A field experiment was conducted to study the effects of different ratios of chemical fertilizer nitrogen substitution by biogas slurry on yield, growth characteristics(development progress, plant height dynamic, population dynamic and dry matter accumulation dynamic), quality and heavy metal content of winter wheat. The results showed that winter wheat yield increased significantly(P<0.05), with the increase of the ratios of chemical fertilizer nitrogen substitution by biogas slurry, and the

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... eld of the treatment with 50% chemical fertilizer nitrogen substitution by biogas slurry(50%Nbs) was the highest, about 7.75 t·hm-2, 18.14% higher than the treatment with total chemical fertilizer nitrogen(Ncf). There were no significant differences between the yields of 100%Nbs and Ncf(P>0.05). The 1000-kernels weight presented a significant declining trend(P<0.05); the grains number per spike and harvest index increased at first and then decreased, with the increase of the ratios of chemical fertilizer nitrogen substitution by biogas slurry. The plant height, tiller number and dry matter accumulation in different stages presented the gradual increment trend; in maturity, the above ground dry matter accumulation of 100%Nbs was significantly higher than that of Ncf(P<0.05), The plant height, tiller number and dry matter accumulation of 200%Nbs were significantly higher than these of Ncf(P<0.05). Biogas slurry could improve wheat quality, and increase grain Cu, Zn contents, decrease grain Cd, Cr contents, significantly(P<0.05), and had no significant influences on grain Pb, As contents (P>0.05). The contents of these grain heavy metal of each treatment were lower than the maximum levels of contaminants in foods. When the ratio of chemical fertilizer nitrogen substitution by biogas slurry raised above 50%, because of the prolonged growth duration and the increased basal internode length could lead to lodge and yield reduction, and because of greater use of biog [...]