Intercropping Legumes in Hard Red Spring Wheat under Semi-Arid Conditions

Abstract

Research has shown that intercropping legumes with grain crops can provide a green manure crop without the loss of a cropping year. The objective of this research was to determine whether legumes could be intercropped with hard red spring wheat (HRSW, Triticum aestivum L. emend Thell.) in a semi-arid cropping system. Alfalfa (Medicago sativa L. ‘Vernal’), hairy vetch (Vicia villosa Roth, local ecotype), and red clover (Trifolium pratense L., ‘Marathon’) were intercropped in the HRSW cultivar ‘Hamer’ at three locations in northwest and west central Minnesota in 1999 and 2000. Intercropping hairy vetch into HRSW reduced grain yield and test weight, but had no effect on grain protein. Hairy vetch was not suitable for intercropping with HRSW, as it grew too tall when the spring wheat crop matured, hindering grain harvest. Intercropping alfalfa or red clover did not affect wheat yields compared to wheat monoculture and neither of the two legume species impeded grain harvest. Thus alfalfa and red clover are more suitable to intercrop with HRSW than hairy vetch. All three legumes evaluated in this experiment grew after the HRSW was harvested and provided a green manure crop at the end of the season when soil moisture in the later part of the summer was not limiting.