Developing Sustainable Stored Grain IPM Systems in Oklahoma and Texas
Poor Oklahoma/Texas harvests and high prices caused cooperators to market wheat by September. Consultants sealed grain storages for improved, sustainable fumigation. Replaced one farmer and elevator.
Aeration fan controllers being built for all sites. Suction aeration systems designed for three concrete silo elevators — one aeration system delivered (photos).
Computer grain-blending model being developed will help elevators/farmers blend grain for optimum storage and marketing. Closed loop fumigation (CLF) systems being designed for installation/use. Diatomaceous earth (D.E.) will be applied/compared as insect barriers. Grain is monitored for temperature and insects.
Sustainable practices — Sealing, CLF, suction aeration, computer-blending, insect/temperature monitoring, D.E.
Demonstrate and compare closed loop fumigation (CLF) technology in well sealed storages with conventional fumigation as a cost effective, sustainable IPM component of Oklahoma and Texas farm and elevator grain storage systems to improve efficacy, safety, and profit.
Conduct physical and economic benefit analysis of suction vs pressure aeration systems operated by electro-mechanical automatic aeration controllers compared with manual control in steel bins and concrete silos at farms and elevators.
Document the practicality, including cost:benefits, of increasing aeration airflow rates from the standard 0.1 cfm/bu to 0.2-0.3 cfm/bu in bolted steel farm and elevator storage systems.
Evaluate physical and economic practicality of installing low airflow suction aeration plus CLF in existing concrete silos to minimize “grain turning” while improving sanitation and safety.
Document worker exposure to phosphine fumigant health hazards and safety using CLF vs conventional fumigation.
Establish a quarterly newsletter focused on grain storage IPM for farmers and elevator operators in OK, TX and other states available via OSU’s Stored Product Internet web-site.
Performance targets will be the methods used to assess the results of Objectives 1-6:
Objective 1: Demonstrate and compare closed loop fumigation (CLF) technology in well-sealed storages with conventional fumigation as a cost effective, sustainable IPM component of Oklahoma and Texas farm and elevator grain storage systems to improve efficacy, safety, and profit.
Performance Target 1: Where possible, side-by-side comparisons will be made of bins or silos which have been sealed and CLF installed compared to similar bins or silos which have not been modified. Grain quality, insect populations, gas levels in base and headspace, gas levels outside the bin or at “leak points” will be monitored to evaluate the CLF vs manual fumigation. Cost/benefit analysis will be developed to compare installation and operating costs (fumigant and labor for turning, house-keeping, etc) of CLF vs conventional fumigation.
Objective 2: Conduct physical and economic benefit analysis of suction vs pressure aeration systems operated by simple, economical electro-mechanical automatic aeration controllers compared with manual aeration control in steel bins and concrete silos at farms and elevators.
Performance Target 2: Where possible, side-by-side comparisons will be made of grain storages with automatic electro-mechanical aeration controllers installed compared to similar grain storages which have manually operated aeration fans. Grain temperature profiles from existing thermocouple data or at the center of the grain mass (for OSU installed thermocouples) will be monitored weekly during the aeration process (or more often if on-site grain managers take more frequent data), then at least monthly after cooling cycles are completed, to evaluate cooling zone profiles of the grain mass before, during and after aeration. Other factors, such as grain quality and insect populations may also be monitored to evaluate the automatic aeration vs manual aeration management. The manual method or procedure of aeration fan operation will be described for each site.
Objective 3: Document the practicality, including cost:benefits, of increasing aeration airflow rates from the standard 0.1 cfm/bu to 0.2-0.3 cfm/bu in bolted steel farm and/or elevator storage systems.
Performance Target 3: Where possible, side-by-side comparisons will be made of grain storages with conventional aeration fans vs storage units where we can increased the air flow rate. This may involve installing larger fans as well as installing additional roof exhaust or inlet vents. Temperature profiles on existing thermocouples or center grain mass temperature profiles (thermocouples added by OSU) will be monitored weekly during the aeration process (or more often if on-site grain managers will take more frequent data), then at least monthly after cooling cycles are completed, to evaluate cooling zone profiles of the grain mass during and after aeration. Other factors, such as grain quality and insect populations may also be monitored to evaluate automatic aeration control vs manual aeration management. The manual method or procedure of aeration fan operation will be described for each site.
Objective 4: Evaluate physical and economic practicality of installing low airflow suction aeration plus CLF in existing concrete silos (and flat storages) to minimize “grain turning” while improving sanitation and safety.
Performance Target 4: Where possible, side-by-side comparisons will be made of grain storage silo systems with suction aeration and CLF installed vs similar silo storage units which have not been modified. We will study grain temperatures and grain insect populations of non aerated vs aerated silos. Grain temperatures will be recorded weekly. Grain insect samples will be taken monthly. Installation and operating costs of the suction aeration and CLF systems will be documented. “Grain turning” time will be documented along with hourly labor and electrical equipment operating costs as well as fixed costs of grain handling. Sanitation conditions will be documented in suction cooled vs “turned to cool” silo elevators.
Objective 5: Document worker exposure to phosphine fumigant health hazards and safety using CLF vs conventional fumigation.
