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    魏光明主页 >> 文章 >> 媒体文摘 >> 浏览信息《黑土地或将消失》

    媒体文摘 | 评论(4) | 阅读(1964)
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    星期一   晴天 
    主题 黑土地或将消失

            作为世界三大黑土区之一,东北黑土区总面积约3523.3万公顷,分布在黑龙江、吉林、辽宁省和内蒙古自治区境内,粮食年产量约占全国五分之一,是我国重要的玉米、粳稻等商品粮供应地,粮食商品量、调出量均居全国首位。
            由中国科学院、东北农业大学、吉林省农业科学院等院所专家联合调研形成的“东北黑土资源利用现状及发展战略研究”指出,东北黑土地初垦时黑土厚度一般在60至80厘米,开垦20年的黑土层则减至60至70厘米,开垦70至80年的黑土层只剩下20至30厘米,水土流失严重地区只剩下表皮薄薄一层,颜色也由黑变黄。
            黑龙江省土肥管理站站长胡瑞轩说,形成1厘米的熟化黑土层大约需要50年,半米就得上千年,而现在东北黑土区平均每年流失0.3至1厘米的黑土层。但是,支撑粮食产量的黑土层却在过去半个多世纪里减少了50%,并在继续变薄,照此速度,部分黑土层或将在几十年后消失殆尽,东北这一中国最大粮仓的产能也将遭受无法挽回的损失。

    魏光明 发表于:2012-6-11 10:07:20

    评论 我国土壤污染严重

            “现在我国土壤污染比各国都要严重,日益加剧的污染趋势可能还要持续30年。”中国土壤学专家,南京农业大学教授潘根兴告诉《经济参考报》记者,这些污染包括随经济发展日益普遍的重金属污染、以点状为主的化工污染、塑料电子废弃物污染及农业污染等。
            国土资源部统计表明,目前全国耕种土地面积的10%以上已受重金属污染,致使10%的土壤基本丧失生产力,成为“毒土”。
            另外,农药化肥污染同样严重。我国农药使用量达130万吨,是世界平均水平的2.5倍。但是目前农药和化肥的实际利用率不到30%,其余70%以上都污染环境了。云南农业大学测算,每年大量使用的农药仅有0.1%左右可以作用于目标病虫,99.9%的农药则进入生态系统,造成大量土壤重金属、激素的有机污染。

    魏光明 发表于:2012-6-11 9:55:15

    评论 土壤质量下降致使农作物减产降质

            农业部全国农技推广中心高级农艺师陈志群认为,由于农药、化肥和工业导致的土壤污染,我国粮食每年因此减产100亿公斤。
            据环保部门估算,全国每年因重金属污染的粮食高达1200万吨,造成的直接经济损失超过200亿元。
    魏光明 发表于:2012-6-11 9:58:46

    评论 我国受重金属污染的耕地面积已达2000万公顷

    中国工程院院士、华南农业大学副校长罗锡文曾公开指出,有调查显示,我国受重金属污染的耕地面积已达2000万公顷(换算成亩为3亿亩),占全国总耕地面积的1/6。其中,受矿区污染的土地200万公顷,石油污染土地约500万公顷,固体废弃物堆放污染约5万公顷,“工业三废”污染耕地近1000万公顷,污染农田面积达330多万公顷。
    魏光明 发表于:2012-6-19 13:40:32

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