Performing Department
(N/A)
Non Technical Summary
The need to feed a growing population while adapting to a changing climate has increased public concern and impacted consumers' food choices, leading multinational companies to develop sustainable sourcing programs for agricultural commodities such as wheat (Triticum aestivum L.). However, these programs are fragmented and not always supported by science. Advancing the science of sustainable intensification of wheat production is essential to improve policy and to ensure that these programs are relevant to the consumer and advance sustainable food chains. Our long-term goal is to support the development of a sustainable winter wheat industry in the US central Great Plains by understanding how crop management decisions impact immediate (farm) and downstream (milling and baking) sustainability indicators. Individual objectives are to: (1) Perform a comprehensive, systematic literature review about sustainable intensification of major crops across the world to characterize the status quo of sustainability studies and existing sourcing programs, while identifying major drivers of changes in value chain downstream indicators; (2) perform economic and life cycle assessment of three comprehensive and complementary databases of 46 field experiments and 656 commercial production fields on wheat agronomic, milling, and baking performances as impacted by management and variety to determine the most relevant factors affecting sustainability across the value chain; and (3) educate wheat stakeholders (growers, millers, bakers, etc.) about best practices to produce more and higher quality food while being more profitable and attaining acceptable standards of environmental quality. Our proposed work will inform the development of sustainable sourcing programs for winter wheat.
Animal Health Component
0%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
The long-term goal of this project is to support the development of a sustainable winter wheat industry in the US central Great Plains by understanding how crop management decisions made at the farm-level impact immediate (i.e., on farm) and downstream (i.e., milling and baking) sustainability indicators. Our proposed work has the potential to become the standard for wheat sustainability assessments to be used by private and multinational companies currently developing sustainable sourcing programs for winter wheat. This work is in direct response to rapidly increasing demand from both society and the wheat industry.To support this goal, our proposed individual supporting objectives are to:1. Perform a comprehensive, systematic literature review about sustainable intensification of major staple crops to characterize the current state of sustainability research and existing sustainable grain sourcing programs, while identifying major drivers of changes in their value chain downstream indicators; 2. Analyze three comprehensive and complementary existing databases of wheat agronomic, milling, and baking performances as impacted by field management to determine relevant factors dictating the sustainability across the wheat value chain;3. Educate stakeholders associated with the wheat value chain (e.g., wheat producers, millers, bakers, etc.) about best practices to produce enough high-quality food to feeding a global population while attaining acceptable environmental quality.
Project Methods
1. In objective 1, we will search databases such as Web of Science and Google Scholar to systematically identify published scientific articles relating to sustainability and sustainable production practices relating to these important food crops. Our group has expertise in publishing systematic reviews, highlighting the feasibility of this approach and best practices will be followed. Relevant articles will be compiled. We will focus on (i) current standards for quantification of the sustainability of an agricultural system, and (ii) current practical decisions that can be made in-season for a given crop, and how these modulate sustainability indicators across the value chain. This will likely be a traditional review paper, written in a book chapter or review paper format, rather than a quantitative synthesis or meta-analysis. The rationale behind this decision is that we expect the sustainability indicators to vary widely among studies and therefore, the opportunities to quantify a given response variable across studies will limit the utility of meta-analytic methods.2. In objective 2, we will explore three complementary databases that allow us to quantify sustainability of wheat production both at the field level as well as across the value chain. Three existing datasets will be used in this objective: (1) a survey data of commercial winter wheat fields collected and reported by our research group; (2) a follow up experimentation to ground truth surveyed findings conducted for two years at 23 locations; and (3) a database of replicated experiments where typical grower management was compared to an "improved practice" across many environments and wheat varieties. These databases are complimentary to one another, as they differ in structure, depth, and breadth; and thus, their addition to this project is justified as they intend to answer different questions regarding how management practices adopted in the wheat season impact the sustainability either at the farm or across the value chain.Here, we propose to expand on these existing databases to entail a complete economic analysis as well