U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2001
Abstract
Use of labeled 15N techniques can help improve and refine knowledge required to understand the dynamics of the N cycle under agricultural systems. The examples reported in this paper illustrate that, with creativity and careful planning, use of 15N-enriched or depleted fertilizers can be used in many types of N experiments with various crops, cropping systems, and in many types of agroecosystems. The objective is to report examples of a wide range of field studies that researchers can hopefully draw upon to design and utilize N isotope techniques that accomplish the objectives for their own research. Examples of microplot studies with and without physical barriers are discussed along with some of the strengths and limitations of each approach. Even though 15N technology offers considerable opportunity to understand N cycling, it too has limitations to its use. Types of fertilizer 15N materials and methods for applying 15N materials are discussed including some discussion about the use of ammonium versus nitrate forms; literature sources are provided for additional reading about the use of 15N techniques.
Comments
Published in COMMUN. SOIL SCI. PLANT ANAL., 32(7&8), 951–979 (2001).