Biological and Agricultural Engineering Faculty Research and Publications

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Open Access
Influence of Kernel Shape and Size on the Packing Ratio and Compressibility of Hard Red Winter Wheat
(2018) Petingco, Marvin C.; Casada, Mark E.; Maghirang, Ronaldo G.; Thompson, Sidney A.; McNeill, Samuel G.; Montross, Michael D.; Turner, Aaron P.
Grain compaction occurs during bin storage, and its determination is important for the grain mass estimation needed for inventory and auditing. The degree of compaction is dependent on grain type, bin type, moisture content, amount of grain, initial grain bulk density, coefficients of friction, lateral-to-vertical pressure coefficient, and variation in kernel size. Previous studies have correlated several of these parameters, such as bulk density and grain packing, with moisture content. This study investigated the influence of wheat kernel shape and size distribution on packing ratio and compressibility. Two dockage-free hard red winter (HRW) wheat samples, with no shrunken or broken kernels, were sieved using U.S. Tyler sieves #6, #7, #8, and #10, and the kernels retained on the sieves were used in the experiments. The kernel dimensional parameters and bulk sample parameters were measured, and additional derived parameters were calculated for each size fraction and variety. Packing ratio and compressibility of the size fractions and of binary and ternary mixtures of the size fractions were also determined for each variety. Packing ratio increased with larger kernel size, while compressibility decreased. Sphericity and flatness shape factor had strong positive linear relationships with packing ratio and strong negative relationships with compressibility, while elongation shape factor behaved the opposite way with packing ratio and compressibility. The higher the percentage mass of the larger kernel fraction in a mixture, the higher was its packing ratio and the lower its compressibility. The two tested varieties of wheat did not significantly differ in packing ratio and compressibility. These findings can be used in developing models for more accurate estimation of grain pack factor and to determine the mass of grain inside bins and other storage structures.
Open Access
Stored Grain Pack Factor Measurements for Soybeans, Sorghum, Oats, Barley, and Wheat
(2018-06-01) Bhadra, Rumela; Casada, Mark E.; Turner, Aaron P.; Montross, Michael D.; Thompson, Sidney A.; McNeill, Samuel G.; Maghirang, Ronaldo G.; Boac, Josephine M.; casada; rbhadra; rmaghir
Grain and oilseed crops stored in bins undergo compaction due to overbearing pressure of the grain inside the structure. Thus, volume measurements of grain in bins need to be combined with the amount of packing—usually called pack factor—in addition to the initial density so that the mass in the structure can be calculated. Multiple pack factor prediction methods are in use in the grain industry, but they have only been validated in the literature and compared with field data for corn and hard red winter wheat. Predictions from WPACKING, the program in ASABE standard EP413.2, and two standard USDA methods, the USDA Risk Management Agency (RMA) and USDA Farm Service Agency-Warehouse Licensing and Examination Division (FSA-W) methods, were compared to field measurements of 92 bins containing soybeans, sorghum, oats, barley, or soft white or durum wheat. The WPACKING predictions had the lowest absolute average error of predicted mass for soybeans, sorghum, barley, and wheat, while the FSA-W method had the lowest error for oats. The RMA method gave the largest prediction errors for all five crops and struggled especially with the low-density, high-compaction crops oats and barley, giving average percent absolute errors near or above 10% in both cases. Overall, WPACKING, the RMA method, and the FSA-W method had average percent absolute errors of 2.09%, 5.65%, and 3.62%, respectively, for the 92 bins. These results can be used to improve pack factor predictions for the grain industry.
