Bioresource and Agricultural Engineering Commons^™

Simulated Performance Of A Renewable Energy Technology – Heat Pump Systems In Semi-Arid California Greenhouses, C. Hardin, T. Mehlitz, Ilhami Yildiz, S. F. Kelly

BioResource and Agricultural Engineering

In addition to the labor, energy and water consumption are the two main cost drivers in current greenhouse systems. Consequently, considerable effort is expended to conserve energy and water, and look for alternative energy sources, especially environmentally friendly renewable energy sources and technologies. Greenhouses in hot and arid regions also require large quantities of water for irrigation. Using proper technologies and environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. This study aims to focus on reducing natural gas, electricity, and water consumption in semi-arid California greenhouses introducing renewable energy heat pump technologies to …

Simulated Effects Of Various Environmental Management Practices On Water Consumption In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The objective of this study was to evaluate the effects of relative humidity, light management, minimum ventilation rates, CO₂ enrichment and canopy size on water consumption in three different greenhouse systems (conventional, open heat pump, and confined heat pump) in winter, spring, and summer months. Using different relative humidity set points resulted in almost the same relative humidity regimes within the confined greenhouse system, resulting in similar transpiration rates. No difference was observed in transpiration rates in the open system in winter either, because the inside relative humidity levels never reached the 70% and 80% set points. Some differences …

Simulated Effects Of Dynamic Row Spacing On Energy And Water Conservation In Semi-Arid Central California Greenhouses, A. Moya, T. Mehlitz, Ilhami Yildiz, S. F. Kelly, C. Hardin

BioResource and Agricultural Engineering

Considerable effort is expended to conserve energy and water in current greenhouse systems, and look for alternative energy sources, especially passive heating and cooling strategies. Proper environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. In this study, specifically, influences of dynamic row spacing on energy and water conservation were investigated. A dynamic computer simulation model was used to compare different row spacings, plant heights, and leaf dimensions to draw a conclusion about energy and water conservation. The results showed that using smaller spacings between cucumber crop rows (for instance, 0.5 m instead of …

Design And Evaluation Of A Greenhouse Interface For Climate Control Programming And Networking, G. Diaz, S. F. Kelly, Ilhami Yildiz

BioResource and Agricultural Engineering

At Cal Poly the motto is “Learn by Doing”. In the College of Agriculture, this is especially true and many of the labs provide an opportunity for students to implement this philosophy. Updated climate controls were installed in a series of greenhouses on the top floor of the Agricultural Science building that are used for student and faculty research projects. A Programmable Logic Controller (PLC) was installed to actuate the various vents, shading, heating, cooling and irrigation. A control program was developed to control and log temperatures and other operating parameters to monitor the greenhouse. An easy to use computer …

Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …

Spatial Distributions Of Heating, Cooling, And Industrial Degree-Days In Turkey, Ilhami Yildiz, B. Sosaoglu

BioResource and Agricultural Engineering

The degree-day method is commonly used to estimate energy consumption for heating and cooling in residential, commercial and industrial buildings, as well as in greenhouses, livestock facilities, storage facilities and warehouses. This article presents monthly and yearly averages and spatial distributions of heating, cooling, and industrial degree-days at the base temperatures of 18 °C and 20 °C, 18 °C and 24 °C, and 7 °C and 13 °C, respectively; as well as the corresponding number of days in Turkey. The findings presented here will facilitate the estimation of heating and cooling energy consumption for any residential, commercial and industrial buildings …

Corn Stover Availability And Collection Efficiency Using Typical Hay Equipment, Robert M. Prewitt, Michael D. Montross, Scott A. Shearer, Timothy S. Stombaugh, Stephen F. Higgins, Samuel G. Mcneill, Shahab Sokhansanj

