Are light autonomous robots the answer to soil compaction?

Soil compaction has become a major issue in crop farming in recent years. Saving soils is a hot topic all over the world. The differences in yields, depending on good or bad soil management, can equate to 10-15%.

No wonder farmers all over the world are applying new technologies in order to minimise soil compaction, such as utomated path planning and accurate guidance. Lightweight autonomous vehicles could also be the answer. We asked Topcon 5 questions about soil compaction and what famers can do to minimise it. Brady Bjornson, senior product manager at Topcon Agriculture provides answers.

Has Topcon collected and analysed data from fields that shows the impact of soil compaction?

“Many extensive studies have demonstrated the impact of compaction on yield and farm profitability, indicating that soil compaction can reduce farm production efficiency by increasing the costs of production whilst simultaneously reducing crop yield. In fact, research in the UK suggests that avoiding soil compaction can actually increase gross margins by more than USD 132 per hectare.

Farmers don’t really know how much compaction they do or don’t have on their farm, or its yield limiting affects

“The reason compaction is considered a silent thief when it comes to crop yield is because farmers don’t really know how much compaction they do or don’t have on their farm, or its yield limiting affects. Differing soil types also contribute as they can cause different levels of compaction – wet clay soils cause the most extreme forms of compaction, while sandy soils cause the least.

This is due primarily to soil particle size, as smaller particle sizes tend to compact more than large ones. The best way to determine if you have any compaction layers or how deep those layers may be is to use a penetrometer. This tool will allow a grower to gauge where compaction is, how much force is required to penetrate it, and at what depth that layer starts.”

How and with what data can farmers themselves map soil compaction on their fields?

“When it comes to farmers mapping soil compaction themselves, tools like Topcon’s Tillage Depth Control (TDC) system enables growers to map where their tillage tools are not hitting their target depth. Many TDC systems currently on the market do not account for actual field conditions the way Topcon’s ultra-sonics sensors do in this TDC application. With these other systems, the tool is assumed to be controlling to a depth, but you have no way of telling if it actually is.

The rotary hall sensors and cylinder transducers are calibrated based on ideal conditions, whereas the Topcon ultra-sonics sensor used in TDC provides feedback in real-time to make adjustments to the tillage depth. This capability is what keeps Topcon’s TDC absolutely accurate in adverse field conditions where tillage tools sink in wet soil or ride up in dry soil.

With disc ripping increasing globally, TDC lends itself to these applications quite readily to ensure the disc ripper can get underneath the compaction layer, lift the compaction layer up, and break it up to allow the crop roots to access more moisture and nutrients lower in the soil profile. Shallow plow pan layers stunt root and crop growth as well as increase root disease issues due lack of soil moisture percolation.”

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Heavy machinery causes soil compaction. But smaller, autonomous vehicles can not be applied everywhere, says Topcon’s Brady Bjornson: “When you take farming at scale, like you see in parts of North America, 1,000 acre fields are the norm and thus larger machines are necessary, with the same level of autonomy.” – Photo: Topcon

Which technologies can farmers already apply to minimise soil compaction in Topcon’s vision?

“At present, the best technology tool that can minimise compaction is accurate guidance along with Controlled Traffic Farming (CTF). CTF paired with good farming practices such as avoiding doing tillage in wet soils, implementing a Tyre Pressure Monitoring System (TPMS), investing in tracked equipment, and better planning of cropping activities can dramatically decrease the effects of compaction in a field. Techniques such as CTF and using tramlines relies on pairing up your implements to common widths to only compact very specific parts of the field, leaving the rest of the field untouched.

For example, in the US its common to see this with base 30’ or base 40’ implements. This attempts to best match up planter, sprayer, and combine widths to drive on one single path. This matches up with 90’ and 120’ sprayer booms well with three passes of the planter or combine per one pass with the sprayer.”

Which new technological developments will help farmers to prevent soil compaction in the future?

“As soil compaction prevention technology continues to develop, we’ll begin to see elements like automated path planning, which is common in sugar cane fields, become more prevalent. Utilising geo-positioning systems and sensors that detect nutrients and water in soil enables machinery to make decisions about what to plant, when to fertilise, and how much to irrigate. Using this technology enables farmers to have greater data acquisition and interpretation abilities. This data then gets turned into information, and this information gets turned into decisions helping farmers to better manage their land.”

Some researchers believe that the ever-growing machines and tractors should end. They believe in small, light autonomous robots that hardly damage the soil. How does Topcon view this development?

“Here at Topcon, we produce solutions for both scales of operations, and both have distinct applications in which they work best. When it comes to areas where size and distance between fields isn’t far, smaller, lighter machines make sense in order to mitigate any soil compaction risk, but these fields are typically in more heavily populated regions of the world.

When you take farming at scale, like you see in parts of North America – The Dakotas, Western MN, MT and the Canadian Prairie Provinces – 1,000 acre fields are the norm and thus larger machines are necessary, with the same level of autonomy.

The same notions of productivity and covering acres/hour are the same in both settings. Smaller machines are in contact with more ground creating less compactions whereas larger machines heavily compact a smaller area but are more gentle over the total covered surface, so it’s important to have the right solution for the area in which you are working. Both small and large machines have their pros/cons and it is up to the grower to determine what is right for them and their operation. Regardless of the growers choice, Topcon Agriculture produces autonomy, guidance, telemetry, and rate/section control solutions for both kinds of operators.”

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