Dataset from a long-term field experiment on the effect of cropping systems and climate on soil physical characteristics, field crop emergence and yield

A long-term field experiment was conducted from 1989 to 2007 in northern France in a laomy soil to assess the cumulative effects of cropping systems on soil compaction, soil porosity, soil structure, crop emergence and yield. Three cropping systems (CSs), including different crop rotations and cultivations (early or late sowing and harvesting), were compared. CS I was the succession of spring pea /winter wheat/oilseed rape (flax from 2001)/winter wheat while CSs II and III were the succession of sugar beet/winter wheat/maize/winter wheat. The latter two CSs consisted of different sowing dates, based on two distinct decision rules aimed at minimizing the risk of soil compaction in the CS II or maximizing the duration of the crop in the CS III. From 2000, a new treatment with superficial tillage (i.e. at 6 cm depth) was introduced into the experiment in order to compare the effects of annual ploughing and reduced tillage on change in soil structure over time. Soil water content was measured for each field operation by taking samples every 0.05 m up to a depth of 0.30 m in the topsoil. Soil compaction and soil structure was evaluated after each sowing using a morphological approach and soil bulk density measurements. The proportion of highly compacted zones, i.e. the zones with a massive structure and no visible macropores in the soil profile, were evaluated with the “profil cultural” method. Dry bulk density was measured with a gamma-ray transmission probe. Seedling emergence rates and crop yield were also measured in relation to cropping systems. This dataset represents an important description of the change in soil compaction level, crop emergence rates and yield, in relation to CSs and climate, and the overall impact on seedbed structure variations for major field crops under northern France conditions. This information can be used as input variables of several soil-crop models aiming at evaluating the impact of CSs and climate on soil compaction and seedbed structures.