文档介绍：现代化农业——真正可持续性农业经营的生态影响和机遇Modern Agriculture: Ecological Impacts and the Possibilities for Truly Sustainable Farming
大约四十年前,农业系统中的作物产量依赖的是内部资源、有机物的循环利用、内在的生物防治机制和将与模式。Until about four decades ago, crop yields in agricultural systems depended on internal resources, recycling anic matter, built-in biological control mechanisms and rainfall patterns.
农业产量虽然不高,但比较稳定。Agricultural yields were modest, but stable.
保证产量的方法是在某一地块的时空范围内多种几类作物,以应对突发的虫害或恶劣的天气。Production was safeguarded by growing more than one crop or variety in space and time in a field as insurance against pest outbreaks or severe weather.
为取得氨肥,采取轮换种植主要农作物和豆类的方法。反过来,轮换种植可有效地破坏害虫、杂草、病害的生命周期,从而抑制它们。Inputs of nitrogen were gained by rotating major field crops with legumes. In turn rotations suppressed insects, weeds and diseases by effectively breaking the life cycles of these pests.
玉米带地区的普通农场主轮换种植玉米和包括大豆在内的几种作物,而种植小粒谷物也是饲养牲畜的内在需求。大部分劳动由家庭成员完成,偶尔会请几个帮手,但不会从农场以外购买专用设备或服务。在此类农业系统中,农业和生态的关系十分密切,很少会出现环境退化的迹象。A typical corn belt farmer grew corn rotated with several crops including soybeans, and small grain occasional hired help and so specialized equipment or services were purchased from off-farm sources. In these types of farming systems the link between agriculture and ecology was quite strong and signs of environmental degradation were seldom evident.
但随着农业现代化的发展,对生态法则的无视和践踏经常会打破生态——农业链。But as agricultural modernizatio