Effects of Interseeding Cover Crops and Split Nitrogen Application on Weed Suppression in Forage Maize

Weeds are one of the major threats for crop production. Interseeding cover crops is an alternative to laborious intertillages and hand weeding. The objective of this study was to evaluate the effect of fertilization and interseeding cover crops on the yield of forage maize, number and dry weight of weeds. Three cover crops, fall rye (Secale cereale L.), hairy vetch (Vicia villosa L.) and berseem clover (Trifolium alexandrinum L.), were interseeded in maize furrows (Zea mays L.). Nitrogen fertilizer timing was consisting of two levels including, the first level (N1= ½ at planting time + ½ in the 8 to 10 leaf stage of maize) and the second level (N2= 1 3 at planting time + 1 3 in the 8 to 10 leaf +1 3 a week before tasseling. The number and dry weight of weeds and main crop yield were recorded at dough stage of main crop. The results showed that weeds growth was suppressed significantly by interseeding cover crops through increasing the soil covered area by main crop and cover crops also and high biomass production by cover crops. In addition, application of nitrogen fertilizer had positive effects on the main crop yield and weed suppression. Therefore, it is concluded, that weeds can be suppressed effectively by interseeding cover crops with sufficient fertilization.