Winter flooding benefits soils by accelerating residue decomposition and building a reservoir of organic N. Where straw decomposition occurs under flooded conditions, nitrogen loss is reduced by minimizing the conversion of organic N to NH₄.

Click here for an illustration of nitrogen cycling in flooded soils.

It has also been found that winter flooding offers greater benefits over non-flooded conditions by facilitating straw decomposition. In multiple years of their study (Horwath and van Kessel, 1998), winter flooding increased straw decomposition while also producing higher concentrations of inorganic N.

Furthermore, winter flooding provides an overwintering habitat for migratory birds in the Pacific Flyway. Click the photo for an enlargment.

Literature Cited
Horwath, W.R. and C. van Kessel. 1998. Reassessing soil N availability and fertilizer recommendations under alternative rice residue management practices. Annual Report, Comprehensive Rice Research 1998, University of California and U.S. Department of Agriculture.

BIFS in Rice Homepage