Open Access
Stored Grain Volume MeasurementUsing a Low Density Point Cloud
(2017-09-01) Turner, A. P.; Jackson, J. J.; Koeninger, N. K.; McNeill, S. G.; Montross, M. D.; Casada, Mark E.; Boac, Josephine M.; Bhadra, Rumela; Maghirang, R. G.; Thompson, S. A.; rmaghir; Maghirang, Ronaldo
This technical note presents the development of a new apparatus and data processing method to accurately estimate the volume of stored grain in a bin. Specifically, it was developed to account for the variability in surface topography that can occur in large diameter bins when partially unloaded. This was accomplished using a laser distance meter to create a low density point cloud, from which a surface was interpolated using ArcMap geoprocessing tools. The manually controlled and portable system was designed to hold the laser distance meter and provided a common reference point. The data from the laser distance meter was transmitted to a tablet PC via Bluetooth. Measurement of an empty hopper bottom bin (4.6 m in diameter and 6.5 m tall) demonstrated that the system was able to measure a known volume within 0.02%, and repeated measures of an empty flat bottom bin (1.8 m in diameter, and 5.7 m tall) were within 0.29% of the known volume. Two applications are presented which highlight the system's ability to capture complex surfaces, as well as limitations that result from fill scenarios where the field of view was limited.
Open Access
Estimating Ambient Ozone Effect of Kansas Rangeland Burning with Receptor Modeling and Regression Analysis
(2017-02-09) Liu, Zifei; Liu, Y.; Murphy, J. P.; Maghirang, Ronaldo; zifeiliu; rmaghir; Liu, Zifei; Maghirang, Ronaldo
Prescribed rangeland burning in April is a long-standing practice in the Flint Hills region of eastern Kansas to maintain the tallgrass prairie ecosystem. The smoke plumes originating from these fires increases ambient PM2.5 concentrations and potentially contributes to ozone (O-3) exceedances in downwind communities. Source apportionment research using Unmix modeling has been utilized to estimate contributions of Kansas rangeland burning to ambient PM2.5 concentrations. The objective of this study was to investigate the potential correlations between O-3 and various sources of PM2.5 that are derived from receptor modeling, and then to specifically estimate contributions of Kansas rangeland burning to ambient O-3 concentrations through regression analysis. Various daily meteorological data were used as predictor variables. Multiple regression models were developed for the eight-hour daily maximum O-3 as well as the daily contributions of the five PM2.5 source categories that were derived from receptor modeling. Cross correlation was analyzed among residuals of the meteorological regression models for O-3 and the daily contributions of the five PM2.5 source categories in order to identify the potential hidden correlation between O-3 and PM2.5. The model including effects of meteorological variables and episodic contributions from fire and industrial emissions can explain up to 78% of O-3 variability. For non-rainy days in April, the daily average contribution from prescribed rangeland burning to O-3 was 1.8 ppb. On 3% of the days in April, prescribed rangeland burning contributed over 12.7 ppb to O-3; and on 7% of the days in April, burning contributed more than 7.2 ppb to O-3. When the intensive burning activities occur in days with high O-3 background due to high solar radiation or O-3 carryover from the previous day, the contributions from these episodic fire emissions could result in O-3 exceedances of the National Ambient Air Quality Standards (NAAQS). The regression models developed in this study demonstrated that the most valuable predictors for O-3 in the Flint Hills region include the O-3 level on the previous day, total solar radiation, difference between daily maximum and minimum air temperature, and levels of episodic fire and industrial emissions. The long term goal is to establish an online O-3 forecasting tool that can assist regulators and land managers in smoke management during the burning season so that the intensive burning activities can be planned to avoid forecasted high O-3 days and thus prevent O-3 exceedance.
Open Access
Effects of Intra-Storm Soil Moisture and Runoff Characteristics on Ephemeral Gully Development: Evidence from a No-Till Field Study
(2017-09-28) Karimov, Vladimir R.; Sheshukov, Aleksey Y.; karimov; ashesh; Karimov, Vladimir R.; Sheshukov, Aleksey Y.
