Land-Use Effect on Soil Carbon and Nitrogen Stock in a Seasonally Dry Tropical Forest

Eunice Maia Andrade,Aldênia Mendes Mascena De Almeida,Antonio Givanilson Rodrigues Da Silva,Gilberto Rosa,Wilner Valbrun

doi:10.3390/agronomy10020158

Eunice Maia Andrade, Aldênia Mendes Mascena De Almeida + Show 3 more

Open Access

https://doi.org/10.3390/agronomy10020158

Copy DOI

Abstract

Total organic carbon (TOC) and total nitrogen (TN) concentration in the soil are an indicator of soil degradation. To understand how land-use may impact these concentrations in seasonally dry tropical forests (SDTF), we analyzed the effect of four land-uses on TOC stocks (STK.TOC) and TN stocks (STK.TN) in a semi-arid region of Brazil. Soil samples were collected in 12 trenches (three sites × four land-uses—dense caatinga (DC), open caatinga (OC), pasture (PA) and agriculture (AG)), in the 0–10; 10–20 and 20–30 cm layers or as far as the bedrock. The data were compared by the Kruskal–Wallis test (p ≤ 0.05) and similarity investigated by cluster analysis. STK.TOC and STK.TN the surface layer (0–10 cm) showed no significant difference (p ≤ 0.05) between the DC; OC and PA land-uses. The similarity in STK.TOC and STK.TN values between DC, OC and PA, indicate that it is possible to explore SDTF to produce biomass and protein by adopting open caatinga and pasture land uses on Neosols with very low TOC stocks. The greatest reduction in STK.TOC and STK.TN in the agriculture land-use may lead to soil degradation and contribute to the addition of CO2 to the atmosphere.

Highlights

Nowadays, humanity faces the great challenge of supplying the demand for food and fibre production and reduce added greenhouse gases (CO2, CH4, and N2 O) to the atmosphere [1,2]
The present study was conducted to estimate the stocks of total organic carbon and total nitrogen in an seasonally dry tropical forests (SDTF) in the Brazilian semi-arid region
We evaluated the total organic carbon and total nitrogen content in the soil in three layers (0–10 cm, 10–20 cm and 20–30 cm) in the following land-uses: dense caatinga (DC), open caatinga (OC), pasture (PA) and agriculture (AG)

Summary

Introduction

Humanity faces the great challenge of supplying the demand for food and fibre production and reduce added greenhouse gases (CO2 , CH4 , and N2 O) to the atmosphere [1,2]. Source [6] has gained importance in studies on reducing greenhouse gases to the atmosphere [7]. The increase in STK.TOC comprises the removal of CO2 from the atmosphere and its storage in areas of long-term reserves [8], with the soil being the largest surface carbon sink (2500 Pg), equivalent to three times the amount stored in the terrestrial biomass [9]. Carbon can remain longer in the soil than in plant biomass and can remain stored for decades, making soil an excellent carbon sink [10]

Methods

Results

Conclusion