A wheat seedling rhizobox approach was used to differentiate between the rhizosphere and non-rhizosphere (bulk) soil amended with low and high rates of biochar (20 and 60 t ha-1 vs. control). Nitrate (NO3 -) was added as the main nitrogen (N) source because emerging biochar research points to reduced NO3 - loss through leaching and gaseous loss as nitrous oxide. The rhizosphere under the different treatments were distinct (P = 0.021), with greater soil-NO3 - and biochar-NO3 - contents in the high biochar treatment. Biochar addition increased wheat root length ratio (P = 0.053) and lowered root N uptake (P = 0.017), yet plant biomass and N content were similar between treatments. The results indicate localisation of NO3 - within the rhizosphere of biochar-amended soils which has implications for NO3 - loss and improved nitrogen use efficiency.
|Number of pages||4|
|Journal||Soil Biology and Biochemistry|
|Early online date||4 Aug 2011|
|Publication status||Published - 1 Nov 2011|