Spotlight

THE USEFULNESS OF PRECISION AGRICULTURE TECHNOLOGIES

Farmers talking about precision agriculture often discuss satellites in space, computers and variable rate fertility equipment. After the initial amazement with the technology, most farmers are asking "Is this profitable? Is this technology worth the cost?"

During my time as an engineering student, I was taught that I need to look at the benefits, and the costs for achieving these benefits.

Benefits often cited in the research include increased production, reduced fertilizer requirements, reduced use of pest control chemicals and less environmental impact. Some of these benefits can be quantified, environmental impact is less easily assessed.

Costs must include not only the production materials (seed, chemicals, fuel), but equipment (including the new technology) and the time costs (purchased expertise and learning time).

Several attempts at determining the economics of precision agriculture have often reached conflicting conclusions and reviews of these studies have concluded that the economics of precision agriculture are site-specific. Yes, there are net benefits for using precision agriculture technologies in some instances, and not in others. But, the best examples of the usefulness of precision agriculture technologies is still anecdotal.

I firmly believe that the more detailed information provided by precision agriculture will benefit the users of this technology. An important benefit of precision agriculture technologies will be in the change that happens in farm management. Improved knowledge of yield patterns, field characteristics and their relationships will affect field management in subsequent years.

Geographic Information System (GIS) software is an important tool for the management and analysis of data collected using precision agriculture technologies. For example, fertility recommendations could integrate soil test, projected yield, soil survey information and management history when developing site-specific nutrient management plans.

GIS software allows us to "stack" maps of different variables for fields that we have monitored, including:

yield maps

soil test maps

field boundary maps

drainage maps

soil type / characteristics maps

nutrient removal maps

profitability maps

We have just begun to explore the possibilities for GIS software as a tool for managing and interpreting the vast amount of data generated by precision agriculture technologies. As we (producers, agri-business and Extension) learn to use these technologies, the industry will perceive the usefulness of precision agriculture technologies.

ON THE ROAD TO PRECISION AGRICULTURE
Methods of Directed Sampling

Topography
Topography sampling is conducted by first measuring elevations. However, dividing the field into zones of elevation is not appropriate because hilltops may be the same elevation as depressions in rolling fields. It is the landscape structure or topographic structure that is important, not the elevation. However, it is difficult to draw lines with confidence around landscape features without other means of support. Other tools can help to define zone boundaries to direct sampling in addition to topography alone.

Soil conductivity sensors
Soil conductivity sensors can be used to identify important zones and for verifying the importance of topography zones. It is important to note that the readings do not correlate directly with nutrient levels. High conductivity may be related to high N, but low conductivity may more often be in areas of medium N content, while medium conductivity corresponded with low N levels. These devices reveal patterns and it is the responsibility of the sampling to reveal the significance of these patterns.

Aerial photography and satellite imagery
Satellite imagery can be effective in identifying fertility patterns if the patterns are larger than the resolution of the pictures. In fields where spatial patterns are small, aerial photography might be a better tool.

Soil surveys
Soil surveys in North Dakota or Illinois have not been helpful in determining management zones. Sometimes the boundaries are drawn incorrectly, other times, too many soil series are combined into one mapping unit. In all of the fields investigated by this researcher (Dr. Dave Franzen), soil series boundaries were not useful for direct sampling for precision farming.

Yield mapping
Yield maps are the result of a number of soil and environmental factors that affect the growth and yield of crops. Yield maps appear to be most useful in defining areas of recurring patterns between years, such as areas with consistently low or no yield. However, those areas of the field that are only slightly different than other areas of the field in yield have not been useful in defining management zones. A great deal of interpretation is essential if yield maps are to be included in any management zone development.

Managing Directed Sampling
The concept of directed sampling is exciting because it usually will result in a reduction in sampling expenses, making it more practical to conduct precision farming activities in lower return crops. However, directed sampling may have additional demands on the quality of help necessary to carry out a directed sampling program.

In a directed approach, the sampler must make a decision prior to entering the field on where to define the zones. This requires some field interpretation skills and a higher level of sampler knowledge and experience than generally would be necessary in a grid program. So, although directed sampling appears less expensive on the surface, there is also attached to the system a need for more advanced employees.

Some progress is being made to automate the process of developing sampling zones. Differences in topography, conductivity, image values and/or yield levels are used to automate the zone development process. Developing zones automatically is in the beginning stages, but if perfected, could make sampling zones as easy to do as grid sampling is today.

