Location: Sugarcane Research
2018 Annual Report
Objectives
1. Measure and model water-driven processes in agricultural production systems to predict and enable production under constrained conditions that affect ecosystem services.
1.A. Measure sugarcane growth, yield (tons and sugar), and residue in conventional (1.8 m) and wide row (2.4 m) production systems under ambient water conditions.
1.B. Identify field properties and utilization of resources that vary between row spacing including soil carbon and soil moisture content.
2. Measure and model fluxes of water and carbon in these systems and how they are affected by management practices.
Approach
Use field experiments to study the effects of water availability on sugarcane establishment, growth, and yield, and how row spacing-induced changes to water availability and crop physiology affects carbon cycling within the soil, plant, and atmosphere continuum. Laboratory experiments will evaluate how post-harvest crop residue, the largest soil carbon input in these field systems, cycling is impacted by the effects of water, temperature, mineral nutrients, and particle size.
Progress Report
During fiscal year 2018 research addressing project plan objectives was conducted. Our first objective is to measure how, and to what extent, common soil and water processes affect sugarcane production systems. Agricultural Research Service scientists at the Sugarcane Research Unit in Houma, Louisiana, are also studying how these processes affect the benefits people obtain from their natural environment, also called ecosystem services. Examples of these include supporting services, such as soil health and nutrient recycling; provisioning services, such as food, water, and energy; regulating services, including carbon sequestration and decomposition; and cultural services, including education and tourism. To accomplish these research goals, we will be measuring crop growth and yield each year in two different systems: a more traditional 6-foot row spacing with one planting furrow on each row; and a newer, but experimental, 8-foot row spacing containing two planting furrows on each row. In fiscal year 2017, we planted the first of two experiments using these two-row configurations along with two different sugarcane varieties. One of the most important objectives of this research is to determine the water balance in sugarcane. We are asking the question, “How does the amount of water available affect sugarcane production and yields?” To answer this question, we place sensors below the sugarcane seed cane, which measure the amount of water in the soil. The sensors are installed before planting, at different depths. Each month, we collect information from the sensors allowing us to calculate how much water is available for the crop to use in each of the row spacing tests. In September (2018), we planted the second set of these experiments. We plan to harvest the fiscal year 2017’s experiments in December of 2018, and fiscal year 2018’s experiments in December 2019. Each year after we will harvest each test again to complete Milestones 1 and 2. We also collect weather data using an eddy covariance tower located near the field experiments. Measurements we collect include rainfall, air temperature, barometric pressure, wind speed and direction, solar radiation, and the amount of water vapor and carbon dioxide in the air. These measurements enable us to estimate different components of the water balance.
A second component of the project is to determine how much carbon is contained in these sugarcane cropping systems. ARS scientists at the Sugarcane Research Unit in Houma, Louisiana, already measured solid carbon present in the soil. We are using the eddy covariance measurements discussed previously to determine how much carbon the sugarcane plants absorb from and release to the atmosphere. This fiscal year we began taking measurements of the amount of gas (carbon dioxide) emitted from the soil in the two different row spacing fields. These measurements are ongoing. This fiscal year we completed two laboratory experiments designed to evaluate decomposition of sugarcane leaves in soil. A third experiment compared sugarcane leaf decomposition to popular cover crops including soybean, cowpea, sunn hemp, and sorghum.
Another project objective is to determine the rates of carbon and water movement (or flux) and how they are affected by crop management practices. The most important research tool is the eddy covariance tower, which detects carbon and water gases in the atmosphere above the crop’s canopy. Fiscal year 2018 was our second full year of these measurements over sugarcane growing at the 6-foot spacing. We installed a second eddy covariance tower in fiscal year 2018 at a nearby farm. The second tower is positioned to monitor sugarcane fields using the 8-foot row spacing format only; We will be able to compare the flux between the traditional 6-foot row spacing and the newer, 8-foot row spacing.
