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Simulating Nitrogen Management Effects Of Subsurface Drainage Water Quality, A S. Azevedo, P. Singh, Ramesh S. Kanwar, Lajpat R. Ahuja Dec 1997

Simulating Nitrogen Management Effects Of Subsurface Drainage Water Quality, A S. Azevedo, P. Singh, Ramesh S. Kanwar, Lajpat R. Ahuja

Agricultural and Biosystems Engineering Publications

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 ...


A Relative-Flux-Correction Scheme For Analyzing Three Dimensional Data Of A Tile-Drained Agricultural Plot, Binayak P. Mohanty Jul 1997

A Relative-Flux-Correction Scheme For Analyzing Three Dimensional Data Of A Tile-Drained Agricultural Plot, Binayak P. Mohanty

Agricultural and Biosystems Engineering Publications

The use of simple geostatistical tools is often constrained by data trend (nonstationarity) to characterize the spatial variability of soil properties in the subsurface environment influenced by any site-specific feature(s). Adaptive approaches, such as site-specific robust-resistant schemes, median polishing, trend analysis, etc., are thus used to preprocess the spatial data before analyzing for their spatial structures. Soil water nitrate–nitrogen (NO3–N) concentration (mg l−1) and soil moisture content (cm) data collected jointly from 175 sites arranged on a 5×7×5 three-dimensional (3-D) grid network of 7.6 m×7.6 m×0.3 m spacings ...


Development And Evaluation Of Drainage-N Model For Predicting No3-N Concentrations And Losses In Subsurface Drainage Water, Ajay Kumar, Rameshwar S. Kanwar Jan 1997

Development And Evaluation Of Drainage-N Model For Predicting No3-N Concentrations And Losses In Subsurface Drainage Water, Ajay Kumar, Rameshwar S. Kanwar

Agricultural and Biosystems Engineering Publications

The DRAINAGE model was used to develop the DRAINAGE-N model with capability to simulate NO3-N concentrations in subsurface drain flows by incorporating the nitrogen component from the GLEAMS model. Field data on NO3-N concentrations in subsurface drain water were used to calibrate and validate the DRAINAGE-N model for the growing seasons of 1984, 1986, 1987, 1990, and 1991. Simulated NO3-N concentrations and losses with subsurface drain flows were compared with the measured values. Predicted daily NO3-N concentrations in the subsurface drain water by the DRAINAGE-N model were close to the observed NO3-N concentrations values (difference over all years –5.7 ...


Modeling And Evaluation Of Dispersion Parameters For Odors From Agricultural Sources, Yong Cheng Chen, Steven J. Hoff, Dwaine S. Bundy Jan 1997

Modeling And Evaluation Of Dispersion Parameters For Odors From Agricultural Sources, Yong Cheng Chen, Steven J. Hoff, Dwaine S. Bundy

Agricultural and Biosystems Engineering Publications

This article presents an evaluation of four models that are widely used in developing Gaussian plume models, based on the atmospheric stability class and the Pasquill-Gifford curves. The four statistics used to evaluate the models are the sum of residuals, the minimized sum of the squared residuals, the correlation coefficient, and the estimated error standard deviation. Evaluation shows that all of the four models have problems in fitting the Pasquill-Gifford data when the downwind distance increases from the source. A new model has been developed which fits the Pasquill-Gifford data more effectively than the previously developed models studied.


Simulating Atrazine Transport Using Root Zone Water Quality Model For Iowa Soil Profiles, L. S. Azevedo, Ramesh S. Kanwar, P. Singh, Lajpat R. Ahuja, L. S. Pereira Jan 1997

Simulating Atrazine Transport Using Root Zone Water Quality Model For Iowa Soil Profiles, L. S. Azevedo, Ramesh S. Kanwar, P. Singh, Lajpat R. Ahuja, L. S. Pereira

Agricultural and Biosystems Engineering Publications

The pesticide component of the Root Zone Water Quality Model (RZWQM) was calibrated and evaluated for two tillage systems: no-till (NT) and moldboard plow (MB). The RZWQM is a process-based model that simulates the water and chemical transport processes in the soil-crop-atmosphere system. Observed data on atrazine concentrations in the soil profile, for model calibration and testing, were obtained from a field study in Iowa.

Two statistical parameters, maximum error (ME) and coefficient of determination (CD), were used to evaluate the ability of the RZWQM to predict atrazine concentrations in the soil profile. The ME, CD, and other statistical tests ...


