C-DRONE GUIDE · 16 SEPTEMBER 2026

Agroforestry and Drones: Counting Trees, Measuring the Effect on Crops, PAC Tree Density, Price

A row of walnut trees between two strips of wheat, an orchard-and-vegetable system bordering arable land, a plot planted under France 2030's "1 billion trees" scheme: intra-plot agroforestry is expanding in France, driven by the CAP eco-scheme and by a potential the French energy and environment agency ADEME estimates at 400,000 additional hectares of agroforestry plots by 2030. How many trees on the plot, what spacing, what effect on the crop growing between the rows — harmful shade, or a beneficial microclimate? Here is what a drone survey objectively documents on an agroforestry plot, what a recent study measured that was unexpected, and why it never settles CAP eligibility on its own.

Published on 16 September 2026, reviewed on 16 September 2026 — regulations in force as of September 2026.

What a drone survey documents on an agroforestry plot: tree count, row geometry, canopy height

Unlike a hedgerow bordering a plot, intra-plot agroforestry plants trees inside the cultivated area itself — in single rows or strips, spaced several dozen metres apart, leaving room for a crop or grazing livestock between the rows. That geometry changes what the survey is for: it is no longer about tracking a boundary line, as for a hedgerow, but about counting and positioning each tree inside the cultivated plot itself.

A high-resolution orthophoto and a photogrammetric canopy height model make it possible to count trees one by one — at planting as well as during a survival count, on the same principle as for tree counting in an orchard — to check actual spacing between trees and between rows against the planting plan, and to measure each tree's canopy height and crown volume. A study by Matthias Wengert and co-authors, published in 2021 in Remote Sensing, tested a related approach on three German silvoarable agroforestry plots: using UAV RGB and multispectral imagery, a random forest model predicted the dry biomass of barley grown between the rows (R² = 0.62) and, with markedly higher accuracy, its leaf area index (R² = 0.92) (see the study on Google Scholar). In other words: a drone-mounted camera objectifies the state of both the trees and the intercropped culture, on the same plot and in the same flight.

The effect of the tree on the neighbouring crop: what a 2026 study measured, and what it does not let you generalise

The most common fear about agroforestry is competition: the tree would shade the crop and take up water and nutrients at its expense. A study by T. Kunzmann, C. Neumann and N. Koellner, published in 2026 in the journal Agroforestry Systems, tested that hypothesis using multispectral UAV imagery on a strip-based agroforestry system planted with maize in eastern Germany: the NDVI vegetation index and crop height were measured as a function of distance from the tree rows. The unexpected result: NDVI rose markedly close to the trees, and that rise was correlated with the height of the trees themselves (see the study on Google Scholar) — the opposite of a pure competition effect, and more a sign of a favourable local microclimate (reduced wind, humidity, organic matter) close to the tree lines.

This result deserves nuance before generalising it to a French farm. The study covers a single crop (maize), a single climate (continental Germany) and a single strip configuration; the measured effect could reverse with a dense-canopy species, a crop more sensitive to shading, or a Mediterranean climate where water availability limits growth more than light does, making root competition matter more. That is exactly what a drone survey repeated over several seasons lets you check for a given plot: comparing crop vigour by distance band from the trees, year after year, rather than trusting a result obtained elsewhere and on a different species.

The central honesty point: what a drone count never settles — PAC tree density, eligibility, young plantations

Intra-plot agroforestry has its own regulatory history, distinct from that of hedgerows. Recognised as eligible for CAP support from 2006 up to a cap of 50 trees per hectare (excluding hedges), agroforestry plots saw that threshold raised in 2010 to 100 trees per hectare for first-pillar support, and to 200 trees per hectare for second-pillar support. Under the 2023-2027 CAP, that 100-trees-per-hectare cap remains the benchmark for an agroforestry plot to keep its eligibility for decoupled aid, while maintaining hedges, isolated or aligned trees and copses — agroecological infrastructure, or IAE — now feeds into the eco-scheme calculation: 7% IAE on eligible utilised agricultural area unlocks the base level, 10% the higher level.

The honesty point. A drone count, however precise, declares nothing: it produces supporting data — tree count, geometry, height — that the farmer or their adviser then feeds into their Telepac declaration, under their own responsibility. Classifying a row of trees as a hedge, agroforestry or a copse, like any compliance check, is a matter for the departmental agriculture authority (DDT) and the payment agency (ASP), never for an aerial survey. Nor does a drone measure the underground root competition between tree and crop, invisible from the sky, or the eventual timber value of the trees planted. Finally, for a recent planting — those under France 2030's "1 billion trees" scheme in particular — a count taken too soon after planting can overstate survival: a good share of a young tree's mortality only shows up after a full growing cycle, a trap already documented for counting missing vines in a drone-surveyed vineyard replanting.

Who commissions this survey, the combined method, and 2026 prices

Driven since December 2015 by a national development plan structured around 5 strands and 23 actions, and by France 2030's goal of planting a billion trees in an agricultural context, agroforestry development speaks to several audiences: farmers committed to a silvoarable or silvopastoral project, on their own or supported by their local chamber of agriculture to build the CAP file, cooperatives and agri-environmental consultancies following several farms, and local authorities running territorial planting programmes. In every case, the drone documents the plot; it never commits the regulatory declaration on its own, which stays the farmer's responsibility.

The most robust method combines a baseline flight at planting — initial count, geo-referencing of each tree — followed by one or two annual monitoring flights comparing survival, growth and the vigour of the intercropped culture by distance band from the rows, on the model already used for multispectral vineyard monitoring.

Ranges observed in France in 2026, excluding VAT:

These missions form part of our precision agriculture by drone service, alongside water stress monitoring and our comparison of drones versus satellites for precision agriculture. The regulatory information on this page reflects the rules in force in September 2026. To price monitoring for your agroforestry plot, request a quote stating the area, the number of trees planted and how long ago they were planted.

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