控制杂草生长的办法

    This is the VOA Special English Agriculture Report.
    这里是美国之音慢速英语农业报道。
     
    Weeds compete with plantings for water and nutrients. So farmers and gardeners may have good reason to hate them. But weeds can also bring pretty flowers and wild beauty to places lacking either. British nature writer Richard Mabey offers support for them in his new book. The title says it all: "Weeds: In Defense of Nature's Most Unloved Plants."
    杂草和植物争夺水分和养分。因此农民和园丁有充分理由不喜欢它们。但杂草也能给某些地方带来漂亮的花朵和野性之美。英国自然作家理查德·玛贝(Richard Mabey)在他的新书中表达了对杂草的支持。书名就说明了一些:“杂草:为自然界这种最没人喜爱的植物辩护。”
     
    But when exactly is a plant considered a weed? Experts at Penn State University say the answer is simple: when the undesirable qualities outweigh the good qualities.
    但是,什么时候一种植物会被认为是杂草?宾夕法尼亚州立大学的专家表示,答案很简单:当其不良品质超过优良品质时就会被认为是杂草。
     
    A crop plant generally produces several hundred seeds. But a weed plant can produce tens or even hundreds of thousands of seeds. And if seeds get buried, they may survive for many years underground.
    考虑到每株农作物通常产生几百颗种子。而相比之下,每株杂草能产生数万甚至数十万颗种子。而且,一些被埋在地里的种子可以存活40年乃至更久。
     
    Eradicating weeds means that you have to remove all the seeds and roots so the plants will not grow back. But birds or the wind can reintroduce them to the land.
    要根除杂草意味着你必须除掉所有的种子和根系,这样杂草才不会再次长出来。但是,鸟类或风会将它们重新带到地里。

    A more common way to deal with weeds is to control them enough so that the land can be used for planting. Experts advise using two or more control methods to deal with weeds.
    一种更常见的对付杂草的方式是严格控制其生长,这样土地才能种植作物。专家建议使用两种或两种以上的方式来对付杂草。
     
    Chemical weed killers or natural treatments like corn gluten can suppress weed growth. But so can dense planting. Bill Curran is a professor of weed science at Penn State. He says a dense, competitive crop that quickly shades the soil from the sun will help reduce weed growth.
    化学除草剂或玉米蛋白粉一类的自然控制手段可以抑制杂草的生长。作物密集种植也行之有效。 比尔·柯伦(Bill Curran)是宾夕法尼亚州立大学的杂草科学教授。他表示,经过密植的竞争性作物会很快遮蔽阳光,这将有助于抑制杂草生长。
     
    Other controls include turning over the soil, pulling the weeds or covering them with mulch made of wood, garden waste or other material.
    其它控制手段包括翻土、拔草或用地膜覆盖杂草。地膜一般由木屑、园林废弃物或其他材料制成。
     
    But even mulch has its limits. Natural resource specialists point out that weeds can be transported in mulch. This is also true of soil, grain, hay and animals.
    但是,地膜也有其局限性。自然资源专家指出,杂草可以在地膜里传播,还可以通过土壤,谷物,干草和动物传播。

    Yet animals like sheep or goats eat weeds, so they can provide a biological control. Insects and other organisms can also act as biological controls.
    然而,像绵羊或山羊之类的动物以杂草为食,因此它们能够提供一种生物控制手段。昆虫和其他生物也可以起到生物控制作用。

    Preventing the spread of weeds is an important part of weed management. Farm vehicles should be kept out of areas with weeds. If that is not possible, then clean off the equipment and your shoes when leaving.
    控制杂草传播是杂草管理中的一个重要环节。农用机械应该远离杂草,如果无法做到,在离开杂草区域时清理干净农用机械和你的鞋子。
     
    Some people burn weeds or bury them deep in the ground or make them into mulch.
    有些人会将杂草烧掉或深埋,或将它们变为地膜。
     
    Professor Curran says another way to make use of weeds is to compost them. The process of making organically rich compost produces heat. This heat kills many, though not all, weed seeds. The same is true for seeds that pass through animals that graze on weeds.
    柯伦教授说,另一种利用杂草的方式是将其制成堆肥。制作有机堆肥的过程会产生热量,这些热量可以杀死绝大部分杂草种子。将杂草喂食动物通过动物消化也能杀死绝大部分杂草种子。