Neural Network Analysis Of Postural Behavior Of Young Swine To Determine The Ir Thermal Comfort, Junqing Shao, Hongwei Xin, Jay D. Harmon Jan 1997

Neural Network Analysis Of Postural Behavior Of Young Swine To Determine The Ir Thermal Comfort, Junqing Shao, Hongwei Xin, Jay D. Harmon

Agricultural and Biosystems Engineering Publications

A novel method that may be used to interactively control the micro-environment for young swine was investigated to classify the thermal comfort state of animals. Early weaned pigs at 13 to 16 days of age were housed in groups of 10 pigs in four environmentally controlled chambers (1.52 m × 1.83 m floor space per chamber). Air temperatures inside the four chambers were set at 24.4°C, 26.7°C, 28.9°C, and 31.1°C, respectively, for the first week , and were reduced by 1.1°C each of the following two weeks. Postural behaviors of ...


Safe Farm: The Impact Of An Iowa Public Information Campaign, Lulu A. Rodriguez, Charles V. Schwab, Jane W. Peterson, Laura J. Miller Jan 1997

Safe Farm: The Impact Of An Iowa Public Information Campaign, Lulu A. Rodriguez, Charles V. Schwab, Jane W. Peterson, Laura J. Miller

Agricultural and Biosystems Engineering Publications

The 1992 public information campaign, Safe Farm, made farm safety messages available to a diverse and independent target audience of 104,000 full-time and parttime Iowa farm operators and their families. The print portion of the campaign reached 5.03 million Iowa newspaper subscribers. A series of public service announcements received at least 180 h of air time on more than 100 Iowa radio stations and nearly 80,000 farm safety publications were distributed by Iowa State University (ISU) Extension during the campaign.

The impact of this public information campaign was measured by a baseline and follow-up telephone survey of ...


Comparison Of Energy Use And Piglet Performance Between Conventional And Energy-Efficient Heat Lamps, Hongwei Xin, Hongsen Zhou, Dwaine S. Bundy Jan 1997

Comparison Of Energy Use And Piglet Performance Between Conventional And Energy-Efficient Heat Lamps, Hongwei Xin, Hongsen Zhou, Dwaine S. Bundy

Agricultural and Biosystems Engineering Publications

A one-year field study compared the conventional 250W IR heat lamp with an energy-efficient 175W radiant heat lamp for swine farrowing operations. The energy-efficient heat lamp showed a $36 annual cash savings per unit (assuming $0.10/kWh electricity); a 1.2% absolute reduction in piglet mortality from birth to weaning (5.0±0.28% vs. 6.2±0.44%) (P<0.01); a 45% lower lamp failure rate (18±4% vs. 32±3%) (P<0.05); and a slightly higher rate of weight gain for the piglets (217±4 g/day vs. 211±4 g/day) (P>0.05). The possible benefits of using the energy-efficient heat lamp include an annual energy savings of $5,400 and 284 more weaned pigs for a 1,000-sow farrowing operation. The study also revealed circadian patterns of thermoregulatory behavior ...


Ridge, Moldboard, Chisel, And No-Till Effects On Tile Water Quality Beneath Two Cropping Systems, Ramesh S. Kanwar, Thomas S. Colvin, Douglas L. Karlen Jan 1997

Ridge, Moldboard, Chisel, And No-Till Effects On Tile Water Quality Beneath Two Cropping Systems, Ramesh S. Kanwar, Thomas S. Colvin, Douglas L. Karlen

Agricultural and Biosystems Engineering Publications

Soil conservation tillage systems, including ridge-tillage, often reduce surface water contamination by pesticides because soil erosion and surface runoff are reduced. However, the effects on losses through subsurface drainage tile are somewhat uncertain. Our field study quantified the effects of four tillage practices in continuous corn (Zea mays L.) and corn-soybean [Glycine max (L.) Merr] rotations on herbicide and nitrate N losses in tile drainage water. Fertilizer and pesticide application methods were uniform for ridge, moldboard, chisel, and no-till systems. Pesticide and nitrate N leaching losses were significantly affected by crop rotation. Tillage practice had little influence on nitrate N ...


Physical And Rheological Properties Of Slaughterhouse Swine Blood And Blood Components, Kurt A. Rosentrater, Rolando A. Flores Jan 1997

Physical And Rheological Properties Of Slaughterhouse Swine Blood And Blood Components, Kurt A. Rosentrater, Rolando A. Flores

Agricultural and Biosystems Engineering Publications

Blood, a valuable by-product of livestock slaughter, has numerous food, industrial, and pharmaceutical uses. Physical and rheological properties, including apparent viscosity, density, surface tension, thermal conductivity, and specific heat, are needed for the design of transport processes and by-product applications such as spray drying, blending, and extrusion. Information about these properties for slaughter by-products, however, is not currently available. Consequently, the objective of this study was to determine these properties for anticoagulated swine blood, blood plasma, and red blood cells between 5 and 35°C. The plasma in this study was enriched with hemoglobin from the red cells as a ...


