Response of phosphorus fractions to land-use change followed by long-term fertilization in a sub-alpine humid soil of Qinghai–Tibet plateau

TY - JOUR

T1 - Response of phosphorus fractions to land-use change followed by long-term fertilization in a sub-alpine humid soil of Qinghai–Tibet plateau

AU - Sun, Xiaolei

AU - Li, Meng

AU - Wang, Guoxi

AU - Drosos, Marios

AU - Liu, Fulai

AU - Hu, Zhengyi

PY - 2019/3/11

Y1 - 2019/3/11

N2 - Purpose: Identification of phosphorus (P) species is essential to understand the transformation and availability of P in soil. However, P species as affected by land use change along with fertilization has received little attention in a sub-alpine humid soil of Tibet plateau. Materials and methods: In this study, we investigated the changes in P species using Hedley sequential fractionation and liquid-state 31P-NMR spectroscopy in soils under meadow (M) and under cropland with (CF) or without (CNF) long-term fertilization for 26 years in a sub-alpine cold-humid region in Qinghai–Tibet plateau. Results and discussion: Land-use change and long-term fertilization affected the status and fractions of P. A strong mineralization of organic P (OP) was induced by losing protection of soil organic matter (SOM) and Fe and Al oxides during land-use change and resulted in an increase of orthophosphate (from 56.49 mg kg−1 in M soils to 130.07 mg kg−1 in CNF soils) and great decreases of orthophosphate diesters (diester-P, from 23.35 mg kg−1 in M soils to 10.68 mg kg−1 in CNF soils) and monoesters (from 336.04 mg kg−1 in M soils to 73.26 mg kg−1 in CNF soils). Long-term fertilization boosted P supply but failed to reclaim soil diester-P (from 10.68 mg kg−1 in CNF soils to 7.79 mg kg−1 in CF soils). This may be due to the fragile protection from the combination of SOM with diester-P when long-term fertilization had only improved SOM in a slight extent. Conclusions: These results suggest that SOM plays an important role in the soil P cycling and prevents OP mineralization and losses from soil. It is recommended that optimization of soil nutrient management integrated with SOM was required to improve the P use efficiency for the development of sustainable agriculture.

AB - Purpose: Identification of phosphorus (P) species is essential to understand the transformation and availability of P in soil. However, P species as affected by land use change along with fertilization has received little attention in a sub-alpine humid soil of Tibet plateau. Materials and methods: In this study, we investigated the changes in P species using Hedley sequential fractionation and liquid-state 31P-NMR spectroscopy in soils under meadow (M) and under cropland with (CF) or without (CNF) long-term fertilization for 26 years in a sub-alpine cold-humid region in Qinghai–Tibet plateau. Results and discussion: Land-use change and long-term fertilization affected the status and fractions of P. A strong mineralization of organic P (OP) was induced by losing protection of soil organic matter (SOM) and Fe and Al oxides during land-use change and resulted in an increase of orthophosphate (from 56.49 mg kg−1 in M soils to 130.07 mg kg−1 in CNF soils) and great decreases of orthophosphate diesters (diester-P, from 23.35 mg kg−1 in M soils to 10.68 mg kg−1 in CNF soils) and monoesters (from 336.04 mg kg−1 in M soils to 73.26 mg kg−1 in CNF soils). Long-term fertilization boosted P supply but failed to reclaim soil diester-P (from 10.68 mg kg−1 in CNF soils to 7.79 mg kg−1 in CF soils). This may be due to the fragile protection from the combination of SOM with diester-P when long-term fertilization had only improved SOM in a slight extent. Conclusions: These results suggest that SOM plays an important role in the soil P cycling and prevents OP mineralization and losses from soil. It is recommended that optimization of soil nutrient management integrated with SOM was required to improve the P use efficiency for the development of sustainable agriculture.

KW - Compost

KW - Hedley sequential fractionation

KW - Liquid-state P-NMR

KW - Meadow soil

KW - Organic phosphates

UR - http://www.scopus.com/inward/record.url?scp=85053428993&partnerID=8YFLogxK

U2 - 10.1007/s11368-018-2132-y

DO - 10.1007/s11368-018-2132-y

M3 - Journal article

AN - SCOPUS:85053428993

SN - 1439-0108

VL - 19

SP - 1109

EP - 1119

JO - Journal of Soils and Sediments

JF - Journal of Soils and Sediments

IS - 3

ER -