The feasibility of subirrigation systems on claypan soils in the Midwest

This was a study to evaluate the suitability of subirrigation along with alternative soil and water trujlnagement practices on claypan soil. Crop yields on these soils are usually low because of limited water management for crop production. Several years of crops, soil and weather data collected on a claypan soil in Illinois were used to study performance of subirrigation and conventional irrigation on these soils. Various drain spacings and depth combinations for both good and poor· quality surface drainage were simulated. Results indicated that optimum drain spacing for subirrigation on these soils would be 6 m under good surface drainage, and a weir setting depth of 35 cm on a 5-year recurrence interval basis. However, such a close drain spacing may not be economically feasible.U.S. Geological SurveyU.S. Department of the InteriorOpe

Method to Partition Between Attached and Unattached E. coli in Runoff From Agricultural Lands 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72554/1/j.1752-1688.2008.00262.x.pd

Comparison of Best Management Practice Adoption Between Virginia\u27s Chesapeake Bay Basin and Southern Rivers Watersheds

Producers in two regions of Virginia (Chesapeake Bay basin and Southern Rivers region) were surveyed to compare farming practices and agricultural best management practice (BMP) adoption. Objectives were to assess farming operations and determine the extent of cost-share and non-cost-share BMP implementation and gain insight into the impact of selected socioeconomic factors on the BMP adoption. Although farming characteristics and producer attitudes toward pollution and water quality were similar, BMP implementation differed between the two regions. Differences in BMP implementation may be due to a more focused, longer-term NPS pollution control educational effort in the Bay basin

Cyberbiosecurity: A New Perspective on Protecting U.S. Food and Agricultural System

Our national data and infrastructure security issues affecting the “bioeconomy” are evolving rapidly. Simultaneously, the conversation about cyber security of the U.S. food and agricultural system (cyber biosecurity) is incomplete and disjointed. The food and agricultural production sectors influence over 20% of the nation's economy ($6.7T) and 15% of U.S. employment (43.3M jobs). The food and agricultural sectors are immensely diverse and they require advanced technologies and efficiencies that rely on computer technologies, big data, cloud-based data storage, and internet accessibility. There is a critical need to safeguard the cyber biosecurity of our bio economy, but currently protections are minimal and do not broadly exist across the food and agricultural system. Using the food safety management Hazard Analysis Critical Control Point system concept as an introductory point of reference, we identify important features in broad food and agricultural production and food systems: dairy, food animals, row crops, fruits and vegetables, and environmental resources (water). This analysis explores the relevant concepts of cyber biosecurity from food production to the end product user (such as the consumer) and considers the integration of diverse transportation, supplier, and retailer networks. We describe common challenges and unique barriers across these systems and recommend solutions to advance the role of cyber biosecurity in the food and agricultural sectors

A LONG-TERM, WATERSHED-SCALE, EVALUATION OF THE IMPACTS OF ANIMAL WASTE BMPs ON INDICATOR BACTERIA CONCENTRATIONS1

ABSTRACT: Driven by increasing concerns about bacterial pollution from agricultural sources, states such as Virginia have initiated cost sharing programs that encourage the use of animal waste best management practices (BMPs) to control this pollution. Although a few studies have shown that waste management BMPs are effective at the field scale, their effectiveness at the watershed scale and over the long term is unknown. The focus of this research was to evaluate the effectiveness of BMPs in reducing bacterial pollution at the watershed scale and over the long term. To accomplish this goal, a 1,163 ha watershed located in the Piedmont region of Virginia was monitored over a ten-year period. Fecal coliforms (FC) and fecal streptococci (FS) were measured as indicators of bacterial pollution. A pre-BMP versus post-BMP design was adopted. Major BMPs implemented were manure storage facilities, stream fencing, water troughs, and nutrient management. Seasonal Kendall trend analysis revealed a significant decreasing trend during the post-BMP period for FC concentrations at the watershed outlet, but not at the subwatershed level. Implementation of BMPs also resulted in a significant reduction in the geometric mean of FS concentrations. FC concentrations in streamflow at the watershed outlet exceeded the Virginia primary standard 86 and 74 percent of the time during pre-BMP and post-BMP periods, respectively. Corresponding exceedances for the secondary standard were 50 and 41 percent. Violations decreased only slightly during the post-BMP period. The findings of this study suggest that although BMP implementation can be expected to accomplish some improvement in water quality, BMP implementation alone may not ensure compliance with current water quality standards. (KEY TERMS: nonpoint source pollution; watershed management; water quality; bacterial pollution; fecal coliform; fecal streptococcus; BMP.) INTRODUCTION Contamination from bacterial sources has been identified as the third leading cause of pollution in the nation's rivers, after siltation and nutrients (USEPA, 1999). Pollution from bacteria accounts for nearly 79,820 impaired river miles or 12 percent of the total river miles surveyed in the United States (USEPA, 1999). In Virginia, fecal contamination of surface waters is the leading pollution problem, and agriculture has been cited as the largest contributor of this pollutant (USEPA, 1999). Land application of animal wastes and runoff from livestock facilities are the major agricultural practices contributing to bacterial pollution Although several studies and reviews have evaluated bacterial pollution from agricultural land

