Zone based Site-specific field management
Neil Power, Langdon, ND
This paper will attempt to define what site-specific management is and show how adding site-specific management to your farm crop production system can be used to obtain greater crop yields, reduce crop management problems and enhance a producer’s bottom line.
What is Site-specific management?
Site-specific crop management is the practice of dividing a field into various areas that differ from each other in ways that allow the use of specific management strategies in each area to attain the most crop production with the lowest possible cost of inputs. These crop management areas are typically called Zones or Grids.
The methods and practices used to attain the benefits of site-specific management are not complex but rather a further refinement of a producers already good field level crop production management. Site-specific management will lead a producer to apply an agronomic practice specific to crop needs in only the area of the field that needs that specific practice to produce the best production level and best economic return.
How do you create zones in a field for site-specific management?
There are several options available to the producer to define the zones needed for best management. The methods used will depend on what information is available to the producer and what information can be gathered in an economic, timely manner.
Here are some of the options available:
Soil type maps:
IF available in a digital format can be very useful.
Soils maps were generally produced from soil sample cores and observations from trained personnel but can generally be refined further by adding in other data.
Veris Electro-conductivity (EC) data:
Very good soils base layer in digital format.
Two depths, 0-1’ and 0-3’ are defined.
Terrain elevation map is also created. (quality depends on GPS accuracy)
This data provides good correlation to other data sources available.
Remote sensing data such as satellite imagery:
Provides a picture of crop vegetative growth intensity.
Can be very helpful in locating areas of a field that are responding differently to environmental factors such as fertility, water availability, etc.
Best definition of fields occurs before crop enters reproductive state.
Can be difficult to get current data some years due to excessive cloudiness when pictures are taken along with the limitation of when the satellite is crossing your area.
Imagery data must be verified because hail, drought or drown out of otherwise productive areas, chemical or fertilizer misapplication, and poor crop emergence can cause misinterpretation of map data.
Airplane imagery can overcome timeliness and cloud problems but is more costly.
Yield maps:
These show actual results of the crop year in each specific area.
Yield data can be very valuable if gathered properly and interpreted correctly.
The combine operator must operate combine in a relatively smooth manner and avoid uneven cutting widths and abrupt changes in speed that cause false data to be recorded as much as possible.
Combinations:
The better ways to define field zones involve using a combination of soils data, in crop measurements such as imagery and yield data. To get these all combined properly so that the result is accurate and defines the zones better than any one specific method requires good knowledge of the data and tools to work with that data to attain desired results.
What can site-specific technology do for us in these zones?
Once Zones are defined for managing a field then the farm manager has to look at what crop is to be produced and what management practices are needed in each zone to attain maximum yield along with maximum profit. The practices involved may include seeding rate management, crop nutrient and crop protectants application among others.
To be able to select appropriate practices and levels of crop inputs in each zone the producer needs to first select the crop to be produced and the attainable yield goals for each zone.
Lets look at some of the options available to you now:
Seeding rate management:
This is used mostly with larger seeded row crops but can easily be applied to small grains and oilseeds.
Each zone would be analyzed to determine what the ideal seeding rate would be based on soil type, water availability, varieties available and other historical data.
Fertility management:
This is one of the areas that has many possibilities and one of the best chances for a return on investment. Depending on what the crop requirements are and types of fertilizers available there are many choices.
Are you trying to fertilize for the current crop or the current crop plus build soil fertility in areas that are deficient?
Are you trying to attain a certain trait or standard in a crop such as malting barley?
On the northern plains glacial soils there is generally a good opportunity to manage Nitrogen applications. This is due to the fact that our soils tend to store some of the unused N and due to varying levels of mineralization occurring on various soil types levels of residual/available N can vary greatly across a field. Add to that the N requirements of the various zone yield goals along with the cost of N and you can see that significant savings along with yield enhancement are possible.
On some soils and with crops such as corn Phosphate management can become critical to attaining top yields. Soil sampling each zone to see where soil P levels are deficient then applying the proper amounts to build these areas up to required levels can be much less expensive than blanket applying an entire field.
For Sulfur sensitive crops such as Canola applying the correct amount is critical for crop seed set and yet there are many areas of a field where sulfur is applied excessively compared to soil levels available resulting in waste of crop input monies.
Crop protectants:
The amount of money that is spent on herbicides, fungicides, and insecticides represents a significant part of a producers crop input costs. As such there are opportunities to apply/not apply or to use different rates of some products across areas of a field to maximize protectant effectiveness and economic return.
