Precision Farming: A Producer's Perspective

Rick Hobbs

Assiniboia, SK

Having a keen interest in new technology and methods and not bound by tradition, I was naturally attracted to the precision part of site specific farming. When combined with the potentially significant benefits in the areas of Economics, Agronomics, the Environment and Ecology, this was exciting.

The geographic area I farm in is known as the Palliser Triangle, described as semi-arid. Referred to as short grass country and known as short country, my experiences have been "damn short of grass" some years. Annual precipitation mean levels are 9-13 inches. In recent years precipitation in the area has been unpredictable and sporadic but pattern specific. It is not unusual to have seasonal differences of as much as 4.2 inches within 4 miles. This introduces another variable into determining realistic target yields when writing prescriptions for different fields within this area of variation. Crops grown range from low value oats and cereals to higher value oilseeds and pulses. In this area, timeliness of precipitation has more effect on production than seasonal totals. An example: 1 inch at three week intervals starting immediately after planting will produce higher yields than 6 inches, when 2 inches fell prior to planting and 4 inches between June 20 and July 8.

In 1994 a stand-alone yield monitor was used. It confirmed what was already known that certain areas within a field produced significantly different yields. Now actual numbers were known, making the differences measurable. The first yield monitor was a Micro Trak, when properly calibrated, gave accurate totals. Sensitivity settings are more challenging. Higher sensitivity settings depend on smooth and calculated control by the operator to prevent erroneous high or low spot specific readings. Even though the totals accuracy is not affected.

The next yield monitor was the Case IH AFS Version of Ag Leader technology. The functions were similar when calibrated properly. In 1996 a revised chip was used and earlier versions were updated. The new chip was pre-set with many parameters and when used in conjunction with the new Agri Logic Software made this combination very user friendly. Case IH offered low cost training sessions and labelled circle seminars to teach operators the Instant Yield Program, as well as more advanced programs. These subscription-based programs avail producers to the full spectrum of Precision Farming Technology.

Yield monitor accuracies of 0.1% of total harvested volumes are common and published reports of 0.003% would not be unrealistic. My concern is not in total volumes, but in differences; measuring response to trials involving varieties; plant population; micro or macronutrient application amounts; pesticide treatments and rates as well as other management decisions. A desensitized yield monitor makes measuring trials more difficult, requiring longer comparison strips of 100 feet to 200 feet over the same topography and soil types to get a valid response result.

With continuous cropping and some drier-than-normal years, yields were becoming more uniform, but uniformly poor, more so than could be attributed to the low levels of precipitation. Soil tests had been regularly taken and nutrients applied as per recommended levels (see sample analysis).

At this time I was fortunate to connect with Dr. Dan Pennock and the Soil Science Dept. at the University of Saskatchewan. Using Provincial Survey aerial photographs and a GIS spectrographic software program, maps depicting management zones were generated according to soil color. The process seems relatively simple, however, these photographs were taken in 1981 when most land was farmed half crop to half summerfallow. Depending on when the photos were taken, half of each land parcel depicted vegetative growth and half depicts bare soil. This requires that the individual fields be processed separately then seamed together. Initially four acceptable management zones were created. Except in cases such as salinity or unusual soil type changes, these maps overlay directly with topographic maps. The lightest shades being hilltops and mid-slopes the two darker shades being tow areas and bottom land, the darkest areas are where water relocates to puddles but many of these areas can be seeded and harvested.

Soil testing was done with between 10-15 individual samples taken from each zone. Previous sampling had been hired. Using the same type probe, the integrity of the previous sampling was questionable. A 2-foot core could result in anywhere from 2-inches to 20-inches of soil coming out with the probe. This required manual side peeling of the soil opening to obtain a truly representative sample. No hired samples had been observed doing this time consuming action. This may possibly explain the dramatic changes in organic matter increase shown in the attached analysis. An auger sampler is now being used to do soil testing.

Results of the zonal testing showed the N available on hills to mid-slopes to be 75 lbs. and 85 lbs. respectively. The toes and bottoms of slopes had zero N available. The N available within zones varied up to 20 lbs. In keeping with uniformity, all samples were taken between rows of the last crop. These results possibly explain some of the yield questions. With 75 lbs. and 85 lbs. being available on hills and mid-slopes, an extra 50 to 60 lbs. of N applied during a dry year could create conditions leading to plant burn. Conversely, an application of 60 lbs. in a low lying area, combined with a low mineralization factor may only allow a 40 bushel crop to be grown in an area that had the potential for 60 to 80 bu/acre.

