Yi Cheng; Zu-cong Cai; Scott X. Chang; Jing Wang; Jin-bo Zhang (2012). “Wheat straw and its biochar have contrasting effects on inorganic N retention and N2O production in a cultivated Black Chernozem.” Biology and Fertility of Soils. 48(8), 941-948. DOI: 10.1007/s00374-012-0687-0
Abstract: A laboratory incubation experiment was conducted to investigate the effects of direct incorporation of either wheat straw or its biochar into a cultivated Chernozem on gross N transformations calculated by the 15N pool dilution technique and nitrous oxide (N2O) production rates. Incorporation of wheat straw stimulated gross NH 4 + (ammonium) and NO 3 − (nitrate) immobilization rates by 302 and 95.2 %, respectively, suppressed gross nitrification rates by 32.2 %, and increased N2O production by 37.7 %. In contrast, the addition of a biochar produced from the wheat straw did not influence any of the above N cycling processes. Therefore, application of biochar could be a possible management strategy for long-term C sequestration (through soil storage of stable C contained in the biochar) in soils without increasing N2O production rates, but could not effectively immobilize NO 3 − in the soil.
Mark J. Gronnow; Vitaliy L. Budarin; Ondřej Maše; Kyle N. Crombie; Peter A. Brownsort; Peter S. Shuttleworth;
Peter R. Hurst; James H. Clark (2012). “Torrefaction/biochar production by microwave and conventional slow pyrolysis – comparison of energy properties.” GCB Bioenergy Published online ahead of print. DOI: 10.1111/gcbb.12021.
Abstract: The energy efficiency of torrefaction/pyrolysis of biomass to fuel/biochar was studied using conventional (slow) and microwave (low temperature) pyrolysis. Conventional pyrolysis is approximately three times as energy efficient as microwave pyrolysis, in terms of the energy required to process a unit of feedstock. However, this is more than compensated for by the higher energy content of the condensable and gaseous coproducts from microwave pyrolysis, as these can be utilized to generate the electricity required to drive the process. It is proposed that the most efficient method of torrefaction/biochar production is a combination of conventional heating with ‘catalytic’ amount of microwave irradiation.
D.N. Mulcahy; D.L. Mulcahy; D. Dietz (2012). “Biochar soil amendment increases tomato seedling resistance to drought in sandy soils.” Journal of Arid Environments 88,. 222-225. DOI: 10.1016/j.jaridenv.2012.07.012.
Abstract: Expanding aridity threatens agriculture in much of the world. Small farms (less than two hectares) produce 90% of the food in Eastern and Southern Africa and provide 70% of employment for women in the Least Developed Countries. Aridity thus endangers both food production and the employment of women. One possible solution is the addition of biochar, a highly porous pryrolysed biomass which is well documented to help retain water and nutrients in soils. Most current literature, however, proposes quantities of biochar which are beyond reach of small farms. The purpose of this research was thus to develop a method which would allow small amounts of biochar to provide significant protection for plants in their most vulnerable stage, the seedling. The test species was the cultivated tomato (Lycopersicon esculentum) because this is an important crop for subsistence farmers, and the seedlings are highly susceptible to drought. The results demonstrate that, in sandy substrates, 30% (v/v) biochar, concentrated in seedling root zones, significantly increases seedling resistance to wilting. Normal cooking can produce about 500 g of biochar a day and thus make possible increased wilting resistance for over 4000 tomato seedlings each year. This benefit is therefore within the reach of a demographic whose success is critically important to global sustainability.