Engineering Commons^™

Canal Seepage Reduction By Soil Compaction, Charles M. Burt, Marcus Gardenas, Mohamed Grissa

BioResource and Agricultural Engineering

Large-scale tests were conducted of in-place compaction of irrigation district earthen canal bottoms and sides. Five canal pools with sandy loam soils were compacted. Seepage reduction of about 86% was obtained when the sides and bottoms were compacted; reductions of 12 – 31% were obtained when only sides were compacted.

Improving Pump Performance, Charles M. Burt, Frankline Gaudi, Daniel J. Howes

BioResource and Agricultural Engineering

Options can be specified to minimize power consumption by vertical pumps – both when new and over the life of the pump. Options discussed include bowl coatings, proper well development, improved suction screens, using closed impeller designs, increasing column size, using new bearings, providing proper bearing lubrication, impeller balancing, and polishing impellers. The proper TDH and flow rate must be specified, and the advantages of VFD controls are covered.

Agricultural Water Conservation And Efficiency In California - A Commentary, Charles M. Burt, Peter Canessa, Lawrence J. Schwankl, David F. Zoldoske

BioResource and Agricultural Engineering

This is a Commentary on some of the key points that are presented in “More with Less: Agricultural Water Conservation and Efficiency in California” by Cooley, ChristianSmith, and Gleick of the Pacific Institute, September 2008 (referred to as the “PacInst Paper” in the remainder of this discussion).

The authors of this Commentary have over 120 years combined of experience in agricultural and landscape irrigation. They have worked world-wide in design and installation of all types of irrigation systems (including automated drip systems from 1975 on), design and implementation of irrigation scheduling programs since 1977; design and implementation of water conservation …

Avoiding Common Problems With Drip Tape, Charles M. Burt

BioResource and Agricultural Engineering

This publication is meant to help farmers, dealers, and manufacturers recognize and understand some of the problems that have been experienced with drip tape – problems that are quite different from manufacturing defects. Problems that are quickly detected and properly identified can often be remedied, or be avoided in the future. The report addresses drip tape damage caused by pests, installation, emitter pressure, plugging, and other categories.

Technical Concepts Related To Conservation Of Irrigation And Rain Water In Agricultural Systems, A. J. Clemmens, R. G. Allen, Charles M. Burt

BioResource and Agricultural Engineering

Forty percent of freshwater withdrawals in the United States are for irrigated agriculture, which contribute more than $50 billion to the economy. Increasing diversions of water for urban, environmental, and other uses will likely decrease water available to agriculture. Water conservation in agriculture is touted as a good method for minimizing the impact of reduced agricultural diversions on production. Because “wasted” water is often reused until it reaches the ocean, there are limitations to the true water savings that result from programs that aim to increase irrigation efficiency. True water savings can come from four areas: reduction of unnecessary evaporation …

Conversion To Groundwater Pumping With Drip/Micro Irrigation Systems, Charles M. Burt, Monte Soto

BioResource and Agricultural Engineering

Twenty one irrigation districts in the Central Valley reported “conversion acres”. Conversion acres are those on which farmers used only groundwater for drip/micro irrigation although surface irrigation water was available.

The twenty one districts include about 2 million acres of irrigated area. Approximately 3.6% of that acreage (73,000 acres) has been “converted” to groundwater when farmers switched to drip/micro. Fourteen of these districts anticipate more conversion in the future. ITRC thinks that the conversion will be more rapid and greater than district personnel suspect.

The dominant factor that influences the conversion was the lack of flexible water delivery service to …

Accuracy Of Global Microirrigation Distribution Uniformity Estimates, Stuart W. Styles, Charles M. Burt, Franklin Gaudi, Sierra Layous

BioResource and Agricultural Engineering

Emitter pressures and flow rates were systematically and extensively sampled in one drip and one microspray field. The data distributions are presented. The accuracy of rapid (limited samples) evaluation pressure sampling procedures was found to be quite good if the pressure distribution was systematic, but erroneous if the pressure distribution throughout a field was random. A simple mathematical combination of two nonuniformity components (due to pressure differences, and other causes of flow variation) provided a better estimate of overall system distribution uniformity than more complex mathematics.

Electric Motor Efficiency Under Variable Frequencies And Loads, Charles M. Burt, Xianshu Piao, Franklin Gaudi, Bryan Busch, N. F. N. Taufik

BioResource and Agricultural Engineering

This paper details a study performed by the Irrigation Training and Research Center to determine motor performances under varying speeds [induced by a variable frequency drives (VFD) controller] and loads. A further goal of the study was to provide sufficient information to designers so that they could estimate total pumping plant power usage with a VFD-controlled installation. Motors were tested with a VFD as well as across-the-line. On average, the relative efficiency of the electrical system with a VFD may be approximately 8% lower than the relative efficiency of a properly designed, full-load across-the-line system. If one considers actual field …

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 …

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 Reflective Mulch On Energy And Water Conservation In Semi-Arid Central California Greenhouses, T. Mehlitz, Ilhami Yildiz, S. Rahman, C. Hardin

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. Greenhouses in hot and arid regions also require large quantities of water for irrigation. Proper environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. This study aims to focus on reducing energy and water consumption in semi-arid California greenhouses. Influences of mulch (having different reflectivities) on energy and water conservation were investigated. The reflectivity of mulch used as a …

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 …

Simulated Effects Of Various Environmental Management Practices On Energy 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 levels, minimum ventilation rates, CO₂ enrichment and canopy size on energy consumption in three different greenhouse systems (conventional, open-loop heat pump, and confined heat pump) in winter, spring, and summer months. No difference was observed in energy consumption with relative humidity set point levels in winter due to the already low relative humidity levels. Some differences were observed in spring and summer due to extra dehumidification required to maintain the inside relative humidity at lower levels. Energy consumption in summer was reduced up 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 …

Irrigation District Energy Survey, Charles M. Burt, Daniel J. Howes

BioResource and Agricultural Engineering

This survey was completed by ITRC on behalf of the California Energy Commission Public Interest Energy Research (PIER) Program. The purpose of the survey was to establish a benchmark for the present status of the pumping systems used by agricultural water districts in California and to determine the districts' needs. The needs discussed involve technical assistance, research grant and low-interest loan funding, and district-related policy issues. Thirty agricultural water districts were selected for the survey. These districts were selected based on energy use per acre of irrigated area, size, geographic location, and distribution infrastructure.