Abstract: To explore the partial availability of biogas fertilizer and its incomplete seasonal release of the nutrients,the experiment was carried in the maize field with the application of equal amounts of N/P/K nutrients. In the first year,six experimental groups were set up,labelled as T₁（no fertilization）,T₂（chemical fertilizer）,T₃（20% biogas fertilizer+80% chemical fertilizer）,T₄（50% biogas fertilizer+50% chemical fertilizer）,T₅（80% biogas fertilizer+20% chemical fertilizer）,T₆（100% biogas fertilizer）,followed by a uniform application of T₂（chemical fertilizer） for every groups in the second year. Results collected indicate that biogas fertilizer has a significant chronic effect. The improvement of soil fertility due to the application of biogas fertilizer in the first crop rotation considerably increases the production,biological characters of plants and soil alkali hydrolysable nitrogen content. Observation shows that there is a noticeable improvement of corn ear growth condition in T₅ comparing to other groups. Group T₃ to T₆ demonstrate an overall advancement in number of kernels per single ear and resistance against lodging over samples of T₁ and T₂. An increase in yield is witnessed in T₃,T₄,T₅ and T₆ by 5.88%,5.35%,11.23% and 13.90% respectively,compared with T₂. The soil alkali hydrolysable nitrogen content of T₃,T₄,T₅ and T₆ in the following crop rotation rises by 37.82%, 76.74%,57.76%,72.76% respectively,based on measurement of T₂.

Key words: biogas fertilizer, maize（Zea mays L.）, aftereffect