Ephemeral gully erosion, prevalent on agricultural landscapes of the Great Plains, is recognized as a large source of soil loss and a substantial contributor to the sedimentation of small ponds and large reservoirs. Multi-seasonal field studies can provide needed information on ephemeral gully development and its relationship to physical factors associated with field characteristics, rainfall patterns, runoff hydrograph, and management practices. In this study, an ephemeral gully on a no-till cultivated crop field in central Kansas, U.S., was monitored in 2013 and 2014. Data collection included continuous sub-hourly precipitation, soil moisture, soil temperature, and 15 field surveys of cross-sectional profiles in the headcut and channelized parts of the gully. Rainfall excess from a contributing catchment was calculated with the Water Erosion Prediction Project (WEPP) model for all storm events and validated on channel flow measurements. Twelve significant runoff events with hydraulic shear stresses higher than the critical value were identified to potentially cause soil erosion in three out of fourteen survey periods. Analysis of shear stress imposed by peak channel flow on soil surface, antecedent soil moisture condition, and channel shape at individual events provided the basis on which to extend the definition of the critical shear stress function by incorporating the intra-storm changes in soil moisture content. One potential form of this function was suggested and tested with collected data. Similar field studies in other agriculturally-dominated areas and laboratory experiments can develop datasets for a better understanding of the physical mechanisms associated with ephemeral gully progression.
Open Access
Annual baseflow variations as influenced by climate variability and agricultural land use change in the Missouri River Basin
(2017-08-01) Ahiablame, Laurent; Sheshukov, Aleksey Y.; Rahmani, Vahid; Moriasi, Daniel; ashesh; vrahmani; Sheshukov, Aleksey Y.; Rahmani, Vahid
Future climate forcing data at the temporal and spatial scales needed to drive hydrologic models are not readily available. Simple methods to derive these data from historical data or General Circulation Model (GCM) results may not adequately capture future hydrological variability. This study assessed streamflow response to daily future climate forcing data produced by a new method using subsets of multi-model GCM ensembles for the mid-21st century period in northeast Kansas. Daily timeseries of precipitation and temperature were developed for six future climate scenarios: stationary, uniform 10% changes in precipitation; shifts based on a 15-GCM ensemble-mean; and shifts based on three seasonally-consistent subsets of GCMs representing Spring–Summer combinations that were wetter or drier than the historical period. The analysis of daily streamflow and hydrologic index statistics were conducted. Stationary 10% precipitation shifts generally bounded the monthly mean streamflow projections of the other scenarios, and the 15-GCM ensemble-mean captured non-stationary effects of annual and seasonal hydrological response, but did not identify important intra-annual shifts in drought and flood characteristics. The seasonally-consistent subset ensembles produced a range of distinct monthly streamflow trends, particularly for extreme low-flow and high-flow events. Meaningful water management and planning for the future will require hydrological impact simulations that reflect the range of possible future climates. Use of GCM ensemble-mean climate forcing data without consideration of the range of seasonal patterns among models was demonstrated to remove important seasonal hydrologic patterns that were retained in the subset ensemble-mean approach.
Open Access
Hydrologic Alterations Predicted by Seasonally-Consistent Subset Ensembles of General Circulation Models
(2017-06-26) Sheshukov, Aleksey Y.; Douglas-Mankin, Kyle R. ; ashesh; Sheshukov, Aleksey Y.
The Missouri River system has a large water storage capacity, where baseflow plays an important role. Understanding historical baseflow characteristics with respect to climate and land use impacts is essential for effective planning and management of water resources in the Missouri River Basin (MORB). This study evaluated statistical trends in baseflow and precipitation for 99 MORB minimally disturbed watersheds during 1950–2014. Elasticity of baseflow to climate variability and agricultural land use change were quantified for the 99 studied watersheds. Baseflow was derived from daily streamflow records with a recursive digital filter method. The results showed that baseflow varied between 38 and 80% (0 and 331 mm/year) of total streamflow with an average of 60%, indicating that more than half of streamflow in the MORB is derived from baseflow. The trend analysis revealed that precipitation increased during the study period in 78 out of 99 watersheds, leading to 1–3.9% noticeable increase in baseflow for 68 of 99 watersheds. Although the changes in baseflow obtained in this study were a result of the combined effects of climate and land use change across the basin, upward trends in baseflow generally coincide with increased precipitation and agricultural land use trends in the basin. Agricultural land use increase mostly led to a 0–5.7% decrease in annual baseflow in the basin, except toward east of the basin where baseflow mostly increased with agricultural land use increase (0.1–2.0%). In general, a 1% increase in precipitation and a 1% increase in agricultural land use resulted in 1.5% increase and 0.2% decrease in baseflow, respectively, during the study period. These results are entirely dependent on the quality of data used; however, they provide useful insight into the relative influence of climate and land use change on baseflow conditions in the Great Plains region of the USA.
