Long-term field trial on tillage in crop rotation - Westerfeld

The long-term field trial started 1992 in Bernburg, Saxony Anhalt, Germany (51°82' N, 11°70', 138 m above sea level). The soil is a loess chernozem over limestone with an effective rooting depth of 100 cm, containing 22% clay, 70% silt and 8% sand in the ploughed upper (Ap) horizon. It has a neutral pH (7.0-7.4) and an appropriate P and K supply (45-70 mg kg-1 and 130-185 mg kg-1 in calcium-acetate-lactate extract, respectively). The 1980 - 2010 annual average temperature was 9.7°C, the average annual precipitation 511 mm. On five large parcels in strip split plot design (1.2 ha each, main plots) the individual crops - grain maize (Zea mays) - winter wheat (Triticum aestivum) - winter barley (Hordeum vulgare) - winter rapeseed (Brassica napus ssp. napus) - winter wheat - are rotated. All crop residues remain on the fields. Conservation tillage cultivator (CT, 10 cm flat non-inversion soil loosening) is compared to sub-plots with conventional tillage (MP; mould-board plough, carrier board with combined alternating ploughshares, ploughing depth 30 cm, incl. soil inversion). The differentially managed soils are either intensively (Int) operated according to usual practice regarding N supply and pesticide application or extensively managed (Ext; reduced N supply, without fungicides and growth regulators).