Abstract: Analysis of energy balance characteristics of cropland and its affecting factors has great significance to improve agricultural production and hydrothermal resource utilization in the region of red soil. Based on the data measured by large aperture scintillometer, Bowen ratio instrument and automatic meteorological station in a hilly region of red soil, we analyzed the characteristics of energy balance and the correlation between water and heat flux and meteorological elements in the hilly region of red soil. The results showed that the diurnal variation of the components of energy balance all showed a monotone trend on the two scales due to the weather conditions. The latent heat flux had the greatest values, while sensible heat flux and soil heat flux values were lower. The monthly variation of components of energy balance presented a same trend on the two scales. The sensible heat flux was lower on the catchment scale than on the field scale, but the latent heat flux was vice versa. The net radiation, air temperature, relative humidity, atmospheric pressure, and average wind speed were the main factors affecting water and heat fluxes on the two scales, while vapor pressure and precipitation had inconsistent effects on water and heat fluxes on the two scales.

Key words: straw-derived biochar, crop growth,  ammonia volatilization., biochar-C loss, successive incorporation