Effects of strip intercropping concept with perennial diversified grass-clover strip and annual winter rye-winter vetch intercrop as energy crops

Summary

The combination of perennials and annuals in a strip cropping system is challenging primarily because the interspecific competitive ability of the perennials towards the annuals seems to be too dominating. Especially at the first harvest (tillering) closest to the adjacent grass-clover strip severe total dry matter production reductions was found ranging from 25%, 5% and 20% in the vetch SC, rye SC and vetch-rye IC, respectively. Rye in particular was suffering from the grass-clover interspecific competition with a SC yield of 700 g DM m-2 (0-25 cm) at maturity as compared to 1025 g DM m-2 when grown > 150 cm away. When grown >150 cm away from the grass-clover strip rye accumulate 8 g soil mineral N m-2,which is in the range of the expected according to organic yield potentials, but only 5 g soil mineral N m-2 when grown 0-25 cm from the adjacent grass-clover. Grass-clover is clearly more competitive towards soil mineral N than adjacent rye plants. The ability of vetch to fix its own N might be an advantage if there is no other limiting growth parameters, like e.g. soil water, indicated by no significant difference between final harvest of vetch SC with 0-25 cm (480 g DM m-2) and >150 cm (550 g DM m-2) distance to grass-clover. The Land Equivalent Ratio (LER = LP+LB) based on aboveground DM production and N accumulation varied between 0.85-1.25 comparing harvests and distance to adjacent grass-clover. At maturity LER values show that available plant growth resources was used 25% more efficiently in intercrops than sole crops when grown with >25 cm and less than 75cm from the adjacent grass-clover strip. Ecosystem services like biomass for energy, functions like leguminous N2-fixation and the capacity of e.g. perennial species to act as carbon sinks should gain more attention when addressing climate change mitigation tools within the framework of organic farming principles and values before these more multipurpose cropping systems like the present strip cropping concept can be fully evaluated. Furthermore, the value of subdividing fields into strips to avoid the buildup of pathogens and pests, depletion of soil nutrients and to improve soil structure and fertility by e.g. alternating deep-rooted and shallow-rooted plants needs further research.

Available Versions of this Item

• Effects of strip intercropping concept with perennial diversified grass-clover strip and annual winter rye-winter vetch intercrop as energy crops. (deposited 27 Jun 2011 15:03) [Currently Displayed]
  • Strip cropping of alternating perennial grass-clover and annual rye - vetch intercrops when grown within an organic farming system. (deposited 13 Jun 2012 06:52)