Green manure is a farming practice used to improve soil fertility by planting certain crops that are later dug into the soil to add organic matter. The spelling of "green manure" is typically pronounced as /ɡriːn məˈnjʊər/ in IPA phonetic transcription, which reflects the pronunciation commonly used in English-speaking countries. The word "green" is pronounced with a long "e" sound, while the second syllable of "manure" is pronounced with a short "u" sound. Spelling accuracy is crucial for effective communication in any field, including agriculture.
Green manure refers to an agricultural technique where specific plants, typically leguminous crops, are grown and incorporated into the soil to enhance its fertility. It involves sowing and subsequently plowing or tilling the plants back into the soil before they reach their full maturity. This practice is commonly utilized in organic farming systems, where synthetic fertilizers are avoided, to improve soil quality, increase organic matter content, and replenish essential nutrients naturally.
The concept behind green manure is rooted in the idea that certain crops have the ability to fix atmospheric nitrogen through a mutually beneficial relationship with nitrogen-fixing bacteria residing in their root nodules. Since nitrogen is an essential nutrient for plant growth, this process provides plants with a sustainable and renewable source of nitrogen. In addition to nitrogen fixation, green manures also contribute to soil health by reducing erosion, suppressing weeds, improving water retention, and enhancing soil structure.
Farmers and gardeners often choose leguminous plants such as clover, lupines, alfalfa, or peas for green manure purposes due to their nitrogen-fixing capabilities. However, non-legume plants like rye grass or buckwheat can also be used as green manure. The specific crop selection may vary depending on regional climate, soil conditions, and desired benefits. The incorporation of green manure into the land plays a crucial role in maintaining and improving soil fertility, ultimately promoting sustainable agriculture practices.
The term "green manure" is derived from the Old English word "mǣġen" which means "power" or "strength", and "ȳwan" which means "to work" or "to cultivate". In medieval English, "mǣġen" evolved into "mān" or "mǣn" which means "manure" or "to enrich the soil". Over time, "green" was added to specify that the manure being referred to is derived from green plants or crops that are grown specifically to improve the soil's fertility. Therefore, "green manure" literally means "powerful or enriching material cultivated from green plants".