Plastic Agriculture

Taiwanese farmers use a lot of plastic, but the more I think about it, the more I understand it. Plastic sheeting (like the stuff shown here) retains moisture and stops weed growth. With regard to the second goal, it may be preferable to pesticides. But a lot of it stays on the ground, chewed up into little pieces and bleached by the sun. What will the landscape be like in 50 years if this continues?