In order to achieve a rapid and accurate identification of soil stratification information and accelerate the development of smart agriculture,this paper conducted soil stratification experiments on agricultural soils...In order to achieve a rapid and accurate identification of soil stratification information and accelerate the development of smart agriculture,this paper conducted soil stratification experiments on agricultural soils in the Mollisols area of Northeast China using Ground Penetrating Radar(GPR)and obtained different types of soil with frequencies of 500 MHz,250 MHz,and 100 MHz antennas.The soil profile data were obtained for 500 MHz,250 MHz,and 100 MHz antennas,and the dielectric properties of each type of soil were analyzed.In the image processing procedure,wavelet analysis was first used to decompose the pre-processed radar signal and reconstruct the high-frequency information to obtain the reconstructed signal containing the stratification information.Secondly,the reconstructed signal is taken as an envelope to enhance the stratification information.The Hilbert transform is applied to the envelope signal to find the time-domain variation of the instantaneous frequency and determine the time-domain location of the stratification.Finally,the dielectric constant of each soil horizon is used to obtain the propagation velocity of the electromagnetic wave at the corresponding position to obtain the stratification position of each soil horizon.The research results show that the 500 MHz radar antenna can accurately delineate Ap/Ah,horizon and the absolute accuracy of the stratification is within 5 cm.The effect on the soil stratification below the tillage horizon is not apparent,and the absolute accuracy of the 250 MHz and 100 MHz radar antennas on the stratification is within 9 cm.The overwhelming majority of the overall calculation errors are kept to within 15%.Based on the three central frequency antennas,the soil horizon detection rate reaches 93.3%,which can achieve accurate stratification of soil profiles within 1 m.The experimental and image processing methods used are practical and feasible;however,the GPR will show a missed detection for soil horizons with only slight differences in dielectric properties.Overall,this study can quickly and accurately determine the information of each soil stratification,ultimately providing technical support for acquiring soil configuration information and developing smart agriculture.展开更多
Labile organic carbon(LOC)is a fraction of soil organic carbon(SOC)with rapid turnover time and is affected by soil fertilization.This investigation characterized the SOC content,LOC content and LOC distribution in th...Labile organic carbon(LOC)is a fraction of soil organic carbon(SOC)with rapid turnover time and is affected by soil fertilization.This investigation characterized the SOC content,LOC content and LOC distribution in the treatment plots of surface soil erosion at five levels(0-,5-,10-,20-and 30-cm erosion).The soil had received contrasting fertilizer treatments(i.e.,chemical fertilizer or chemical fertilizer+manure)for 6 years.This study demonstrated that both SOC and various LOC fractions contents were higher in the plots with fertilizer+manure than in those with fertilizer alone under the same erosion conditions.The SOC and LOC contents decreased as the erosion depth increased.Light fraction organic carbon,particulate organic carbon,easily oxidizable organic carbon(KMnO4-oxydizable organic carbon),and microbial biomass carbon were 27%–57%,37%–47%,20%–25%,and 29%–33%higher respectively in the fertilizer+manure plots,than in the fertilizer alone plots.Positive correlations(p<0.05)between SOC content and different fractions contents were observed in all plots except the correlation between total SOC content and water-soluble organic carbon content in the different fertilization treatments.Obviously,fertilizer+manure treatments would be conducive to the accumulation of LOC and SOC in the Black soil of Northeast China.展开更多
基金Under the auspices of the National Key R&D Program of China(No.2021YFD1500100)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28100000)。
文摘In order to achieve a rapid and accurate identification of soil stratification information and accelerate the development of smart agriculture,this paper conducted soil stratification experiments on agricultural soils in the Mollisols area of Northeast China using Ground Penetrating Radar(GPR)and obtained different types of soil with frequencies of 500 MHz,250 MHz,and 100 MHz antennas.The soil profile data were obtained for 500 MHz,250 MHz,and 100 MHz antennas,and the dielectric properties of each type of soil were analyzed.In the image processing procedure,wavelet analysis was first used to decompose the pre-processed radar signal and reconstruct the high-frequency information to obtain the reconstructed signal containing the stratification information.Secondly,the reconstructed signal is taken as an envelope to enhance the stratification information.The Hilbert transform is applied to the envelope signal to find the time-domain variation of the instantaneous frequency and determine the time-domain location of the stratification.Finally,the dielectric constant of each soil horizon is used to obtain the propagation velocity of the electromagnetic wave at the corresponding position to obtain the stratification position of each soil horizon.The research results show that the 500 MHz radar antenna can accurately delineate Ap/Ah,horizon and the absolute accuracy of the stratification is within 5 cm.The effect on the soil stratification below the tillage horizon is not apparent,and the absolute accuracy of the 250 MHz and 100 MHz radar antennas on the stratification is within 9 cm.The overwhelming majority of the overall calculation errors are kept to within 15%.Based on the three central frequency antennas,the soil horizon detection rate reaches 93.3%,which can achieve accurate stratification of soil profiles within 1 m.The experimental and image processing methods used are practical and feasible;however,the GPR will show a missed detection for soil horizons with only slight differences in dielectric properties.Overall,this study can quickly and accurately determine the information of each soil stratification,ultimately providing technical support for acquiring soil configuration information and developing smart agriculture.
基金Under the auspices of National Natural Science Foundation of China(No.41271313,41172229,41071171)Harbin Bureau of Science and Technology for Outstanding Scientist(No.2010FXYN044)
文摘Labile organic carbon(LOC)is a fraction of soil organic carbon(SOC)with rapid turnover time and is affected by soil fertilization.This investigation characterized the SOC content,LOC content and LOC distribution in the treatment plots of surface soil erosion at five levels(0-,5-,10-,20-and 30-cm erosion).The soil had received contrasting fertilizer treatments(i.e.,chemical fertilizer or chemical fertilizer+manure)for 6 years.This study demonstrated that both SOC and various LOC fractions contents were higher in the plots with fertilizer+manure than in those with fertilizer alone under the same erosion conditions.The SOC and LOC contents decreased as the erosion depth increased.Light fraction organic carbon,particulate organic carbon,easily oxidizable organic carbon(KMnO4-oxydizable organic carbon),and microbial biomass carbon were 27%–57%,37%–47%,20%–25%,and 29%–33%higher respectively in the fertilizer+manure plots,than in the fertilizer alone plots.Positive correlations(p<0.05)between SOC content and different fractions contents were observed in all plots except the correlation between total SOC content and water-soluble organic carbon content in the different fertilization treatments.Obviously,fertilizer+manure treatments would be conducive to the accumulation of LOC and SOC in the Black soil of Northeast China.
