a negative trendgold
Although the yield RR was not significantly affected by the type of fertilizer applied (manure, ashes, soluble P, control (no P fertilizer), municipal waste composts, rock P, sewage sludge, digestates, biochar) (P=0.155; Figure 7 ), animal waste products tended to have the strongest increase in the RR of BE addition, whereas Biochar even showed a negative trend.