NIAB TAG’s New Farming Systems (NFS) research programme, currently in year nine and based at Morley in Norfolk, consists of several long-term field trials aiming to develop bio-sustainable cropping systems for conventional arable cropping. A component of the trials is evaluating the impact on energy efficiency of reduced or non-inversion tillage, a technique that has been cited by a number of previous studies as a potential means to improve the efficiency and resilience of arable cropping. Plough-based systems, used traditionally in arable cropping, in which soil is inverted with a mouldboard plough, are compared with non-inversion alternatives. These are either shallow (5-10 cm) with crop residues remaining mostly on the soil surface, or deep (15-20 cm) where a proportion of residues are incorporated into the topsoil. Soil compaction, a potential risk associated with reduced cultivations, is removed with a subsoiler. Although non-inversion tillage is reported to be advantageous due to decreased operational time and decreased energy input per ha, the effect on crop yield and impact on energy consumption per t of crop output needs accounting for. Previous work undertaken at NIAB TAG had shown an initial decrease in crop yield immediately after conversion to a noninversion tillage system and then a yield that then increases in following seasons, although it is unclear if this was a trend or associated with responses to specific seasonal conditions. However, a key question to address is whether this yield reduction reduces energy efficiency, and if so, in which crops and what are the longer term rotational implications