as a life-cycle assessment (LCA) either from cradle to gate (i.e., from manufacturing, packaging, and transportation of the inputs used for wheat production until harvest of the wheat crop in the farm; Databases 1 and 3) or from cradle to grave (i.e., until the production of bread) to quantify the environmental footprint and profitability across the wheat value chain. Below, we provide evidence for the feasibility and rationale of the proposed approach by citing refereed publications adopting similar approaches.Economic: Within each environment, net returns will be calculated over variable costs, with values of grain price and field operations retrieved from regional crop budgets published yearly by university extension. Variable costs will include those associated with tillage operations (chiseling, disking, and field cultivating) for conventional tilled experiments or commercial fields, or a pre-plant herbicide (product plus application) for no-tilled experiments/commercial fields, plus crop input (seed, fertilizer, herbicide, and fungicide), operations (sowing, spreading, spraying, harvesting, and hauling), and labor. All costs and profits will be calculated by replication using different costs and grain price for each year of the study using its respective crop budget to represent actual conditions.Life cycle analysis: A number of environmental indicators will be estimated based on the combination of management practices adopted and the associated inputs in each system at each site-year following approaches proposed in previously published literature.Nitrogen partial factor productivity (PFPN) will be calculated as the ratio between grain yield and the amount of applied N inputs and N use efficiency (NUE) will be calculated as grain yield over total N available, including that present in to 0-60 cm soil profile at sowing. Next, we will calculate the N balance during the crop season [i.e., N input minus N output (both in kg N ha-1)]. Nitrogen input in each environment-management combination will consider the fertilizer-N applied and the N output was calculated as the grain N removal (i.e., the product between grain yield and grain N concentration). The crop N balance will then be used to calculate the potential for nitrate leaching. The potential for N2O-N emissions will be calculated based on applied N rates. We will then calculate the yield-scaled variables N balance, N leaching, and N2O-N emissions by dividing each by grain yield.Energy values for manufacturing, packaging, and transportation of inputs will be combined with input levels (tillage practice, herbicide application, in-furrow diammonium phosphate fertilizer, seeding rate, pesticide seed treatment, fertilizer N rate, and foliar fungicide) for each management intensity in each site-year to estimate energy inputs. For each operation (tillage, pre- and post-sowing herbicide spraying, sowing, fertilizer spreading, fungicide applications, and harvesting), the total energy used will be calculated based on direct (fuel) and indirect (seed, fertilizer, pesticides) sources, including the embodied energy in machinery manufacturing, transportation, and repair, as well as on labor. The energy equivalents for each input and operation will be retrieved from literature and, when needed, updated according to the Ecoinvent database, similar to previous research. For each management intensity at each field-year, energy input (GJ ha−1) will be calculated as the sum of annual fossil-fuel energy inputs. Two metrics will be used to evaluate the energy balance: the net energy yield and the net energy ratio.Global warming potential (GWP) calculations will have two main components: we will account for greenhouse gas (GHG) emissions (including CO2, CH4, and N2O) according to the energy inventory above, considering fossil fuel use on-farm plus for manufacturing, repair, packaging, and transportation of inputs and machinery. Similar to energy values, the values for CO2 equivalent for each field operation will be retrieved from. Second, we will add the N2O emissions from soil which will be calculated from N fertilizer application based on total N rates applied (Eq. 2). As each site-year was planted in different fields each study year, we will not consider changes in soil carbon due to the short-term nature of each experiment. The GWP will then be calculated as the sum of CO2 equivalent (CO2e) considering intensities of 25 times for CH4 and 298 times for N2O [62] and reported in kg of CO2e ha-1. The yield-scaled GPW (GWPy) will be calculated as GWP over grain yield.Freshwater ecotoxicity potential of each system will be calculated based on herbicide and fungicide usage in each management intensity in each site-year following the approach proposed by literature. Potential freshwater ecotoxicity per mass of active ingredient applied will consider the transport and persistence of chemicals in the environment via air, soil, and water pathways.The above methods will be used in the LCA of field production of wheat, and therefore will be common across Databases 1, 2, and 3. For the LCA involving milling and baking properties, we will follow the detailed approach suggested by literature for wheat usage.3. The Extension portion of this project will be conducted as a combination of traditional and modern Extension avenues, including training for extension agents, wheat schools focused on the sustainability of the wheat value chain, producer field days, pre-plant wheat meetings, audio-visual materials, radio interviews and social media.