| 干土效应对土壤生物组成及矿化与硝化作用的影响 |
| |
| 引用本文： | 林江辉,李辉信,胡锋,赵海燕.干土效应对土壤生物组成及矿化与硝化作用的影响[J].土壤学报,2004,41(6):924-930. |
| |
| 作者姓名： | 林江辉 李辉信 胡锋 赵海燕 |
| |
| 作者单位： | 南京农业大学资源与环境科学学院,南京,210095 |
| |
| 基金项目： | 中国科学院红壤生态开放实验站基金(2001-K-03)资助 |
| |
| 摘 要： | 将经过风干、过筛后的2种旱地红壤加水培养,并和新鲜土培养条件相比较,研究干土效应对土壤生物组成及矿化与硝化作用的影响.试验共4个处理(1)农田旱地风干土加水培养(RU);(2)农田旱地新鲜土培养(FU);(3)苗圃旱地风干土加水培养(RN);(4)苗圃旱地新鲜土培养(FN).结果表明红壤风干土加水预培养5 d后,细菌、放线菌、真菌数量比新鲜土显著增加(p＜0.01),细菌数量增加最为明显,农田旱地和苗圃旱地风干土处理分别是新鲜土的6.26倍和6.84倍,红壤风干土加水培养处理的微生物量碳、氮也随之增加.培养28 d后土壤中微生物数量趋于稳定,与预培养5 d时的数量相当或稍有下降,但风干后加水培养处理的微生物数量仍保持大于新鲜土的趋势(农田旱地的放线菌除外),微生物量碳、氮也存在同样的趋势.风干土加水培养后微生物数量的迅速增加,使得氮素矿化速度加快,由此导致NH+4-N量显著增加(p＜0.01),培养28 d后,NH+4-N量较预培养5 d时有所增加,且明显高于新鲜土培养处理;NO-3-N含量也增加,但新鲜土处理显著高于风干土处理.土壤风干处理对土壤自由生活线虫的影响比较大,农田旱地和苗圃旱地风干土加水培养28 d后,其自由生活线虫数量仅为新鲜土的16.0%和30.1%,显示风干土加水培养难以恢复土壤微型动物的数量.28 d的矿化和硝化培养试验结果显示,风干土加水培养处理的净矿化量和矿化率均高于新鲜土处理,苗圃旱地风干土处理的增量达到了显著水平(p＜0.05),但是硝化作用却刚好相反,农田旱地和苗圃旱地的净硝化量及硝化率均是新鲜土处理显著高于风干土处理(p＜0.05),其原因是对硝化作用起重要作用的硝化菌(氨氧化细菌和亚硝酸氧化细菌)数量在经历了风干过程后很难恢复到新鲜土水平.
|
| 关 键 词： | 干土效应 矿化作用 硝化作用 土壤生物 |
| 收稿时间： | 2003/11/7 0:00:00 |
| 修稿时间： | 2004/6/22 0:00:00 |
EFFECTS OF REWETTING ON SOIL BIOTA STRUCTURE AND NITROGEN MINERALIZATION, NITRIFICATION IN AIR-DRIED RED SOIL |
| |
| Lin Jianghui,Li Huixin,Hu Feng and Zhao Haiyan.EFFECTS OF REWETTING ON SOIL BIOTA STRUCTURE AND NITROGEN MINERALIZATION, NITRIFICATION IN AIR-DRIED RED SOIL[J].Acta Pedologica Sinica,2004,41(6):924-930. |
| |
| Authors: | Lin Jianghui Li Huixin Hu Feng and Zhao Haiyan |
| |
| Institution: | College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China;College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China;College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China;College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China |
| |
| Abstract: | Effects of rewetting of air-dried red soil on soil biota composition, nitrogen mineralization and nitrification were studied in the laboratory.Four treatments were designed: (1) rewetting of air-dried upland red soil (RU);(2) fresh upland red soil (FU);(3) rewetting of air-dried nursery red soil (RN);(4) fresh nursery red soil (FN).The results indicate: the populations of soil microorganisms including bacteria, fungi, actinomycetes in the rewetted red soil increased obviously after 5 days incubation when compared with those in the fresh red soil, especially the population of bacteria, which were 6.26 and 6.84 times as large as that in the fresh of upland and nursery soil, respectively.As a result of the increase in soil microbes, the soil microbial biomass C (SMBC) and soil microbial biomass N (SMBN) increased in the rewetted air-dried red soil treatments.The increasing population of soil microbes after 28 days.incubation leveled off and was still somewhat equal to or a bit smaller than that after 5 days's preincubation of all the treatments.However, the population of microbes in the rewetted air-dried red soil was still larger than that in the fresh red soil after 28 days.incubat ion.With the increase in microbe population and biomass, nitrogen mineralization was sped up, which led to increase in NH4+-N concentration.After 28 days.incubation, the NH4+-N concentrations in the rewetted ai-rdried soils increased in comparison with those after 5 days.preincubation and obviously higher than in the fresh soils.At the same time, NO3--N concentrations also increased, but they were significantly higher in the fresh soils than in the rewetted red soil.The experiment also shows that after 28 days.incubation, the population of freeliving nematodes in the treatments of rewett ing air-dried upland and nursery red soil of could hardly recover, being 16.0% and 30.1% of that in the fresh red soil, respectively.After 28 days.incubation of the rewetted air-dried red soil, the net mineralization and mineralization rate increased significantly (p < 0.05), but the net nitrification and the net nitrification rate decreased significantly (p < 0.05), when compared with that in the fresh red soil.The possible reason was that the populations of ammonium oxidi-zers and nitrite oxidizers, which play a key role in the process of nitrification, could hardly get recovered from the damage of air-drying. |
| |
| Keywords: | Drying effect N-mineralization N-nitrification Soil organism |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《土壤学报》浏览原始摘要信息 |
| 点击此处可从《土壤学报》下载免费的PDF全文 |
|