Open Access
Reservoir Sedimentation and Upstream Sediment Sources: Perspectives and Future Research Needs on Streambank and Gully Erosion
(2016-02-17) Fox, Garey; Sheshukov, Aleksey Y.; Cruse, Rick; Kolar, Randall; Gesch, Karl; Dutnell, Russ; ashesh; Sheshukov, Aleksey Y.
The future reliance on water supply and flood control reservoirs across the globe will continue to expand, especially under a variable climate. As the inventory of new potential dam sites is shrinking, construction of additional reservoirs is less likely compared to simultaneous flow and sediment management in existing reservoirs. One aspect of this sediment management is related to the control of upstream sediment sources. However, key research questions remain regarding upstream sediment loading rates. Highlighted in this article are research needs relative to measuring and predicting sediment transport rates and loading due to streambank and gully erosion within a watershed. For example, additional instream sediment transport and reservoir sedimentation rate measurements are needed across a range of watershed conditions, reservoir sizes, and geographical locations. More research is needed to understand the intricate linkage between upland practices and instream response. A need still exists to clarify the benefit of restoration or stabilization of a small reach within a channel system or maturing gully on total watershed sediment load. We need to better understand the intricate interactions between hydrological and erosion processes to improve prediction, location, and timing of streambank erosion and failure and gully formation. Also, improved process-based measurement and prediction techniques are needed that balance data requirements regarding cohesive soil erodibility and stability as compared to simpler topographic indices for gullies or stream classification systems. Such techniques will allow the research community to address the benefit of various conservation and/or stabilization practices at targeted locations within watersheds.
Open Access
Pasture BMP effectiveness using an HRU-based subarea approach in SWAT
(2016-01-15) Sheshukov, Aleksey Y.; Douglas-Mankin, Kyle R.; Sinnathamby, Sumathy; Daggupati, Prasad; ashesh; Sheshukov, Aleksey Y.
Many conservation programs have been established to motivate producers to adopt best management practices (BMP) to minimize pasture runoff and nutrient loads, but a process is needed to assess BMP effectiveness to help target implementation efforts. A study was conducted to develop and demonstrate a method to evaluate water-quality impacts and the effectiveness of two widely used BMPs on a livestock pasture: off-stream watering site and stream fencing. The Soil and Water Assessment Tool (SWAT) model was built for the Pottawatomie Creek Watershed in eastern Kansas, independently calibrated at the watershed outlet for streamflow and at a pasture site for nutrients and sediment runoff, and also employed to simulate pollutant loads in a synthetic pasture. The pasture was divided into several subareas including stream, riparian zone, and two grazing zones. Five scenarios applied to both a synthetic pasture and a whole watershed were simulated to assess various combinations of widely used pasture BMPs: (1) baseline conditions with an open stream access, (2) an off-stream watering site installed in individual subareas in the pasture, and (3) stream or riparian zone fencing with an off-stream watering site. Results indicated that pollutant loads increase with increasing stocking rates whereas off-stream watering site and/or stream fencing reduce time cattle spend in the stream and nutrient loads. These two BMPs lowered organic P and N loads by more than 59% and nitrate loads by 19%, but TSS and sediment-attached P loads remained practically unchanged. An effectiveness index (EI) quantified impacts from the various combinations of off-stream watering sites and fencing in all scenarios. Stream bank contribution to pollutant loads was not accounted in the methodology due to limitations of the SWAT model, but can be incorporated in the approach if an amount of bank soil loss is known for various stocking rates. The proposed methodology provides an adaptable framework for pasture BMP assessment and was utilized to represent a consistent, defensible process to quantify the effectiveness of BMP proposals in a BMP auction in eastern Kansas.
