Apparatus for the measurement of losses of nitrogen as gas from the field and simulated field environments

Abstract

The intensive, short duration activity of many of the transformations and translocations of N in field soils is briefly discussed. Significant gaseous losses of N by volatilization and denitrification are considered to occur episodically. Apparatus which measures losses by such pathways can be relatively simple in design if only the specific gaseous products of the transformation are measured and if the duration of the activity is short thus enabling better simulation of field conditions. Simulation may be achieved with different types of apparatus but all should provide a climatic environment similar to that found in the field, an undisturbed pedon and a design which does not create artifacts. Various types of apparatus are discussed and a detailed description given of a volatilization chamber suitable for studying NH 3 volatilization. Development of a large gas lysimeter for denitrification is also discussed and preliminary information given on the design and on the method of sampling the pedon.