Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Effects of biochar addition and N reduction on the contents of NH4+-N (A) and NO3−-N (B) in soil at different fertilizer stages. The BF, SF1, and SF2 refer to the basal, first and second supplementary fertilizations, respectively. Different lowercase letters above the columns indicate significant differences between treatments (p < 0.05).