Open Access
Reducing Post-Harvest Loss in Developing Countries through the Feed the Future Initiative
(05-01-2017) Bhadra, Rumela; rbhadra; Bhadra, Rumela
The Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss (PHLIL), housed at Kansas State University (KSU), is a research and education program aimed at improving food security by reducing post-harvest loss of seeds and staple crops, such as grains, oilseeds, and legumes. Feed the Future is the U.S. Government’s initiative for food security and ending global hunger in developing countries. PHLIL’s efforts are focused in four Feed the Future countries—Bangladesh, Ethiopia, Ghana, and Guatemala—as well as Afghanistan as a short term engagement.
Open Access
Ammonia and Methane Emission Factors from Cattle Operations Expressed as Losses of Dietary Nutrients or Energy
(2017-02-23) Liu, Zifei; Liu, Yang; Murphy, James P.; Maghirang, Ronaldo; Zifeiliu; yliu16; jmurphy; rmaghir; Liu, Zifei; Liu, Yang; Murphy, James P.; Maghirang, Ronaldo
The objective of this study was to conduct a systematic review of published literature on ammonia (NH3) and enteric methane (CH4) emissions from beef and dairy cattle operations to obtain statistically representative emission factors based on dietary intakes of nutrients or energy, and to identify major causes of emission variations. NH3emissions from lagoon or other manure storage facilities were not included in this review. The NH3 and CH4 emission rates, expressed as a percentage losses of dietary nutrients or energy, demonstrated much less variation compared with emission rates expressed in g/animal/day. Air temperature and dietary crude protein (CP) content were identified as two major factors that can affect NH3 emission rates in addition to farm type. Feed digestibility and energy intake were identified as two major factors that can affect CH4 emission rates expressed as a percentage losses of dietary energy. Generally, increasing productivity and feed efficiency represented the greatest opportunity for mitigating NH3 or CH4 emissions per unit of livestock product. Expressing CH4loss on a digestible energy basis rather than a gross energy intake basis can better represent the large variation among diets and the effects of varying dietary emission mitigation strategies.
Open Access
Optimization and Modeling of Flow Characteristics of Low-Oil DDGS Using Regression Techniques
(2017-04-01) Bhadra, Rumela; Ambrose, R.P. Kingsly; Casada, Mark E.; Simsek, Senay; Siliveru, Kaliramesh; rbhadra
Storage conditions, such as temperature, relative humidity (RH), consolidation pressure (CP), and time, affect the flow behavior of bulk solids such as distillers dried grains with solubles (DDGS), which is widely used as animal feed by the U.S. cattle and swine industries. The typical dry-grind DDGS production process in most corn ethanol plants has been adapted to facilitate oil extraction from DDGS for increased profits, resulting in production of low-oil DDGS. Many studies have shown that caking, and thus flow, of regular DDGS is an issue during handling and transportation. This study measured the dynamic flow properties of low-oil DDGS. Flow properties such as stability index (SI), basic flow energy (BFE), flow rate index (FRI), cohesion, Jenike flow index, and wall friction angle were measured at varying temperature (20°C, 40°C, 60°C), RH (40%, 60%, 80%), moisture content (MC; 8%, 10%, 12% w.b.), CP (generated by 0, 10, and 20 kg overbearing loads), and consolidation time (CT; 2, 4, 6, 8 days) for low-oil DDGS. Response surface modeling (RSM) and multivariate analysis showed that MC, temperature, and RH were the most influential variables on flow properties. The dynamic flow properties as influenced by environmental conditions were modeled using the RSM technique. Partial least squares regression yielded models with R2 values greater than 0.80 for SI, BFE, and cohesion as a function of MC, temperature, RH, CP, and CT using two principal components. These results provide critical information for quantifying and predicting the flow behavior of low-oil DDGS during commercial handling and transportation.
