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Improving phosphorus sustainability in intensively managed grasslands: The potential role of arbuscular mycorrhizal fungi
- Source :
- The Science of the total environment. 706
- Publication Year :
- 2019
-
Abstract
- Long-term nutrient fertilization of grassland soils greatly increases plant yields but also profoundly alters ecosystem phosphorus (P) dynamics. Here, we addressed how long-term P fertilization may affect ecosystem P budget, P use efficiency (PUE) and the abundance of arbuscular mycorrhizal fungi (AMF), which play a key role in the acquisition of P by plants. We found that 47 years of organic P applications increased soil P availability and total soil P stocks up to 1600% and 400%, respectively, compared to unfertilized-control soils. Grassland soils could retain up to 62% and 48% of P applied since 1970 in organic and inorganic forms, respectively. Nutrient treatments significantly affected rates of AMF root colonization (%), which were higher in control and NPK-fertilized plots when compared to soils receiving increasing applications of organic P. Plant PUE increased with greater AMF root colonization, which remained high (i.e. 50-to-75%) even after ~50 years of continuous ‘normal’ rates of agronomic P inputs (~30 kg P ha−1 year−1). AMF abundance, however, decreased under higher P applications and we found a negative relationship between soil P availability or soil P stocks and rates of AMF root colonization. Our study demonstrates that (1) AMF root colonization is still high in soils, which have received consistent but moderate P inputs for over four decades, and (2) moderate rates of P fertilization are related to a more conservative P ecosystem budget whereby the amount of P retained in soils and up-taken by plants on an annual basis is higher than the amount of P added through fertilization. This is possible only if extra P is ‘mined’ from the soil P ‘bank’ and made available to plant uptake. We suggest that AMF could play a significant role in intensively-managed grasslands contributing to increase P sustainability by reducing the need for extra P fertilizer.
- Subjects :
- Environmental Engineering
010504 meteorology & atmospheric sciences
chemistry.chemical_element
010501 environmental sciences
Biology
engineering.material
01 natural sciences
Plant Roots
Grassland
Soil
Nutrient
Human fertilization
Mycorrhizae
Environmental Chemistry
Colonization
Ecosystem
Waste Management and Disposal
Soil Microbiology
0105 earth and related environmental sciences
geography
geography.geographical_feature_category
Phosphorus
fungi
Fungi
Pollution
Agronomy
chemistry
Soil water
engineering
Fertilizer
Subjects
Details
- ISSN :
- 18791026
- Volume :
- 706
- Database :
- OpenAIRE
- Journal :
- The Science of the total environment
- Accession number :
- edsair.doi.dedup.....8d99da67dcfd987141e02bc9a1cfbd2d