Environmental Tradeoffs between Nutrient Recycling and Greenhouse Gases Emissions in an Integrated Aquaculture–Agriculture System

Abstract

The unlimited nitrogen (N) availability that has characterized crop production in the last few decades is accompanied by environmental burdens, including the greenhouse gas (GHG) emissions associated with fertilizer production, post-application nitrate (NO 3 – ) pollution of water bodies, and emissions of reactive gaseous N forms into the atmosphere. Here, we quantified the environmental tradeoffs of replacing mineral N fertilizer with NO 3 – and ammonium (NH 4 + ) originating from effluent water of aquaculture in a cucumber ( Cucumis sativus ) cultivation system. While the yield, nitrogen use efficiency (NUE), and NO 3 – leaching were similar between the cucumbers fertilized and irrigated (fertigated) by aquaculture effluent water containing 100 mg of NO 3 – -N L –1 (AN), by aquaculture effluent water supplemented with NH 4 + (AN+), or by tap water with NO 3 – and NH 4 + added (FN+), there were significant differences in the nitrous oxide (N 2 O) emissions between the systems. The N 2 O emissions peaked after each irrigation event followed by an exponential decline. The cumulative N 2 O emissions were between 60 and 600 g N 2 O-N ha –1 , smaller than predicted based on a fertilizer application rate of 600 kg N ha –1 and were in the order AN+ ≫ FN+ > AN.

Mapping the Spatial Heterogeneity of Anthropogenic Soil Nitrogen Net Replenishment Based on Soil Loss: A Coastal Case in the Yellow River Delta, China

“…In this case, the proximity to the sea results in poorer soil fertility, resulting in greater anthropogenic nitrogen resupply. Otherwise, according to the survey data of this study, there was a large proportion of aquaculture and other nonagricultural industries near the coast, which significantly supplements the soil nitrogen [81,82].…”

Recent trends in nitrogen cycle and eco-efficient nitrogen management strategies in aerobic rice system

“…Leaching of NO 3 – -N from rice soils is also a major source of pollution spread in groundwater reserves, where NO 3 – entering the soil surface via leaching or runoff may stimulate eutrophication ( Wick et al, 2012 ). N oxides emitted during nitrification or denitrification pathways are major GHGs that compromise the availability of a sustainable and healthy environment ( Subbarao et al, 2013 ; Hu et al, 2017 ; Groenveld et al, 2020 ; Hassan et al, 2022 ). Various forms of reactive oxygen can pose impacts on environmental sustainability if immobilized or denitrified in previous N 2 forms ( Pan et al, 2022 ).…”