Biosystems and Agricultural Engineering Faculty Publications

Corn stover has been identified as a potential feedstock for the production of fermentable sugars and thermochemical processes. The availability and efficiency of typical hay equipment for collecting corn stover has not been well quantified. Corn stover was collected for two years on a central Kentucky farm near Louisville. Six different harvesting treatments, using traditional hay equipment, were used to harvest corn stover. A rotary mower, rotary scythe (flail-type mower with windrow-forming shields), parallel bar rake, and a round baler were utilized. The average stover moisture content prior to grain harvest was above 40%, and field drying was required before …

Rational Risk/Benefit Analysis Of Genetically Modified Crops, Stanley P. Kowalski

Law Faculty Scholarship

Safety concerns over the use of molecular biotechnology in the improvement of crops has generated substantial, heated and confusing debates, often driven by ideology and hysterics. Modification of crops is not new, and biotechnology (in its broadest sense) has been used for over a century to accelerate the development of new crops for food, feed and fibre, so as to meet the demands of a growing global community. The introduction of crops developed via molecular biotechnology [Genetically Modified Crops (GMCs)] represents the latest step in this inexorable innovative progression of technology. However, misinformed concern has led to a broad embrace …

Hydrologic Properties Of Pervious Concrete, Joe D. Luck, Stephen R. Workman, Stephen F. Higgins, Mark S. Coyne

Plant and Soil Sciences Faculty Publications

Pervious concrete is concrete made by eliminating most or all of the fine aggregate (sand) in the concrete mix, which allows interconnected void spaces to be formed in the hardened product. These interconnected void spaces allow the concrete to transmit water at relatively high rates. The main objective of this project was to conduct research on the potential application of pervious concrete in agricultural settings, specifically for use in animal feed lots, manure storage pads, animal manure and bedding compost facilities, or floor systems in animal buildings. Laboratory tests were conducted on replicated samples of pervious concrete formed from two …

The Land Is In Your Hands : A Practical Guide For Owners Of Small Rural Landholdings In Western Australia, Department Of Agriculture And Food, Wa

Bulletins 4000 -

This Bulletin discusses various aspects of managing a small farm or property in Western Australia, including soil and land care, vegetation and plant control on farm holdings, water resource management, biosecurity, plant, animal and insect pest control and livestock management.

Simulated Performances Of A Heat Pump System For Energy And Water Conservation In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The purpose of this study was to determine and compare the performances of conventional and heat pump systems for energy and water conservation in open and confined greenhouse systems. Conventional gas furnaces and evaporative cooling, respectively, provided heating and cooling in the conventional system. In the heat pump systems, gas-fired heat pump units provided both heating and cooling. The greenhouse with heat pump units also had an option to be operated as a completely confined system, using one of the heat pump units as a dehumidifier. Average energy consumption in winter was 56.9, 23.5, and 11.3 MJ/day.m² in the conventional, …

Trees And Ice Storms: The Development Of Ice Storm–Resistant Urban Tree Populations (Second Edition), Richard J. Hauer, Jeffrey O. Dawson, Les P. Werner

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Severe ice storms occur every year in the United States and Canada, particularly in the midwestern and eastern regions of the United States. Along with fires and wind, ice storms are a frequent and major natural disturbance factor in eastern deciduous forests. Likewise ice storms are responsible for deaths and injuries of people and cause dramatic damage and tree loss to urban forests. Ice storms annually result in millions of dollars in loss, and potentially billions of dollars in losses for extreme and widespread ice storms. Damage to electric distribution systems, blocked roadways, and property damage from fallen trees and …

Dynamic Modeling Of Microclimate And Environmental Control Strategies In A Greenhouse Coupled With A Heat Pump System, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The purpose of this study was to develop and validate a dynamic simulation model to be employed in accurate prediction of microclimate in a greenhouse as a function of dynamic environmental factors. The model has options to evaluate the effects of location, time of the year, orientation, single and double polyethylene glazings, conventional and heat pump heating and cooling systems, open and confined greenhouse systems, CO₂ enrichment, variable shading, and the use of night curtains. Conventional gas furnace and evaporative cooling, respectively, provided heating and cooling in the conventional system. In the heat pump systems, gas-fired heat pump units …

