an increase in the number of each group of micro-organisms in paddy soils, greatly enhancing the activity of soil microorganisms.