Presentation on theme: "Google images 2011 Biochar Application to Subarctic Soils: Effect of biochar on microbial activity after freeze-thaw cycles and plant response at different."— Presentation transcript:
1Google images 2011Biochar Application to Subarctic Soils: Effect of biochar on microbial activity after freeze-thaw cycles and plant response at different application rates.S. Castillo., A. Soria., C. Ping., G. Michaelson., M. LeighUniversity of Alaska Fairbanks
2IntroductionHigh latitude soils are weakly developed and are a challenge to producers (1)Alaska has some has harsh climatic conditions that affect agriculture (2)The demand for locally grown produce is gradually increasing .Abundance of black spruce as feedstock.There is a need more more local renewables practices that can enhance the local soils.
3Research questionsWhat are the differences among black spruce biochar created at different residence times?What is the influence on microbial activity of soils amended with different biochar types and amounts before and after freeze-thaw?What is the effect of black spruce biochar on plant yield and nutrient retention at different application rates?
4Picea marianna Biochar Five different types of biochar were created based on a response surface model conditions.Black spruce biochar was produced in a pilot scale, fixed bed pyrolysis unit, with a capacity of 1 kg/hrTemperature was maintained at 550 °CChemical analysis of samplesThis feedstacks undergo a chemical and chemical trasnformation that makes it resitant to biotic and abiotic degradability making a it a long lasting soil amendment. This biochar can be made from different sources or organic waste.
5Black Spruce biochar chemical analysis Biochar type(Residence time seconds)Biochar unit RPMpHECmmho/cmCEC cmol/kgC/N ratios %(1) 160.78.564.730.1212.1568.59 – 0.26(2) 134.410.85.060.119.7771.0 – 0.27(3) 97.316.24.550.1517.3667.30 – 0.23(4) 81.9721.64.290.216.4968.90 – 0.24(5) 73.6523.84.770.1717.07The skeletal porous structure of biochar serves as a Refugio for soil organism, increase water and nutrient retention and increases exchange sites for essential nutrients. which in turn benefits plant yield and reduce fertilizer cost.
6Nutrient analysis Mehlich III BiocharP (ppm)K(ppm)CaMgCuZnMnFe1<1441004198.6166.65.821424062128.6113.02.617833864168.0160.810.8101848786176.0161.67.0656513017211113534.5558.86.1349
7Freeze-thaw and charcoal effect on soil biota Forest fire charcoal presence on boreal forest has shown greater efficiency of nutrient uptake.( Wardle, 1997)Freeze and thawing destroys microbial tissue (Haines, 1938)Burst of CO2 during freeze and thaw (Ross,1972)Soil goes through physical and chemical changes (DeLuca, 1992)
8Biochar influence on microbial activity before and after freeze-thaw RunRetention timeBiochar amount (g)116.26.2520.95310.82.5421.65623.84710898.56111211.2513Methods:Treatments based on a response surface model, constructed using Design Expert v7 softwareActively cropped soil and forest soil were collected from the Matanuska Experiment FarmMicrobial activity was measured with 8210-CO2 gas analyzer Columbus instruments 180 C.Samples underwent 1 cycle of freeze-thaw .
13Remaining workGoogle imagesAmend soils with the optimal biochar and evaluate plant response.Examine the physical change of biochar after freeze – thaw cycles.
14SummaryResidence time influenced the chemical characteristics of black spruce biochar specially at the shortest residence time.Biochar treatments increased microbial activity especially on cultivated soils before and after freeze thaw. It stabilization after few days confirms that biochar can be a long term carbon storage on soils.The response surface model indicated significance in all models except for forest soils before and after freeze-thaw.