Location: Sugarcane Research
Title: Carbon pools and fluxes under continous sugarcane production in LouisianaAuthor
White, Paul | |
WEBBER III, CHARLES - Retired ARS Employee |
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only Publication Acceptance Date: 4/30/2019 Publication Date: 6/1/2019 Citation: White Jr, P.M., Webber III, C.L. 2019. Carbon pools and fluxes under continous sugarcane production in Louisiana [abstract]. Journal American Society of Sugarcane Technologists. 39:48-49. Interpretive Summary: Technical Abstract: Sugarcane (Saccharum spp.hybrids) is produced on >180,000 ha in south Louisiana, and growers produced over 15 million t of cane, or 83 t ha-1, in 2018. However, continuous cultivation has reduced observed soil organic carbon (SOC) levels from 2.3 to 1.5%. Stakeholders want to increase SOC levels to improve crop sustainability and to conserve natural resources. But, a detailed knowledge of the SOC pools and fluxes below Louisiana sugarcane fields is needed to develop sustainable cultural practices. Therefore, the objective was to characterize above and belowground carbon (C) pools and fluxes in the dominant soil type, Cancienne silt loam, at the USDA-ARS Ardoyne Farm in Schriever, LA, under long-term (>180 y) sugarcane production. A soil pit 3 m long x 1 m wide x 2 m deep was excavated using a back hoe to collect soil samples and measure soil bulk density. The SOC concentrations were 0.82% (0-30 cm), 0.71% (30-60 cm), and 0.76% (60-100 cm). Soil OC stocks at the surface (0-10 cm), plow layer (10-30 cm), and deeper (30-60 and 60-100 cm) were 9.7, 38.9, 32.3, and 44.9 t C ha-1, respectively. Few sugarcane roots penetrated below 30-cm due to soil compaction. In 2016, the cultivar ‘HoCP 04-838’ was planted contributing about 2.0 t C ha-1. The plant cane (2017) and first ratoon (2018) crops yielded 84.9 and 104.1 t cane ha-1, respectively, or 12.4 and 15.2 t C ha-1, and post-harvest crop residue added 2.3 t C ha-1. During 2017, the net carbon sequestration rate ranged from -0.193 t C ha-1 in January to 2.39 t C ha-1 in July. Further observations will be used to determine if SOC sequestration rates can be increased using cover crops and/or reduced tillage. |