Roger Brook

At the Precision Agriculture session during ANR week this year, Dr. Dave Franzen North Dakota State University, discussed this topic with those in attendance. This is the first of a two part summary of the handout. Copies of the handout are available to MSU Extension staff on request from: brook@msue.msu.edu

COVERING EARTHEN MANURE STORAGES WITH STRAW

One of the new methods for controlling odors from earthen manure storages is to create a cover by blowing a 12-inch depth of straw on the liquid surface during late spring. During the summer of 1998, straw was applied to six demonstration sites in southern Minnesota. One observation was a distinct reduction in odor from the storages after the straw was applied. The straw cover reduces odor release by providing a physical barrier between the liquid surface and the air. Within the straw mat that forms, a biologically active zone develops that is well aerated and is inhabited by aerobic organisms that consume odorous gases and release low-odor by-products. The light colored straw also reflects sunlight and acts as an insulator to the liquid. This tends to slow biological activity within the manure and somewhat reduces odorous gas production.

In the Minnesota experiment, the length of time the straw covers remained intact and functioning ranged from 1½ to 5 months. An 11-inch rainfall caused the cover that lasted 1½ months to become totally saturated and to sink prematurely. The remaining storages remained functional for 3 to 5 months. By fall, the straw became decomposed, the storage was agitated and the manure was removed with a chopper pump.

The straw cover is created with either wheat or barley straw. While earlier research in Canada indicated that barley straw was superior to wheat straw, the Minnesota experiment indicated both functioned equally well. A depth of 12-inch seems to be the minimum depth to prevent winds from creating openings in the straw cover. This requires approximately 100 large round bales (800 to 1100 lbs.) per acre of liquid surface or approximately 2200 lbs. of straw per 1000 square feet of liquid surface. The cost for the straw ranges from 5 to 10 cents per square foot per year or $2200 to $4400 per acre of liquid surface per year.

Using long stems of straw helps maintain the integrity of the straw cover. The straw is applied to the liquid surface with a tub grinder equipped with a blower. During the season there are likely to be patches of straw that sink. Additional straw should be applied at these locations. Plan to apply additional straw (20% of the original amount) for maintenance.

Howard Person

MICHIGAN FARMEDIC AGRICULTURAL RESCUE
TRAINING SEMINAR CANCELED

The unique Professional Agricultural Rescue Training for Fire Fighters and EMTs’ scheduled for June 12^th was canceled. Hopefully, this weekend of hands-on outside training and visually stimulating classroom discussion will be rescheduled for September or October. The class will take place at the MSU farm campus.

Howard Doss

NATIONAL FARM SAFETY WEEK IS SEPTEMBER 19-25, 1999

Hopefully we will receive information for county offices in July or early August from the National Safety Council for use in Michigan.

Howard Doss

MICHIGAN FARM, SAFETY & HEALTH NEWS HEADLINES:

49-YEAR-OLD MAN KILLED WHILE PULLING A STUMP WHEN A FARM TRACTOR FLIPS ON TOP OF HIM in Muskegon county ,4/1/99, according to a news clip. SAFETY TIP: Pulling stumps with an agricultural tractor is usually a misapplication of what a farm tractor was designed to do. Using equipment with a lower center of gravity and greater stability for this activity could reduce injury and death associated with agricultural tractors.

2-YEAR-OLD BOY HURT ON FARM in Hillsdale County, 4/13/99, according to a news clip from a MSUE office. The clip indicated that the boy's father was backing a skid-steer loader into the barn when the little boy went behind the loader and was run over. The boy was transported to a local hospital and is recovering. SAFETY TIP: Children must be supervised. A fenced play-yard can help keep children out of agricultural work areas and away from moving farm machinery.

56-YEAR-OLD OVERTURNS FARM TRACTOR USING BLADE ON PILE OF SOIL in Muskegon county ,4/26/99, according to a MSUE new clip. He suffered a broken leg with possible internal injuries and was transported via helicopter to the hospital. A trench was dug by firefighters to drain away the leaking gasoline during the hour-long extrication of the victim's leg from under the tractor. SAFETY TIP: Due to the high center-of-gravity of a tractor and the stability of an agricultural tractor, other types of earthmoving equipment may be more efficient and appropriate to move dirt.

DID YOU KNOW THAT MICHIGAN RANKS SECOND IN LIGHTNING STRIKES IN THE USA and each year, on average, three people die and 19 are injured in our state due to lightning strikes. Ball parks, playgrounds, golfing, water activities and FARM EQUIPMENT are the highest locations of lightning related injuries in Michigan. Most lightning strikes are in April through September with most in June, July and August. Source of this information is in your files: MSU Agr. Engr. Safety News 07/98

HEAT STRESS CAN HAPPEN TO ANYONE and about 20 percent of people affected by heat strike die. Drink water before you become thirsty. Preferable water temperature is between 50-60 degrees, most people tend not to drink warm or very cold water. Note: Satisfaction of thirst is not a good indicator of how much water a person needs to drink. Source in your files: MSU Agr. Engr. Safety News 08/98.

Howard Doss

THIS IS THE TIME OF YEAR THAT MORE FARM AND ORCHARD ACCIDENTS OCCUR, so your office should be sending news clips and e-mails on accidents that are farm related. If any follow-up is need, it will occur immediately when details are still available. Send Michigan accident clips and information to me as soon as you can. We can learn from the mistakes and misfortunes of others working in Michigan's Industry of Agriculture. Safety tips can provide knowledge to prevent accidents. Reports of injury or death on Michigan farms and orchards provide the basis for a safety tip.