Spatial Variation Of Protein, Oil, And Starch In Corn, Samuel G. Mcneill, Michael D. Montross, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Significant spatial yield variations are known to exist in cornfields with different soil types, topsoil depth, and other variables. Similarly, variations might also be found among the highly valued chemical components (oil, protein, and starch) in corn kernels due to local differences in soil type, fertility, acidity/pH, organic matter, etc. This study quantified the spatial variability of protein, oil, and starch content of corn from two conventional cornfields and two high-oil cornfields. Whole ears were harvested by hand from 20 to 40 randomly selected locations within each field. A differential global positioning system (DGPS) receiver recorded the location of each …

Permeability Of Corn, Soybeans, And Soft Red And White Winter Wheat As Affected By Bulk Density, Michael D. Montross, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Darcy’s law is a function of viscosity, permeability, and velocity and can be used to predict the airflow resistance in granular materials at low air velocities. Permeability also governs the magnitude of natural convection currents during periods of non-aerated grain storage. The permeability of corn, soybeans, soft white winter wheat, and soft red winter wheat were measured as a function of bulk density and moisture content. Air was passed through a column of grain and the flow rate and pressure drop measured. Bulk density and kernel density were also measured to determine the porosity of grain in the test column. …

Airflow Resistance Of Seeds At Different Bulk Densities Using Ergun's Equation, Marek Molenda, Michael D. Montross, Samuel G. Mcneill, Jozef Horabik

Biosystems and Agricultural Engineering Faculty Publications

Airflow resistance of grains and oilseeds has been extensively studied. Traditionally the data has been presented using Shedd’s curves. However, this assumes that airflow resistance is independent of grain depth. Grain undergoes compaction during storage that changes the bulk density, porosity, and therefore the airflow resistance. Ergun’s equation is a function of particle size and porosity of the granular material. Airflow resistance by Ergun’s equation was used to predict the pressure drop across a column of corn, soft white winter wheat, soft red winter wheat, and soybeans at three moisture content levels and two bulk densities. The maximum root mean …

Crop Yield Response To Precision Deep Tillage, Larry G. Wells, Timothy S. Stombaugh, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Experimental precision deep tillage was applied at three sites in central Kentucky with relatively well-drained silt loam soils in no-till crop production. Fields were divided into 0.4 ha (1 ac) grid cells using DGPS mapping. Assessment of soil compaction by machinery traffic was made using multiple soil cone penetrometer measurements and expressed as cone index (CI). Corn, wheat, and soybean yields were depressed in grid cells with CI_avg ≥ 1.5 MPa (218 psi) prior to application of tillage treatments at sites 1 and 3, whereas at site 2, where most of the highest average CI values ranged from 1.44 …

Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Numerous factors influence the sizing of aeration fans for summer-harvested crops. Thirty years of weather data for Lexington, Kentucky, were analyzed and the cost of aeration was compared for two axial fans (afan1, afan2) and one centrifugal fan (cfan1). Aeration costs were defined as the sum of the following components: the cost of owning the fan, the cost of electricity for operating the fan, a cost for wheat shrinkage during aeration, and a cost for dry matter loss (DML). The fans were selected to deliver airflow rates of approximately one, two, and three times the recommended aeration rate of 0.11 …

The Influence Of Environmental Temperature And Substrate Initial Moisture Content On Aspergillus Niger Growth And Phytase Production In Solid−State Cultivation, Seaborn B. Carter, Sue E. Nokes, Czarena L. Crofcheck

Biosystems and Agricultural Engineering Faculty Publications

Aspergillus niger is being used commercially for phytase production utilizing solid-state cultivation; however, no studies have been published that investigated the optimal environmental temperature and initial substrate water content to maximize fungal growth and/or phytase production. Solid-state cultivations of Aspergillus niger on wheat bran and soybean meal were conducted at three temperatures (25°C, 30°C, and 35°C) and three initial moisture contents (50%, 55%, and 60% wet basis) in a split-plot full-factorial experimental design. Fermentations were conducted for 0, 24, 48, 72, and 120 h. The containers were sampled destructively and assayed for phytase activity and glucosamine concentration as an estimate …