Trickle Irrigation; A Study of Moisture Distribution in the Soil Profile

139 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.Irrigation in Illinois has increased fourfold in the last decade. Sprinkler irrigation accounts for most of the irrigation in Illinois. While originating in arid regions of the world, trickle irrigation is beginning to receive notice in the humid and sub-humid sections of the United States. Whether trickle irrigation is a good supplementary irrigation system in an area of variable precipitation, similar to central Illinois, has not been investigated. The irrigation water requirement of vegetable crops for maximum yield and the effect of discharge rate on the distribution of moisture in heavy soils under a trickle source were subjects of this investigation.Tomatoes and bell peppers were trickle irrigated for two consecutive growing seasons in east-central Illinois. Results showed a considerable yield advantage for tomatoes using the highest level (1.0 Epan) of irrigation. However bell peppers responded better to a lower level of irrigation (0.5 Epan). Results are promising and indicate the feasibility of the use of trickle irrigation for the sub-humid Midwest area.Laboratory studies indicated that increasing trickle discharge rate resulted in an increase in the vertical component and a decrease in the horizontal component of the wetted zone. The percentage of applied water lost below the root zone and the volume of the wetted soil were related to the discharge rate. A comparison was made between the laboratory results and those computed using a simulation model (Bresler, 1975). The agreement between the predicted and measured soil moisture distribution pattern was generally quite good. A better correlation was found for lower discharge rates than higher ones. However, in most cases, the differences between the model prediction and measured values were in the 0-5 percent range. Pulsed treatments wetted more volume of soil with the same amount of applied water, and the downward restriction of soil moisture under pulsed application resulted in less water loss below the root zone.Based on both laboratory and field experiments, it was concluded that continuous discharge rates of greater than 4 liters/hour should not be recommended for trickle irrigation of crops grown on heavy soils similar to the experimental soil because of excessive water loss below the root zone and surface runoff problems.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Die-Off of E. coli and Enterococci in Dairy Cowpats

E. coli and enterococci re-growth and decay patterns in cowpats applied to pasturelands were monitored during the spring, summer, fall, and winter. First-order approximations were used to determine die-off rate coefficients and decimal reduction times (D-values). Higher-order approximations and weather parameters were evaluated by multiple regression analysis to identify environmental parameters impacting in-field E. coli and enterococci decay. First-order kinetics approximated E. coli and enterococci decay rates with regression coefficients ranging from 0.70 to 0.90. Die-off rate constants were greatest in cowpats applied to pasture during late winter and monitored into summer months for E. coli (k = 0.0995 d-1) and applied to the field during the summer and monitored until December for enterococci (k = 0.0978 d-1). Decay rates were lowest in cowpats applied to the pasture during the fall and monitored over the winter (k = 0.0581 d-1 for E. coli, and k = 0.0557 d-1 for enterococci). Higher-order approximations and the addition of weather variables improved regression coefficients to values ranging from 0.82 to 0.96. Statistically significant variables used in the models for predicting bacterial decay included temperature, solar radiation, rainfall, and relative humidity. Die-off rate coefficients previously reported in the literature are usually the result of laboratory-based studies and are generally higher than the field-based seasonal die-off rate coefficients presented here. To improve predictions of in-field E. coli and enterococci concentrations, this study recommends that higher-order approximations and additional parameters such as weather variables are necessary to better capture re-growth and die-off trends over extended periods of time.This article is from Transactions of the ASABE 51, no. 6 (2008): 1987–1996.</p

Influence of Sample Holding Time on the Fluvial Erosion of Remolded Cohesive Soils

Despite extensive research on bridge scour and channel erosion, predicting the occurrence and rate of cohesive soil erosion remains problematic. The lack of standard procedures for sample preparation and testing has resulted in wide variations in testing conditions, devices, and soil properties across erosion studies, ultimately preventing the synthesis of cohesive erosion studies and progress in understanding the fundamental processes of cohesive soil erosion. Therefore, the objective of this study was to evaluate the effects of sample holding time on the fluvial erosion of remolded cohesive soils to inform the development of standard testing procedures. Three different soils (fat clay, lean clay, and silty sand) were tested in a flume following multiple sample holding times. Results show that erosion rate can decrease 85-95% within 72 h of soil wetting, depending on clay mineralogy. These results highlight the importance of maintaining a consistent soil preparation protocol in cohesive soil erosion experiments and reporting soil sample holding durations when conducting cohesive erosion research using remolded samples