人口危機population crisis
氣候的不穩(wěn)定性instability of climatic conditions
種植業(yè)crop cultivation
畜牧業(yè)livestock farming
乳品業(yè)dairy farming
園藝horticulture
小麥wheat
玉米corn, maize
棉花cotton
谷物grain
高粱sorghum
煙草tobacco
灌溉irrigation
天然肥料animal waste
化肥pesticide
殺蟲劑pesticide, insecticide
輪種crop rotation
間種companion planting
牛cattle
奶牛cows
羊goat
獸群/牧群herd
鹿deer
馴化domesticate
家禽家畜domestic animals
草原prairie,pasture. Ranch
放牧graze
過度放牧over grazing
植被 vegetation
加速水土流失accelerated erosion
自給自足self-sufficient
犁plow