TY - JOUR

T1 - Effects of long-term fertilization with contemporary Danish human urine, composted household waste and sewage sludge on soil nematode abundance and community structure

AU - Johansen, Jesper Liengaard

AU - Dam, Marie

AU - Kudjordjie, Enoch Narh

AU - Santos, Susana Silva

AU - Palmqvist, Annemette

AU - Magid, Jakob

AU - Vestergård, Mette

N1 - Publisher Copyright: © 2022 The Authors

PY - 2023

Y1 - 2023

N2 - It is desirable to recycle the urban waste products human urine, composted household waste and sewage sludge as fertilizers to agricultural fields. This could minimize the use of NPK fertilizer, improve soil structure and store carbon. However, waste products may contain heavy metals, persistent organic pollutants (POP) and plastics, and there are concerns that long-term build-up of these substances will cause unwanted effects on soil health. Nematodes are ubiquitous and numerous in soil ecosystems. Abundance and community structure of soil nematodes can be used as indicators of soil health, as some species are vulnerable to pollution. There are well-developed methods for detecting environmental changes based on nematode community structure. At the long-term CRUCIAL field experiment, where alternative fertilizer products have been applied since 2003, we measured effects of long-term fertilization with human urine, composted household waste and sewage sludge on soil properties (pH, soil organic matter and nitrogen availability), abundance of soil microorganisms (bacteria, fungi, small protozoa and ciliates) and nematode trophic groups compared to plots with unfertilized, NPK and cattle manure treatment. Sampling and assessments were done three times during a growth season. Further, we assessed the composition of nematode communities using metabarcoding. Treatments with a high input of organic matter (cattle manure, composted household waste and sewage sludge) had high abundances of bacteria and thus bacterial grazers (small protozoa, ciliates, and bacterial feeding nematodes). We found a significant correlation between nematode community structure and pH and organic matter. We calculated the nematode Maturity Index 2–5 (pollution indicator) based on metabarcoding data, which did not differ significantly between the treatments. We conclude that long-term fertilization with different types of contemporary Danish urban waste products affects both soil properties and abundance of soil organisms, the latter largely reflecting the organic matter input of the fertilizer treatments. We found no adverse effect on nematode communities that could indicate pollution-induced stress on nematofauna or decreased soil fertility.

AB - It is desirable to recycle the urban waste products human urine, composted household waste and sewage sludge as fertilizers to agricultural fields. This could minimize the use of NPK fertilizer, improve soil structure and store carbon. However, waste products may contain heavy metals, persistent organic pollutants (POP) and plastics, and there are concerns that long-term build-up of these substances will cause unwanted effects on soil health. Nematodes are ubiquitous and numerous in soil ecosystems. Abundance and community structure of soil nematodes can be used as indicators of soil health, as some species are vulnerable to pollution. There are well-developed methods for detecting environmental changes based on nematode community structure. At the long-term CRUCIAL field experiment, where alternative fertilizer products have been applied since 2003, we measured effects of long-term fertilization with human urine, composted household waste and sewage sludge on soil properties (pH, soil organic matter and nitrogen availability), abundance of soil microorganisms (bacteria, fungi, small protozoa and ciliates) and nematode trophic groups compared to plots with unfertilized, NPK and cattle manure treatment. Sampling and assessments were done three times during a growth season. Further, we assessed the composition of nematode communities using metabarcoding. Treatments with a high input of organic matter (cattle manure, composted household waste and sewage sludge) had high abundances of bacteria and thus bacterial grazers (small protozoa, ciliates, and bacterial feeding nematodes). We found a significant correlation between nematode community structure and pH and organic matter. We calculated the nematode Maturity Index 2–5 (pollution indicator) based on metabarcoding data, which did not differ significantly between the treatments. We conclude that long-term fertilization with different types of contemporary Danish urban waste products affects both soil properties and abundance of soil organisms, the latter largely reflecting the organic matter input of the fertilizer treatments. We found no adverse effect on nematode communities that could indicate pollution-induced stress on nematofauna or decreased soil fertility.

KW - Heavy metals

KW - Maturity Index 2–5

KW - Microplastics

KW - Nematode feeding types

KW - Soil health

U2 - 10.1016/j.scitotenv.2022.160485

DO - 10.1016/j.scitotenv.2022.160485

M3 - Journal article

C2 - 36436626

AN - SCOPUS:85142723293

VL - 860

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

M1 - 160485

ER -