Editorial: Overview and comparison of conservation tillage practices and organic farming in Europe and North America

Overview and comparison of conservation tillage practices and organic farming in Europe and North America Tillage has been ubiquitous to crop production in most of the world for millennia.Implements used to till the soil that were pulled by animals are known to have existed at least as far back as 8000 BC. 1 However, growing concerns about the negative consequences of tillage on soil quality 2-4 spurred widespread interest in reducing tillage practices on farms, particularly in the Great Plains of North America where farming practices brought by immigrants from eastern regions and from Europe were not adapted because of the dry conditions that were encountered.This realization and other developments culminating in the Dust Bowl era during the 1930s made it obvious that innovative farming practices were needed to protect soil from erosion and degradation in quality.A logical consequence is modern no-till farming, where soil is disturbed minimally, if at all, when growing annual cash and forage crops.Advantages of no-till compared with clean or conventional tillage farming have been widely described in the scientific literature, with an excellent recent summary by Triplett and Dick 5 .Growth in modern no-till farming coincided with the development and commercial use of synthetic herbicides, notably first with 2,4-dichlorophenoxyacetic acid (2,4-D) in the USA 6 , and paraquat in Europe 1 .Herbicides provided farmers with an effective alternative to tillage for controlling weeds but, unlike tillage, did not bury crop residue.The resultant vegetative mulch protected soil from water and wind erosion and, in semi-arid regions, reduced evaporation and improved soil-water storage efficiency 7 .The development of improved herbicides, along with seeding and harvesting equipment designed for use in no-till systems, resulted in the steady growth of this farming method, beginning in the 1990s 5 .Few herbicide options are available to organic farmers, in contrast to conventional farmers, forcing a continued reliance on tillage for weed control in systems managed organically.Research on alternative tillage methods for organic farmers is limited and has lagged behind comparable efforts directed at conventional farmers.Moreover, the so-called bio-herbicides such as natural vinegar, corn gluten and pine extracts that are permitted for use in certified organic farming in some regions of the globe are not, to date, allowed in Europe (European Council (EC) Regulation No. 834/2007 on organic production).Consequences of this dependence on tillage are the negative impacts on soil quality described elsewhere 2-4 .Arguments have been made about the inferiority of organic farming compared with conventional no-till