[Effects of applying inorganic P and wheat straw on the microbial biomass P and microbial P concentration in a calcareous soil with low concentration available P].
In an incubation test, a calcareous soil with low concentration of available P was amended with KH2PO4 (0, 25, 50, and 100 mg P x kg(-1)) and ground wheat straw (5 g C x kg(-1)), and incubated at 25 degrees C for 90 days. The aim was to investigate the change patterns of soil microbial biomass P and microbial P concentration as well as their relationships with soil available P. The results showed that both soil microbial biomass P and microbial P concentration increased with increasing inorganic P addition, with the maximum being 71.37 and 105.34 mg x kg(-1), respectively. The combined application of inorganic P (except 100 mg P x kg(-1)) and wheat straw decreased the soil microbial biomass P and microbial P concentration, being most obvious at early incubation period. Soil microbial biomass P and microbial P concentration had significant positive correlations (P < 0.05) with soil available P (R2 = 0.26 and 0.40, n = 49, respectively). The applied P could rapidly transform into microbial biomass P. The maximum apparent contribution rate of applied P to microbial biomass P was 71%. The added wheat straw could further improve the apparent contribution rate.
Zhao
Xiao-Rong
XR
College of Resource and Environment, China Agricultural University, Beijing 100094, China. zhaoxr@cau.edu.cn
Zhou
Ran
R
Li
Gui-Tong
GT
Lin
Qi-Mei
QM
D000383:Agriculture / Q000379:methods; D007287:Inorganic Chemicals / Q000737:chemistry / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D018547:Plant Stems / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D014908:Triticum
D007287:Inorganic Chemicals; D012987:Soil; D010758:Phosphorus