Wastewater reuse in irrigation: short-term effect on soil carbon and nitrogen stocks in Brazilian semi-arid region

Marcus Metri Corrêa,Fernando Cartaxo Rolim Neto,Rômulo Simões Cezar Menezes,Isaque De Souza Mendes,Lívia Regina Dos Santos Medeiros,Marília Costa Cavalcanti,Antonio Celso Dantas Antonino,Jean Manuel Martins,Dário Costa Primo

doi:10.4136/ambi-agua.2623

Marcus Metri Corrêa, Fernando Cartaxo Rolim Neto + Show 7 more

Open Access

https://doi.org/10.4136/ambi-agua.2623

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Abstract

The main process that opposes the Greenhouse Effect is called “carbon sequestration”, a phenomenon that essentially seeks to establish a dynamic balance between greenhouse gas (GHG) emissions from the immobilization of its elements, especially C and N. This work evaluated the stocks of carbon and nitrogen in soils of the Brazilian semi-arid submitted to irrigation with treated wastewater from domestic sewage. For this purpose, the carbon and nitrogen stocks in the soil of the semi-arid region of Brazil were compared for four different uses: Open Native Caatinga (ONC); Treated Wastewater Effluent Irrigation (TSEI); Surface Water Irrigation (SWI); and Traditional Rainfed Agriculture (TRA). The hypothesis considered in this research was that the application of treated effluents in agriculture, besides being an alternative that can mitigate the problem of water scarcity of the semiarid region, is also capable of influencing the storage capacity of C and N in the soil, due to its organic load. The results indicate that among the different land uses evaluated, soil C and N stocks were highest in ONC, and decreased with the agricultural land use. The greatest accumulation of C and N in Caatinga is due to the presence of forest litter, and the influence of irrigation with treated sewage effluent was not detected in the present study. It can be concluded that the contribution of vegetation residues to the soil surface is the main factor contributing to C and N storage.

Highlights

Climate variation is part of the evolution of the planet, human activities significantly potentiate greenhouse gas (GHG) emissions and global warming (Zhou et al, 2019)
Land use changes can alter the stock of nitrogen (N) in the soil that is closely linked to the Soil Organic Carbon (SOC) stock (Heyn et al, 2019)
The objective of this work was to assess the stocks of C and N in a Planosol soil, located in the municipality of Santana do Seridó, state of Rio Grande do Norte, semi-arid region of Brazil, under four different uses: Open Native Caatinga (ONC); Treated Sewage Effluent Irrigation (TSEI); Surface Water Irrigation (SWI); and Traditional Rainfed Agriculture (TRA)

Summary

Introduction

Climate variation is part of the evolution of the planet, human activities significantly potentiate greenhouse gas (GHG) emissions and global warming (Zhou et al, 2019). Terrestrial ecosystems have been considered as important as oceans in absorbing and storing C and N from the atmosphere, thereby minimizing the problem of the greenhouse effect. The largest C compartment of terrestrial ecosystems is the soil, where it is estimated that up to 30 cm deep it is about twice the amount of C present in the atmosphere as CO2 and up to four times that present in plant biomass (Powlson et al, 2011). It is clear that any increase or decrease in soil carbon stock has a significant impact on the atmospheric concentration of CO2 affecting the global climate (Gao et al, 2017). Land use changes can alter the stock of nitrogen (N) in the soil that is closely linked to the Soil Organic Carbon (SOC) stock (Heyn et al, 2019)

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