Dynamics of clay-fixed ammonium as a sink or source of exchangeable ammonium in a paddy soil
Dynamics of clay-fixed ammonium as a sink or source of exchangeable ammonium in a paddy soil
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DOI：
10.1080/00380768.2011.628271
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发表时间：
2011-12
影响因子：
2
通讯作者：
K. Matsuoka;N. Moritsuka
中科院分区：
文献类型：
--
作者：
K. Matsuoka;N. Moritsuka
粘粒固定态铵在土壤氮素的动态和有效性中起着重要的作用，既是交换性氮的汇，也是交换性氮的源。然而，关于可交换和固定之间交换过程的定量信息是有限的。在这项研究中，我们开发了一种顺序提取交换性和固定性的方法，并评价了固定物在水稻土中作为交换性物质的汇或源的作用。对一种水稻土进行了70天的厌氧培养，分别在添加和不添加水稻粉的情况下进行了试验。Hinohikari)秸秆作为前处理，并将风干和不风干作为后处理。通过厌氧培养，土壤中弱固定态量显著增加，交换性态量显著增加，说明交换性态态库是水稻土中弱固定化态源的主要来源。而稻草培养前施稻草显著降低了土壤交换性含量，使弱固定含量略有下降。孵化后风干造成了交换性物质的固定。总体而言，土壤交换性和弱固定性含量呈正相关(r=0.58；p<；0.05)，说明弱固定性土壤在强固定和可交换性之间起着过渡池的作用。提出的序贯提取方法能有效地评价可交换性与固定性之间的相互作用。将该方法与培养试验相结合，证明了水稻土中固着物，特别是弱固着物的释放量或滞留量足以影响交换性物质的动态变化。
Clay-fixed ammonium ( ) plays an important role in the dynamics and availability of soil nitrogen (N), acting as a sink or source of exchangeable . However, quantitative information about exchange processes between exchangeable and fixed is limited. In this study, we developed a method to sequentially extract exchangeable and fixed , and evaluated whether fixed acts as a sink or source of exchangeable in a paddy soil. A paddy soil was subjected to anaerobic incubation for 70 days with and without the application of powdered rice (Oryza sativa L. cv. Hinohikari) straw as a pre-treatment, and with and without air-drying as a post-treatment. By the anaerobic incubation, the content of weakly fixed increased significantly with a significant increase in exchangeable , implying that exchangeable in the paddy soil is the main pool as a source of weakly fixed . On the other hand, a significant decrease in the exchangeable content by rice straw application before the incubation slightly lowered the content of weakly fixed . Air-drying after the incubation caused the fixation of exchangeable . Overall, the contents of exchangeable and weakly fixed were positively correlated (r = 0.58; p < 0.05), indicating that weakly fixed acted as a transitory pool between strongly fixed and exchangeable . The proposed sequential extraction method was effective to evaluate the interaction between exchangeable and fixed . Combining this method with an incubation experiment, it was demonstrated that fixed , especially weakly fixed , in the paddy soil can be released or retained in quantities sufficient to affect the dynamics of exchangeable .