CT-measured macropores as affected by agroforestry and grass buffers for grazed pasture systems

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffers have been proposed for improving water quality in watersheds. Buffer vegetation influences soil porosity, essential for water, gas and nutrient transport in soils. The objective of the study was to compare differences in CT-measured macropore ([greater than] 1000-[micro] m diam.) and coarse mesopore (200- to 1000-[micro] m diam.) parameters within agroforestry (AgB) and grass buffer (GB) systems associated with rotationally grazed (RG) and continuously grazed (CG) pasture systems, and to examine relationships between CT-measured pore parameters and saturated hydraulic conductivity (K[subscript]sat). Soils at the site were Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalf). Six replicate intact soil cores, 76.2 mm diam. by 76.2 mm long, were collected using a core sampler from the four treatments at five soil depths (0-50 cm at 10-cm intervals). Image-J software was used to analyze the five equally spaced images from each core. CT-measured soil macroporosity ([greater than] 1000 [micro] m diam.) was 13 times higher (0.053 m3m3) for the buffer treatments compared to the pasture treatments (0.004 m3m3) for the surface 0-10 cm soil depth. Buffer treatments had greater macroporosity (0.020 m3m3) compared to pasture (0.0045 m3m3) treatments. The K[subscript sat] values for buffer treatments were five times higher and bulk density was 5.6 [percent] lower compared to pasture treatments. CT-measured pore parameters (except macropore circularity) were positively correlated with K[subscript sat]. This study illustrates the benefits of agroforestry and grass buffers for maintaining soil pore parameters critical for soil water and nutrient transport.Sandeep Kumar (1), Stephen H. Anderson (1), and Ranjith P. Udawatta (1, 2) ; 1. Department of Soil, Environmental and Atmospheric Sciences, University of Missouri- Columbia. 2. Center for Agroforestry, University of Missouri-Columbia. Columbia, MO 65211, USA.Includes bibliographical references

Agroforestry and grass buffer effects on water quality on grazed pasture watersheds

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Conservation practices including agroforestry and grass buffers are believed to reduce non point source pollution (NPSP) from grazed pasture watersheds. Agroforestry, a land management practice that intersperses agricultural crops with trees, recently received increased attention in the temperate zone due to its environmental and economic benefits. However, studies are limited that examined buffer effects on water quality on grazed pasture watersheds. Six small watersheds, two with agroforestry buffers, two with grass buffers, and two control watershdeds were used to test the hypothesis that agroforestry and grass buffers reduce NPSP from grazed pasture watersheds. Vegetation in grass buffer and pasture areas include red clover (Trifolium pretense L.) and lespedeza (Kummerowia stipulacea Maxim.) planted into fescue (Festuca arundinacea Schreb.). Eastern cottonwood trees (Populus deltoids Bortr. ex Marsh.) were planted into fescue in agroforestry buffers. Soils at the site are mostly Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs). Watersheds were instrumented with two-foot H flumes, water samplers, and flow measuring devices in 2001. Composite water samples were analyzed for sediment, and total nitrogen after each runoff event to compare treatment differences. Watersheds with agroforerstry and grass buffers had significantly lower runoff volumes as compared to the control watersheds. The loss of sediment, and total nitrogen were smaller for the buffer watersheds. The results of the study suggest that establishment of groforestry and grass buffers help reduce NPSP pollution from grazed pasture watersheds. It is anticipated as trees grow and roots occupy more soil volume, the reduction in N in runoff should increase on the agroforestry watershed.Ranjith P. Udawatta (1, 2), Harold E. Garrett (2), and Robert L. Kallenbach (3) ; 1. Department of Soil, Environmental and Atmospheric Sciences. 2. Center for Agroforestry. 3. Department of Plant Sciences, University of Missouri, Columbia, MO 65211.Includes bibliographical references

Agroforestry interactions and soil water use in watersheds under corn-soybean management