Points to note on the Soil test and Prescription Data chart:

• Organic matter content within zones would indicate previous sampling represented lower areas more so than hilltops or mid-slopes.
• Converse relationships of nitrogen to phosphorous.
• pH levels and slope position.
• Mapping software also calculates area contained within each zone. This facilitates the calculation of product required and average bu/acre targeted yield.
• The number of zones defined could be increased or decreased to match individual criteria such as topography, soil type or other influencing factors.

The economic comparisons of variable rate and straight rate were determined using this criteria:

• Soil testing for variable rate was collected and analyzed in accordance with the four zone mapping system. The straight rate samples were collected by a local service supply company. All were analyzed by the same soil testing laboratory.
• By coincidence all of the fields used for straight rate were assessed to be more productive than the variable rate counterparts.
• All the fields in the comparison were approximately 160 acres, and in each comparison of summerfallow, first year stubble and continuous crop were adjacent to one another on one side. Similar amounts of precipitation occurred on fields compared.
• Precipitation amounted to 6 inches during the growing season, 1.2 inches between April 15 and June 1, 4.2 inches between June 22 and July 8. There was no beneficial precipitation between July 8 and harvest with seasonal temperatures being higher than average.
• Not considered is an additional $0.50/acre in soil test costs.

The planting operations were performed using a Flexi-Coil 6000 no-till air drill equipped with Barton II double shoot disc openers, in combination with a 50 series variable rate air cart, Flexi-Coil multi-function controller monitor and tasker. This unit was connected to a Trimble Ag 132 GPS receiver L band differential correction and parallel swathing option light bar.

The Flexi-Coil 6000 can be configured with 7.2" or 10" row spacings and is available in 30-foot or 40-foot widths. I found it to be precise and very adjustable as to depth of nutrient, depth of seed and the separation between each. The design of the angle discs eliminates the traditional problems of penetration and hairpinning. The unit was also very versatile and with minor adjustments performed equally well over a wide range of conditions including pre-tilled loose soil, hard packed soil, wet and dry as well as heavy and light textured soils.

The Flexi-Coil 50 series air cart equipped with variable rate drive technology which is available on all their carts, combines low uses of electrical and hydraulic energy in a simple, reliable wide rate range yet highly accurate metering system. Meter rollers are available from extra fine to extra coarse to provide tailored precise metering of products from fine granular pesticides to coarse seeds such as peas or beans.

The multi purpose controller monitor from Flexi-Coil Electronics is used to monitor and control a 3-tank air cart with an as-applied seed treated or to monitor and control Flexi-Coil chemical spraying equipment. When connected to Flexi-Coil's tasker, a PCMCIA card can be inserted to control functions and events at specific sites when connected to a global positioning system. The monitor is completely programmable as related to antennae offsets as well as distances to tillage tool, air cart, and pre-set delays.

Speed of rate change and amount of rate change can be configured to each tank or product controlled. Minimum, maximum or averaging can be selected to application across the width of the seeding tool (cell size for this application was 5 meters or 16.4 feet and the minimum, maximum or average refers to changes in prescribed application differences cells). Flexi-Coil uses the emerging ISO11783 CAN bus system to transfer information. This would appear to be the North American industry standard of future device connections. Flexi-Coil's electronics system is compatible with many other taskers such as Rockwell-Vision, Ashtech Navigator, Aim Navigation System, RDI Agmap, Satloc Triton and precision farming solutions. Maps can be created for the Flexi-Coil tasker with many of the leading GIS software programs. The monitoring and controlling features are all available with touch screen ease. Having reviewed what has been displayed by other manufacturers, it would appear that Flexi-Coil is probably the leader in variable rate technology.

The Trimble Ag 132 with light bar guidance system hooks directly to Flexi-Coil's electronic system. The dual port feature of the 132 lets the operator hook more than one peripheral device to the receiver, which is especially convenient when devices which may require different NUMEA strings, Baudrates or Hertz (update) rates. The receiver can be mounted so as to be an auxiliary display screen. The sub-meter 2-sigma accuracy of this unit provides accurate and precise guidance towards the elimination of misses and overlaps. It is well supported and user-friendly.

