Types of Fertilizers

1. Organic fertilizers are primarily derived from organic matter and are considered the earliest type of fertilizer used in China. The most common examples include poultry and livestock manure such as chicken, sheep, and cow manure, as well as human waste; Next are green manures formed from the decomposition of crop stalks; then there are miscellaneous fertilizers formed from weeds in fields that wither and decompose into the soil, or from wood ash produced by burning, as well as silt from ponds and small streams. Additionally, by digging pits near fields and piling together rice straw, manure, urine, or household wastewater and food scraps, the resulting fertilizer—commonly known as “compost”—also falls under the category of organic fertilizers.
2. Inorganic fertilizers, often referred to simply as “chemical fertilizers,” are actually inorganic fertilizers, most of which are synthesized from inorganic compounds. Common types of inorganic fertilizers (chemical fertilizers) include single-component fertilizers, compound (mixed) fertilizers, controlled-release fertilizers, and water-soluble fertilizers.
3. Microbial fertilizers are increasingly being adopted by farmers. For example, certain probiotic fertilizers significantly enhance crop disease resistance; while nitrogen-fixing or rhizobium fertilizers help crop roots perform aerobic respiration more efficiently, supplying nutrients to stems and leaves and improving flowering and fruit-setting rates. Given the wide variety of microorganisms, there is considerable flexibility in selecting specific bacterial types and formulations; some farmers also refer to microbial fertilizers as biological bacterial fertilizers.