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Biotic strategies to increase plant availability of sewage sludge ash phosphorus
Author(s) -
Raymond Nelly Sophie,
Müller Stöver Dorette,
Richardson Alan E.,
Nielsen Henrik Hauggaard,
Stoumann Jensen Lars
Publication year - 2019
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.201800154
Subject(s) - shoot , phosphorus , agronomy , chemistry , biomass (ecology) , sewage sludge , phosphate , soil ph , sewage treatment , soil water , horticulture , environmental science , biology , environmental engineering , organic chemistry , soil science
Sewage sludge incineration‐ash (FB‐I) represents a potential alternative phosphorus (P) fertiliser with a high concentration of P, although with relatively low crop availability. In this study, we investigated two P‐solubilisation approaches (acidification and P mobilisation by citrate) to enhance plant P uptake from the FB‐I ash in a pot study by using various biotic strategies: (1) a pre‐treatment of ash with a Penicillium bilaiae inoculum, (2) an isogenic line of wheat that excretes citrate from the root tip, (3) nitrogen (N) provided asNH 4+combined with nitrification inhibitor dicyandiamide (DCD). All strategies were tested combined with each other and with different methods for ash application: (1) completely mixed within the top one third of soil in a pot, or (2) applied as distinct band at 10 cm depth. Triple super phosphate (TSP) at a rate of 15 mg P kg −1 soil per pot was sufficient to support maximum shoot growth. Ash mixed into the first top third part of soil in the pot at a rate of 180 mg P kg −1 soil (equivalent to 60 mg P kg −1 soil throughout the pot) significantly increased the soil water‐extractable P and the subsequent shoot P uptake and shoot biomass for both wheat lines and microbial pre‐treatment to support maximum plant performance. Shoot P concentration in these treatments was further enhanced when the plants receivedNH 4+and DCD, although not leading to a significant increase in shoot biomass. The citrate secretion by the root tips and pre‐inoculation with P. bilaiae of the ash did not influence plant growth. In conclusion, root‐zone soil acidification byNH 4+nutrition is regarded as a promising strategy to improve the fertilising effect of such alternative P fertilisers originating from urban waste streams.