TY - JOUR
T1 - Plant biomass management impacts on short-term soil phosphorus dynamics in a temperate grassland
AU - Boitt, Gustavo
AU - Simpson, Zachary P.
AU - Tian, Jihui
AU - Black, Amanda
AU - Wakelin, Steve A.
AU - Condron, Leo M.
PY - 2018/2/17
Y1 - 2018/2/17
N2 - The objective of this study was to quantify the combined effects of long-term plant biomass retention/removal and environmental conditions on soil microbial biomass phosphorus (P), bioavailable P, and acid phosphomonoesterase activity. Topsoil samples (0-2.5 and 2.5-5 cm) were collected from replicate field-based plots that had been maintained under contrasting plant biomass retention and removal regime for 21 years. Samples were collected on 14 occasions over a 17-month period and assessed for microbial P, bioavailable P, and phosphomonoesterase activity. All P measurements were consistently and significantly higher under plant biomass retention compared with biomass removal. Temporal variations in microbial P and phosphomonoesterase activity were evident in top soil (0-2.5 cm) and were driven by environmental conditions, mainly soil moisture, rainfall, and potential evapotranspiration, while bioavailable P had no temporal variation. Detailed analysis of microbial P data for the top 2.5-cm soil depth revealed that annual P flux through this pool was two times greater under biomass retention (10.3 kg P ha−1 year−1) compared with plant biomass removal (5.0 kg P ha−1 year−1). Similar and consistent trends were observed in soil from 2.5-to 5-cm sampling depth; however, differences were not significant. The findings of this study confirm the importance of the microbial biomass in determining the bioavailability of P in temperate grassland systems.
AB - The objective of this study was to quantify the combined effects of long-term plant biomass retention/removal and environmental conditions on soil microbial biomass phosphorus (P), bioavailable P, and acid phosphomonoesterase activity. Topsoil samples (0-2.5 and 2.5-5 cm) were collected from replicate field-based plots that had been maintained under contrasting plant biomass retention and removal regime for 21 years. Samples were collected on 14 occasions over a 17-month period and assessed for microbial P, bioavailable P, and phosphomonoesterase activity. All P measurements were consistently and significantly higher under plant biomass retention compared with biomass removal. Temporal variations in microbial P and phosphomonoesterase activity were evident in top soil (0-2.5 cm) and were driven by environmental conditions, mainly soil moisture, rainfall, and potential evapotranspiration, while bioavailable P had no temporal variation. Detailed analysis of microbial P data for the top 2.5-cm soil depth revealed that annual P flux through this pool was two times greater under biomass retention (10.3 kg P ha−1 year−1) compared with plant biomass removal (5.0 kg P ha−1 year−1). Similar and consistent trends were observed in soil from 2.5-to 5-cm sampling depth; however, differences were not significant. The findings of this study confirm the importance of the microbial biomass in determining the bioavailability of P in temperate grassland systems.
KW - Acid phosphomonoesterase activity
KW - Bioavailable phosphorus
KW - Microbial phosphorus flux
KW - Turnover rates
U2 - 10.1007/s00374-018-1269-6
DO - 10.1007/s00374-018-1269-6
M3 - Article
SN - 0178-2762
VL - 54
SP - 397
EP - 409
JO - Biology and Fertility of Soils
JF - Biology and Fertility of Soils
IS - 3
ER -