The effect of row orientation, date and latitude on light absorption by row crops

Abstract

SUMMARYA model study of light absorption by rectangular hedgerows with different row orientations was made.The effect of row orientation on daily light absorption is greatest around 25° latitude. North–south orientation gives highest absorption for most of the year near the equator. At higher latitudes, up to 55°, absorption is highest with N–S orientation during the summer months and with E–W orientations for the rest of the year, but the magnitude of the difference between orientations decreases with increasing latitude. From 65° upwards, E–W orientation gives highest absorption all the year round, but the difference among orientations is minor. The effect of orientation will be smaller as cloudiness is greater.The results of this study are wholly consistent with yield differences due to different orientations, reported in the literature.

A flexible and explanatory model of light distribution and photosynthesis in row crops

“…Some of these models assume the row cross-section to be ellipsoidal (Charles-Edwards and Thorpe, 1976) or an array of ellipsoidal sub-canopies randomly distributed in the row (Mann et al, 1980;Whitfield, 1986). Others assume a triangular or rectangular cross-section of the rows (Allen, Jr., 1974;Rabbinge, 1976;Goudriaan, 1977;Palmer, 1977;Jackson and Palmer, 1979;Mutsaers, 1980).…”

Weed management in cotton (Gossypium hirsutum L.) through weed-crop competition: A review

“…At higher latitudes (up to 55 ) absorption was highest with north-south during the summer and east-west during the rest of the year. Beyond 65 , the eastewest orientation gave the greatest light absorption all year (although the difference between orientations is minor) (Mutsaers, 1980).…”

“…The use of row crop orientation to maximise crop yield and supress weed growth has been reported in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) (Borger et al, 2010(Borger et al, , 2016, and sugar beet (Beta vulgaris L.) (Anda and Stephens, 1996). Orienting crop rows in a nearly perpendicular angle to incident sunlight maximises light interception by crops (Mutsaers, 1980) and with less light penetrating the interspaces, less light is available to weeds. Interception of reduced red to far-red light ratio (R/FR) induces a series of physiological and developmental adjustments including reduction in stem diameter, suppression of branching, and changes in biomass partitioning (Afifi and Swanton, 2011;Ballare et al, 1987Ballare et al, , 1990Smith, 1982).…”

“…Interception of reduced red to far-red light ratio (R/FR) induces a series of physiological and developmental adjustments including reduction in stem diameter, suppression of branching, and changes in biomass partitioning (Afifi and Swanton, 2011;Ballare et al, 1987Ballare et al, , 1990Smith, 1982). Maximising light interception by row orientation is dependent on latitude and seasonal tilt of the earth in relation to the sun (Mutsaers, 1980). Models by Mutsaers (1980) estimated that near the equator, north-south (as opposed to east-west) gave the highest absorption all year round.…”

“…Maximising light interception by row orientation is dependent on latitude and seasonal tilt of the earth in relation to the sun (Mutsaers, 1980). Models by Mutsaers (1980) estimated that near the equator, north-south (as opposed to east-west) gave the highest absorption all year round. At higher latitudes (up to 55 ) absorption was highest with north-south during the summer and east-west during the rest of the year.…”