SEED YIELD AND RESIDUE PRODUCTION OF LENTIL CULTIVARS GROWN AT DIFFERENT SLOPE POSITIONS

The presence of crop residue on the soil surface is important in contr olling soil erosion, but residue amounts from lentil (Lens culinaris M edik) are often insufficient to control soil erosion during subsequent phases of the cereal-grain legume cropping systems of the U.S, Pacifi c Northwest. To gain knowledge of residue production by lentil in typi cal production environments, six lentil cultivars were grown at four s lope positions in southeastern Washington over 3 yr. Residue and seed production varied significantly among cultivars and slope positions (P < 0.01), Total residue production ranged from four to 20 times the 29 0 lb/acre required by conservation standards, however, the amount rema ining after sowing of the subsequent winter wheat (Triticum aestivum L .) crop was much less, indicating that large losses occurred during ha rvesting and tillage operations, On lower slope positions, grain and r esidue yields were inversely correlated for all cultivars. On upper sl ope positions, grain yields were nearly constant among cultivars, but 'Laird' produced an average of 42% more residue than 'Brewer', No sing le cultivar met yield and residue production criteria across all lands cape positions, Growers can improve erosion control by site-specific s owing of high-residue cultivars such as Laird. Breeding programs shoul d consider the differences in the upper and lower slope positions for seed and residue production when selecting for cultivars with improved biomass production.