The AERIS Aglink GIS software program was used to enter the prescriptions developed onto flash disc PCMCIA cards. I felt this was an affordable program, which has the functionality to be used by a producer or commercial professionals. The economic functions of the program combine costing of products or billing in conjunction with target yields and production. This can be used to show profitability pictures using application and cost values to determine maximum economic returns to aid in development of prescriptions, as well as keeping a complete cost and return account for each parcel or field. This also simplifies determining benefits from on-farm testing or trials.

Another economic benefit realized as a result of site-specific technology was in the area of phosphorous application. Three years of application trials at 2-times the recommended rates, recommended rates and no application on several fields resulted in no measurable response. Factors examined were date of maturity, yield, and protein. Soil sample analysis recommended low to medium application rates, which may partially explain the lack of response. Application trials and soil analysis will be monitored on an ongoing basis for response to and depletion of phosphorous. Until such time phosphorous will not be included in planting prescriptions, resulting in savings of $1100 to $1300 per 160 acres.

Through all the testing and data acquisition, for every question an answer was sought, 10 more questions have surfaced. Realizing the complexities of soil biology, plant biology, and the interrelationship that occurs, this should not be surprising. The technology that makes site-specific farming possible was in existence and was simply adapted to agriculture, outpacing research, which is normally conducted in concert with technology development.

Testing and trials will continue with varieties, macro and micronutrients, inoculants, and pesticides. Flexi-Coil's variable rate technology that incorporates, AS APPLIED logging functions, when combined with GPS will be used to generate maps of planting and treatment applications. These maps, when overlayed with yield maps, are necessary for measuring responses (positive, negative or immeasurable) to be used in management decisions. As the information database compilation increases, management strategies, which can be used to further maximize economic returns will increase as well.

Remote imaging and sensing is now, and will become more significant, as a tool for the agricultural industry. Ground penetrating radar, infrared, multi-spectral and hyperspectral imagery as well as interferometry are some of the technologies, which can be applied to agriculture. As resolution becomes finer and data is interpreted and defined, it is not unrealistic to believe that sites within fields stressed by nutrient deficiency, moisture levels, weeds, insects or diseases, could be isolated and identified as to specific minerals, drought or excess, species and strains. An example might be the AGRI IMAGES INC. infrared soil moisture map depicting differing levels of soil moisture. Pre-plant maps on rolling terrain would show areas of water relocation as well as areas of deeper snow deposition on slopes. Soil sample sites and target yields used for prescriptions would pay bigger dividends than outdated solid color maps or previous yield maps. It has been said snow won't grow a crop, however, experience and research has shown snow depth has a definite impact on yield potential.

Real time on the July soil sensing and analysis technology can be very effective in planting applications. I am planning to incorporate Crop Technology Inc. Soil Dr. application and analysis equipment to more accurately apply nitrogen and seed as required to meet my target yields. This technology can be used in conjunction with other prescription data to apply by-the-foot nitrogen and planting rates. As with any sophisticated equipment, proper setup and configuration is probably necessary for accurate operation.

There are advertisements that read "Every farm is the same", "Every farm is different". This is very true. In fact every field and every foot within a field may be different. The analytical findings and observations in this article may not be applicable or define correlations involving nutrients, etc. for other circumstances. Management history, soil structure and type as well as climatic conditions are all factors, which determine current values and are subject to change.

The advent of Global Positioning Systems to agriculture might be comparable with the telescope to Astronomy. When combined with peripherals, such as yield monitors, soil sensors, variable rate applications, and remote sensing to give rise to possibilities and production techniques that are astronomical.

As the economic buoyancy of agriculture improves, the purchase and adoption of this new technology will increase. Employment opportunities will be in demand and attractive. Producers may likely require the services of people skilled in soil science, plant science, economics, and computer operators trained to utilize the functions of high powered software programs that included the previous disciplines, as well as remote sensing. Producers may be occupied full time procuring inputs, physically implementing the operations and maybe marketing production.

Not having much formal education in any of the disciplines concerned in this presentation, none of the thoughts or opinions expressed can be regarded as theories. I refer to them as "WAGS" (wild ass guesses), not reserved to the field of non-academics.

In closing a word of caution - Implementation of this technology may lead to ineligibility for the Disaster known as Disaster Assistance Program.

SOIL TEST & PRESCRIPTION DATA

32 bu./acre Average

pcmcia CARD ENTRY

VARIABLE RATE COMPARISON