Yield Parameters as Affected by Introduction or Discontinuation of Catch Crop Use

A 24‐yr‐old permanent field trial on coarse sand (Orthic Haplohumod) under temperate coastal climate conditions was used to determine (i) the effect of introducing perennial ryegrass ( Lolium perenne L.) as a catch crop on plots with a history of low input of organic matter, and (ii) the residual effect of long‐term use of ryegrass as a catch crop on main crop yield and N uptake. The catch crop (8–10 kg ha −1 ) was undersown in spring wheat ( Triticum aestivum L.). From 1993 to 1996, four treatments were included: catch crop since 1968, catch crop since 1993, no catch crop, and catch crop until 1993. Each treatment was conducted at two previously established N rates (60 and 120 kg N ha −1 yr −1 ), which were subdivided into four new N rates (0, 60, 90, and 120 kg N ha −1 yr −1 ). Two years after introduction of the catch crop, yields were no longer different from yields with long‐term previous catch crop use. The residual effect of long‐term catch crop use on yield persisted for more than 4 yr. With previous long‐term use of a catch crop compared with no previous use, N fertilization could be reduced by 15 or 27 kg N ha −1 yr −1 at the 60 or 120 kg N ha −1 yr −1 rate, respectively, without yield reductions. The experiment shows that the use of ryegrass as a catch crop has the potential to benefit main crop yield and soil fertility.