Costs can be slashed and crop yields increased
Hence the European Commissio’s conclusion that the size and diversity of farms in the EU make widespread adoption of ‘precision agriculture’ challenging.
The most successful example of precision agriculture (PA) on arable land is the use of Controlled Traffic Farming (CTF), which has been able to reduce machinery and input costs up to 75% in some cases, whilst also increasing crop yields.
In conventional farming, fertilisers and crop control substances are applied uniformly over fields, leading to over-application in some places and under-application in others. PA methods enable fertilisers to be spatially applied to optimise the application, using Variable Rate Application (VRA) methods .
The profitability of such methods is debatable, depending upon a range of factors.
The main benefits associated with CTF are increased profit and improved sustainability.
CTF aims to confine soil compaction to minimal areas of permanent traffic lanes, leaving 80-90% of the field area without compaction.
The aim is to reduce production costs and increase yields, while improving soil health and delivering other positive benefits to the environment.
A good example is seen in a 1,300 hectare (3,212 acres) farm in the UK, with soils mostly of clayey river alluvium, but some light clay over gypsum, cropping mostly oilseed rape and wheat.
Traditional minimum tillage was replaced by no-till on this farm.
CTF was conducted with RTK correction providing plus or minus 2cm accuracy and positioning.
Large savings are expected in fuel, capital investment, and power consumption on the farm.
The no-till practice is more risky without CTF methods (too much compaction), whilst benefits include a better weed control and inter-row cultivation , reduction in overlaps, reduction in machinery use, better crop establishment, improved soil health and reduced compaction damage.
With CTF, the new maximum tractor size is 350 instead of 550hp, contributing again to a cut in fixed costs.
Variable rate application (VRA) supplies crop inputs at a precise location.
Yield maps obtained with yield monitors on board machinery show the potential for this site-specific crop management, both from an economic and environmental perspective.
There are examples of success when using VRA methods, but other cases showed little increase in yields, and the effort in managing inputs can raise costs, leaving little profit incentive.
It is estimated that the economic gross advantage of site-specific management of nitrogen fertiliser in Germany is between 10 and 25/ha. Nitrogen efficiency improves by 10-15%, by reducing the application without impact on crop yield. Other studies in winter wheat and oil seed rape claimed larger benefits, of 48-83/ha, improving protein content, and reducing fuel use.
However, studies in Denmark claim that economic and statistical analyses over ten years showed no statistically significant economic advantage of sensor-based fertiliser application.
Other studies calculated profitability below 8/ha, which hardly covers the costs of application. However, it has been demonstrated that the economic margins of precision fertiliser applications increase with increasing fertiliser and crop prices.
In high-value crops, higher profitability can be achieved with quality-specific harvesting based on the sensing of the nutrient status of the crop canopy.
