Location: Sugarcane Research
2019 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
Progress was made and milestones were met on both objectives and their subobjectives - all of which fall under National Program 211, Problem area 4, Watershed Management to Improve Ecosystem Services in Agricultural Landscapes, Sub-heading C, measure and predict water-driven agroecosystem productivity and other ecosystem services.
Under Objective 1.A., we quantified sugarcane yield and crop residue in conventional and a more intensive production system under naturally-occurring rainfall conditions (e.g., no irrigation) for the first year’s field trials, as well as planted the second year’s field trials. In each of the experiments, we monitored soil moisture changes continually using probes inserted into the soil at different depths (Milestone 1).
For Objective 1.B., we measured soil respiration throughout most of the growing season (March to October) using a long-term chamber developed by Li-Cor biosciences (Milestone 2).
For Objective 2, we continued to collect data from the eddy covariance tower to quantify carbon and water flux in the conventional sugarcane production system (Milestone 3). In addition, we began collecting eddy covariance data in an area that uses a more intensive production system, similar to our field trials established and maintained for the first objective. We are able to collect these additional data using a second eddy covariance tower, first installed in August 2018, and online in the fall of 2018.
Progress was also made in regards to our involvement as a satellite-location within the Long-Term Agroecosystem Network (LTAR) Lower Mississippi River Basin site, including establishing a cellular-based data collection system, creating geospatial files of our field trial locations, and working with Natural Resource Conservation Service personnel to identify conservation measures that can be applied as part of the LTAR common experiment. These include cover cropping, reduced tillage, and a reduction in burning of crop residues.
Accomplishments
1. Chemical seed treatment of sugarcane billets. Sugarcane is not produced from seeds, but by planting vegetative stalks laid end to end in the soil. Tropical weather, saturated soils, and/or heavy winds can lodge sugarcane stalks, making them difficult to plant. Lodged cane can be cut into smaller pieces, called billets, using a machine harvester and then mechanically planted. However, conditions such as Louisiana’s cool/wet winters and the rotting of stalks (caused by fungi) are detrimental to billet-planted sugarcane establishment. Therefore, cultural practices that improve the vitality of billet-planted cane are needed. ARS scientists at Houma, Louisiana, in collaboration with LSU AgCenter scientists, completed multi-year field trials at two locations in which they found that dip-treating billets with certain chemicals prior to planting significantly improved crop yields by more than 40%, when compared to non-treated billets. Moreover, yields for chemically-treated billets were similar to or better (by as much as 14%) than traditionally-planted, non-treated stalks. The highest yielding treatment consisted of a fungicide-insecticide combination. The results offer growers an option to increase crop yields when climactic conditions are sub-optimal and non-conducive to planting whole stalks.
Review Publications
White Jr, P.M., Webber III, C.L., Viator, R.P., Aita, G. 2019. Sugarcane biomass, dry matter, and sucrose availability and variability when grown on a bioenergy feedstock production cycle. BioEnergy Research. 12:55-67. https://doi.org/10.1007/s12155-018-9951-y.
Webber III, C.L., White Jr, P.M., Shrefler, J.W., Spaunhorst, D.J. 2018. Impact of acetic acid concentration, application volume, and adjuvants on weed control efficacy. Journal of Agricultural Science. 10(8):1-6. https://doi.org/10.5539/jas.v10n8p1.