Accomplishments
1. Sugarcane residue improves soil health and water quality while maintaining crop yields. Green-cane harvesting of sugarcane results in large amounts of post-harvest crop residues that must be managed, usually by burning, to sustain subsequent crop yields. However, retaining crop residue increases soil carbon sequestration, reduces erosion, and facilitates nutrient recycling, all of which are noted to improve soil health. Improved water quality is achieved by management practices that reduce soil erosion, and runoff-associated dissolved solids and nutrients including nitrate-nitrogen, ammonium-nitrogen, and soluble phosphorus. While residue management can achieve both of these goals, widespread stakeholder adoption hinges on the effects of crop residue management on sugarcane yields. Therefore, ARS researchers at Houma, Louisianna, participated on research to investigate how sugarcane residue management practices (mulching, sweeping, and burning) affect crop yield, water quality, and sediment/nutrient loading in runoff. Yield and water quality data were collected at five different sugarcane farms in Paincourtville, Duson, and St. Gabriel, LA, over a period from 2013-2017. Conservation residue management resulted in similar runoff and erosion estimates to the burn treatment. Additionally, yields in the conservation treatments (mulching or sweeping) were equal to those where crop residue was burned. Thus, the study demonstrates to stakeholders that residue management options that conserve resources, including carbon and nutrients, also support high yields of cane and sugar.
Review Publications
Webber III, C.L., White Jr, P.M., Spaunhorst, D.J., Petrie, E.C. 2017. Comparative performance of sugarcane bagasse and black polyethylene as mulch for squash (Cucurbita pepo L.) production. Journal of Agricultural Science. 9(11):1-9.
Webber III, C.L., White Jr, P.M., Landrum, D.S., Spaunhorst, D.J., Wayment, D.G. 2017. Sugarcane field residue and bagasse allelopathic impact on vegetable seed germination. Journal of Agricultural Science. 9(11):10-16.
Webber III C.L., White Jr, P.M., Spaunhorst, D.J., Lima, I.M., Petrie, E.C. 2018. Sugarcane biochar as an amendment for greenhouse growing media for the production of cucurbit seedlings. Journal of Agricultural Science. 10(2):104-115. https://doi.org/10.5539/jas.v10n2p104.
White Jr, P.M., Webber III, C.L. 2017. Green-cane harvested sugarcane crop residue decomposition as a function of temperature, soil moisture, and particle size. Sugar Tech. 20(5):497-508. https://doi.org/10.1007/s12355-017-0579-6.
Selim, H.M., Tubana, B.S., Arceneaux, A., Elrashidi, M.A., Coreil, C.B., White Jr, P.M. 2018. Yield and water quality for different residue managements of sugarcane in Louisiana. Journal of the American Society of Sugar Cane Technologists. 38:1-22.
Webber III, C.L., White Jr, P.M., Landrum, D.S., Spaunhorst, D.J., Wayment, D.G., Dorvil, E.N. 2018. Sugarcane field residue and root allelopathic impact on weed seed germination. Journal of Agricultural Science. 10(1):66-72. https://doi.org/10.5539/jas.v10n1p66.
Webber III, C.L., White Jr, P.M., Gu, M., Spaunhorst, D.J., Lima, I.M., Petrie, E.C. 2018. Sugarcane and pine biochar as amendments for greenhouse growing media for the production of bean (Phaseolus vulgaris L.) seedlings. Journal of Agricultural Science. 10(4):58-68. https://doi.org/10.5539/jas.v10n4p58.
Webber III, C.L., White Jr, P.M., Spaunhorst, D.J., Wayment, D.G., Landrum, D.S. 2018. Sugarcane crop residue and bagasse allelopathic impact on oat (Avena sative L.), tall morningglory (Ipomoea purpurea L. Roth), and redroot pigweed (Amaranthus retroflexus L.) germination. Journal of Agricultural Science. 10(2):15-22. https://doi.org/10.5539/jas.v10n2p15.
White Jr, P.M., Viator, R.P., Webber III, C.L., Eggleston, G. 2018. Potential losses of soil nutrients and energy content on the complete removal of sugarcane leaf material as a biomass feedstock. Sugar Tech. 20(1):40-49. https://doi.org/10.1007/s12355-017-0523-9.
