HARTBEESPOORT, South Africa — Dozens of tiny black weevils cling onto a fern plant as it is tossed onto a leafy green mat coating the surface of South Africa's Crocodile River. Those weevils ...

Azolla is a fast-growing, nitrogen-fixing water fern offering a sustainable, low-cost alternative to chemical fertilisers and expensive livestock feed in India. Learn how to cultivate Azolla for ...