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N ational and international open-access agricultural research databases are needed to help solve problems at watershed, regional, and national scales, and to connect productivity, soil health, and environmental quality to food quantity and quality. There are some established, open-access agricultural research networks with extensive research data in the United States, but there is a major need to improve connections between those networks and the emerging data in order to address complex questions. Improving the connections and flow of information among agricultural research networks will enhance the scientific community's ability to simultaneously increase crop yield, sustainability of natural resources, and environmental quality, as well as food, feed, and forage quality, and thus human and animal health. Establishing a network of agricultural databases is crucial for facilitating information flow among different research disciplines. Doing so will also enhance multidisciplinary research opportunities and help build transdisciplinary teams that can provide answers to complex, whole-system research questions and thus solve some of the globe's greatest challenges. GLOBAL CHALLENGES The ever-growing human population is facing one of the greatest challenges of the twenty-first century: to ensure the sustainability of agricultural and natural systems. Both are under the pressure of a changing climate and the increase in…

Excessive nutrients transported from the Mississippi River Basin (MRB) have created a hypoxic zone within the Gulf of Mexico, with numerous negative ecological effects. Furthermore, federal expenditures on agricultural conservation practices have received intense scrutiny in recent years. Partly driven by these factors, the USDA Conservation Effects Assessment Project (CEAP) recently completed a comprehensive evaluation of nutrient sources and delivery to the Gulf. The modeling framework used in the CEAP Cropland National Assessment, or Cropland CEAP, consists of the Agricultural Policy/ Environmental eXtender (APEX) and Soil and Water Assessment Tool (SWAT) models. This CEAP modeling framework was successfully calibrated for flow, sediment, and nutrients at 38 sites and validated at an additional 17. Simulation results indicated that cultivated cropland was the dominant source of nitrogen (N) and phosphorus (P) to both local waters and the Gulf, but this was not true for each water resource region within the MRB. In addition, the results showed that point sources remain significant contributors of P loads, especially in the Tennessee and Arkansas/Red River basins where point source P loads exceeded those from cultivated cropland. Similarly, urban nonpoint sources were significant nutrient sources. The Upper Mississippi, Lower Mississippi, and Ohio basins contributed the largest amounts of nutrients delivered to the Gulf. The high delivery areas near the Mississippi River main stem, from which 87% of N and 90% of P was predicted to reach the Gulf, also coincided with elevated nutrient yields to local waters. Conservation practices established on agricultural lands within the MRB were predicted to have reduced nutrient loads to the Gulf by 20% as compared with a no conservation condition. The results indicate the importance of targeted implementation of conservation practices and consideration of local water and/or Gulf impacts depending on program goal(s). The present application illustrates the value of the Cropland CEAP modeling framework as a useful, science-based tool to evaluate pollutant sources and delivery and effects of agricultural conservation practices.

T he USDA Agricultural Research Service (ARS) organized a workshop entitled, “Collaborative Research and Data Networking: Leveraging GRACEnet-REAP Successes,” that was held on June 14 to 16, 2016, in Fort Collins, Colorado. One of the primary workshop goals was to create and encourage development of multi-location database teams that can provide meaningful networks to collect, store, and make ARS data and other data more accessible to stakeholders, research partners, technology transfer personnel, and other users. This workshop was intended to be aligned with but not duplicate actions associated with the ARS big data effort or National Program (NP) goals. In fact, the workshop was organized to help advance cross-location activities associated with NP-212 (Soil and Air) and its 2016 to 2020 Action Plan. A direct workshop outcome was the decision to create a national Nutrient Uptake and Outcome Network (NUOnet), which had been under discussion by ARS scientists from several different national programs for several months. The Fort Collins workshop brought together an initial invited group of members, which was subsequently expanded during and after the meeting to develop a NUOnet steering committee. The steering committee has now developed a flexible roadmap outlining how to jumpstart coordinated, multi-location NUOnet efforts. The…

T his study, which is one component of a broader, long-term project on the environmental and agro-economic impacts of land applying poultry litter off-site of animal production operations, was designed to determine the water quality effects of repeated annual poultry litter application. To date, more than eight years of data have been collected from ten field-scale cropland and pasture watersheds. On cropland, increasing litter rates from 0.0 to 13.4 Mg ha−1 (0 to 6 ton ac−1), with corresponding decreases in supplemental inorganic nitrogen, increased soluble phosphorus concentrations in runoff but reduced extreme high nitrate-nitrogen concentrations. On pasture, increasing litter rates increased both soluble phosphorus and nitrate-nitrogen concentrations in runoff because litter was the only nutrient source. Following seven annual litter applications, soluble phosphorus concentrations in runoff were strongly correlated with phosphorus levels in the soil on both land uses; however, the dynamic interactions of rainfall, runoff, vegetation condition, soil nutrient levels, and fertilizer application limited consistent, long-term trends in nitrogen and phosphorus runoff. In addition to these and other issues of scientific interest, the present study produced several practical outcomes. First, combining inorganic and organic fertilizers can be an effective fertilization strategy on farms and ranches. With this strategy, organic fertilizers…