Rice accounting in COMET-Farm is unique because it is only available in certain regions and the location will inform the IPCC Tier 2 method that is used in the tool. Rice accounting in COMET-Farm is available in Arkansas, California, Louisiana, Mississippi, and certain counties in Missouri and Texas. Figures 3-4 and 3-5 from the USDA methods document (page 3-66) can assist users in determining whether or not their rice crops can be accounted for in COMET-Farm.
Planting and Harvest: After entering a planting and harvest/kill date, a dry matter removal percentage, and selecting the check box next to Grain/Fruit/Seed/Root/Tuber, enter a value for Yield. For rice accounting, yield is used to estimate the rate of application of organic amendment types (e.g., straw incorporation). Yield should be entered in hundredweight per acre (cwt/ac). COMET-Farm will only utilize the user-entered yield if a tillage event is included in management or if the dry matter removal is less than 100%.
Tillage System Intensity and Field Operations: This section is specific to rice accounting in California*. After entering a pre-planting and/or post-harvest tillage intensity from the drop-down menus (or using the Tillage Intensity Calculator), please select a Seeding Method.
Water-seeded: Rice seeds are broadcast into a flooded field.
Drill-seeded: Rice seeds are planted directly into the soil using a drill before the field is flooded. This requires careful management of water post-planting.
*In the mid-South regions, water-seeding is assumed for the seeding method
Irrigation: the only management style for rice that is parameterized in COMET-Farm is the flooded method. The tool requires at least one flood event, but more may be added if both pre-season flooding occurred as well as winter flooding. The flood event may end in the subsequent year.