Glossary
Farming words,
explained plainly.
Every term used in the guides and tools has its own page: what it means, how it is measured, and where it shows up in a calculation.
Every term in the glossary, A to Z.
Select a tile
TGW, germination rate, seed rate, field emergence — the numbers that connect a seed bag to a plant count.
Showing 19 of 19 terms
A crop grown to protect and feed the soil rather than to be harvested.
A factor that scales reference evapotranspiration to one crop at one growth stage.
Growing different crops in sequence on the same field to manage soil, pests and disease.
The share of seeds that sprout under test conditions, printed on the seed label.
The water content of grain as a share of its weight. It decides when to harvest and how safely grain stores.
Heat accumulated above a crop base temperature, used to track development.
How these pages work
More than a definition.
Each term page is structured the same way, so you always know where to look.
Definition and body
What the term means in plain language, then a second paragraph explaining why it matters in practice — not just what it is, but when and why you encounter it.
Typical values
Range charts for terms that have one — TGW by crop, pH by crop — with the source and the region they apply to. Always labelled Typical range so you know it is a reference, not a prescription.
Live tool
Where the term feeds a calculation, a live tool sits on the page. Change an input and the result updates instantly — no page reload, no server call.
Sources and review date
Every factual claim links to where it came from — FAO technical papers, FAO Irrigation and Drainage Paper 56, FAO GAEZ crop data, or peer-reviewed agronomy journals. Each page carries a last-reviewed date and reviewer name.
Primary sources
Definitions grounded in agronomic science.
Fieldbook does not invent its own definitions. Terms are drawn from the same references used by agronomists and extension services — then restated in plain language with the calculation context that makes them useful.
Where definitions differ slightly between sources, Fieldbook states which interpretation it uses and why. The goal is clarity, not novelty.
The authoritative reference for ET₀, crop coefficients (Kc) and the Penman-Monteith equation. Used for water and climate terms.
fao.org ↗Crop temperature ranges, pH preferences and calendar windows for 2,500+ species. The primary source for crop requirement data.
gaez.fao.org ↗Global modelled soil properties (pH, texture, organic carbon). Used for soil term examples — always flagged as modelled estimates.
soilgrids.org ↗Authoritative pest and disease terminology from the European and Mediterranean Plant Protection Organisation.
gd.eppo.int ↗Common questions
About this glossary.
Why does every term have its own page?
Most glossaries give a one-line definition and stop. Fieldbook adds how the term is measured, where it appears in a calculation, typical values with their source, and links to related terms. The goal is that you leave the page able to use the concept, not just recognise it.
Where do the definitions come from?
Definitions are written in-house and tied to primary sources: FAO technical papers, the IPCC glossary of agronomic terms, peer-reviewed crop science references, and national extension service materials. Every page lists its sources and carries a last-reviewed date.
What is the difference between a "typical range" and a "calculated" figure?
"Typical range" is a commonly cited reference value — for example, the preferred soil pH for wheat across temperate climates. It comes from a cited source and applies to a stated region. "Calculated" is what a tool produces from your specific inputs. Fieldbook always labels which kind of number you are looking at, because the right advice for your field may differ from the general range.
Are the terms metric only?
All internal logic uses metric units (kg, ha, mm, °C). The display can switch to imperial equivalents (acres, lbs, bushels, °F) using the unit toggle. Volume conversions for grain — bushels per acre — are crop-specific, because a bushel weighs a different amount for each crop.
Can I suggest a term that is missing?
Yes — use the contact link at the bottom of this page. The glossary is deliberately narrow in V1 (the 19 terms that appear most often in tools and guides). More terms will be added as new crop pages are published.
How are the terms linked to the tools?
Each term page shows which growth stage it is used in and links directly to the relevant tool. For example, TGW links to the seed rate calculator; crop coefficient (Kc) links to the irrigation planner. Clicking a term from inside a tool explanation opens the term page without losing your tool inputs.