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Energy Input and Output Analysis of four Field Crops in California 1
Author(s) -
Reed W.,
Geng Shu,
Hills F. J.
Publication year - 1986
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.1986.tb00054.x
Subject(s) - fodder , sweet sorghum , sorghum , agronomy , sugar beet , crop , irrigation , fertilizer , mathematics , biology
Four crops, corn ( Zea mays L.), sweet sorghum ( Sorghum bicolor L.), fodder beet ( Beta vulgaris L.) and sugarbeet ( Beta vulgaris L.) were grown in irrigated plots at the experimental farm of the University of California, Davis, in 1980 and 1981. Six fertilizer N levels ranging from 0 to 280 kg ha −1 were used to estimate the most efficient N input for each of the tested crop in terms of energy input and output analysis. Calculations of cultural energy input costs in relation to potential ethanol yield showed production requirements of: corn 30.9 GJ ha −1 , sweet sorghum 30.4 GJ ha −1 , fodder beet 49.4 GJ ha −1 and sugarbeet 41.0 GJ ha −1 . Highest average energy inputs were for liquid fuels for operations 35%, irrigation 23% and fertilizer nitrogen 19%. Fodder beet had the highest fermentable carbohydrate yield at 13.05 Mg ha −1 followed by sugarbeet at 11.5 Mg ha −1 . Sweet sorghum and corn yields were lower at 9.71 and 8.09 Mg ha −1 , respectively. Crop production inputs of energy per liter of potential ethanol were: corn 6.42 MJL −1 sweet sorghum 5.25 MJL −1 , fodder beet 6.35 MJL −1 and sugarbeet 5.95 MJL −1 .