有機食物一定有營養嗎？Does organic food always have nutrition?

撰寫：註冊營養學家 ( 公共衛生 ) (英國)吳珮瑜

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。

Written by: Registered Nutritionist (Public Health) (UK), Ng Pui Yu

Many families choose to consume organic foods such as fruits, vegetables, and eggs. When asked about the reasons for purchasing organic food, most people respond with, “Because organic food is safer and more nutritious.” In this issue, the author will educate everyone about what organic farming is.

What is organic farming?

Organic farming refers to agricultural practices that replace synthetic substances with methods involving agriculture, biology, or machinery. It avoids using chemical fertilizers, pesticides, or genetically modified crops and instead relies on local natural resources while adhering to the laws of natural ecology. The scope of considerations is broad, for example: an organic production area on a farm must be at least 2 meters away from non-organic areas to prevent crop contamination.

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

Crop and Variety Selection and Diversity:

Seeds or propagating material used for organic cultivation should be certified as organic.
Farms must practice crop rotation and intercropping while striving for diversification to avoid monoculture.

Nutrient Management:

Fertilization should be applied appropriately to prevent nutrient excess and environmental pollution.
The sources, quality, quantity, and application methods of fertilizers used on the farm should be ecologically benign.
Soil fertility should be restored through fallow periods.
The use of chemically synthesized fertilizers, human excreta, sewage sludge, and chemical waste is prohibited.

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！

常規種植 vs 有機種植

	常規種植	有機種植
安全	較常用化學農藥、肥料	化學農藥少注重生態環境使用非基因改造物資
營養	沒有大分別
健康	同樣需要注意低脂、低糖、低鹽的健康飲食原則

Management of Pests, Diseases, Weed, and Crop Growth:

Implement appropriate fertilization and irrigation management.
Utilize physical methods, including manual techniques, fencing, light, sound frequency, heat, etc.
Plant crops that have pest control properties (including pest repellent and attracting natural enemies).
Prohibit the use of chemically synthesized herbicides, fungicides, insecticides, and other pesticides.

From this perspective, organic farming emphasizes ecological conservation in the cultivation process. However, when it comes to nutritional value, there isn’t a significant difference between organic and non-organic foods. Furthermore, there is no evidence to suggest that children who consume organic foods are healthier or more intelligent. Of course, due to the environmental friendliness and reduced use of chemical pesticides in organic farming, I also encourage everyone to make more organic choices!

Conventional Farming vs. Organic Farming

	Conventional Farming	Organic Farming
Safety	More commonly uses chemical pesticides and fertilizers	l Fewer chemical pesticide l Emphasizes ecological environment l Uses non-genetically modified materials
Nutrition	No significant difference
Health	Also need to pay attention to the principles of a healthy diet: low fat, low sugar, and low salt.