Abstract: A field experiment was carried out on using biochar-based fertilizers (BCF) in rice production. The BCFs used in the experiment were kind of blends of chemical fertilizers(CF) and biochar prepared out of wheat straw, maize stalk, peanut shells, pig dung, and domestic waste, separately. The field experiment was designed to explore effects of the BCFs on rice yield and N recovery rate in a paddy field in Chizhou, Anhui Province. Results show that compared to CF, the BCFs reduced the dosage of N fertilizer by 19.94% and increased rice yield at least by 6.7% and even by 39.34% as a result of the use of wheat straw biochar. The BCFs also significantly increased the number and weight of grains per ear and the ratio of nitrogen content in grain/stem-and–leaf by 11.64% - 59.91%, indicating that the use of BCFs improved N distribution to grains, partial factor productivity of nitrogen by 33.41% -74.09%, and nitrogen harvest index and nitrogen grain production efficiency of the crop were improved as well. It is, therefore, concluded that BCF is a nitrogen-saving alternative to the traditional way of “chemical fertilizer plus organic manure”.Especially, the wheat straw biochar-based fertilizer has a significant extension potential in increasing rice yield and improving N using efficiency.

Key words: biochar-based fertilizers, fertilization rate, rice, yield, nitrogen use efficiency