Changes In Dissolved Organic Matter During Main and Ratoon Rice Production In Southern Texas.

High dissolved organic matter content may impact water quality. Information about changes in dissolved organic matter during rice production, especially rice rationing, is limited. Flooding and ratooning affect C and N dynamics in rice paddy soils. Changes in microbial activity following urea application, as well as dissolved organic matter derived from rice straw decay impact the C and N cycling in rice ecosystems. The current study objective is to elucidate the effects of N fertilization and ratooning on dissolved organic matter and N transformations in flooded rice ecosystem. Research plots with hybrids and conventional varieties of rice at two sites with sandy and clayey soil have been established and dissolved organic carbon and N forms were determined in the surface soil and water. Effects of rice varieties on soil C and N changes will be evaluated.