Composts

fertilizers obtained through the decomposition of various organic substances by microorganisms.

Composting increases the content of the nutrient elements (nitrogen, phosphorus, potassium) available to plants in the organic mass; renders harmless any pathogenic microflora and helminth eggs contained in the fertilizer; reduces the amount of cellulose, hemicellulose, and pectinic substances, which change the soluble forms of nitrogen and phosphorus in the soil to less assimilable organic forms; and loosens the fertilizer, making it easier to apply to the soil.

The basic materials used in preparing composts are livestock manure, peat, liquid manure, poultry manure, flax and hemp roughage, leaves, sunflower stalks, corn stumps, unusable feeds, urban trash, fecal matter, sewage sediments, and the waste products of leather plants and slaughterhouses. Common types of composts are peat-manure (the ratio of components is 1: 0.25–1), peat-liquid-manure and peat-fecal-matter (1: 0.5–1), manure-soil (up to 30 percent soil), and manure-phosphorite (1–2 percent phosphorite meal).

Composts are used for all crops in about the same doses as manure (15–40 tons per hectare). They are applied to fallow land, before autumn plowing and replowing, and in the seed holes when planting seedlings. In terms of fertilizing properties, composts are as good as manure, and some types, such as peat-manure composts with phosphorite meal, are superior.