| Aggregates |
“Clumps” in the soil; see soil structure definition. |
| Clay |
Smallest particle in soil; has high nutrient holding capacity. |
| Compost |
A type of organic matter that builds soil structure and assists in retaining moisture and nutrients. |
| Cover cropping |
Crop used to benefit the soil rather than the main crop species. |
| Fertilizer analysis |
N-P-K content of a bag of fertilizer; shown in percentages by weight. |
| Granular aggregation |
Interaction of small soil aggregates; it is important to have a mixture of large and small holes between the aggregates to allow for water and gas exchange. |
| Green manure |
Crop grown to purposefully be tilled back into the soil to increase the organic matter (and thus change the soil structure); can also smother weeds. |
| Humus |
Sticky material made from organic matter that helps bind soil particles together into aggregates; can absorb and hold up to 6x its weight in water, releases nitrogen, and holds positively charged cations for plant growth. |
| Nitrogen (N) |
One of the most important elements for plant growth (by quantity); a key element found in protein. |
| Organic molecule |
Chemical compound associated with living organisms that contain carbon atoms. |
| Organic material/matter |
Material that has come from a recently living organism (such as plants) that may be partially or fully decomposed. |
| Phosphorus (P) |
One of the most important elements for plant growth (by quantity); a key component in energy transfer molecules like ATP and as part of the DNA backbone. |
| Potassium (K) |
One of the most important elements for plant growth (by quantity); a key part of the mechanism for moving nutrients into and out of cells. |
| Sand |
Largest particle in soil; helps increase aeration. |
| Silt |
Particle of intermediate size in soil. |
| Soil compaction |
When the pore spaces between soil aggregates are compressed. |
| Soil organic matter |
Carbon-based plant, animal, and/or microbe tissues that are in the process of breaking down; increasing soil organic matter improves and stabilizes soil aggregation. |
| Soil structure |
The way in which the soil particles and other materials, like the organic matter in the soil, bind together into clumps. |
| Soil texture |
Relative proportion of sand, silt, and clay particles in the soil. |
| Tillage |
Process of incorporating the residue from the top of the soil into the soil; there are many types. |