An example on herbicides would be thistle control. Generally thistles expand their growth through the root system and are generally in patches. A maximum rate could be used on the larger, thicker thistle patches and a standard rate or no rate used across the balance of the field.
An example of fungicides would be for head scab or leaf disease control. By applying the high rate of the protectant where the crop has the highest yield potential and the heaviest vegetation and then reducing or stopping application in areas with limited yield potential significant savings can be attained.
Field Drainage:
In areas where drainage is inadequate and there are available choices to relocate the unwanted moisture crops can be saved and yields can be protected by making sure that unwanted surface water does not stay too long in growing crops.
Technology can help by letting you create accurate maps of where drains are located and how deep they need to be.
In level areas such as the Red River Valley RTK accuracy level GPS equipment can be used for land leveling operations or for creating correct drainage channels on what otherwise looks like level land.
Some of the most productive soils in the glacial till areas of the northern plains are in the lower lying areas of fields. Only if water can be managed properly on these soils can maximum productivity be attained on a consistent basis.
How do we measure the results?
This is the area where yield mapping equipment can really open your eyes as to what has happened in your fields and how your applied management practices are working.
Yield mapping a field will tell you not only where the yields levels came from that created your field average but can also tell you what is working for you and what isn’t. Most producers are surprised to see how high some areas of a field can yield and how low some areas produce without much visual difference in the crop from the combine window! As you see what some areas can do it becomes hard to not question what is happening in the rest of the field. You start looking for the items that limited yield in these areas so that you can learn which items are manageable and start applying practices that will improve lagging areas and ensure that productive areas are really at maximum productivity.
It is a good practice to try different fertility applications on a crop or apply/not apply crop protectants or try different varieties so that you can use the yield mapping process to show you what worked best and help you plan to make better management decisions on future crops. This allows you to perform your own experiments on your own farm with your equipment and in your soils and weather conditions TODAY! Then you can use this information along with published information relating to what you are experimenting on and better your farming operation faster.
What economic and other benefits are possible?
A good site-specific farming plan should allow you to manage each area or zone in a field as if it was a field in itself while still allowing you to farm the field as a whole unit to maintain efficiency of equipment, time and labor resources.
Some specific benefits producers can achieve are:
Higher yields in each defined zone that bring up the field average.
Less waste of costly inputs on areas that don’t require the "average" rate.
The ability to apply more than average levels of inputs specifically to highest productivity areas for greater yield.
Creating site-specific prescriptions on each field will force you to plan ahead and give you the benefit of knowing how much of each input you will need to take advantage of early buyer purchase programs.
With site-specific farming you can send others involved in your operation out to do a crop application and know that the product to be applied will be applied according to your previously thought out plan in the areas that you want and at the rates that you meant to apply. You will also get a recording of what actually happened during the application and when it occurred. Very good information to have especially during crop protectant applications.
You can manually insert check strips and do experiments in a field and have it all recorded for later observation and analysis. No more field flags and hand drawings in a field notebook. Find out what really works for you on your farm!
Most producers find that their crop input costs do not change greatly up or down but they are now applying the inputs they are buying where they will bring the most return. This results in the best net return on the investment in your growing crop and the most net dollars in your pocket.
One of the biggest benefits is the greater yields that are possible by not farming by the averages. By applying inputs to reach maximum yield for each area in a field and not the field as a whole you are no longer shortchanging high productivity areas and not wasting expensive inputs on areas that do not make good use of those inputs.
What equipment does the producer need to apply site-specific technology on their farm?
You will need only a few items to apply this technology on your farm.
GPS receiver:
If you don’t already have a GPS receiver capable of sub-meter accuracy you will need to acquire one. The GPS receiver gives the rest of your site-specific equipment a latitude/longitude location signal along with date/time and usually elevation. The location signal can also be used to calculate ground speed. This enables you to record where you are when you are doing something and return to that area later to review results.
Many good GPS receivers are available on the market today. You will find that many are now packaged with a guidance system. The guidance system can be used to reduce crop input wasting overlap losses and will give you more use out of your dollars spent on this equipment throughout the farming season.
Data Recorder/Application controller:
This device is the heart of your site-specific equipment. This device is really a small computer not much different than the one in your home. This device will hook to your GPS for the necessary location signal and to your product controller, yield monitor, etc. to record information as it happens in your field and to run prescription maps (your field application plans) that tell an application controller whether to be on or off and what rate of product to apply in a specific area of a field. The unit also usually includes some kind of removable data card so that you can transfer data quickly and easily to a standard home computer.
