Is it time to re-think our love-affair with tractors?

Tuesday, 10 July 2018

Tractors have been a staple of the British countryside since the first world war but will we soon be seeing swarms of small robots running through fields, rather than our traditional machinery?

Better mechanisation of farming and the introduction of more modern tractors into the agricultural sector in the 1950s resulted in a significant increase in productivity on farms.

With the gradual loss of skilled labour across the agricultural and horticultural sectors, tractors have grown steadily larger, with greater horsepower, to offset these shortages.

So while there is no-doubt tractors have transformed the sector, experts speaking at the Agricultural and Innovation Conference and Exhibition at Harper Adams University in July this year argued that they are now too big and are having a negative impact on farming.

Soil Health

Large tractors, quite obviously, are very heavy, with 600hp tractors weighing around 27 tonnes. Used in marginal conditions often found in the UK, this weight is causing soil compaction which is detrimental to soil health and can cause problems like water and nutrient run-off. While precision farming techniques CTF (controlled traffic farming) is designed to reduce this compaction, could the answer be to move to smaller, lighter automated tractors or robots?

Clive Blacker, CEO of Precision Decisions, believes the modern tractor has also reduced our knowledge of soils. Blacker described his theory of the seat-soil relationship as a result of taller modern cabs: “The further you are away from the soil, the less you are paying attention to it.”

Precision and Data

Another challenge is the width of tramline. Sprayer and fertiliser spreaders are, as yet, unable to vary the application rate across the tramline width so the resolution and therefore the ability to treat the field more variably is being lost. Even yield maps from 12-meter cut combines may not pick out differences in yield to better inform the grower of in-field variances.

With increasing costs, product availability and environmental pressures around these inputs, it makes sense to be thinking differently about how we treat our fields. As Blacker explains: “Because of tractors, we currently treat the whole field, not the diseased or affected crop. You wouldn’t treat your whole body with a cream for a sore on your arm.”

So if size and working width of tractors, drills and sprayers are considered to be causing the problem on farm, what is the alternative?

Several presenters at the conference believe that light-weight nimble machines or swarms of small autonomous tractors could very well be a reality on our fields in the not-so-distant future.

Owen Kinch, Field Research Manager for DOT Technology Crop believes small nimble machines have several benefits: they cause less soil compaction as they’re lighter; provide greater precision and control with less overlapping of applied products; require less horsepower per acre; and if used autonomously or monitored remotely, have lower labour requirements and costs.

© See Dot Run

An additional benefit may be price. With new fancy machines costing in-excess of £500,000, they aren’t cheap. Sam Watson Jones, founder of the Small Robot Company argued that he considers farmers to be trapped in a cycle of investment: “With prices going up by 10 per cent every year, farmers aren’t seeing the same return in profits.”

Kinch believes these smaller units will require significantly less overall capital investment, and be much easier to scale up and down to your farm’s need. However there may be challenges to overcome with smaller units, like how they deal with tall broad-acre crops like oil-seed rape.

The Hands Free Hectare project, delivered in collaboration with Harper Adams and Precision Decision and funded in its second year by AHDB, developed their autonomous tractor to prove that the reality of small robots in fields is closer than we think. Kit Franklin, from the Hands Free Hectare Project, said: “We automated a small 38HP tractor in the project as we believe small robots are the future, and this project was designed to show just how close that reality is.”

© Hands Free Hectare

So what is next after the success of the Hands Free Project? What is the future for automated broad-acre growing? Harry Henderson, AHDB’s Technical Knowledge Exchange Manager, argues: “We need to now be thinking completely differently about the machines we are using in the field to prevent soil damage. New technology should be developed that treats the individual plant, or targets the weed, rather than covering the whole field. I would also like to see more investment in precision planting, not only in spacing but also in depth and live response to soil condition”

AHDB was the primary sponsor for The Agricultural Innovation Conference and Exhibition, held 3 July 2018 at Harper Adams University. Experts Harry Henderson and Gracie Emeny hosted round-table discussions as part of AHDB’s SmartHort and Precision Farming activity to help drive innovation in automation and robots for the industry.

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