Open Access
Field-Observed Angles of Repose for Stored Grain in the United States
Bhadra, Rumela; Casada, Mark E.; Thompson, Sidney A.; Boac, Josephine M.; Maghirang, Ronaldo G.; rbhadra; rmaghir; Bhadra, Rumela; Maghirang, Ronaldo G.; Boac, Josephine M.
Bulk grain angle of repose (AoR) is a key parameter for inventorying grain, predicting flow characteristics, and designing bins and grain handling systems. The AoR is defined for two cases, piling (dynamic) or emptying (static), and usually varies with grain type. The objective of this study was to measure piling angles of repose for corn, sorghum, barley, soybeans, oats, and hard red winter (HRW) wheat in steel and concrete bins in the United States. Angles were measured in 182 bins and 7 outdoor piles. The piling AoR for corn ranged from 15.7° to 30.2° (median of 20.4° and standard deviation of 3.8°). Sorghum, barley, soybeans, oats, and HRW wheat also exhibited a range of AoR with median values of 24.6°, 21.0°, 23.9°, 25.7°, and 22.2°, respectively. Angles of repose measured for the seven outdoor piles were within the ranges measured for the grain bins. No significant correlation was observed between AoR and moisture content within the narrow range of observed moisture contents, unlike previous literature based on laboratory measurement of grain samples with wider ranges of moisture content. Overall, the average measured piling AoR were lower than typical values cited in MWPS-29, but higher than some laboratory measurements.
Open Access
Performance of variable-orifice nozzles for liquid fertilizer applications
(2016-05-01) Sharda, Ajay; Fulton, J. P.; Taylor, R. K.; asharda; Sharda, Ajay
Variable-rate application continues to gain interest among precision agriculture practitioners including the use of crop sensor technology for application of nitrogen in grain crops. For liquid fertilizers, variable-orifice nozzles are being implemented since they provide a much larger nozzle flow range compared to traditional fixed orifice nozzles. However, understanding the performance of variable-orifice nozzles under different field operating conditions has been limited. Therefore, the objective of this study was to evaluate the performance of variable orifice nozzles in support of variable-rate application. Two common variable-orifice nozzles offered by different companies were selected for this study. They were tested over three flow ranges (0.76 to 1.89 L/min) with all tests replicated three times. A commercially available 18.6-m, wet boom sprayer equipped with 37 nozzle bodies was used. Nozzles were numbered but then randomly assigned a position along the boom. To evaluate the performance of an individual nozzle, three random nozzle locations along the spray boom were established for both sets of nozzles. Therefore, 18 tests per replication were required to include the 3 flow rates, 3 different locations, and 2 nozzle types. Once the desired flow rate test was established, tip flow was measured using SpotOn Sprayer Calibrator technology. Tip flows were recorded and statistical analyses performed to evaluate flow uniformity (CV) across the boom but also detect off-rate errors by individual nozzles and locations across the boom. With the exception of a few nozzles, the uniformity across the spray boom, as defined by the CV, was acceptable for both nozzle types over approximately a 2:1 flow range. Both nozzle types were less uniform at the low flow rate. There were three nozzles of each type that resulted in unacceptable flow errors in multiple tests. © 2016 American Society of Agricultural and Biological Engineers.
Open Access
Characterization of biochar from rice hulls and wood chips produced in a top-lit updraft biomass gasifier
(2016-01-01) James, M.; Yuan, W.; Boyette, M. D.; Wang, Donghai H.; Kumar, A.; dwang; Wang, Donghai H.
