For every GVF participant: one visit, at harvest
Download as PDF · For researchers: SVH-2: What Researchers Measure
GVF asks one question: does the crop do better near vetiver than farther away? You answer it by looking at the same crop at fixed distances from your vetiver, and writing down what you see and harvest. It takes one visit, at harvest.
1. Where to measure
- Start point: the edge of the hedge. For a single plant, start at its center.
- Both sides: Side 1 is upslope (or above, or inside a block); Side 2 is downslope (below, or outside).
- Distances: 0 (the edge), 2, 5, 10, 15 and 20 m. If the next hedge or plant is less than 40 m away, stop at the mid-point between them (M) and record it as the last point.
- Sample: at every point use the same small sample, for example 3 plants, 1 m of row, or 1 m², and write down what you used (B01).
- Tree crops (coffee, citrus, avocado, banana and others): record tree by tree, noting where each tree stands (Side 1, Side 2 or mid-point) and its age and variety.
2. What to record at each point
| Code | What to record | How |
|---|---|---|
| B10 | Crop vigor | Score 1–5 (1 very poor … 5 excellent) |
| B11 | Harvest from the sample | Weigh or count the same sample at each point (unit in B03) |
| B12 | Pest damage | Score 0–3 (0 none … 3 severe); name the pest, e.g. stem borer |
| B13 | Root galling (nematodes) | Dig up 3 plants; score 0–3 |
| B14 | Striga or other parasitic weed | Plants per m² |
| B15 | Termite damage | Score 0–3 |
| B16 | Soil crumbles | Score 1–5 (1 hard clods … 5 crumbles easily) |
| B17 | Soil darker? | Yes / No, compared with the last point |
3. Also record
- About the site: farm model, crop and variety, hedge age, plant spacing in the hedge, gaps, and how the hedge is cut (and whether cuttings go to mulch, thatch or are left).
- Anything that differs along the gradient: manure, compost or fertilizer placed near the hedge, or parts of the field managed differently. This matters: it can make the hedge look better or worse than it is.
- Photos: up to six, including one that shows the near and far difference.
- In your own words (D01): anything you noticed near and far from the hedge, including where water ran during heavy storms, dry patches, and whether the crop stayed greener near the hedge in a dry spell. Optional: where the crop wilted first.
4. What you may see
- Annual crops on older contour hedges: often the best crop is just above the hedge, where soil and water collect, and a weaker strip is just below it. That is soil moved within the field over the years, not harm from the vetiver. The average across the whole strip shows the net benefit.
- Right at the hedge edge: the crop can be a little poorer, especially in dry years or if the hedge is tall and uncut. This is normal.
- Tree crops among closely spaced hedges: the benefit is usually more even across the strip, and shows as healthier trees, steadier yields and less fruit drop in dry spells.
- Other signs worth noting: fewer dead hearts from stem borers, less root galling, darker and more crumbly soil, and mulch from the hedge keeping the soil moist.
These are things to look for, not results we promise. SVH-1 shows the combined effect; working out the causes is the job of SVH-2 researchers.
5. Tips
- Leave a box blank if you did not check it; 0 means you checked and found none.
- Honest estimates are welcome: a farmer’s estimate stated plainly is better than false precision.
- If you have a similar field nearby without vetiver, say so (D02). It makes your result much more useful.
Back to the GVF page · Register: vetiver.org/gvf-register · Questions: [email protected]