Such annual crops are high in yield, but they require vast amounts of artificial fertilizer, and their impermanence contributes to soil erosion. Perennial grain crops, if they existed, could require less fuel, less fertilizer, less herbicide and pesticide, and help prevent erosion by remaining deeply rooted in the soil throughout the winter (and indeed for years). Perennials return nutrients to the soil, where annuals require artificial fertilizers to supplement depleted soil, and return nothing. According to a paper in the current issue of Science, perennial grains, currently being researched at a number of universities, including Washington State University (WSU), could become the norm within two decades.
