Reduction of Nitrate to Ammonium in Selected Paddy Soils of China *1English Full Text

YIN SHIXUE 1, SHEN QIRONG 2, TANG YAN 1 and CHENG LIMING 1 1 Department of Agronomy, Agricultural College, Yangzhou University, Yangzhou 225009 (China) 2 College of Resources and Environmental Science, Nanjing Agricultural University,

Abstract: Three paddy soils were examined for their capacities of dissimilatory reduction of nitrate to ammonium （DRNA）. 15 N labelled KNO 3 was added at the rate of 100 mg N kg -1 . Either glucose or rice straw powder was incorporated at the rate of 1.0 or 2.0 mg C kg -1 respectively. Three treatments were designed to keep the soil saturated with water: A) a 2 cm water layer on soil surface （with beaker mouth open）; B) a 2 cm water layer and a 1 cm liquid paraffin layer （with beaker mouth open）; and C) water saturated under O 2 free Ar atmosphere. The soils were incubated at 28 oC for 5 days. There was almost no 15 N labelled NH + 4 N detected in Treatment A. However, there was 1.4 to 3.4 mg N kg -1 15 N labelled NH + 4 N in Treatment B and 2.1 to 13.8 mg N kg -1 in Treatment C. Glucose was more effective than straw powder in ammonium production. Because there was sufficient amount of non labelled NH + 4 N in the original soils, 15 N labelled NH + 4 N produced as such should be the result of dissimilatory reduction. Studies on microbial population showed that there were plenty of bacteria responsible for DRNA process （DRNA bacteria） in the soils examined, indicating that number of DRNA bacteria was not a limiting factor for ammonium production. However, DRNA bacteria were inferior in number to denitrifiers. DRNA process in soil suspension seemed to start after 5 days of incubation. Glycerol and sodium succinate, though both are readily available carbon sources to organisms,did not facilitate DRNA process. DRNA occurred only when glucose was available and at the C/NO 3 - N ratio of over 12. It seemed that both availability and quality of the carbon sources affected DRNA.

Keywords：

carbon source; dissimilatory reduction of nitrate to ammonium; microbial population;

Series：
(D) Agriculture; (A) Mathematics/ Physics/ Mechanics/ Astronomy
Subject：
Biology; Physical Geography and Topography; Fundamental Science of Agriculture; Agronomy
Classification Code：
S154.3,S153.6

Mobile Reading

Read on your phone instantly

Step 1
Scan QR Codes

"Mobile CNKI-CNKI Express" App

Step 2
Open“CNKI Express”

and click the scan icon in the upper left corner of the homepage.

Step 3
Scan QR Codes

Read this article on your phone.
CAJ Download
PDF Download

Reduction of Nitrate to Ammonium in Selected Paddy Soils of China *1English Full Text

YIN SHIXUE 1, SHEN QIRONG 2, TANG YAN 1 and CHENG LIMING 1 1 Department of Agronomy, Agricultural College, Yangzhou University, Yangzhou 225009 (China) 2 College of Resources and Environmental Science, Nanjing Agricultural University,

Read on your phone instantly

Citation Network

Related Literature