|Blaser, B - IA STATE UNIVERSITY|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 30, 2007
Publication Date: June 26, 2007
Citation: Singer, J.W., Sauer, T.J., Blaser, B.C., Meek, D.W. 2007. Radiation use efficiency in dual winter cereal - forage production systems. Agronomy Journal. 99(4):1175-1179. Interpretive Summary: Winter cereal production systems in the northern USA are inefficient with respect to the capture of sunlight. Our objectives were to determine radiation use efficiency in winter wheat and triticale at different plant densities and radiation use efficiency of interseeded red clover. The wheat/red clover system was less variable than the triticale/red clover system for grain radiation use efficiency and intercepting sunlight after cereal harvest. Interseeding red clover into winter cereals can increase system efficiency, with multiple benefits to the agroecosystem. This information will benefit producers, Extension, and agricultural researchers.
Technical Abstract: Winter cereal production systems in the northern USA are inefficient with respect to the capture of photosynthetically active radiation (PAR) during the year. Our objectives were to determine radiation use efficiency (RUE) in winter wheat (Triticum aestivum L.) and triticale (x Triticosecale Wittmack) at low (67-125 plants m-2), medium (116-170 plants m-2), and high (205-332 plants m-2) plant densities and RUE of interseeded red clover (Trifolium pratense L.) during two growth periods after cereal harvest. During the linear phase of cereal growth (GS 30 to 80), RUE averaged across plant density was 3.50 g MJ-1 for wheat and 3.21 for triticale in 2004 and 3.37 for wheat in 2006. In 2006, triticale RUE was similar at the low and medium plant density (3.28 g MJ-1) but lower at the high plant density (2.84 g MJ-1). Red clover RUE following wheat and triticale differed by growth period and exhibited varying levels of plant density dependence within growth period. Following wheat at the high plant density, RUE ranged from 1.40 to 1.97 g MJ-1 across years and growth periods. Following cereal harvest in mid-July until early October, red clover interseeded in wheat intercepted on average 65% (2004) and 35% (2006) of incident PAR. The wheat/red clover system was more robust than triticale/red clover for grain RUE and intercepting PAR after cereal harvest.