The Role of Trees and Pastures in Organic Agriculture.

Environmental concerns associated with annual row crop grain – soil erosion, soil carbon loss, chemical and petroleum intensive, limited arable land, etc. - could be solved by converting livestock production to an organic pasture based system.  The inclusion of tree crops would further enhance the opportunity for feeding pasture raised livestock.  Biodiversity is an essential aspect of an organic farm plan.  The idea of including tree crops and other perennials into the vision of an organic farm as a kind of “living organism” is very much compatible with the goals and philosophy of organic farming.  Before modern no-till farming systems were developed, tree crops and pasture systems offered the same benefits for controlling soil erosion and conserving soil carbon.  J. Russell Smith published Tree Crops, A Permanent Agriculture (1929) and pioneered tree crop agriculture as the alternative to annual row crops for protecting soils from erosion and for their role in producing livestock feed as acorns, nuts, and fodder.  A survey of Mid-Atlantic USA soils under pasture found 60% higher organic matter content than cultivated soils.  A recent comparison of organic versus conventional cow’s milk evaluated the nutritional quality.  Because standards for organic dairy require that cattle consume more forage from pasture and less grain, organic milk contains higher concentrations of omega-3 and fewer omega-6 fatty acids than conventional milk.   Organic standards also require that “the producer must not use lumber treated with arsenate or other prohibited materials for new installations or replacement purposes in contact with soil or livestock.”     Black locust (Robinia pseudoacacia) is a fast growing renewable alternative to treated lumber with many attributes compatible with organic farming.  This versatile tree fixes N, provides flowers for honey bees, and produces a highly durable dense wood that is ideal for fence posts useable for 50 year.