Services
Sap, leaf, soil, water, reserve and kernel testing, and integrated pest management, for pecan orchards and other irrigated crops. Sampling goes where the satellite shows a block changing, and every result is tied to the irrigation or fertilizer event it followed.
Five layers of one orchard
One orchard and five of the layers its report is built from: greenness, leaf response and the water signal from the satellite, the terrain from LiDAR, and the zones they add up to. Move the lens over the block, switch layers and open the three sample sites.
Under the lens: Zone: middle
Sample site · higher zoneThe higher zone covers 45% of the block. Field samples for this zone are taken here.
Sample site · lower zoneThe lower zone covers 20% of the block. Field samples for this zone are taken here.
Sample site · middle zoneThe middle zone covers 35% of the block. Field samples for this zone are taken here.
Keyboard: with the map selected, the arrow keys move the lens; Tab reaches the three sample sites.
An aerial photo of one orchard, and five of the layers its report is built from. Gold pins mark the three sample sites. Move the mouse over the map: the tag under the lens names the zone.Tap a layer above, or a point on the map to see its zone. Every layer is real data.
USDA NAIP aerial photo · Sentinel-2 · USGS LiDAR · 13 measures per 20 m square for the zones
How a sample plan is made
- 1
Imagery every 14 days
Multispectral satellite images of each block, March 15 to October 15, checked every 14 days. Cloudy images are skipped until the next clear one.
- 2
Find what changed
Each image is compared with the last one and with the block’s irrigation, fertilizer and lab records.
- 3
A GPS sample plan
A few fixed sites that cover every part of the block, plus the spots that changed, with GPS points so the next visit returns to the same trees.
- 4
Field and lab checks narrow the cause
Imagery shows a pattern, not a cause. The visit and the sap, leaf, soil or water tests help tell the possible causes apart before anything changes in the program.
- 5
A decision for the block
Irrigation timing, fertilizer adjustments and the next follow-up, written for that block.
- Farm
- Orchard
- Block ID
- Date
- Irrigation event
- Pre-irrigation moisture
- Fertilizer input
- Post-irrigation sap
- Satellite observation
- Harvest quality
75%
66%
60%
In 12 days, 75% of one field’s area fell more than the rest of the block; two other fields, 66% and 60%. That is image area, not stressed trees or lost yield: it is a reason to visit.
Sentinel-2 NDMI, a signal related to water in the canopy
A field note, as the grower gets it
Three signals pointed at the same corner of one block. Before anyone says why, the photos from other years are checked and the visit decides.
The site
- IrrigationIt is the high part: water may arrive late or in smaller amounts.
- Older trees, sparse canopyWith less canopy, more soil shows, and soil reads hotter and drier.
- In a corner6 m from the edge, the satellite square can mix the field border and the road.
Reading a green pixel · Orchard F
From 10% to 97% green cover within 60 m
Drag across the square. A satellite square mixes canopy, cover crop and bare ground. Before reading a low value as stress, the field’s cover and management are checked.
USDA NAIP aerial photo, 30 cm pixels
Every 14 days, all season
An example: one orchard, 36 usable satellite images from early March to late September, played in order. The dashed line is the same block the year before: this season it greened up about two weeks earlier. Any part of a block that falls behind shows up between visits.
Mean NDVI of the block, one dot per usable image. Sentinel-2, 10 m squares. Cloudy dates are skipped, never filled in. Dashed: the same block the year before.
How sample sites are chosen
We choose a few fixed sites that, together, stand for every part of the block: high and low ground, different soils, dense and sparse canopy, parts that green up early and parts that lag. Sites picked at random can miss half of that.
Technical note
The method is conditioned Latin hypercube sampling (cLHS). Terrain and slope (USGS LiDAR), canopy (aerial photo) and eight years of satellite signal (NDVI, NDRE, NDMI) are each split into ranges with the same number of 20 m squares, and the sites are chosen so that every range of every layer is sampled. The soil map is used as well.
See the illustration: five sites, chosen two ways
Across: ground height, lower to higher. Up: canopy, sparse to dense.
All six layers, five ranges each
- Ground height
- Slope
- Canopy cover
- Greenness over 8 years
- Leaf response
- Water signal
- Ground height
- Slope
- Canopy cover
- Greenness over 8 years
- Leaf response
- Water signal
Every range of every layer gets a sample.
Several ranges get no sample: parts of the block are never checked.
An illustration with made-up dots, not field data. Each dot stands for a square of a block. The chart draws two of the layers and the list adds the other four; gold marks the ranges that get a sample.
A few samples, the whole block
A handful of sites stand for every part of the block, so a few lab samples speak for all of it.
Fixed sites
The same GPS points at every visit, so each result can be compared with the last one.
Plus what the satellite flags
Sites where the block is changing this season are added, each with a comparison site nearby.
What we test, and when
The 2027 program. Field sampling follows your real irrigation and fertilizer events, so those dates move with your schedule; results are reported in seven monthly periods, mid-March to mid-October.
| # | Test | When | What it tells you |
|---|---|---|---|
| 1 | Satellite imagery | Every 14 days, Mar 15 – Oct 15 | Where the canopy changed. |
| 2 | Soil moisture | Before each irrigation, Mar – Oct | Whether the root zone needs water yet. |
| 3 | Sap NO3-N, K, Ca, Na, pH, EC | After each irrigation, Mar – Oct | What the tree is taking up now. |
| 4 | Fertilizer input | Every application or batch, Mar – Oct | That what went in matches the plan. |
| 5 | Leaf tissue | Twice: once in July, once in August | Season-long nutrient status. |
| 6 | Irrigation water | Every irrigation, or when the source changes | Salinity, sodium and pH. |
| 7 | Carbohydrate reserves | Late Aug, mid-Oct and dormancy | What the tree stored for next year. |
| 8 | Soil chemistry | After harvest and before budbreak | The baseline for next season. |
| 9 | Soil biology | Nov – Dec and Feb – Mar | Biological activity in the root zone. |
| 10 | Kernel quality | At harvest | Size, moisture, kernel percentage, quality. |
Each test, when it is taken and what it tells you. The pecan year, month by month
Tests and dates: the 2027 program. Tree stages: typical for Southern New Mexico and West Texas.
A drop of sap on the meter. Each reading is tied to the irrigation it follows.
Leaves and nuts, checked on the tree. Size, color and spots point to what the lab should test.
Flowers under a hand lens. Bloom stage and early damage show up here first.
A nut opened on the bench. Size, moisture and kernel percentage are checked at harvest.
Records for conservation programs
Our field and laboratory records can support a grower’s conversation about conservation goals. NRCS makes every eligibility, practice, contract and funding decision.
What the records include
- Georeferenced samplingGPS sample points, dates, block IDs, sample custody and repeat visits, linked to what the imagery showed.
- Water and nutrient recordsWell conditions, delivery, soil moisture, irrigation timing, water chemistry, soil, sap and leaf trends.
- Reviewable reportsTraceable lab results, imagery snapshots and recommendations a planner can follow.