A Reduced–Cost Mechanized System For Handling And Curing Mechanically–Harvested Burley Tobacco, Greg A. Camenisch, Larry G. Wells, Timothy D. Smith, George A. Duncan

Biosystems and Agricultural Engineering Faculty Publications

An experimental system was tested in which mechanically harvested burley tobacco plants placed onto steel slotted receivers were retrieved from a field, transported to a field curing structure, and placed onto the structure for air curing by a single worker. The system consisted of a tractor–towed, trailer mechanism that engaged and hoisted loads of approximately 360 burley plants of approximately 1 Mg mass. Ten slotted steel rails, 3.05 m long, holding 36 notched plants were placed onto parallel wooden beams suspended at a height of 2.13 m by wooden posts set in the ground. Burley tobacco was cured in this …

Monitoring Subsurface Drainage Flow At Remote Locations, Stephen R. Workman, Stephen F. Higgins, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Laboratory evaluations and field results are presented for a slotted weir used to measure discharge from subsurface drains. The head–discharge curve for the vertical slot is a simple power function with an exponent of 1.5. There was excellent agreement (r² > 0.99 and 1:1 slope) between predicted and observed discharge in laboratory testing of 12 test weirs representing five slot widths. The primary advantages of the vertical slot weir are its simplicity, ease of maintenance, and ability to measure small flow rates. Disadvantages include a tendency for the slot to close a small amount over time as a result of …

Evaluation Of Residual Chlorothalonil Levels On Processing Tomato Foliage Using The Tom-Cast Spray Program, Jane M. Patterson, Sue E. Nokes, Mark A. Bennett, Richard E. Riedel

Biosystems and Agricultural Engineering Faculty Publications

Field tomatoes were sprayed with chlorothalonil on a fixed–interval spray program and a TOM–CAST spray program with disease severity value threshold of 18. Foliage samples from upper and lower canopy layers were collected prior to spray re–applications. Chlorothalonil residue data were compared to the chlorothalonil efficacy threshold (1.2 μg/cm²). Using a seven–day interval program, eight of the nine and seven of the nine spray intervals had chlorothalonil residues above the critical level for the upper and lower canopy layers, respectively. Using the TOM–CAST program, four of the five spray intervals had chlorothalonil residues above the critical level for …

Improving Irrigation For Ord Sugar Cane, Jim Engelke, Joe Sherrard, Gae Plunkett, Tim Triglone

Journal of the Department of Agriculture, Western Australia, Series 4

Major changes are underway in irrigation practices for the Ord sugar industry as it moves to implement recent findings on improving irrigation efficiency and managing rising groundwater. Significant improvement in efficiency is expected by more accurately matching water application with crop water requirements and by minimising drainage losses through improved water application techniques.

Based on findings from this work, drying off may not be an appropriate strategy for the ORIA as a means of improving crop sucrose content, but could allow for some reduction in water use towards the end of the crop cycle without adversely impacting on sucrose yield. …

Non–Water–Stressed Baseline As A Tool For Dynamic Control Of A Misting System For Propagation Of Poinsettias, Sérgio Zolnier, Richard S. Gates, Robert G. Anderson, Sue E. Nokes, George A. Duncan

Biosystems and Agricultural Engineering Faculty Publications

A technique is presented for dynamically adjusting misting intervals during propagation of vegetative cuttings. A crop setpoint temperature for activation of misting was defined by a "non-water-stressed baseline" concept, using infrared thermometry to acquire canopy temperature for plant feedback. The critical crop setpoint temperature was calculated from instantaneous values of air temperature, incident radiation, and air vapor pressure deficit (VPD_air). Misting was activated when the actual crop temperature exceeded the critical crop setpoint temperature. The dynamic control was shown to have the potential to reduce the amount of applied water from 9 to 12 times during low levels …

