NOVA

自然 · 历史

S5 E16 The Desert's Edge

本集简介

For thousands of years people have managed to live in deserts all over the world. But in recent years, a growing population and the demands of the international market have put more stress on these poor and easily exhausted lands. NOVA examines the consequences and possible solutions to desertification.

上一集

1978/05/24 S5 E15

The Insect Alternative

In a world that each year loses up to 40 percent of its crops to insects, some form of pest control is desperately needed. But chemical pesticides have backfired. Pesticide-resistant insects frequently develop, and previously harmless insects have become devastating infestations. Farmers have found themselves trapped on a "pesticide treadmill"—the more they spray, the more they have to spray. NOVA examines several alternatives for pest control.

下一集

1978/06/07 S5 E17

The Tse Tse Trap

NOVA explores Bovine sleeping sickness. Spread by a fly, it is a deadly disease that poses a threat to Africa's cattle.

当前季

1978-01-04

哇，窗口太小啦

NOVA