The clayey soil it is generally fertile, but difficult to cultivate. This depends on the very fine size of the particles that compose it, making it poorly oxygenated and even less drained. To recognize a soil of this type, compress a bit of earth between the index and thumb of a hand: if it keeps the same shape as if it were plasticine, it is certainly a clayey soil.
Clayey soil: what to do?
The clayey soil it is difficult to cultivate because, despite being as we said fertile and good retainer for water, when it dries in the summer sun it becomes very hard, it cracks deeply and loses moisture (which usually retains quite well) even in the most deep.
To make a garden characterized by clayey soil it is necessary to amend it, that is to correct the composition of the soil by adding more soil of a different type. Which is not easy because in the case of the clayey soil large quantities of organic matter and sand are usually required.
The sand serves to improve drainage, while the addition of organic material rich in fibers prevents excessive cohesion of the particles and the formation of hard blocks (such as clay bricks). As an organic substance to correct a clayey soil compost, dry leaves, well-seasoned manure and peat are fine.
The clayey soil it is characteristic of many areas of Italy, but farmers are almost always able to transform it into an excellent fertile medium-textured soil with proper autumn manure and proper agricultural use (which also includes periodic resting years).
The opposite of clayey soil it is sandy soil, which has no cohesion and where the water never stops, often leaving the roots dry. In this case, the soil amendment consists in adding only organic material, for example manure and compost.
After the physical characteristics (clayey soil, sandy, loamy, peaty, humiferous) of the soil, the pH should be assessed, also possibly 'amendable' with 'plastering' (if too alkaline) or 'liming' if too acidic. A land can be:
- neutral (pH between 6.8 and 7.3);
- subacid (6-6.8);
- acid (5-6);
- strongly acidic (less than 5);
- weakly alkaline (7.3-8);
- alkaline (8-8.5);
- strongly alkaline (more than 8.5).
To measure the pH of the soil with a simpler and almost always more accurate system than the old litmus papers you can use this Analog soil pH meter