The objective of this study was to characterize biochar produced from rice hulls and wood chips in a top-lit updraft gasifier. Biochar from four airflows (8, 12, 16, or 20 L min-1) and two insulation conditions (not insulated or insulated with 88.9 mm of fiberglass on the external wall of the gasifier) were evaluated. Measurement of elemental composition, higher heating value (HHV), and BET surface area and proximate analyses of the biochar were carried out. It was found that the airflow rate and reactor insulation significantly influenced the chemical composition of the biochar depending on the biomass type. For instance, the carbon content of biochar from rice hulls decreased from 40.9% to 27.2% and the HHV decreased from 14.8 to 10.2 MJ kg-1 as the airflow increased from 8 to 20 L min-1 when the reactor was insulated. In contrast, the carbon content of biochar from wood chips increased from 82% to 86% and the HHV stayed stable at 32.0 to 33.2 MJ kg-1 at the same conditions. Despite these variations, the BET surface area of biochar from both biomass types increased with increased airflow and additional insulation. For example, rice hull biochar had a maximum BET surface area of 183 m2g-1 at 20 L min-1 airflow with insulation. The BET surface of biochar from wood chips peaked at 405 m2 gg-1 at the same conditions.
Open Access
Invisible leash: Object-following robot
(2015-12-21) Frink, Elizabeth; Flippo, Daniel; Sharda, Ajay; dkflippo; asharda; Flippo, Daniel; Sharda, Ajay; Frink, Elizabeth
This study looked at developing a simple concept for an object-following robot, meant to follow a person in an agricultural setting. A KIPR Link was used as the framework, and simple mathematical relationships were derived to control the motion of the robot. The work described is meant as a proof-of-concept, not as a full-scale development. Reasonable results were obtained, indicating that the robot could successfully follow the object. © 2016, Industrial Research Institute for Automation and Measurements. All rights reserved.
Open Access
Correlating Bulk Density (With Dockage) And Test Weight (Without Dockage) For Wheat Samples
Bhadra, Rumela; Casada, Mark E.; Boac, Josephine M.; Turner, Aaron P.; Thompson, Sidney A.; Montross, Michael D.; Maghirang, Ronaldo G.; McNeill, Samuel G.; rbhadra; jmboac; rmaghir
In grain bins, the compaction of stored grain is caused by the overbearing pressure of the bulk material in the bin. To predict the amount of grain in the bin, compaction values must be determined based on the average bulk density (BD) of the stored material. However, BD is determined following the Federal Grain Inspection Service (FGIS) guidelines for measuring test weight (TW), which require that dockage be removed prior to measuring wheat TW. Thus, this creates a problem for predicting grain compaction and conducting inventory studies, because the average BD of the grain in a bin for these calculations should include dockage. Therefore, regression models between the TW without dockage and the BD with dockage were obtained based on the reported scale data during wheat harvest from three elevators located in Kansas and Oklahoma. A power model was used to predict BD with dockage when TW without dockage and dockage levels are given. Laboratory samples of HRW and SRW wheat with dockage levels ranging from 0.05% to 5% showed a second order polynomial trend when plotted against decrease in BD with dockage values compared to TW without dockage. These results will be crucial for determining grain packing inventory parameters for HRW wheat bins.
Open Access
Health and Environmental Impacts of Smoke from Vegetation Fires: A Review
(2016-11-01) Liu, Zifei; Murphy, James P.; Maghirang, Ronaldo; Devlin, Daniel; zifeiliu; rmaghir; ddevlin
Smoke exposure is often an inevitable side effect of open vegetation fires (both planned and wild) and is an important public health concern. The objective of this paper is to summarize state-of-the-art knowledge on health and environmental impacts of smoke from vegetation fires, to identify research gaps, and to provide needed information to researchers, land managers, policymakers, health care workers, and the general public. The main components of vegetation fire smoke and their characterizations are identified and evaluated. Concentrations, emission ratios, and emission factors of smoke components and the combined health and environmental effects of all hazardous smoke components from vegetation fire smoke exposure are summarized. Trends in risk assessment of vegetation fire smoke, limitations of current research, and future research needs are discussed.
