Solute movement in the rhizosphere with the effect of soil moisture and plant uptake
Abstract
Nutrient loads from land to a water body effects the eutrophication processes. The assessment of leakage of dissolve inorganic nitrogen (DIN) solute from land provides useful information for nutrient management. Solute transport in the rhizosphere is a complicate process, which depends on solute property, water supply and movement, soil physiologic property, plant transpiration and uptake, etc. This presentation focuses on the effect of soil moisture and plant uptake on DIN leakage from soil. Plant nitrogen uptake is not a monotonic function with soil moisture. When moisture is deficient, increasing moisture will increase water uptake and increase nitrogen uptake; when moisture is sufficient (e.g., at the field capacity), increasing it may dilute the solution, decrease nitrogen uptake, and increase nitrogen export. Under moisture over-sufficient conditions, anaerobiosis may harm plant and cause even lower nitrogen uptake. In nutrient management, it is important to know how flow affects nutrient leakage from the land. A proper mathematic function describing such processes is desirable to establish a correct mathematical model for nutrient management. A mechanistic computer model procedure for DIN uptake as a function of soil moisture is also presented.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2004
- Bibcode:
- 2004AGUSM.H23B..02W
- Keywords:
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- 0400 Biogeosciences;
- 1851 Plant ecology;
- 1866 Soil moisture;
- 1871 Surface water quality