Energetics Of Segregated Early Weaned Pigs, Jay D. Harmon, Hongwei Xin, Junging Shao Jan 1997

Energetics Of Segregated Early Weaned Pigs, Jay D. Harmon, Hongwei Xin, Junging Shao

Agricultural and Biosystems Engineering Publications

The energetics of early weaned (13 to 16 days old) pigs were examined under four temperature regimes. The pigs, in groups of 10 (0.28 m2/pig), were housed in the indirect calorimeter chambers at initial air temperatures of 31.1, 28.9, 26.7, or 24.4°C which then were decreased by 1.1°C per week for the three weeks of the post-weaning period. The feed efficiency and average daily gain during the three-week trial for the four temperature regimes were 1.30, 360 g/day; 1.33, 380 g/day; 1.38, 370 g/day; and ...


Evaluation Of Tractor And Grain Wagon Safety Marking At Selected Commercial Iowa Grain Elevators, H. Mark Hanna, Charles V. Schwab, Carol J. Lehtola, Richard W. Steffen Jan 1997

Evaluation Of Tractor And Grain Wagon Safety Marking At Selected Commercial Iowa Grain Elevators, H. Mark Hanna, Charles V. Schwab, Carol J. Lehtola, Richard W. Steffen

Agricultural and Biosystems Engineering Publications

The three categories of agents involved in the largest number of agricultural fatalities in Iowa are tractors, other farm machinery, and motor vehicles. All are involved during harvest as grain is transported on public roadways. Forty-eight percent of all motor vehicle collisions involving farm equipment in Iowa occur from October through December. Tractors and wagons delivering grain to six elevators during fall harvest were evaluated. Vocational agriculture student teams inspected for compliance with Iowa code and ASAE standards for lighting, marking, hitch, and ROPS safety equipment.

A majority of tractors complied with safety standards for: headlights, front amber flashing lights ...


Energetics, Mortality, And Body Mass Change Of Breeder Chicks Subjected To Different Post-Hatch Feed Dosages, Akihiro Tanaka, Hongwei Xin Jan 1997

Energetics, Mortality, And Body Mass Change Of Breeder Chicks Subjected To Different Post-Hatch Feed Dosages, Akihiro Tanaka, Hongwei Xin

Agricultural and Biosystems Engineering Publications

Newly hatched leghorn breeder chicks (averaging 38.5 g body mass) housed in shipping containers were subjected to four limited feeding regimens for a three-day (3-d) period. The chicks were then raised for five days with adlibitum access to feed and nipple drinkers. For the 3-d treatment, the chicks received an average of 2.0, 2.5, 3.0, or 3.5 g starter feed (20.5% protein and 12,754 kJ/kg ME) and twice as much Aqua-Jel® (a water supplement) (AJ) placed directly on the honeycomb bedding of the containers. Air temperature at the chick level was maintained ...


Effects Of Structural And Stacking Configuration Of Containers For Transporting Chicks In Their Microenvironment, Akihiro Tanaka, Hongwei Xin Jan 1997

Effects Of Structural And Stacking Configuration Of Containers For Transporting Chicks In Their Microenvironment, Akihiro Tanaka, Hongwei Xin

Agricultural and Biosystems Engineering Publications

Breeder (layer) chicks in transit are vulnerable to oxygen shortages that stem from the lack of mechanical ventilation in holding areas such as warehouse and cargo compartments of aircraft. Such vulnerable periods tend to occur around departure time of an aircraft when the cargo door is closed but the compartment has not been pressurized, and vice versa upon landing. To maintain the well-being of the chicks, sufficient air exchange through the containers is essential during these periods. This study examined the air flow rates and internal thermal conditions of a commercial chick container as influenced by its structural and stacking ...


Neural Network Analysis Of Postural Behavior Of Young Swine To Determine The Ir Thermal Comfort State, Junging Shao, Hongwei Xin, Jay D. Harmon Jan 1997

Neural Network Analysis Of Postural Behavior Of Young Swine To Determine The Ir Thermal Comfort State, Junging Shao, Hongwei Xin, Jay D. Harmon

Agricultural and Biosystems Engineering Publications

A novel method that may be used to interactively control the micro-environment for young swine was investigated to classify the thermal comfort state of animals. Early weaned pigs at 13 to 16 days of age were housed in groups of 10 pigs in four environmentally controlled chambers (1.52 m × 1.83 m floor space per chamber). Air temperatures inside the four chambers were set at 24.4°C, 26.7°C, 28.9°C, and 31.1°C, respectively, for the first week , and were reduced by 1.1°C each of the following two weeks. Postural behaviors of ...


