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United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCED MIDWESTERN CROPPING SYSTEMS FOR SUSTAINABILITY AND ENVIRONMENTAL QUALITY Title: Winter cereal canopy effect on cereal and interseeded legume productivity

Authors
item Blaser, B -
item Singer, Jeremy
item Gibson, L -

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 29, 2011
Publication Date: May 25, 2011
Citation: Blaser, B.C., Singer, J.W., Gibson, L.R. 2011. Winter cereal canopy effect on cereal and interseeded legume productivity. Agronomy Journal. 103(4):1180-1185.

Interpretive Summary: Interseeding red clover or alfalfa into winter cereals in the North Central USA can provide forage and a green manure crop. This study was conducted from 2005 to 2007 to evaluate the impact of diverse cereal canopy traits on the establishment of frost-seeded legume intercrops. In March, red clover and alfalfa were frost-seeded into three winter wheat and three triticale varieties selected for differences in leaf area index, plant height, and dry matter. The cereals produced a range of leaf area index and whole plant dry matter and affected legume dry matter. Alfalfa and red clover plant numbers were similar, but dry matter production was 42% higher in red clover 40 d after cereal grain harvest. The presence of a legume intercrop did not affect cereal grain yield or yield components, but reduced weed densities and dry matter 40 d after harvest. Producers implementing this intercrop may select cereal varieties based on grain yield, but must be cautious of varieties known to produce above normal leaf area index values because of the potential to reduce legume productivity.

Technical Abstract: Interseeding red clover (Trifolium pratense L.) or alfalfa (Medicago sativa L.) into winter cereals in the North Central USA can provide forage and a green manure crop. We hypothesize that winter cereal canopy traits such as leaf area index (LAI) and whole plant dry matter (DM) influence interseeded legume establishment and productivity, yet the effect of canopy traits on resource competition in interseeded systems is not well understood. This study was conducted from 2005 to 2007 to evaluate the impact of diverse cereal canopy traits on the establishment of frost-seeded legume intercrops. In March, red clover and alfalfa were frost-seeded into three winter wheat (Triticum aestivum L.) and three triticale (X Triticosecale Wittmack) varieties selected for differences in LAI, plant height, and DM. Across three growing seasons, the cereals produced a range of LAI from 2.1 to 6.2 and whole plant DM at harvest of 817 to 2029 g m-2. During two seasons, legume densities and DM were influenced by cereal in one and two years, respectively. Alfalfa and red clover densities were similar, yet DM production was 42% higher in red clover 40 d after cereal grain harvest. The presence of a legume intercrop did not affect grain yield or yield components, but reduced weed densities and DM 40 d after harvest. Producers implementing this intercrop may select cereal varieties based on grain yield, but must be cautious of varieties known to produce above normal LAI values because of the potential to reduce legume productivity.

Last Modified: 12/18/2014