摘要
采用常规方法研究了西北干旱半干旱地区5种栽培措施及3种施氮量水平对小麦根区根外土壤细菌、真菌及放线菌数量的影响。结果表明:1覆膜条件下小麦根区、根外细菌在3种施氮水平下的平均数量高于常规条件(即10.7×106个/g·土覆膜根区>7.0×106个/g·土常规根区和7.5×106个/g·土覆膜根外>6.1×106个/g·土常规根外),而且覆膜和常规2种栽培模式下根区细菌的平均数量均高于根外细菌的平均数量。25种栽培模式下根区真菌数量(×103个/g·土)按覆膜(4.0)>常规(3.0)>覆草(1.0)>补灌、垄沟(0.6)排列,而根外真菌数量差异不显著;只有覆膜时表现为根区真菌数量高于根外(4.0×103个/g·土>3.1×103个/g·土),其余4种栽培模式均为根外真菌数量高于根区。3覆膜、覆草、补灌和垄沟4种模式下根区放线菌在3种施氮水平下的平均数量均高于常规条件(31.1×105～33.2×105个/g·土>20.7×105个/g·土),而根外放线菌数量差异不显著;常规条件根区放线菌数量低于根外,其余4种模式均为根区高于根外放线菌数量。4小麦根外细菌、真菌及放线菌数量随施氮量的增加有减少的趋势;而根区真菌和放线菌在N16时数量最高(分别为2.1×103和32.8×105个/g·土),根区细菌则在N8时较N0和N16的数量高,即随施氮量的增加,根区微生物数量有增加的趋?
In the paper, the effect of the soil bacteria, fungi and actinomycete quantity at the wheat rhizosphere and outrhizosphere under 5 different cultural conditions and 3 lever of nitrogen fertilizer in the arid and semiarid area in northwest were studied by normal methods. The results indicated that: ①The bacteria average amount of wheat rhizosphere and outrhizosphere under 3 nitrogen lever was more than the amount of routine cultural condition (that is:10.7×10~6/g _(Covered film)_(of rhizosphere)>7.0×10~6/g_(Normal way of )_(rhizosphere)and 7.5×10~6/g_(Covered film of outrhizosphere) >6.1×10~6/g_(Normal way of outrhizosphere)), and the average amount of bacteria at rhizosphere was more than the average amount at outrhizosphere under the covered film and normal way. ②The sequence of the fungi amount(×10~3/g) at rhizosphere under 5 different cultural conditions was covered film(4.0)>normal way (3.0)>covered grass(1.0) >winter irrigate and furrow(0.6). ③The actinomycete average amount of wheat rhizosphere under 3 nitrogen lever under covered film, covered grass, winter irrigate and furrow was more than normal way (31.1~33.2×10~5>20.7×10~5 /g), while the difference of actinomycete amount under the 4 cultural conditions was not notable; the actinomycete amount at rhizosphere was less than the amount at outrhizosphere, under the other 4 cultural conditions the amount of actinomycete at rhizosphere was more than that of outrhizosphere. ④The amount of bacteria ,fungi and actinomyceteat wheat outrhizosphere was declining with the increase of nitrogen; while the amount of fungi and actinomycete was the most at N16(that is: 2.1×10~3 and 32.8×10~5 /g), the amount of bacteria at N8 was more than at N0 and N16, that is the amount of microorganism at rhizosphere was increasing with the decline of nitrogen.
出处
《西北农业学报》
CAS
CSCD
北大核心
2005年第2期38-43,共6页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家自然科学基金重点项目(西北旱地优质高产高效栽培的生理生态基础:30230230)部分内容。
