Do effects of soil compaction persist after ploughing? Results from 21 long-term field experiments in Sweden

摘要: Abstract The extent and persistence of the effect soil compaction in a system with annual ploughing were investigated 21 long-term field experiments Sweden total 259 location-years. Crop yield, physical properties plant establishment determined. All had two common treatments: control (no extra traffic) compacted (350 Mg km ha −1 experimental traffic autumn prior to ploughing), using tractor trailer traditional wheel equipment an axle load restricted 4 Mg. During rest year, both treatments conventionally equally tilled. was repeated each for at least 7 years, yield determined year until 5 years after termination treatment. Compaction decreased porosity proportion large pores increased tensile strength dry aggregates. On clay loam soils, it fine aggregates seedbed gravimetric water content seedbed. treatment declined compared during first which reached steady state. this state, caused loss 11.4%, averaged over 107 Within 4–5 treatment, returned level. average individual sites increasing content. Results from additional indicated that linearly correlated amount up 300–400 . With greater ground contact pressure or time traffic, there loss. Soil effects on similar all spring-sown crops, percentage seemed be independent yield. In few location-years winter wheat no decrease. There 5.1% less plants than control. decrease significantly number plants. Between results highly variable, consistent correlations between weather conditions growing period found. affected good as well poor crop growth.