Location:2011 Annual Report
1a. Objectives (from AD-416)
1)Quantify the ability of best management practices (BMPs) to mitigate the impact of land-use change and extreme climatic events on hydrology and water quality a)Quantify weather and precipitation inputs to watershed models; b)Quantify impacts of land use on runoff and water quality; 2)Quantify the effects of grazing systems on surface runoff and subsurface flow and soil and water quality. 3)Quantify the rate, fate and transport of sediment, nutrients, and agricultural chemicals after implementing agricultural management systems.
1b. Approach (from AD-416)
Precipitation, weather, water-quality, and runoff data will be monitored from experimental watersheds and plots subjected to different conservation, pasture, and land-management practices. Archived data will be used for estimations of baseline and treatment effects, for precipitation studies, and for concept development.
3. Progress Report
Progress was made on all 3 NP211 objectives. Urbanization (PA5-Product 1 (P1). Data collection continues. Precipitation-runoff data were assembled and curve numbers for the 4 watersheds computed. Organic grazing investigations (PA6-P1). Water samples were collected from grazing watersheds & data analyses initiated. Progress was made by comparing forage species composition, animal health, and impact on water and soil. No differences were observed in quality of groundwater. The experiment has been transitioned into an organic grazing system which uses poultry litter instead of mineral fertilizer. A manuscript on carbon loss from pasture sediment was published, and one comparing the water quality aspects of these systems is in journal review. Project investigating stochastic storm simulation (PA5-P2). Preliminary analysis of North Appalachian Experimental Watershed air temperature data suggests that it has increased since 1979, thus evaluation of climate effects must be completed prior to exploring further parameter-estimation relationships. Times between storms for 5yr periods since 1938 show no consistent statistically significant trend due to climate change. National Weather Service hourly data for other Ohio gauges showed no consistent significant trend also. This suggests that durations of storms may also not show a trend, but storm depths may be increasing – further analysis is required. Modified within storm simulation algorithm is underway. Application of manure to Frozen Soil (PA6-P1). Progress was made for the 5th winter manure application (swine manure) to 4 plots on frozen ground and in 4 watersheds. All treated areas were planted to no-till corn. NAEW soil and air temperatures and runoff data continue to be checked for analysis of frozen-soil runoff. A presentation was made at a national scientific society meeting, and a journal article was published from the first three years of data. Analysis of soil carbon due to land management (PA6-P1). In addition to soil sampling & analysis, collaboration continues with Ohio State University scientists to compare impacts of various land management practices on soil organic carbon & soil properties. Capture of chemical constituents by using Filter Socks (PA6-P4). The effect of filter socks filled with hardwood-derived biochar on nutrient and herbicide concentrations in surface runoff was investigated beginning in spring 2011 by installing filter socks in grassed waterways downstream from two watersheds used to grow corn. Herbicide analysis and sorption studies are being performed in collaboration with the ARS Soil Erosion Laboratory. Analysis of runoff data using duration curves (PA6-P6). A start on developing basin characteristics from nested watersheds are being computed from a Geographic Information System of the 7 mi2 Little Mill Creek watershed and subwatersheds. These data will be used as independent variables to combine with duration curves. Little Mill Creek runoff and precipitation (20 stations total) were checked and final archive files generated. Additionally, curve numbers grouped in 5-yr increments showed no apparent statistical trend due to climate change.
1. Grass buffers reduce nutrient movement from manures applied to frozen crop land soils. If guidelines prescribed by Ohio Natural Resources Conservation Service (NRCS) are followed, detrimental aspects of winter manure application can be reduced. Applying manure to crop land and pastures during the winter months is a common practice, especially among small to medium sized livestock operations with limited manure storage facilities. Manure applications during this time of year pose increased environmental risks. Soils that are saturated and/or frozen may have considerable surface runoff following rainfall or snowmelt. Although winter manure application is not recommended, guidelines have been developed to minimize the detrimental aspects of this practice if it is necessary. Using some of these guidelines, experiments were conducted by ARS scientists at the North Appalachian Experimental Watershed (NAEW) near Coshocton, OH to evaluate the effectiveness of these recommendations. During winter, liquid swine manure and turkey litter were applied at recommended rates to small watersheds (approximately 2 acres in area), which were in a no-till corn cropping practice. There was a 100 ft buffer area (no manure application) downslope from the area receiving manure. The highest concentrations of nutrients, such as nitrogen and phosphorus, in runoff were measured when runoff occurred soon after manure application. However, most events with high concentrations occurred with low flow volumes, and transport was minimal. Because of manure composition, applying manure at the nitrogen rate for crop needs resulted in phosphorus being applied at rates in excess of crop needs. This contributed to elevated phosphorus losses, which in turn contributed to a greater potential of detrimental impacts with phosphorus than with nitrogen. These results will help to refine future manure application guidelines.