Performance Target 5: Where possible, side-by-side comparisons will be made of grain storage systems with CLF vs conventional fumigation; periodic monitoring of key leak points and personal working locations will be documented to characterize the compared storages. Electronic gas detectors with a sensing range of 0-20 PPM will be used for safety monitoring to document readings above and below 0.3 PPM.
Objective 6: Establish a quarterly newsletter focused on grain storage IPM for farmers and elevator operators in OK, TX and other states available via OSU’s Stored Product Internet web-site.
Performance Target 6: OSU has an existing Stored Product Management web-site. During the summer, fall and winter, 2003, SARE Project newsletter style reports will be developed and listed on the websites. These website reports will be distributed to OK and TX county extension offices via e-mail for distribution to grain farmers and grain elevators in each county at the county’s option. The Grain and Feed Association in OK and TX will be contacted to see if they want to distribute quantities of OSU’s SARE Newsletter to their elevator clients. If requested, SARE Newsletter copies will be printed and bulk quantities sent to Grain and Feed Associations.
During the summer, 2002, I met with both field consultants and visited all twelve cooperator sites, decided which facilities to seal for closed loop fumigation (CLF) and aeration. I also picked two concrete elevators in OK and one in TX for installing low-airflow suction aeration cooling systems combined with CLF.
The extremely poor Oklahoma and Texas High Plains wheat harvests (worst harvest in past 35-40 years) with approximately 60% of normal yields resulted in most of the wheat being marketed in August and September at prices $1.50-$2.00/bu higher than normal. This widespread early movement of wheat resulted in a major disruption of this SARE project as there was no grain to monitor at almost all sitets.
One OK farmer dropped out of the program in late August as he had an opportunity to sell all his wheat to local farmers for seed wheat for 2003. Fortunately, we had already sealed his bins in preparation for CLF, so he will gain some sustainable benefit from the study.
Another OK farmer said he felt he should drop out of the project since he would have very little wheat that he had not already targeted to sell for seed wheat, which would be moved by mid-September. I convinced him to stay in the project through 2003.
I replaced the OK farmer cooperator dropout with a young, progressive seed wheat farmer who felt he would have some carry-over wheat in the fall of 2003. I talked to him in mid-April and he is very interested in proceeding with bin-sealing, DE, aeration control and CLF. I met with the OK field consultant and my research engineer and they have scheduled the remaining sealing work.
Cone Elevator, Lubbock, TX dropped out of the program in March and was replaced in mid-April by Sunray Coop Elevator, Sunray, TX as a site for installation of suction cooling and CLF. The TX field consultant said the Sunray Coop Elevator manager was excited to be included in this field study. The field consultant will visit the Sunray elevator to obtain digital photographs and elevator silo annex data for my design of his system. Mr. Meers said it will be very similar to the Cone Elevator facility at Lubbock, so revision of the suction aeration system design should be relatively quick so materials and equipment should be ordered within the next 3 weeks..
The primary in-field project activities conducted during the past fall and winter in both OK and TX were sealing bins and silos. The three OK concrete silo annexes and one flat storage warehouse have been sealed, as well as most of the steel bins at the two original farms.
Suction aeration was installed in one flat storage warehouse in July and August, 2002. However, due to the wide base and shallow grain depths, flat storage is the hardest structure to aerate, and the 2002 design was not adequate. The aeration system for this facility has now been redesigned to provide a perforated centerline main duct under the full length (except for 10-15 feet on each end where the grain slopes to the end walls) of the ridge/peak of the grain mass during suction cooling after the 2003 harvest. A specific type of perforated duct material with cross outlets is being sourced at this time to lay along the 200 ft. centerline of the building. All lateral pipes used in 2002 will “Tee” off of this new partially perforated center duct (perforations sealed near each end).
During September/October, 2002 I designed aeration controllers for all 12 sites, purchased materials and initiated the fabrication of the aeration controllers at my departmental (Biosystems and Agricultural Engineering) research and tooling laboratory. All aeration controller fabrication and assembly will be completed and the controllers delivered before 2003 harvest.
I designed suction cooling systems for two OK concrete elevators and one TX concrete elevator. The materials and equipment for one suction aeration system has been delivered to Ponca City, OK. Also delivered to Ponca City is the aeration controller that will control their new aeration systems for silo suction cooling, flat storage suction cooling, as well as five existing aeration fans on four other systems.
Although the aeration controller for the Ponca City elevator is designed to sequence start all of their existing and new aeration fans, I will encourage them to use manual control of the older systems for 2003 to provide comparative results with the automatic control system, then connect the aeration system to all aeration fans for 2004 and beyond.
Because of budget constraints due to the bad harvest, one of the OK elevators chose to wait until late April to decide whether to install the suction aeration system. My field consultant, research engineer and I met with the officers of this elevator at their headquarters on Tuesday, April 22 to discuss the system design and operation. The officers decided to move ahead with the suction aeration and CLF installation.