Thermal Characteristics Of A Hoop Structure For Swine Production, Akihiro Tanaka, Hongwei Xin Jan 1997

Thermal Characteristics Of A Hoop Structure For Swine Production, Akihiro Tanaka, Hongwei Xin

Agricultural and Biosystems Engineering Publications

The thermal performance of a low-cost, hoop-type swine building (3.55 × 5.7 × 10.3 m) was evaluated under the winter weather conditions of Central Japan. The hoop building had two curved roofs made from 2.5 cm diameter tubular steel pipes each covered with a reflective film. There was a 20 cm air space between the inner and outer covers through which the exhaust air flowed. A positive-pressure ventilation fan and an air distribution duct were used to supply the fresh air. The evaluation was conducted for three opening configurations of the air distribution duct (one, two, or four ...


Statistical Analysis Of Rural Well Contamination And Effects Of Well Construction, Thomas D. Glanville, James L. Baker, James K. Newman Jan 1997

Statistical Analysis Of Rural Well Contamination And Effects Of Well Construction, Thomas D. Glanville, James L. Baker, James K. Newman

Agricultural and Biosystems Engineering Publications

A previous statewide survey showed that 14% of rural wells in Iowa contained detectable concentrations of pesticides. To determine if improved private well construction regulations should be included in Iowa’s State Pesticide Management Plan, a two-year study was undertaken to determine: the effects of well construction on pesticide, nitratenitrogen, and bacterial contamination of wells; and the possible role of point sources of contamination. Eighty-eight rural water supply wells in nine Iowa counties were sampled daily for five weeks during late spring and summer of 1993, and 20% of these were resampled in 1994. Short-term variation in nitrate-nitrogen concentrations was ...


Constructing And Testing Of A Facility For Measuring Water And Agrochemical Transport Through The Vadose Zone, Dean I. Olson, Rameshwar S. Kanwar, John H. Bischoff Jan 1997

Constructing And Testing Of A Facility For Measuring Water And Agrochemical Transport Through The Vadose Zone, Dean I. Olson, Rameshwar S. Kanwar, John H. Bischoff

Agricultural and Biosystems Engineering Publications

A large borehole cavity was constructed to study the transport of agricultural chemicals through the vadose zone and to the shallow groundwater system. A metal culvert (3.05 m dia and 3.65 m long) was installed vertically in the excavated cavity to provide a permanent structure. Stainless steel suction lysimeters were installed radially from the cavity wall to collect water samples for chemical analysis from the vadose zone and the shallow groundwater system at five depths in the soil profile. A monitoring system consisting of electronic tensiometers and a data logger were also installed to measure soil water pressure ...


Groundwater Residues Of Altrazine And Alachlor Under Water-Table Management Properties, Prasanta K. Kalita, Rameshwar S. Kanwar, James L. Baker, Stewart W. Melvin Jan 1997

Groundwater Residues Of Altrazine And Alachlor Under Water-Table Management Properties, Prasanta K. Kalita, Rameshwar S. Kanwar, James L. Baker, Stewart W. Melvin

Agricultural and Biosystems Engineering Publications

This study was conducted to investigate the effects of various water-table management (WTM) practices on the concentrations of two surface-applied herbicides, atrazine and alachlor, in a shallow groundwater system. Groundwater samples were collected by installing piezometers and suction tubes at Iowa State University’s research centers near Ames and Ankeny during three corn-growing seasons, 1989-1991. At the Ames site, experiments were conducted by maintaining constant water-table depths (WTD) of 0.3, 0.6, and 0.9 m in nine field-type lysimeters, and groundwater samples were collected from various depths during the corn-growing seasons. At the Ankeny site, a dualpipe subirrigation ...


Incorporating Preferential Flow And Herbicide Fate And Transport Into The Drainage Model, Ajay Kumar, Rameshwar S. Kanwar Jan 1997

Incorporating Preferential Flow And Herbicide Fate And Transport Into The Drainage Model, Ajay Kumar, Rameshwar S. Kanwar

Agricultural and Biosystems Engineering Publications

The DRAINAGE model was modified by incorporating a pesticide component and a preferential flow component in order to simulate pesticide concentrations in subsurface drain flows. Field data on subsurface drain flows and their atrazine concentrations were used to calibrate and validate the enhanced DRAINAGE model for growing seasons of 1990, 1991, and 1992. Simulated subsurface drain flows and their atrazine concentrations were compared with the measured values. Predicted daily flows by the modified DRAINAGE model were close to the observed values (difference over all years + 6.3%). Overall mean difference (Md) and correlation coefficient (R2) were + 0.1 mm and ...