HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Li, H. Articles by Chen, Y. PubMed Articles by Li, H. Articles by Chen, Y. Agricola Articles by Li, H. Articles by Chen, Y. Related Collections Rice Nutrient Management Plant and Environment Interactions

NUTRIENT MANAGEMENT & SOIL & PLANT ANALYSIS

Reduction of Ammonia Volatilization from Urea by a Floating Duckweed in Flooded Rice Fields

^a Key Laboratory of Non-point, Source Pollution Control, Ministry of Agriculture and Institute of Environmental Science and Technology, Zhejiang University, HangZhou 310029, China
^b Key Laboratory of Water Pollution Control and Environmental Safety Technology, Zhejiang Province, HangZhou 310029, China
^c Research Academe of Environment and Science of Zhejiang Province, HangZhou 310007, China

^* Corresponding author (lisar2002{at}zju.edu.cn).

Effective nutrient management to reduce high N losses and to improve N use efficiency has been an important focus of agricultural and environmental science research. Understanding the influence of duckweed (Lemna minor L.), a common floating macrophyte in flooded rice (Oryza sativa L.) fields, on NH₃ volatilization and grain yield is required for better management of applied N fertilizer. We conducted an on-farm experiment with three levels of urea (0, 90, 180 kg urea N ha^–1) applied alone or in combination with duckweed. Our results indicate that total ammoniacal-N concentration, pH, and temperature of the floodwater were significantly lower in the plots with a duckweed cover. As a consequence, NH₃ volatilization rates were reduced by duckweed from 20.0 to 53.7% and from 19.0 to 33.2% in plots supplied with 90 and 180 kg urea-N ha^–1, respectively. Duckweed increased rice grain yields by approximately 0.7 and 0.7 Mg ha^–1 (9.8 and 9.4%) in plots supplied with 90 and 180 kg urea N ha^–1, respectively. Ammonia losses from urea-N applications can be reduced and N use efficiencies can be improved by the presence of duckweed in flooded rice fields.

Abbreviations: DW, duckweed • TAN, total ammoniacal nitrogen