CLF equipment systems for all 12 sites will be designed and purchased in May/June 2003. CLF systems can be installed in all units with bins, silos or flat storage units filled. Delivery and installation is planned for June/July with installation of all CLF systems targeted for completion by September 1, 2003. Most elevators typically fumigate from mid-September to mid-October.
A new “sustainable product” that I’ve added to this study is the development of a computer software program “grain inventory and blending model” (Blending-Model)that allows grain elevators and large farmers to “segregate their grain” as it arrives, grade and inventory their grain by bin or silo according to selected USDA grain grade factors, as well as storage and market quality characteristics. The Blending-Model will allow grain managers to blend grain for safer storage, minimize discounts at time of marketing, and meet contract specifications using minimum quantities of their premium grain. Thus, the Blending-Model will assist grain managers in obtaining optimum value from their grain crops.
The preliminary version of this computer model was discussed and demonstrated to OK grain elevator personnel at a series of elevator workshops or seminars during March, 2003. There is strong interest by cooperating elevator managers in the SARE study as well as other OK elevators when discussed. A group of OK elevator grain mangers will “beta-test” the “grain inventory and blending model” software during the wheat harvest and summer of 2003, and provide feedback on problems, suggested changes, edits, to enhance the product.
IPM practices that will be recommended for use in this study
(1) Suction aeration for fast early cooling of top surface grain where most insects infest initially;
(2) Coring of bins to reduce peaked grain and reduce aeration time by 15-30% will be encouraged;
(3) Closed loop fumigation (CLF) — recirculation fumigation systems will be installed at all farm and commercial grain storage sites where agreeable;
(4) Sealing of base, sidewall, eave and roof peak openings (leaving roof vents open to keep fresh air in head space) to minimize or eliminate insect entry (except into headspace) and gas leakage during fumigation will be conducted to improve both aeration and fumigation;
(5) Automatic aeration control will be used to improve aeration timeliness and reduce cycling of cool and warm air during summer and fall aeration; minimizing wasted electricity during aeration.
(6) Use of increased aeration airflow rates for faster aeration cooling — increasing from 0.1 to 0.15-0.3 cfm/bu — will be encouraged and demonstrated where possible.
(7) Close, timely monitoring of grain and ambient air temperatures and insect populations will be used to determine optimum fumigation and aeration timing.
(8) Diatomaceous earth (DE) will be recommended as “natural” sustainable empty-bin pre-storage insecticide and top-dress applications to provide barriers to insects in test bins.
Impacts and Contributions/Outcomes
IMPACT AND CONTRIBUTIONS/OUTCOMES
Since the 2002 OK and TX wheat harvest was poor, there was very little grain retained in any cooperator’s storages beyond September. Thus, virtually no demonstration activity was conducted during the fall, winter and spring. However, we sealed external under-roof vents in 14 concrete silos at our cooperator elevator at Yukon, OK where we will be installing suction cooling. The sealed concrete silo annex and the adjacent unsealed silo annex were both fumigated by conventional methods. The new silo annex will contain our suction cooling and CLF, the older silo annex will be our side-by-side comparison for temperature and insect activity.
Grain samples pulled last fall from both silo annexes after conventional automatic pellet dispenser with “grain-turning” fumigation showed that the sealed annex had very few live insects while the older, unsealed annex had more live insects, using the same dosage per 1,000 bushels. This indicates that with sealing of under-roof exterior vents as the only major variable, gas retention was much better in the silo annex with sealed under-roof vents compared to the unsealed silo annex.
Proper sealing of a grain storage structure of any type is one of the most sustainable, cost effective actions that an elevator manager or farmer can do for his grain storage facility. Sealing improves fumigation of any type of structure by a factor of 2X to 8X (or more, based on a concrete silo sealing study by Noyes in 2001), depending on how leaky it was initially. Proper base and sidewall sealing provides barriers to insect entry to the base and sidewalls of storage units, forcing insects to enter at the grain surface where they are easier to identify, contain and control.
Thus, demonstrating and publicizing the proper method of sealing bins, silos and warehouses as a primary sustainable IPM practice is the base and core practice of this study.
I have some excellent photo documentation of the sealing processes for steel and concrete developed at the OSU Stored Product Research and Education Center (SPREC) as well as on SARE project cooperator sites.
Bin and Silo Sealing will be the focus of the first OSU Stored Product Website SARE Newsletter. That will be made available by website to elevators and county extension offices in the grain regions of OK and TX, which should make for a solid impact on grain managers. The OSU Stored Product Website address can be shared with producers/grain people throughout the Southern Region, so they will be able to access that report as well as other IPM grain management information.
Although much work has been done, major impacts have not yet registered. But, they are coming!
The “grain inventory and blending model” has the potential for major improvement in sustainable profit generation for country grain elevators, grain terminals and mills in OK, TX and throughout the U.S.
I believe the Website reporting of the work and the results will have very broad-based application throughout Central and Southern U.S. in late 2003, 2004 and beyond.
Ronald T. Noyes, Ph.D., P.E.
Professor, Extension Agr. Engr.
Biosystems & Agricultural Engineering Dept.
Oklahoma State University
APPENDIX — Project Site Photos (as Power Point Attachment)
Digital Photos of Sealing Procedures