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffer practices reduce non point source pollution from corn-soybean watersheds, yet little is known about the processes and mechanisms involved. The objective of this study was to compare the soil water dynamics in crop, grass, and agroforestry areas throughout the growing season to understand soil water use and recharge differences among the treatments. The study was conducted on two corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotational watersheds with grass and agroforestry buffers at the Greenley Research Center, Knox County, MO. Campbell soil moisture sensors were installed in crop, grass, and agroforestry areas with six replications at 5, 10, 20, and 40 cm depths to record volumetric soil water content at 10 minute intervals for 2004 through 2007. Initial soil moisture was lower in tree and grass buffer areas than crop areas probably due to water use by the permanent vegetation before crops were established. The differences were larger for shallower depths as compared to the 40 cm depth. The trend continued throughout the growing season. Weekly soil moisture content was significantly higher in the crop treatment as compared to the buffer treatments. During rain events water content increased in all depths and treatments and the differences in water content among treatments diminished. At the end of the growing season, soil water content increased when water use was low and as the profile recharged by rain events. The results of the study suggest that establishment of grass and agroforestry buffers help reduce non point source pollution from row crop agriculture by using additional water that would have otherwise have been lost in runoff carrying sediments, nutrients, and pesticides.Ranjith P. Udawatta (1,2), Stephen H. Anderson (1), Peter P. Motavalli (1), and Harold E. Garrett (2) ; 1. Department of Soil, Environmental and Atmospheric Sciences. 2. Center for Agroforestry, and University of Missouri, Columbia, MO 65211.Includes bibliographical references

Agroforestry and grass buffer influences on water infiltration for a grazed pasture system

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffers are often adopted as an alternative resource management system in agriculture for environmental and economic benefits. The objective of the study was to compare agroforestry (AgB) and grass buffer (GB) systems under rotationally grazed (RG) and continuously grazed (CG) pasture systems on water infiltration measured using ponded infiltration and tension infiltration methods. Buffer areas were fenced which prevented cattle grazing in buffer areas. Soils at the site are Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs). Infiltration rates were measured using ponded ring infiltration units in 2007 and 2008 for the four treatments with six replicates. Infiltration rate as a function of tension (at 50-, 100-, and 150-mm) was also measured using a tension infiltrometer in 2007. Water infiltration parameters were estimated using Green-Ampt and Parlange infiltration equations. Quasi-steady state infiltration rates (qs) and field-saturated hydraulic conductivity (Kfs) for the buffers were about 30 and 40 times higher compared to pasture treatments, respectively. Green-Ampt and Parlange models appeared to fit measured data with r2 values ranging between 0.91 to 0.98. The infiltration rate in 2007 for the GB treatment was the highest (221.4 mm h-1) and for the CG treatment was the lowest (3.73 mm h-1). Estimated sorptivity (S) and saturated hydraulic conductivity (Ks) parameters were higher for buffers compared to the pasture treatments. Grazing reduced infiltration rates for the pasture (CG and RG) treatments. Results show that the buffer areas have higher infiltration rates which imply lower runoff compared to pasture areas.Sandeep Kumar (1), Stephen H. Anderson (1), Ranjith P. Udawatta (1,2), and Robert L. Kallenbach (3) ; 1. Soil, Environmental and Atmospheric Sciences, University of Missouri-Columbia. 2. Center for Agroforestry, University of Missouri-Columbia. 3. Division of Plant Sciences, University of Missouri-Columbia Columbia, MO 65211, USA.Includes bibliographical references

Water Quality Improvement and Agroforestry Practices

This item was presentation # 17 at the April 2007 Water Quality Short Course. More information on the 2007 Water Quality Short Course, including an agenda and links to to other presentations, may be found at http://www.mowin.org/WQSC/April2007/index.htmlFor the items in MOspace regarding the 2007 Water Quality Short Course, please see https://mospace.umsystem.edu/xmlui/browse?value=Water+Quality+Short+Course+2007&type=subjectThis presentation includes two parts. The first part (83 slides) discusses riparian forest buffers, including function, types and design considerations. The second part (68 slides) discusses findings that agroforestry and grass buffers increase water stable soil aggregates and soil enzyme activity

Microclimate studies of crop environments under different agroforestry arrangements [abstract]

Abstract only availableOne of the factors influencing crop yields is evapotranspiration; the evaporation of water from both plants and soil. Soil moisture provides many nutrients to crops, so evapotranspiration rates are of concern. This study will focus on the environmental conditions above crop fields in Northeastern Missouri and see which conditions lead to higher evapotranspiration rates. The fields also contain two kinds of buffers: a tree and a grass buffer. Weather instrumentation was placed above the crops between the different buffers and data was collected in regular intervals throughout each day over the past two years. The first year the crop was corn, and soybeans the second year. Some of the variables looked at include temperature, humidity, net radiation, wind speed, and wind direction. In this project a comparison is made between the conditions over soybeans between the tree and grass buffer to see which buffer creates which environmental conditions. The main hypothesis was that grass buffers would lead to higher evapotranspiration rates due to higher winds (grass being shorter than trees) advecting moisture away. Evapotranspiration rates were derived using a Penman equation and, using MATLAB, graphs were made of each of the variables using 10-day averages. It was determined that the hypothesis was correct by looking at the data output qualitatively. However, the significance of the difference between the grass and agroforestry buffers has yet to be found since the time period used in the Penman equation is questionable. Therefore the equations used thus far will be examined thoroughly and modified if need be to set the quantitative data to the correct time period. In this results will be obtained that will be more understandable to the general public and science community.CAFNR On Campus Research Internshi

