It’s gaining widespread use in countries such as Niger, Burkina Faso, Malawi and Zambia, among others. The trees are planted among maize, millet or sorghum. They not only add nitrogen to the soil through their roots, but also through their leaves when they fall off and decay. At other times of the year the trees can shade plants from the harsh sun. Reganold said colonial English and French farmers believed crops should be separated from trees, not mixed together.

Besides planting trees, the perenniation also calls for the use of the doubled-up and the push-pull systems. The doubled-up system has farmers mixing pigeon pea plants among soybean and maize crops. Pigeon pea, a large shrub, adds nutrients to the soil, but can later be used for fuel and fodder. Some parts are edible.

The push-pull system also uses perennials, such as napier grass, which is grown around the maize, and desmodium, which is planted among the stalks. Reganold says desmodium

is a natural pest management system. It pushes away the stem bore moth from the crops, while the napier grass pulls or lures the moth to the perimeter of the crops. Thus push / pull.

Reganold gave an example of one woman who had great success with perenniation.

“She’s a grandmother in her 50s. Her name is Rhoda Mang’yana and she started using this system about 20 years ago. She used actually two of the systems – the doubled-up legume and she also started using these evergreen agriculture trees. And her yields initially were about a ton of maize per hectare. Now with a good year she gets four tons per hectare. Four times what she was getting,” he said.