由于扩大耕地面积的可能性越来越小，研究已主要集中于提高单位面积产量。
Because of the diminishing opportunity to expand cultivated land, researches have been mostly focused on the rise of yield per unit area.
农业天生就对环境有害，自从人类在大约11,000年前开始从事起就从未变过。它对环境的损害主要是大规模的伐林开荒以扩大耕地面积。
Farming is inherently bad for the environment: since humans took it up around 11,000 years ago, the result has been deforestation on a massive scale.
像明永这个山村，冰川消融使得河流的水量增加，给村庄带来了些许好处：耕地面积扩大了，作物的生长季节也延长了。
In alpine villages like Mingyong, the glacial melt has swelled rivers, with welcome side effects: expanded croplands and longer growing seasons.
近年来中国耕地面积年净减少量呈扩大之势，2003年净减少量与当年耕地面积之比达2.06%。
The annual net decrease of the cultivated area in China in rent years had a big increase, the ratio between which and the total area in 2003 was 2.06%.
这样就提供了有关扩大可耕地面积的宝贵数据。
This has provided valuable data for extension of cultivable land.
这样就提供了有关扩大可耕地面积的宝贵数据。
This has provided valuable data for extension of cultivable land.
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