介绍： CHEMICAL OR ORGANIC FARMING?

Over the past half century, using chemical fertilizers has become very common in farming. Many farmers welcomed them as a great way to stop crop disease and increase production. Recently, however, scientists have been finding that long-term use of these fertilizers can cause dama...

介绍： CHEMICAL OR ORGANIC FARMING?

Over the past half century, using chemical fertilizers has become very common in farming. Many farmers welcomed them as a great way to stop crop disease and increase production. Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land and, even more dangerous, to people's health.
What are some of the problems caused by chemical fertilizers? First, they damage the land by killing the helpful bacteria and pests as well as the harmful ones. Chemicals also stay in the ground and underground water for a long time. This affects crops and, therefore, animals and humans, since chemicals get inside the crops and cannot just be washed off. These chemicals in the food supply build up in people's bodies over time. Many of these chemicals can lead to cancer or other illnesses. In addition, fruit, vegetables and other food grown with chemical fertilizers usually grow too fast to be full of much nutri在过去的半个世纪里，在耕作中使用化肥已经非常普遍。很多农民喜欢使用化肥，把化肥作为防治病虫害和提高产量的重量手段。然而，最近科学家发现长期使用这些肥料会造成土地受损，甚至更危险的是，会对人们的健康造成危害。
化肥带来的问题有哪些呢？首先，化肥在杀死病菌和害虫的同时也会杀死有益的细菌和昆虫，从而破坏土地。化学物质还会在地里和地下水保存很长时间，而这会影响到农作物，进而影响到动物和人类，因为化学物质会进入到农作物中，并且不能被冲洗掉。随着时间的推移，食物中的这些化学成分会在人体中堆积。很多化学物质会导致癌症或其他疾病。另外，施过化肥的水果、蔬菜和其它食物通常生长得过快而营养不足。它们表面上很好看，但是里面通常含太多的水分，而不是维他命和矿物质。
由于这些发现，一些农民和消费者开始转向有机耕作。有机耕作就是不用任何化学肥料的耕作。农民关心的是保持土壤肥沃并且免受病害。健康的土壤会减少病虫害并且帮助农作物茁壮成长。因此，有机耕作的农民通常喜欢把天然的动物粪便当做肥料。他们认为这样会使地里的土壤更富含矿物质，因而也会更加肥沃，同时还可以让空气、土壤、水以及农作物不受化学物质的污染。
有机耕作的农民也使用很多其他的方法来保持土壤肥沃。在同一块地里，他们经常每隔几年就换种农作物。例如，种玉米或小麦后来年再改种豌豆或大豆。像豌豆或大豆这样的农作物将重要的矿物质带回土壤，从而使之适宜于种植要求土壤肥沃的农作物，比如玉米或小米。有机耕作的农民还种植多种农作物来利用不同层次的土壤。比如，他们先种植生长于浅层土壤的花生，然后再种植生根于深层土壤的蔬菜。还有一些有机耕作者喜欢在农作物之间种草，以防止水土流失，并且把草留在地里，从而成为来年农作物的天然肥料。这些不同的有机耕作的方法有着同样的目标：种植好的粮食，避免损害环境或者人们的健康。