Effects of wide ridge and double row planting of maize in cold regions

To explore the mechanism of yield improvement and proper density of maize under wide ridge and double row cropping,an experiment was conducted with three planting densities by using narrow ridge cropping as the control,and soil temperature,soil moisture,illumination intensity and yield traits were measured. The results showed that wide ridge and double row cropping had little effect on soil temperature,but increased soil moisture in0 ~ 20 cm layer. Under the condition of wide ridge and double row cropping,the light capture of top leaves in furrow decreased,and the bottom layer of plants( 1 /3 above ground) remained certain illumination intensity( 72. 5μmol·m-2·s-1) in the treatment of high planting density( 60 000 plants·hm-2),which contributed to decrease rate of barren stalk and to increase dry weight obviously at milky maturity stage. The yield of wide ridge and double row cropping with high planting density( S3) was 9 193. 5 kg·hm-2in 2008,being 911. 3 kg·hm-2higher than the control( CK3). Wide ridge and double row cropping affected yield mainly by increasing soil moisture and regulating illumination intensity among maize population.