7 To reduce over-winter nitrate leaching from temperate soil under cereal cropping, nitrate catch 8 crops can be grown between main crops. We hypothesize that earlier sowing can replace catch 9 crops sown before winter wheat (Triticum aestivum L.) and improve wheat yields and N uptake. 10 Early sown (late August) and timely sown (late September) wheat were tested over two cropping 11 seasons (2011-12 and 2013-14) using two contemporary cultivars (Hereford and Mariboss) and 12 increasing rates

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... N (0 to 300 kg total-N ha -1 ) with animal manure (AM; cattle slurry) or mineral 13 fertilizers (NPK), surface-applied in late March. We measured over-winter N uptake in wheat, 14 harvest yields and N concentrations in grain and straw. Over-winter N uptake was 11 kg ha -1 higher 15 for early than for timely sown wheat; at harvest this benefit increased to 19 kg N ha -1 . Mariboss 16 yielded more straw than Hereford whereas grain yields did not differ. Early sowing increased grain 17 yields by 0.5 and 1.0 Mg ha -1 for NPK and AM, respectively, regardless of N rate. Grain and straw 18 N concentrations were higher with NPK than with AM, and NPK showed higher N use efficiency 19 (0.48-0.53) than AM (0.15-0.22). Moving sowing of winter wheat from late September to late 20 August provided higher grain and straw yields; the increased over-winter N uptake suggests that the 21 beneficial effect of earlier sowing may surpass that of a catch crop. Cattle slurry surface applied in 22 late March gave poor N use efficiency and low grain protein content. 23 2 Abbreviations: AM, animal manure (cattle slurry); DM, dry matter; NPK, mineral fertilizers; NUE, 24 nitrogen use efficiency; SEM, standard error of the mean 25 26