摘要
The contents of the soil microbial biomass nitrogen (SMBN) in the soils sampled from the Loess Plateau of China were determined using chloroform fumigation aerobic incubation method (CFAIM), chloroform fumigation anaerobic incubation method (CFANIM) and chloroform fumigation-extraction method (CFEM).The N taken up by ryegrass on the soils was determined after a glasshouse pot experiment. The flushes of nitrogen (FN) of the soils obtained by the CFAIM and CFANIM were higher than that by the CFEM, and there were significantly positive correlations between the FN obtained by the 3 methods. The N extracted from the fumigated soils by the CFAIM, CFANIM and CFEM were significantly positively correlated with the N uptake by ryegrass. The FN obtained by the 3 methods was also closely positively correlated with the plant N uptake. The contributions of the SMBN and mineral N and mineralized N during the incubation period to plant N uptake were evaluated with the multiple regression method. The results showed that the N contained in the soil microbial biomass might play a noticeable role in the N supply of the soils to the plant.
The contents of the soil microbial biomass nitrogen (SMBN) in the soilssampled from the Loess Plateau of China were determined using chloroform fumigation aerobicincubation method (CFAIM), chloroform fumigation anaerobic incubation method (CFANIM) and chloroformfumigation-extraction method (CFEM). The N taken up by ryegrass on the soils was determined after aglasshouse pot experiment. The flushes of nitrogen (F_N) of the soils obtained by the CFAIM andCFANIM were higher than that by the CFEM, and there were significantly positive correlations betweenthe F_N obtained by the 3 methods. The N extracted from the fumigated soils by the CFAIM, CFANIMand CFEM were significantly positively correlated with the N uptake by ryegrass. The F_N obtained bythe 3 methods was also closely positively correlated with the plant N uptake. The contributions ofthe SMBN and mineral N and mineralized N during the incubation period to plant N uptake wereevaluated with the multiple regression method. The results showed that the N contained in the soilmicrobial biomass might play a noticeable role in the N supply of the soils to the plant.
基金
the National Natural Science Foundation of China(Nos.49890330,39770425 and 30070429)
the National Key Basic Research Support Foundation of China(No.G1999011707).
