1. Effects of biochar on organic nitrogen mineralization of Northeast forest soil Reporter : SiYao Du First-graduate student Beijing Normal University, Academy of Disaster Reduction and Emergency Management Siyao Du, Jun Tao*, Xianxiang Luo, Yingjun Xu, Wei Gu 2016.04.22, Vienna

2. 2 Background 1 Contents Materials&Methods 2 Results 3 Discussion 4

3. 3 Background Soil degradation and lower fertility Special physical and chemical properties of biochar Biochar addition increases soil fertility and nutrient Biochar added as a soil conditioner Effect soil organic nitrogen mineralization process Forest soil excessive reclamation unreasonable land use

4. 4 Background scholarresultsreason Priit Tammeorg Biochar reduces soil nitrogen mineralization Biochar promotes microbial fixation DempsterBiochar can inhibit the mineralization of organic nitrogen in the soil Reduces the amount of soil MBC KolbBiochar may promote the N mineralizationThe adsorption of phenol compounds AngusAdding biochar did not change the mineralization of organic nitrogen DeLucaAdding biochar to forest soil can promote the nitrogen mineralization; Adding biochar to agricultural soil, the influence of the organic nitrogen mineralization is uncertain. Controvertial! Effects of biochar on organic nitrogen mineralization of Northeast forest soil

5. 55 Materials&Methods

6. Soil Forest soil from Harbin, Heilongjiang Province, China (0-10cm deep) Biochar Corn straw through slow pyrolysis at 550 ℃ 66 Materials&Methods pHTC(%)TN(%)NH 4 + -N mg/kg NO 3 - -N mg/kg Organic-N g/kg Ash(%) Soil6.5711.191.565.9138.729.52- Biochar9.3468.780.67---14.53 Table 1. Chemical properties of the soil and biochar used in the experiment

7. 77 Materials&Methods Experimental design 18 ℃ 30 ℃ Soil CK(18 ℃ )CK(30 ℃ ) Soil+1 ％ BC550BC550(18 ℃ )BC550(30 ℃ ) Table 2. Experimental treatments  40g biochar-amended soil  Incubator (set temperature at 18 ℃ and 30 ℃ )  Soil moisture was adjusted to 80% field capacity  Measure at 1, 3, 5, 11, 17days in triplicate

8. 88 Materials&Methods PropertiesMethod TCFLASH-2000 elemental analyzer TNFLASH-2000 elemental analyzer NO 3 - -Nphenol disulfonic acid using spectrophotometric methods NH 4 + -Nindophenol blue reagent using spectrophotometric methods Urease activities Spectrophotometer colorimetric method after incubation at 37ºC for 24h Moisture contentGravimetry pHpH-meter Experimental method

9. 9 Materials&Methods Calculation and statistical analysis Calculate with Excel software Draw with origin 8.6 Analyse with SPSS20.0 Test with ANOVA (Duncan’s test) Evaluate the correlation with correlation analysis

10. 10 Results 3.1NH 4 + -N dynamics Trend of growth first 11d decreased at 17d Two biochar treatments are significantly lower Two 30 ℃ treatments are significantly higher

11. 11 Results 3.2NO 3 - -N dynamics Trend of growth Since 5d, two biochar treatments are significantly lower Two 30 ℃ treatments are significantly higher

12. 12 Results 3.3Net N mineralization dynamics Trend of growth Two biochar treatments are significantly lower Two 30 ℃ treatments are significantly higher

13. 13 Results 3.4Net N mineralization rate dynamic Trend of growth Two biochar treatments are significantly lower Two 30 ℃ treatments are significantly higher

14. 14 Results 3.5 pH dynamics Trend of decline Two biochar treatments are significantly higher Two 30 ℃ treatments are significantly lower

15. 15 Results 3.6 Soil urease activity dynamics Trend of growth Two biochar treatments are significantly lower two 30 ℃ treatments are significantly higher

16. 16 Conclusion  Corn biochar significantly inhibits forest soil N mineralization  Forest soil organic nitrogen mineralization degree of two 30 ℃ treatments are significantly higher

17. 17 Discussion  Biochar factor had more obvious effect on soil nitrogen mineralization  Biochar inhibits soil N mineralization by changing soil physicochemical properties, such as soil pH, EC, and urease activities

18. 18 and thanks to: Jingjing Chang ; Xiao Wang ; He Zhang Thanks for your attention!