Drainage and Water Quality in Great Lakes and Cornbelt States

The soils and the climate of the Great Lakes and Cornbelt states dictate that drainage is required to carry out economically viable farming activities. When drained, the soils are very productive and this eight-state region accounts for nearly 80% of the agricultural production of the United States. Drainage played an important role in the development of the region and a historical perspective is included to indicate the impetus for drainage and the amount of drainage application. Research results of agricultural drainage effects on water quality indicate that agricultural subsurface drainage has both positive and negative impacts; i.e., reduction in sediment and phosphorous, and increase in nitrate-nitrogen delivery to receiving waters. Research is needed to evaluate the full potential of controlled drainage and water-table management systems for managing agricultural effects on water quality. This information is needed by state and federal agencies to help landowners meet existing and impending water-quality requirements. Drainage is an important management practice for improving water quality while sustaining agricultural viability

Soil Infiltration and Wetland Microcosm Treatment of Liquid Swine Manure

Management systems are needed to minimize water quality concerns associated with liquid swine manure from large swine production facilities. Experiments were conducted to investigate the removal of ammonium–N, nitrate–N, and total phosphorus from liquid swine manure through the use of a soil infiltration and wetland system. Experimental treatments applied directly to the soil infiltration areas included a full–rate application of liquid swine manure, a mixture of 3/4 manure and 1/4 water, and a control application of water only. For three months during both summers of 1998 and 1999, nutrient concentrations were determined in the infiltration area influent, the infiltration area effluent, and the wetland effluent on a weekly basis. Approximately 93% of the ammoniacal nitrogen (NH3–N and NH4–N) from the applied swine manure was removed by the soil infiltration areas with a corresponding 99% increase in the nitrate nitrogen (NO3–N) concentrations were found. The wetland systems removed 94% of the remaining NH3–N and NH4–N and 95% of the NO3–N. The total P levels were decreased in the soil infiltration areas and wetlands by 89 and 84%, respectively

Calibration and Evaluation of Subsurface Drainage Component of RZWQM V.2.5

This study was designed to calibrate and evaluate the subsurface drain flow component of the Root Zone Water Quality Model (RZWQM; Version 2.5) for four tillage-systems: chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT). Measured subsurface drain flow data for 1990 was used for model calibration. Main parameters calibrated were lateral saturated hydraulic conductivity, and effective porosity. Subsurface drain flow predictions were made using calibrated parameters and compared with measured subsurface drain flows for 1991 and 1992. Measured subsurface drain flow data for all 3 yrs was obtained from the Nashua Water Quality Site in Iowa. The model, in general, showed a good agreement between measured and predicted subsurface drain flow values, although discrepancies existed for several days of a given year. Coefficients of determination calculated for predicted vs. measured daily subsurface drain flows ranged from 0.51 to 0.68 for 1990, 0.70 to 0.78 for 1991, and 0.54 to 0.69 for 1992. Simulated tillage effect on subsurface drain flows for 1991 and 1992 were consistent with those for calibrated year 1990 (maximum subsurface drain flow was observed under NT and minimum under MB). However, observed tillage effects varied from year to year, indicating a change in soil hydraulic properties, e.g., macroporosity. Other factors that could have caused the discrepancies between measured and simulated subsurface drain flows were: groundwater flux due to natural gradient, deep seepage, inaccuracies involved in the estimation of breakpoint rainfall data, and spatial variability in soil properties

Simulating nitrogen management effects of subsurface drainage water quality

Increased level of NO3-N in the drinking water supplies is a major health concern these days. The long-term effects of actual nitrogen (N) fertilizer management practices are not well understood. The use of computer models allows the simulation of different N management practices on a long-term basis and their related effects on water quality. The RZWQM (Root Zone Water Quality Model, Version 3.0) was used to simulate the long-term (1978–1992) impacts of N management practices (single N applications at 50, 100, 150, and 200 kg per ha; and single and split N applications at 150 and 200 kg per ha) on NO3-N losses with subsurface drain flows and crop yields under two tillage systems (moldboard plow (MB) and no till (NT)). Simulations conducted in this study were based on input parameters calibrated by Singh et al. (J. Environ. Qual., in press) for NO3-N transport to subsurface drains. However, calibration of some additional parameters was required in this study for long-term simulations. The long-term climatic data and soil properties data for these simulations were obtained from a water quality research site at Nashua, Iowa. The results of this study showed that increasing rates of N applications (50, 100, 150, and 200 kg per ha) resulted in increased NO3-N losses with subsurface drain flows and increased crop yields. However, increasing rates of NO3-N losses and crop yields were not linearly proportional with increasing rates of N applications. These trends were similar for both MB and NT treatments. Also, NO3-N losses and crop yields were not significantly different under single and split N applications at both 150 and 200 kg per ha levels of application. The single N application of 150 kg per ha was considered the best N application practice as the simulated NO3-N losses under this practice were reduced considerably (40.3% less in MB and 52.4% less in NT) when compared with the single N application of 200 kg per ha. At the same time, the reduction in crop yields at 150 kg per ha single N application was very small (5.9% reduction under MB and about 6.1% under NT) when compared with the crop yields at 200 kg per ha single N application. This study also shows that RZWQM can be used successfully in evaluating similar N management schemes for other geographic regions of the world by utilizing site-specific data on soils, geological features, crops, and climatic parameters such as rainfall and evaporation

Escherichia coli Transport from Surface-Applied Manure to Subsurface Drains through Artificial Biopores

Bacteria transport in soils primarily occurs through soil mesopores and macropores (e.g., biopores and cracks). Field research has demonstrated that biopores and subsurface drains can be hydraulically connected. This research was conducted to investigate the importance of surface connected and disconnected (buried) biopores on Escherichia coli (E. coli) transport when biopores are located near subsurface drains. A soil column (28 by 50 by 95 cm) was packed with loamy sand and sandy loam soils to bulk densities of 1.6 and 1.4 Mg m−3, respectively, and containing an artificial biopore located directly above a subsurface drain. The sandy loam soil was packed using two different methods: moist soil sieved to 4.0 mm and air-dried soil manually crushed and then sieved to 2.8 mm. A 1-cm constant head was induced on the soil surface in three flushes: (i) water, (ii) diluted liquid swine (Sus scrofa) manure 48 h later, and (iii) water 48 h after the manure. Escherichia coli transport to the drain was observed with either open surface connected or buried biopores. In surface connected biopores, E. coli transport was a function of the soil type and the layer thickness between the end of the biopore and drain. Buried biopores contributed flow and E. coli in the less sorptive soil (loamy sand) and the sorptive soil (sandy loam) containing a wide (i.e., with mesopores) pore space distribution prevalent due to the moist soil packing technique. Biopores provide a mechanism for rapidly transporting E. coli into subsurface drains during flow events

Burn out and depression in paramedical workers of tertiary care hospital during COVID-19 pandemic

Background: Medical/paramedical professionals are prone to various behavioral disorders due to work pressure. The aim of the study was to evaluate burnout and depression in paramedical workers of a tertiary care hospital during COVID-19.Methods: Paramedical health care workers were assessed using online questionnaire containing self-administered questionnaire in this cross-sectional study between March 2021 and May 2021. Burnout self-test, depression, and anxiety were measured.Results: In this study, only 2.6% had at very severe risk of burnout and 7.8% were at severe risk of burnout while 3.9% had no signs of burnout. Approximately 80% of the patients had no depression. While there were 19.5% had mild to severe depression. Only eight out of 77 subjects had clinically significant symptoms of anxiety. Two subjects were having comorbid illness.Conclusions: A considerable percentage of HCWs experience burnout, depression, and anxiety