Lentil green manure as fallow replacement in the semiarid northern Great Plains

Green manures (GM) may offset inorganic N needs and improve soil quality. Study objectives were to determine effects of green ma-nure on soil-N fertility, water use, soil quality, and yield of spring wheat (Triticum aestivum L.). On two treatments, lentil (Lens culinaris Medikus cv. Indianhead) was green manured in a green manure–spring wheat rotation. Lentil was killed by disking (GMMF) or chemicals (GMCF). Additional treatments were annually cropped wheat (AW) in a mechanical fallow (MF) or chemical fallow (CF) sequence. No inorganic N was used on GMMF and GMCF. Experiments were started in 1991 on a Williams loam (fine-loamy, mixed Typic Argibor-oll) near Culbertson, MT. Green-manure treatments used 56 mm more water than fallow treatments when lentil was grown to lower-pod set. When lentil was killed at full bloom, there were no differences in water use among GM and fallow treatments. There were no differ