Pervasive soil phosphorus losses in terrestrial ecosystems in China

Future phosphorus (P) shortages could seriously affect terrestrial productivity and food security. We investigated the changes in topsoil available P (AP) and total P (TP) in China's forests, grasslands, paddy fields, and upland croplands during the 1980s–2010s based on substantial repeated soil P measurements (63,220 samples in the 1980s, 2000s, and 2010s) and machine learning techniques. Between the 1980s and 2010s, total soil AP stock increased with a small but significant rate of 0.13 kg P ha−1 year−1, but total soil TP stock declined substantially (4.5 kg P ha−1 year−1) in the four ecosystems. We quantified the P budgets of soil–plant systems by harmonizing P fluxes from various sources for this period. Matching trends of soil contents over the decades with P budgets and fluxes, we found that the P-surplus in cultivated soils (especially in upland croplands) might be overestimated due to the great soil TP pool compared to fertilization and the substantial soil P losses through plant uptake and water erosion that offset the P additions. Our findings of P-deficit in China raise the alarm on the sustainability of future biomass production (especially in forests), highlight the urgency of P recycling in croplands, and emphasize the critical role of country-level basic data in guiding sound policies to tackle the global P crises.

SONG Xiao-Dong;  ALEWELL Christine;  BORRELLI Pasquale;  PANAGOS Panagiotis;  HUANG Yuanyuan;  WANG Yu;  WU Hua-Yong;  YANG Fei;  YANG Shunhua;  SUI Yue-Yu;  WANG Liang-Jie;  LIU Si-Yi;  ZHANG Gan-Lin; 

2024-02-22

WILEY

JRC132381

1354-1013 (online),   

https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.17108,    https://publications.jrc.ec.europa.eu/repository/handle/JRC132381,   

10.1111/gcb.17108 (online),