Resource-Conserving Agriculture: Undersowing and Mixed Crops as Stepping Stones Towards a Solution

In today’s agricultural environment, the conservation of water, soil and energy is of utmost importance. In the past, various approaches have been tested in a practical environment. Two practical approaches that were, once, commonplace have been neglected, namely, undersowing and mixed cultivation where various species are simultaneously grown with or between plantings of a main crop. These have been researched in multiyear field studies.
White clover and lucerne have proven to be suitable for undersowing in Moldova where undersowing of these legumes significantly reduced weediness. In Moldova, spring barley grown with white clover or lucerne produced significantly higher yields than a pure crop. In Switzerland, the seeding of an undersown crop was found to produce only slightly less yield of winter barley without application of herbicide compared with barley alone and treated with herbicide.
Field studies with mixed crops were primarily conducted with false flax (Camelina sativa) within a field pea crop. Camelina effectively inhibits weeds, so herbicide treatment is no longer necessary. But it is hard to calculate the amount of seed needed to prevent weed infestation; well-developed false flax will compete with the peas, reducing their yield and resulting in diminished profit. The problem is of no concern if the Camelina can be marketed as oil – which can be used for human consumption, cosmetics, paints and fuel.