A Closer Look at RIPE’s Qualifying Practices: Dry-Seeded Rice

Dry seeding for rice provides robust environmental benefits

RIPE’s researchers continually work to expand the set of practices that would qualify for a $100 per unit payment under the proposed RIPE100 program by collecting research that demonstrates the combined environmental value of climate-smart practices.

Here we are highlighting dry seeding for rice grown in California or regions south of 1-10. This protocol has been accepted by California’s offset program, which is one of the strictest programs in the world.

Farmers who adopt dry seeding provide significant climate benefits. The practice reduces greenhouse gas emissions by 1 metric ton per acre, but even that significant benefit is only around $22 per acre. However, the practice also delivers nearly $80 in air quality benefits and $8 in water conservation per acre, reaching a total of $109 per acre.  

Review our methodology and sources for this practice, which compiles research from USDA, land-grant universities and peer reviewed studies, below. Access our current list of proposed qualifying practices here

Dry-Seeded Rice

Ecosystem ServiceValue ($/acre/year)Source
Climate Change Mitigation (Methane and N2O Reduction)

$22Low-end value:
A 2020 report by the Environmental Defense Fund finds that replacing wet seeding with dry seeding, as approved by California Air Resources Board, would reduce greenhouse gas emissions by 260,800 tCO2eq/year in the Sacramento Valley. NRCS indicates that 500,000 acres of rice are grown in this region. Therefore, dry seeding provides a GHG mitigation value of .47 metric tons CO2eq/acre. Multiplying this value by $20/metric ton CO2eq equals $10/acre.

Sources:
Jeremy Proville, et al. Agricultural Offset Potential in the United States. EDF, April 2020. Agricultural Offset Potential in the United States: Economic …https://papers.ssrn.com › sol3 › papers
Creating and Quantifying Carbon Credits from Voluntary Practices on Rice Farms in the Sacramento Valley: Accounting for Multiple Benefits for Producers and the Environment. NRCS. 2010. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044916.pdf

High-end value:
Methane:
A 2015 study found that in California trials, dry seeded rice reduced emissions by 149kg methane/ha compared to wet seeded rice, or 1.5 metric tons of CO2e/acre. Multiplied by $20/ton, this equals $30/acre.

Source: Maegan B. Simmonds, et al. Modeling Methane and Nitrous Oxide Emissions from Direct-Seeded Rice Systems. 2015. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JG002915

Nitrous Oxide:
According to the Arkansas Rice Production Handbook, wet seeded rice requires 25% more Nitrogen fertilizer than dry seeded rice. The handbook provides guidance for N application for dry seeded rice at an average rate of 135 pounds N/acre, or 61.23 kg N/acre. A 25% increase would equal 15kg N/acre. Keeler et al. (2016) find the social cost of N fertilizer to be at least $.5/kg in each county of Minnesota due to N2O emissions. They derived this number using a SCC of $38/metric of CO2e. Therefore, a SCC of $20/metric of CO2e would convert $.5/kg of N to $.26/kg of N. Multiplying 15kg N/acre by $.26/kg N = $4/acre.

Sources:
Jarrod Hardke and Bob Scott. Water Seeded Rice, Arkansas Rice Production Handbook. 2018. https://www.uaex.edu/publications/pdf/mp192/chapter-5.pdf
Trenton Roberts, et al. Soil Fertility, Arkansas Rice Production Handbook, 2018. https://www.uaex.edu/publications/pdf/mp192/chapter-9.pdf
Bonnie L. Keeler, et al. The Social Costs of Nitrogen. 2016. https://advances.sciencemag.org/content/2/10/e1600219

Water Savings$8A 2015 study shows a mean water use reduction of 271.5 fewer cubed meters per acre, or .22 acre-feet/acre, for dry seeded rice compared to wet seeded rice in California.

Linquist et al. Water balances and evapotranspiration in water- and dry-seeded rice systems. Irrigation Science. 2015.
https://link.springer.com/article/10.1007/s00271-015-0474-4/tables/3

NRCS values water savings at $36/acre-foot in current dollar values. Multiplying the two values equals $8/acre. (California).

USDA – NRCS. Final Benefit-Cost Analysis for the Environmental Quality Incentives Program (EQIP). 2010. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/16/nrcs143_007976.pdf

Air Quality (Human Health)

$79According to the Arkansas Rice Production Handbook, wet seeded rice requires 25% more Nitrogen fertilizer than dry seeded rice.

Jarrod Hardke and Bob Scott. Water Seeded Rice, Arkansas Rice Production Handbook. 2018. https://www.uaex.edu/publications/pdf/mp192/chapter-5.pdf

The handbook provides guidance for N application for dry seeded rice at an average rate of 135 pounds N/acre, or 61.23 kg N/acre. A 25% increase would thus equal 15kg N/acre.

Keeler et al. (2016) found the human health cost of N fertilizer in each county of Minnesota due to NH3 emissions. The average cost in a single county was $4.75/kg of N fertilizer, or $5.24/kg N in 2021USD. Multiplying 15kg N/acre by $5.24/kg = $78.60/acre. https://advances.sciencemag.org/content/2/10/e1600219

Total$109