2. Sediment attached carbon losses from pastures are best reduced by reducing sediment losses. One of the environmental issues today is what kind of “carbon footprint” is left by various activities of energy generation and use, including agriculture. Pasture systems lose organic carbon dissolved in surface runoff and attached to sediment, and these losses were studied by ARS scientists at the North Appalachian Experimental Watershed near Coshocton, Ohio. In a system where a beef cow-calf herd was rotated weekly through 4 pastures during the grazing system, one pasture was used for winter feeding.Surface runoff was measured from each of these pastures throughout the year.Only the pasture used for winter feeding had runoff with measureable amounts of sediment, and those losses occurred during the winter feeding period. Because the cattle were constantly in this pasture during the winter months, the vegetative cover was reduced to less than 50%, which increased the potential for soil loss. Most of the sediment loss and carbon loss occurred with a few large, runoff producing storms. On an individual storm event basis, there was no correlation between the amount of sediment lost and the organic carbon concentration on that sediment. Dissolved organic carbon and sediment attached organic carbon were lost in similar amounts on an event basis and an annual basis. This research indicates that pasture organic carbon losses (i.e. loss of soil quality) can be reduced by using management practices that reduce sediment losses, such as rotational stocking during the winter months.
3. Dormant season (Nov-April) livestock management can have detrimental impacts on soil properties. The impacts of a variety of livestock grazing management practices have been studied in regards to several general parameters, such as forage sustainability, animal production and health, and water quality. Soil quality and various aspects of this have not received as much study as some of the other parameters. A variety of mechanical and hydrological characteristics of soils in a rotational, summer only grazing pasture were compared by ARS scientists at the North Appalachian Experimental Watershed near Coshocton, OH with soils in an area that has dormant season grazing as well as rotational summer grazing. This comparison indicated that dormant season grazing with beef cows, especially continuous stocking, adversely affects soil quality. Soil penetration resistance and bulk density were greater with the dormant grazing; coarse root biomass, moisture capacity, and infiltration rate were lower with the dormant grazing than with the rotational summer only grazing. These are factors to be considered when deciding on dormant season management of livestock, but there is a need for more investigations with other management systems, types of grazing livestock, and topographies. This information is used by university extension personnel and land managers to improve management practices.
4. Compared with no-till, conventional tillage caused degradation of soil properties as well as lower soil nitrogen and carbon. Interest in conservation tillage continues to increase because conventional tillage adversely affects numerous soil properties. Sometimes tillage is used in rotation with no-till or in some years as a weed or insect control. Even without continuous conventional tillage, the occasional tillage year can greatly diminish the soil properties developed during the no-till years. A comparison of soil properties was made between continuous no-till systems and systems where conventional tillage was included in the crop rotation. One system had 10 years that included hay followed by no-till corn and soybeans. The other system had 5 years of hay followed by corn, oats, alfalfa, and 2 years of corn. The first and last years of corn were conventionally tilled. Soil properties that were compared included soil penetration resistance, field moisture capacity, water stable aggregates, and infiltration as well as total nitrogen and soil organic carbon. The system with conventional tillage caused degradation of these properties and lower nitrogen and soil organic carbon. This resulted in lower corn yields in 2008 with conventional tillage. In general, the impacts of tillage on soil properties decreased with increased soil depth.
Stavi, I., Lal, R., Owens, L.B. 2011. Effects of cattle grazing during the dormant season on soil surface hydrology and physical quality in a moist-temperate region. Ecohydrology. 4(1):106-114.