Increasing the Sustainability of Agricultural Systems
ARS builds the science-based foundations for future farming systems that satisfy human food and fiber needs, sustain the economic viability of agriculture, enhance environmental stewardship, and improve quality of life. Through transdisciplinary research approaches that integrate information and technology, ARS provides producers with several options for increasing the sustainability of their production systems. The following FY 2019 accomplishments highlight ARS advances in farming for carbon capture, improving the sustainability of organic cropping systems, and optimizing water use. Hyperlinked accomplishment titles point to active parent research projects.
Intercropping bioenergy crops with trees captures and stores atmospheric carbon in soil. Perennial herbaceous crops such as switchgrass are important sources of cellulosic biomass for the developing bioenergy industry. Assessments of how much carbon will be lost or sequestered into soil and the turnover rates of that carbon are needed to assist producers and policymakers who need to determine the long-term sustainability of biomass production. The natural abundance of soil carbon was used to calculate the quantity and turnover of soil carbon in a switchgrass/poplar intercropping system. After 4 years of cropping, soil organic carbon increased 16 percent in the 0- to 15-cm depth, and on average, 10 percent of this soil organic carbon was derived from switchgrass. The results show that intercropping switchgrass with hybrid poplar gives forest plantation landowners greater economic returns from biofuel production by improving water use and nutrient cycling. Intercropping also promotes additional ecosystem services including carbon sequestration. These benefits directly affect air, water, and soil quality, which are increasingly challenged by climate change.
Innovative method for cover crop termination using engine exhaust heat. Heat in the form of an open flame is used to control weeds. However, these systems require a fuel source. Researchers in Auburn, Alabama, focused on utilizing exhaust heat to terminate cover crops and control weeds in a conservation system. To evaluate this concept, a mechanical pusher using the exhaust heat from a gasoline-based internal combustion engine with supplemental heat from heater strips was developed to terminate cover crops. The prototype was developed for a walk-behind tractor powered by a single cylinder gasoline engine. In addition, a generator powered by the tractor’s Power Take-Off mechanism provided electrical energy for three parallel, supplemental heater strips. Results demonstrated that using exhaust heat (otherwise lost to the environment) is an economical means of terminating cover crops.
Novel planter developed for small-seeded plants. Precisely planting the seeds of herbs, vegetables, and other species with extremely small seeds akin to the size of a salt grain can be difficult to do with standard planters. Small seeds are often pelleted so they can be planted with precision, but this process is expensive. An ARS researcher in Salinas, California, developed a simple planter, called the Slide Hammer Seeder, for precision hand-seeding of unpelleted, small-seeded species. The planter works well for seeding a variety of small-seeded herbs and vegetables and has been used to interseed sweet alyssum plants among vegetable crops. Sweet alyssum helps to control pest aphids on many vegetable crops and this novel seeder will help farmers do this more efficiently.
Making decisions easier with Irrigator Pro. Irrigator Pro is an irrigation decision support tool for scheduling irrigation for corn, cotton, and peanuts deployed on the web and as an application for smart phones and tablets. Researchers shared irrigation logic with commercial service providers at customer/stakeholder meetings and industry press. Currently, customers are farmers, crop consultants, extension agents, and students. Users following irrigation recommendations apply water in a timely manner while maintaining or improving crop yields. Users can access, enter field data, and receive irrigation decisions anywhere they have internet access (desktop, WiFi, 4G, etc.) for corn, cotton, and peanuts. Software also forecasts irrigation needs up to 7 days into the future.
Toolkit for daily water use monitoring in California Central Valley vineyards. Persistent and extreme drought has plagued California in the last decade with enormous implications on surface and groundwater water resources for agriculture. Achieving long-term water use sustainability in an economically viable way will require more efficient irrigation management to successfully address future water shortages. ARS scientists in Beltsville, Maryland, have led the Grape Remote Sensing Atmospheric profile & Evapotranspiration eXperiment (GRAPEX) project with the goal of developing a new remote sensing-based data fusion technique that allows, for the first time, accurate estimation of daily water use and stress information from field to regional scales for high-valued perennial crops. Operational application of this technique has begun and is expected to facilitate substantial reductions in irrigation water usage for these crops.