Journal Article

Managing soil denitrification

J. W. Doran, J. R. Freney, A. R. Mosier

2002

Overview

Denitrification of nitrate in the soil can be a mechanism of significant loss of fertilizer and soil nitrogen, but it can also serve to remove excess NO 3 that is leached below the root zone. Inappropriate management of irrigation water and fertilizer N in irrigated corn has resulted in leaching of excess N from the rooting zone and contamination of groundwater and also has contributed to the increasing concentration of N 2 O in the atmosphere. Denitrification can be both microbial and chemical, but the microbial process dominates in most soils through a stepwise reduction of NO 3 to N 2 . Soil atmosphere O 2 concentration, which is regulated by soil water content interactively with soil texture and microbial respiration, is the main controller of the process. The oxygen consumption rate depends on the amount of easily degradable organic C compounds and the interplay of water and carbon in developing in the soil reduced oxic conditions, which regulate not only the amount of total denitrification but also the ratio of N 2 O to N 2 produced. Appropriate management of nutrient input, relative to crop demand and soil water status, can limit nitrogen loss from denitrification. This paper describes the role of denitrification in the nitrogen economy of crop production and the environment, describes the process involved, and presents suggestions for limiting N loss caused by denitrification.

• Publisher: Soil and Water Conservation Society,Soil & Water Conservation Society,Taylor & Francis Ltd
• Subject: Agricultural production / Agronomy. Soil science and plant productions / Applied sciences / Atmosphere / Atmospheric pollution / Biological and medical sciences / Company business management / Crop production / Crops / Crops and nitrogen / Denitrification / denitrifying microorganisms / Dispersed sources and other / emissions / Environmental aspects / Exact sciences and technology / Fertilizers / Fundamental and applied biological sciences. Psychology / Irrigation water / Leaching / losses from soil / Management / Moisture content / nitrification / Nitrogen / Nitrogen content / Nitrogen in agriculture / nitrous oxide / Nutrient status / Oxygen consumption / Pollution / Pollution sources. Measurement results / Prevention / Root zone / Soil and water pollution / soil bacteria / Soil chemistry / Soil management / Soil nitrogen / soil pore system / Soil science / Soil texture / Soil water / Soils / Statistics / Water content