Runoff and Sediment from Row-crop, Row-crop with Grass Strips, Pasture, and Forest Watersheds

Comparisons of runoff and sediment loss from row-crop with and without riparian buffers, pasture and grass filter strips are limited. Effects of precipitation, landuse and buffer condition on runoff and sediment loss were examined from 1997 to 1999 in eight watersheds with varying proportions of row-crop, pasture, riparian buffers and grass filter strips. Runoff volume and sediment mass from row-crop watersheds were inversely related to the percentage of forest and pasture cover. Forest (n = 2), pasture (n = 3), row-crop (n = 2) and a row-crop watershed with grass filter strips (RC-GFS) had 3‑yr mean runoff of 939, 1,560, 3,434 and 1,175 m3 ha‑1 yr‑1, respectively. Runoff was greater from all landuses in a year when precipitation was 36% above normal (1998). The largest single runoff event from each watershed accounted for 11 to 25% of its total runoff. Forest, pasture, row-crop and RC-GFS watersheds lost 1,017, 1,241, 3,679 and 2,129 kg ha‑1 yr‑1 of sediment, respectively. In 1998, the RC-GFS watershed lost more sediment than row-crop watersheds and had less runoff and sediment loss in years with normal or below normal precipitation. Row-crop watersheds with 55% pasture reduced runoff and sediment loss by 55 and 66%, respectively, compared to row-crop watersheds. During 90% of the runoff events, more soil was lost from row-crop watersheds than pasture or forest watersheds. Results suggest that 3‑4 m grass filter strips, maintenance of 55% or more pasture/CRP land within row-crop watersheds and intact riparian buffers significantly reduce runoff and sediment losses from row-crop watersheds.Les études comparant les volumes de ruissellement et les charges sédimentaires de bassins versants avec cultures en lignes et pâturages avec et sans zones tampons et bandes riveraines sont peu nombreuses. Les effets des précipitations, de l’occupation du sol et des conditions des zones tampons sur le ruissellement et les charges sédimentaires ont été analysés de 1997 à 1999 pour huit bassins versants comportant en proportions diverses des cultures en lignes, des pâturages, des zones tampons et des bandes riveraines. Il a été montré que les volumes de ruissellement et les charges sédimentaires pour les bassins versants avec cultures en lignes étaient inversement proportionnels aux pourcentages de forêt et de pâturages présents sur ces bassins. Les moyennes mesurées sur trois ans des volumes de ruissellement des bassins versants de type forestier, avec pâturages, avec cultures en lignes et avec cultures en lignes et bandes riveraines (RC‑GFS) sont de 939, 1 560, 3 434 et 1 175 m3/ha/an respectivement. Les volumes de ruissellement mesurés pendant une année pour toutes les occupations du territoire ont été plus grands lorsque les précipitations ont été supérieures de 36 % à la normale (1998). L’événement générant le volume de ruissellement le plus important à survenir sur chaque bassin versant génère à lui seul de 11 % à 25 % du volume de ruissellement total mesuré. Les charges sédimentaires pour les bassins versants forestiers, avec pâturages, avec cultures en lignes et RC‑GFS ont été respectivement de 1 017, 1 241, 3 679, et 2 129 kg/ha/an respectivement. En 1998, les charges sédimentaires des bassins versants RC‑GFS ont été plus importantes que les bassins avec cultures en lignes alors que les volumes de ruissellement et les charges sédimentaires sur ces mêmes bassins ont été plus petits lors d’années avec des précipitations égales ou inférieures à la moyenne. Les bassins avec cultures en lignes et comportant 55 % de pâturages permettent une réduction de l’ordre de 55 % des volumes de ruissellement et de 66 % des charges sédimentaires lorsque comparés aux bassins avec cultures en lignes. Les charges sédimentaires mesurées à l’exutoire des bassins avec cultures en lignes ont été plus élevées pour 90 % des événements que celles issues des bassins avec pâturages ou forestiers. Les résultats de cette étude montrent que des bandes riveraines de 3 à 4 m, le maintien de plus de 55 % du territoire sous forme de pâturages/CRP pour des bassins avec cultures en lignes et la présence de bandes riveraines permettent de réduire de façon significative les volumes de ruissellement et les charges sédimentaires des bassins versants avec cultures en lignes

