Annual maize and perennial grass-clover strip cropping to produce biomass for bioenergy – within an organic farming approach

This is the latest version of this item.

Summary

A field experiment was carried out including alternating perennial ryegrass (Lolium perenne L.) – clover (Trifolium repens + Trifolium pretense L.) pasture mix with annual maize (Zea mays L.). Maize was established after soil incorporation of a 1st-year grass-clover in a 6-m wide strip, whereas grass-clover was established without incorporating the 1st-year grass-clover in an equivalent 6-m wide strip. This resulted in an early interspecific competitive advantage for the perennial strip and when growing maize in close proximity to grass-clover total dry matter production was reduced with about 50% compared to >150 cm distance. However, it was partly compensated by greater yields by especially the 50-100 cm harvest. In contrast there was no significant difference in grass-clover yields according to distance to adjacent maize. Across years and harvest time there was less clover when grown in close proximity to maize (0-25 cm; 30%) compared to with > 25 cm distance (40%) indicating potential soil mineral interspecific competitive interactions. This was supported by a 50% maize soil N uptake reduction when grown in close proximity to grass-clover. Additional fertilizer application increased maize yields significantly averaging 1250 g DM m-2, with significant differences were found between the use of green manure (950 g DM m-2) and anaerobic digestate (1400 g DM m-2). The distance towards the grass-clover strip was still influencing the maize yields significantly despite the additional plant available N in the order of 50-100 cm > 150 cm = 100-150 cm > 0-50 cm distance. At the final harvest maize aboveground biomass was equal to 250 g carbon (C) m-2 when grown in close proximity to grass-clover (0-50 cm) and increased to 500 g C m-2 grown with > 50 cm distance. During establishment there was an inner row (50-100 cm distance) effect of 26% compared to traditional maize cropping which was not found at the later growth stages. The maize energy density was 17 megajoule (MJ) kg-1 independent of year, harvest time and distance to the grass-clover strip, with no effect of additional N application either. The maize energy yield was 0.8, 13 and 18 MJ m-2 at establishment, the vegetative growth stage and ripening, respectively. When comparing the ”occupation” of land by the present maize strip cropping system as compared to the traditional maize and grass-clover single field cropping during 1 full year the relative yield advantages was 0.96 and 1.01 in 2008 and 2009, respectively. Thus, the total land area required under traditional cropping attaining the yields achieved when dividing the field in strips are the same. It is concluded that the combination of maize with grass-clover does not possess the right level of co-existence and complementarity. To fulfill the society needs for increased used of biomass for bioenergy more emphasis on practices including rotational principles of dissimilar types of crops is required when developing cropping systems for the future.

Available Versions of this Item

• Evaluation of strip intercropping concept with grass-clover and maize strips to produce biomass for bioenergy. (deposited 27 Jun 2011 15:04)
  • Annual maize and perennial grass-clover strip cropping to produce biomass for bioenergy – within an organic farming approach. (deposited 13 Jun 2012 06:48) [Currently Displayed]