Comparison of Drought Tolerance of Maize, Sweet Sorghum and Sorghum‐Sudangrass Hybrids

Abstract

In drought-prone environments, sweet sorghum and sorghum-sudangrass hybrids are considered worthy alternatives to maize for biogas production. The biomass productivity of the three crops was compared by growing them side-byside in a rain-out shelter under different levels of plant available soil water (PASW) during the growing periods of 2008 to 2010 at Braunschweig, Germany. All crops were established under high levels of soil water. Thereafter, the crops either remained at the wet level (60-80 % PASW) or were subjected to moderate (40-50 % PASW) and severe drought stress (15-25 % PASW). While the aboveground dry weight (ADW) of sweet sorghum and maize was insignificantly different under well-watered conditions, sweet sorghum under severe drought stress produced 27 % more ADW than maize. The ADW of sorghum-sudangrass hybrids significantly lagged behind sweet sorghum at all levels of water supply. The three crops differed markedly in their susceptibility to water shortage. Severe drought stress reduced the ADW of maize by 51 %, but only by 37 % for sweet sorghum and 35 % for sorghum-sudangrass hybrids. The post-harvest root dry weight (RDW) in the 0-100 cm soil layer for maize, sweet sorghum and sorghum-sudangrass hybrids averaged 4.4, 6.1 and 2.9 t ha À1 under wet and 1.9, 5.7 and 2.4 t ha À1 under severe drought stress. Under these most dry conditions, the sorghum crops had relatively higher RDW and root length density (RLD) in the deeper soil layers than maize. The subsoil RDW proportion (20-100 vs. 0-20 cm) for maize, sweet sorghum and sorghum-sudangrass hybrids amounted to 6 %, 10 % and 20 %. The higher ADM of sweet sorghum compared with maize under dry conditions is most likely attributable to the deep root penetration and high proportion of roots in the subsoil, which confers the sorghum crop a high water uptake capacity.

To integrate or to segregate food crop and energy crop cultivation at the landscape scale? Perspectives on biodiversity conservation in agriculture in Europe

“…Different crop varieties or species may be grown in comparison to A1 [79]. In drought-prone environments, for example, sweet sorghum and sorghum-sudangrass hybrids were tested as alternatives to maize for biogas production in Germany [80]. Like in A1, the combined systems do not differ from pure food/fodder systems in their farming intensity and hence are most likely to have negative effects on biodiversity.…”

Biomass sorghum and maize have similar water-use-efficiency under non-drought conditions in the rain-fed Midwest U.S.

“…Some studies have shown greater biomass production for biomass sorghum than other C4 species, including maize and switchgrass (Hallam et al, 2001). Sweet sorghum, a variety with sugar-rich stems (Rooney et al, 2007), and grain sorghum, both with deep, extensive roots (Rooney et al, 2007;Zegada-Lizarazu et al, 2012), produced comparable biomass to maize when water was not a limiting factor, and more biomass than maize in water limited environments (Farré & Faci, 2006;Schittenhelm & Schroetter, 2014). Sweet sorghum was found to be less sensitive to drought than maize (Zegada-Lizarazu et al, 2012), and more water-useefficient than maize and other major grain crops (Steduto et al,1997;Katerji & Mastrorilli, 2014).…”

Caracterización Del Crecimiento Y Desarrollo Del Maíz en Condiciones De No Laboreo en La Mancha Oriental

“…MS frente a Altura de plantas de maíz. Schittenhelm & Schroetter (2014), comparando la MS de plantas de maíz con su altura, encontraron que las plantas con altura media de 280 cm tenían una producción de MS de 1.910 g m -2…”