APEX simulation : environmental benefits of agroforestry buffers on corn-soybean watersheds

Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.The Agricultural Policy Environmental Extender (APEX) model has the ability to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. The objectives of this study were to calibrate and validate the APEX model for three adjacent watersheds and determine optimum buffer dimensions and placement locations. ArcAPEX and APEX0604 versions were used for the simulations. The simulated corn and soybean yields were within 13% and 27% of the measured yields, respectively. The agroforestry, grass buffer, and control watershed models were calibrated (1998 to 2001) and validated (2002 to 2008) for eventbased runoff with r2 and Nash-Sutcliffe Coefficients (NSC) values of 0.7-0.8 and 0.4-0.8, respectively. The models could not be calibrated for sediment losses. The simulated grass and agroforestry buffers reduced average annual runoff by 5.2% and 4.3%, respectively. Increase of buffer widths to 5.5 m and 7.5 m were not effective. The buffers located on the backslopes were the most effective for the agroforestry watershed but this trend was not seen in the grass buffer watershed. The study provides guidance on how to parameterize APEX to simulate grass and agroforestry buffers. It contributes to the validation of APEX and will be useful to scientists in need of parameterizing the model for watersheds that include upland buffers.Anomaa Senaviratne (1, 2), Ranjith P. Udawatta (1, 2), Claire Baffaut (3), Stephen H. Anderson (1) and Shibu Jose (2) ; 1. 302 ABNR Bldg., Dept. of Soil, Environ. and Atmos. Sciences, University of Missouri, Columbia, MO 65211. 2. 203 ABNR Bldg., The Center for Agroforestry, University of Missouri, Columbia, MO 65211. 3. USDA-ARS Cropping Systems and Water Quality Research Unit, 241 Ag. Eng. Bldg., University of Missouri, Columbia, MO 65211.Includes bibliographical references

Veterinary antibiotic sorption to agroforestry buffer, grass buffer and cropland soils

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Veterinary antibiotics are used to treat infectious animal diseases and enhance animal growth. In Missouri, the increased growth of confined animal feeding operations (CAFOs) and the need to dispose of manure generated by CAFOS may be problematic due to co-application of antibiotics during land application of manure. Surface runoff events from claypan or claypan-like soils are relatively frequent; thus, there is a need to develop and evaluate the use of vegetative buffer strips (VBS) as management tools to reduce antibiotic transport to surface water resources. The objectives of this study were to (1) investigate oxytetracycline (OTC) and sulfadimethoxine (SDT) sorption to agroforestry (tree/grass) buffer, grass buffer, and cropland soils, (2) evaluate differences in antibiotic sorption between soils collected from different vegetative species, and (3) elucidate relationships between soil properties and antibiotic sorption. Sorption/desorption isotherms generated using batch techniques were well-fitted by the Freundlich isotherm model (r2 [greater than] 0.80). Oxytetracycline was strongly adsorbed by all soils, and the antibiotic was not readily desorbed; hysteresis was observed between all adsorption and desorption isotherms. Solid-solution distribution coefficients (Kd) values of OTC are an order of magnitude greater than those of SDT. Statistical analyses indicate that OTC Kd values are significantly greater for VBS soils relative to cropland soil, and STD Kd values are significantly greater for agroforestry soils as compared to other soils studied. Regression analyses correlating antibiotic sorption to soil properties are in progress. Results indicate that agroforestry and grass buffers may effectively mitigate antibiotic loss from agroecosystems due to enhanced antibiotic sorption properties.Bei Chu (1), Keith Goyne (1), Stephen H. Anderson (1), Ranjith P. Udawatta (2) and Chung-Ho Lin (2) ; 1. Department of Soil, Environmental and Atmospheric Sciences, University of Missouri, 302 ABNR Building, Columbia, MO 65211. 2. Center for Agroforestry, University of Missouri, 203 ABNR, Columbia, MO 65211.Includes bibliographical references

Mixtures of native warm-season grasses, forbs and legumes for biomass, forage and wildlife habitat (2017)

This guide provides information to help Missouri landowners and property managers make informed decisions on growing native warm-season grasses, forbs and legumes for biomass, livestock forage and wildlife habitat