Howard Doss

ROTARY PARLORS
An Update

In the August, 1998, issue of this newsletter, I discussed the shortcomings of rotary milking parlors. Specific concerns centered on cows entering and exiting the platform, available machine-on time and the pre-milking udder preparation routine. Each of these concerns relates to the rotation rate of the platform.

A full pre-milking hygiene routine is generally preferred because of its potential benefits to udder health, milk quality and milk flow rate. But a full pre-milking udder preparation routine will suffer in a rotary parlor because of the natural tendency of the operator to attach the milking machine to the cow soon after she enters. In fact, since current rates of rotation are often less than 15 seconds per stall, a single operator cannot both prepare the udder and attach the milking machine. This adds extra people.

Rotary parlor throughputs are often based on the rotation rate per stall; e.g., 15 seconds per stall yields a theoretical throughput of 240 cows per hour. Unfortunately, platform rotation is often interrupted because of balking cows at the entrance, milking not being completed as cows arrive at the exit, operators falling behind in their work routine due to machines dropping off or other malfunctions, etc. Rotating the platform at a faster rate (which reduces the time per stall) gives greater theoretical throughput but accentuates all of the above problems. Plus, rotating the platform at a faster rate requires that more stalls be on the platform in providing the same available milking time.

Data presented recently by John Smith (KS), Dennis Armstrong (AZ) and others have confirmed all of these shortcomings. From time studies on 14 rotary parlors on commercial dairies, they found that actual throughput averaged about 80% of the calculated theoretical throughput. Average labor efficiency was 112 cows per person-hr. However, the pre-milking udder preparation routine in the majority of parlors was minimal (including only strip and/or wipe) or no udder preparation (machine attachment only). Furthermore, milk production averaged only 64 lbs milk per cow per day. Thus, rotary parlors, costing more than conventional parlors, offer no particular advantage with respect to labor use.

High-producing cows and a full pre-milking udder preparation routine both increase the number of stalls on the platform. Smith, et al., recommend that the parlor be large enough to allow at least nine minutes of available machine on time. Thus, a platform with 56-60 stalls would be required to provide this, assuming 5 stalls for entry and exit, 3 stalls for pre-milking hygiene and 2 stalls to detach machines.

While rotary parlors may appeal to some dairy farmers, my opinion is that others will find that a rotary parlor does not encourage the work routine called for by their management style, does not meet throughput expectations and, generally, is not a positive contribution to the environment preferred for high-yielding cows.

Bill Bickert

WHO GETS THIS NEWSLETTER?

For a long time, we have distributed the Agricultural Engineering Newsletter to extension field staff—our target audience—by mailing multiple copies in an envelope to each county office. This method works well for us and we want to make sure that it works well for you.

Although many of the topics in our newsletter apply directly to production agriculture, some articles are of more general interest. For example, the articles on safety may be directed specifically to 4-H agents or others. Other articles, including some related to production agriculture, may be of more general interest and pertain to everyone. As a result, we have tried to include sufficient copies in each mailing so that each board-appointed staff person in the following categories may have a copy: County Director, Ag and Natural Resource Agent, Home Economist, and 4-H Youth Agent. Also, we would like for the AoE agents with an office in that county to receive a copy.

To help the person who distributes the newsletter in the county office, we will be inserting in each mailing a suggested distribution list, not by individual name but by position category as listed above. (Thanks to Dann Bolinger for suggesting this idea.)

We would like to hear from you how this process works. For example, do you need more copies for your office (or less)? Please give Nancy your comments (517.353.3297 or aitches1@pilot.msu.edu).

Bill Bickert

Agricultural Engineering Extension Faculty

William G. Bickert. Livestock Facilities and Environment.
Roger C. Brook. Handling, Storage and Drying of Agricultural Products; Computer Applications in Agriculture.
Howard J. Doss. Safety Leader for Michigan Cooperative Extension Service; Agricultural Safety Specialist.
Daniel E. Guyer. Post-Harvest Storage and Handling and Value-Added Processes for Fruit and Vegetables; Machine Vision and Pattern Recognition.
Timothy M. Harrigan. Forage and Field Crop Power and Machinery. Ag Expo Chairman.
Richard L. Ledebuhr. Fruit and Vegetable Mechanization. Chemical application equipment.
Theodore L. Loudon. On-Site Wastewater Treatment; Agricultural Water Quality Impacts; Irrigation; Drainage; Livestock Waste.
Howard L. Person. Livestock Facilities; Environmental Control; Management Of Manure and Organic Residues.
Robert D. von Bernuth. Irrigation and Water Management; Coordinator, Animal Waste Management Programs.

Nancy Aitcheson - Plan Service Secretary, Co-Editor
William Bickert - Extension Agricultural Engineer, Co-Editor