[Effects of Biochar on Nitrous Oxide Fluxes and the Abundance of Related Functional Genes from Agriculture Soil in the North China Plain].

To explore the effect and mechanism of biochar application in reducing nitrous oxide (NO) content in agricultural soil, from March 27 to June 5 2015, pot experiments were conducted to study the effects of biochar application rates (CK, C1:5%, C2:10%, C3:15%, and C4:30%) (mass fraction) on soil NO fluxes and the functional marker genes ammonia monooxygenase (), , and , which are responsible for nitrification and denitrification. The results revealed the following. ①The application of low doses of biochar (5%) promoted NO emission.

[Heredity analysis of main characters of nitrogen use efficiency in maize.].

With P1, P2, F1, F2, B1 and B2 generations of two combinations of maize with high nitrogen use efficiency, hereditary capacity and genetic progress of seventeen characters were studied. The random block design was used in the experiment. The results showed that the heritability of each traits was different at different N levels.