Reconditioning Corn And Soybeans To Optimal Processing Moisture Contents, Michael D. Montross, Dirk E. Maier

Biosystems and Agricultural Engineering Faculty Publications

Experimental trials were carried out to evaluate the technical feasibility of reconditioning overly dry corn and soybeans to optimal market and processing moisture contents. Data obtained from experimental trials were used to validate an aeration simulation model. This model was used to evaluate the feasibility of reconditioning soybeans and corn. Reconditioning of grain was feasible at low airflow rates (0.11 m³ min^–1 t^–1) over a six-month period when an automatic aeration controller was used. Using downflow aeration and monthly unloading of the bin allowed for the greatest net economic gain. Predicted reconditioning in Des Moines, Iowa, …

Simulated Performance Of Conventional High-Temperature Drying, Dryeration, And Combination Drying Of Shelled Corn With Automatic Conditioning, Michael D. Montross, Dirk E. Maier

Biosystems and Agricultural Engineering Faculty Publications

Combination drying, based on computer simulation, was evaluated as an alternative drying technique to traditional high-temperature drying and dryeration. Simulation models of high-temperature crossflow drying and in-bin drying and conditioning were used to evaluate the performance of conventional crossflow drying and full-heat crossflow drying followed by dryeration or natural-air drying for Indianapolis, Indiana, and Des Moines, Iowa. Energy costs from propane, electricity, moisture shrink below the market moisture content, and dry matter loss were estimated to find the total average drying cost over 29 years. Dryeration and combination drying reduced the total drying cost by approximately 10% compared to conventional …

Evaporation Reduction Potential In An Undisturbed Soil Irrigated With Surface Drip And Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The efficiency of drip irrigation is highly dependent on evaporation losses occurring from the constantly saturated soil beneath emitters. Advent of subsurface drip irrigation is in part an approach to curb this inefficiency. An irrigation method, Sand Tube Irrigation (STI), is proposed to increase the efficiency of “Normal” surface applied drip Irrigation (NI method) on permanent tree crops without the need for burying the irrigation tubing. The sand tube consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was constructed in the laboratory and instrumented to directly measure temporal evaporation …

Optimization Of Solid-State Fermentation Parameters For The Production Of Xylanase By Trichoderma Longibrachiatum On Wheat Bran In A Forced Aeration System, Elizabeth R. Ridder, Sue E. Nokes, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

The effect of aeration on the production of xylanase by Trichoderma longibrachiatum on wheat bran in a solid-state fermentation (SSF) system has not been investigated. This study was conducted to investigate the interactive effects of aeration, initial moisture content of the substrate, and depth of the substrate on xylanase activity produced in a tray fermenter. The experiment was conducted as a split plot experiment with factorial treatments and three replications of each treatment combination. The whole plot treatment was aeration rate (0, 2.9, 5.7 L/min/kg bran). Initial moisture content (45, 55, 65% w.b.) and depth of substrate (1.0 and 2.5 …

Pesticide Residue Regulation: Analysis Of Food Quality Protection Act Implementation, Linda-Jo Schierow

RISK: Health, Safety & Environment (1990-2002)

Dr. Schierow discusses the effects of a recent statute on food safety.

Modeling Surface And Subsurface Pesticide Transport Under Three Field Conditions Using Przm-3 And Gleams, Robert W. Malone, Richard C. Warner, Stephen R. Workman, Matt E. Byers

Biosystems and Agricultural Engineering Faculty Publications

Contaminant transport models should be evaluated over a wide range of conditions to determine their limitations. The models PRZM and GLEAMS have been evaluated many times, but few studies are available in which predicted movement in runoff and percolate were simultaneously evaluated against field data. Studies of this type are essential because pesticide leaching and runoff are mutually dependent processes. For this reason, PRZM-3 and GLEAMS were evaluated for their ability to predict metribuzin concentrations in runoff, sediment, subsurface soil, and pan lysimeters under three field conditions (yard waste compost amended, no-till, and conventional-till) on a Lowell silt loam soil. …