Open Access
Estimating ventilation rates of animal houses through CO2 balance
Liu, Zifei; Powers, W.; Harmon, J. D.; zifeiliu
The CO2 production rates from various animal species were measured as well as the ventilation rates (VR) in environmental rooms at Michigan State University over the course of 15 studies that considered dietary strategies to alter air emissions, including two dairy cow studies, four steer studies, two swine studies, one Turkey study, four laying hen studies, and two broiler chicken studies. The objectives of this article are to summarize the baseline data on CO2 production from various animal species and determine uncertainties of the CO2 balance approach for estimating VR of animal houses by evaluating the model performance in these studies. In the poultry (broiler, laying hen, and Turkey) and dairy studies, the CO2 production rates per heat production of animals or respiratory quotient (RQ) showed a decreasing trend with increasing animal age or days in milk (DIM). Higher variation in CO2 production rates per heat production of animals were observed in young broiler chicken (<3 weeks) and Turkeys (<10 weeks) and in the dairy cow studies. The modeled and measured CO2 production rates were generally comparable with each other for each species, and the standard deviation of model residuals was about 20% to 30% of the average measured CO2 production rate for each species except dairy cows. By only including data in which the differences between exhaust and inlet CO2 concentrations were larger than 50 ppm, the standard deviations of model residuals were less than 32% of the average measured VR in the broiler, laying hen, swine, and steer studies. Based on the results, when using the CO2 balance approach to estimate VR for broiler, laying hen, swine, and steer operations, a minimum of ten replicate measurements is required to achieve a margin of error less than 20% in modeled VR with 95% confidence. © 2016 American Society of Agricultural and Biological Engineers.
Open Access
Assessing deficit irrigation strategies for corn using simulation
(2016-01-01) Kisekka, Isaya; Aguilar, Jonathan P.; Rogers, Danny H.; Holman, Johnathon; O'Brien, Daniel M.; Klocke, N.; drogers; ikisekka; jholman; dobrien
Declining groundwater levels in the Ogallala aquifer due to withdrawals exceeding annual recharge result in diminished well capacities that eventually become incapable of meeting full crop water needs. Producers need recommendations for deficit irrigation strategies that can maximize net returns in most years under low well capacities. The objectives of this study were to (1) calibrate and validate the CERES-Maize model in DSSAT-CSM v4.6 under southwest Kansas soils and climatic conditions and (2) apply the calibrated model to assess three factors related to irrigation management: (i) the optimum plant-available water threshold to initiate irrigation for maximizing net returns, (ii) the effect of percentage soil water depletion at planting on yield, seasonal transpiration, water productivity, extractable soil water at maturity, and net returns, and (iii) the effect of late irrigation season termination on extractable soil water at physiological maturity, yield, and net returns. The CERES-Maize model in DSSAT-CSM v4.6 in conjunction with short-term experimental data and 63 years (1950 to 2013) of historical weather data were used in this study. The calibrated model was able to predict end of season grain yield with acceptable accuracy (NSE > 0.9, 0.13 < %RMSE < 0.19), indicating that the model could be used for assessing alternative management strategies for optimizing the use of limited water for irrigating corn in southwest Kansas. Irrigation scheduling based on a 50% plant-available water threshold maximized net returns compared to initiating irrigation at greater soil water content at corn prices ranging from $0.10 to $0.26 kg-1. Accounting for inter-annual variations in weather and irrigation downtime due to repairs, 14 to 17 irrigation applications of 25 mm of water each would be needed to maintain soil water at 50% of plant-available water during the season. Having soil water in the top 1.2 m of the soil profile between 0% and 25% depleted at planting maximized net returns, although it also resulted in more extractable soil water at physiological maturity. Terminating irrigation 90 or 95 days after planting depending on corn price maximized net returns and resulted in the lowest amount of extractable soil water at physiological maturity, implying that opportunities exist to mine stored soil water toward the end of the season even under deficit irrigation. We recommend that late season irrigation termination be done in conjunction with soil water monitoring and management- allowable depletion techniques to minimize potential reduction in yields. Before adopting any of the management strategies assessed in this study, producers should consider the unique yield potential constraints for their farm. The concepts explored in this analysis, which combined experimental data, computer simulation, and long-term weather data to generate optimum management recommendations, could be applied in other areas with constrained water supplies for irrigation. © 2016 American Society of Agricultural and Biological Engineers.