撰寫:註冊營養學家 ( 公共衛生 ) (英國)吳珮瑜 (Phoebe)
很多家庭都會選擇食用有機食品,如水果、蔬菜、雞蛋等,當被問及選購有機食品的原因時,大部分人都會回答:「因為有機食物較安全,又有營養。」今期筆者就教大家甚麼是有機種植。
什麼是有機種植?
有機種植是指以農業、生物或機械方法,代替人工合成的物質以進行農耕活動。不採用化學肥料、不用殺蟲劑或基因改造作物,善用當地的天然資源,順應自然生態的規律,當中顧及的範圍甚廣,例如:農場的有機生產區與非有機範圍之間,必須設有相距不少於 2 米的緩衝區,以防止作物受污染。
作物及品種的選擇及多樣性
● 用於有機耕種的種子或營養繁殖器官都應經有機認證
● 農場必須實行輪作及間作,並應盡量多樣化,避免單一種植
養分的管理
● 須適量施肥,以防養分過剩,亦避免污染環境
● 農場內使用的肥料,其來源、質素、施用量及施用方法應對生態環境無害
● 應透過休耕,讓土地恢復肥力
● 禁止使用化學合成的肥料、人類排泄物、污水廠污泥和化學廢料
病蟲草害及作物生長的管理
● 採取合適的施肥及灌溉管理
● 使用物理方法,包括人手、圍欄、光、聲頻、熱力等
● 種植具防治蟲害作用(包括驅蟲及吸引天敵)的植物
● 禁止使用化學合成的除草劑、殺菌劑、殺蟲劑及其他農藥
由此可見,有機種植是指種植過程中較注重生態保護,但於營養價值而言,有機食物與非有機食物的分別其實不大,更未有證據顯示進食有機食物的小朋友會更健康或更聰明。當然,由於有機食物較環保和少用化學農藥,筆者亦鼓勵大家多選購!
Written by: Registered Dietitian (Public Health) (UK) Phoebe Wu
Many families choose to consume organic foods such as fruits, vegetables, and eggs. When asked why they choose organic foods, most people respond: “Because organic food is safer and more nutritious.” In this issue, I will teach what organic farming is.
What is organic farming?
Organic farming refers to agricultural activities conducted using agricultural, biological, or mechanical methods instead of synthetic substances made by humans. It does not use chemical fertilizers, pesticides, or genetically modified crops, but rather utilizes local natural resources and adheres to the natural ecological order. The scope of consideration is very broad, for example: there must be a buffer zone of at least 2 meters between the organic production area of a farm and the non-organic areas to prevent contamination of the crops.
Crop and variety selection and diversity
● Seeds or vegetative propagating organs used for organic cultivation must be organically certified.
● Farms must implement crop rotation and intercropping and should diversify as much as possible to avoid monoculture.
Nutrient Management
● Fertilization must be done in appropriate amounts to prevent nutrient excess and environmental pollution.
● The fertilizers used on the farm should be harmless to the ecological environment in terms of their source, quality, application rate, and method of application.
● Fallowing should be practiced to allow the land to recover its fertility.
● The use of chemically synthesized fertilizers, human excreta, sewage sludge, and chemical waste is prohibited.
Management of diseases, pests, and weeds, as well as crop growth
● Implement appropriate fertilization and irrigation management.
● Use physical methods, including manual labor, fencing, light, sound frequency, heat, etc.
● Plant crops that have pest control functions (including repelling pests and attracting natural enemies).
● The use of chemically synthesized herbicides, fungicides, insecticides, and other pesticides is prohibited.
Hence, organic farming focuses more on ecological protection during the cultivation process. However, in terms of nutritional value, the difference between organic and non-organic food is actually not significant. Moreover, there is no evidence to suggest that children who eat organic food are healthier or smarter. Of course, since organic food is more environmentally friendly and uses fewer chemical pesticides, I also encourage everyone to purchase more of it.
常規種植 vs 有機種植
Conventional Farming vs. Organic Farming