Forages underseeded in barley for residue management for potatoes

Producers have attempted to increase soil organic matter content in a 2-yr rotation of barley potato by underseeding barley with forage grasses and le gumes. A study beginning in 1996 was initiated to evaluate the effect of th is practice on barley yields, root biomass, soil organic matter content, ea se of post-harvest tillage as measured by a soil penetrometer and surface p lant residue levels for the first year of a 2-yr rotation of barley-potato. Barley seeded alone, barley under seeded with berseem clover, barley under seeded with timothy/red clover, barley underseeded with timothy/red clover fall chisel plowed and barley underseeded with Italian ryegrass were evalua ted with and without a fall application of glyphosate on a well-drained, fi ne sandy loam, Orthic Humo-Ferric Podzol soil. Barley yields were not affec ted by underseeding. Despite an increase in root biomass for some of the un derseeded crops, soil organic matter content was not affected. Potato produ cers attempting to increase soil organic matter content in a 2-yr rotation of barley-potato by underseeding barley with a forage crop are advised to c onsider using annual forages such as berseem clover or other solutions such as residue management. Underseeding barley with red clover/timothy will re quire either a fall application of glyphosate or extra spring tillage to el iminate living plants. By underseeding barley, producers are incurring addi tional costs and eliminating the option of practising residue management, a soil conservation practice, unless they use glyphosate at an additional co st.