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Macropore and Preferential Flow

  1. Nicholas Jarvis

Published Online: 15 APR 2003

DOI: 10.1002/047126363X.agr156

Encyclopedia of Agrochemicals

Encyclopedia of Agrochemicals

How to Cite

Jarvis, N. 2003. Macropore and Preferential Flow. Encyclopedia of Agrochemicals. .

Author Information

  1. Swedish University of Agricultural Sciences, Uppsala, Sweden

Publication History

  1. Published Online: 15 APR 2003

Abstract

Until recently, the prevailing conceptual model of water infiltration into soils was based on the idea that “new” incoming water displaced existing “old” water uniformly, with water moving downward in the soil profile as a broad and well-defined “wetting front.” Similarly, the prevailing view of agrochemical transport was that leaching took place as a chromatographic process, with the chemical as fully exposed to adsorption sites in undisturbed field soils as it would be both in laboratory batch experiments on water–slurry mixtures, and in column leaching experiments on repacked soils. The idea that water flow and chemical transport normally takes place as a uniform displacement process in soils has now been abandoned, and it has been replaced by an understanding that the heterogeneity of undisturbed soils in the field often leads to markedly nonuniform patterns of water flow and agrochemical displacement.

Keywords:

  • water infiltration;
  • agrochemical transport;
  • preferential flow;
  • macropore flow;
  • leaching;
  • vadose zone;
  • water–slurry mixtures;
  • uniform displacement process