Product Controller:
This is the part of the system that actually does the work of running the application equipment. A typical example would be a Raven 440 spray controller. This part of the system will actually operate the on/off valves, flow valves, hydraulic valves or motors etc to get the products applied on your field. Not all controllers will hookup to other site-specific equipment. This item usually will need to have a computer compatible data port either on the controller or in the units wiring harness.
Yield Mapping system:
This is really more of a function than a certain piece of equipment in some cases. It involves hooking a data recorder to grain flow and moisture sensors on the combine so that yield data can be displayed and recorded for future use.
Note that only a Yield MAPPING system can actually record data second by second based on GPS location to give you a map of what happened in each part of your field.
A Yield Monitoring system only displays the instant yield and moisture as you combine the field and then gives you an average of the field when you finish. Nothing is recorded on a data card for future reference and none of the information is referenced to GPS location. Many combines are now equipped from the factory with a yield monitoring system that can be easily upgraded to a yield Mapping system by adding a GPS receiver and a data recording device.
Yield Mapping systems can also be installed on most combines built in the last 20 years.
Note that today’s equipment offerings are starting to combine many of the functions listed above into "one screen" solutions. This is a good advancement in the industry as you do not have to deal with as many boxes, wiring harnesses, software and the general cab clutter of a few years ago.
Another recent offering is the Auto steering systems now available from many manufacturers. These systems are starting to come down in cost and can provide many benefits to the producer. You can place a less experienced operator in a tractor and still get a straight field with a minimum of overlap. The operator will be less fatigued on a long day and will be able to better monitor equipment operation which will hopefully result in better results in your field.
What are the steps to get started applying site-specific technology on your farm?
As you have seen above there are really only a few electronic and mechanical components required to actually do site-specific management of fields. The biggest questions on every producers mind though is usually where do I start and how am I going to learn enough about this new technology to put it to profitable use on my farm.
We have found that a systems approach usually works best. This means that you need to look at the crops you grow, the soil that your grow them on, your farming system, the equipment that you get your field operations done with, and who is going to actually do the site-specific practices.
First you need to determine what areas of your field management would benefit most from site-specific technology. Generally I have noticed that most producers start with fertility management.
Then you need to decide how much of your farm to incorporate these practices on. If you start too small it is difficult to justify the equipment purchases and if you tackle the whole farm at once it may be too much of a management change to do at once.
Then it needs to be decided what parts of the technology you will do yourself (especially at first) and what parts may be hired from others. Some examples would be custom variable rate fertilizer application and custom harvesting with a yield mapping system. These decisions will be influenced by the equipment you currently have and what needs to be added or changed to use site-specific technology.
What further steps are needed to fully implement site-specific technology?
To fully implement site-specific practices across your farm over a period of time it is recommended that you do as many of these practices yourself as practical. We see most producers that are moving forward with this technology purchasing their own GPS equipment, application controllers, product controllers, and yield mapping equipment so that they have control over the cost and quality of their site-specific production system.
An approach where the producer looks ahead over a period of years at their planned equipment purchases so that their whole farming operation can eventually benefit from site-specific technology is best.
The 80/20 rule works here as it does in many other decisions. You want to first purchase the equipment that will allow you to implement the site-specific farming practices that give you the biggest immediate benefit. Then fill in with the rest of what you need to get the complete system in operation as time and money allow.
What resources can you use to make implementing this technology easier and faster?
There are several good sources of information on various pieces of the site-specific farming system.
Your university research system is constantly doing work to find methods and practices that are proven to benefit you in your operation.
A good, properly trained site-specific equipment provider can provide specific information about what equipment of theirs will meet your needs and can provide the service to make sure that it will function as promised.
A good crop consultant or agronomist can assist you in selecting the best management practices to use so that you benefit the most from applying site-specific technology on your farm.
A site-specific farming consulting / data processing center such as TotalCrop Farming Systems can help you wade through all of the data that comes from site-specific farming and help you turn that data into management usable knowledge. This also will allow you to spring forward with your site-specific plans without having to learn about GIS software or how to manage and take care of your important information. A good site-specific consultant will give you a helping hand in integrating site-specific technology into your farming operation seamlessly.
Summary:
In conclusion site-specific farming is not just a new practice or piece of equipment. It is really a new, advanced level of farm management that uses the best of agronomic practices and applies them specifically to each area of a field as needed automatically by utilizing today’s advanced ag technology equipment.