Long-term impact of grazing and tillage on soil quality in the semi-arid Chaco (Argentina)


Deforestation of Chacoan native forests and reorientation of land use are transforming the region into agricultural use. The main purpose of this work was to evaluate the impact of different land uses on soil quality in the semi-arid Chaco (Argentina). We assessed the behaviour of soil parameters over four years of experimental conditions: 1) Exclosure pasture (EP) used as reference level, 2) Grazed pasture (GP), 3) Grazed pasture transformed to agriculture with Zero tillage (ZT) and 4) Grazed pasture transformed to agriculture under Conventional tillage (CT). Soil organic carbon, particulate and heavy organic carbon (C), total nitrogen (N), C:N ratio, pH, electric conductivity and soil respiration were measured. Soil samples were taken yearly at 0-5, 5-20 and 20-40 cm of soil depth. Differences among treatments across time were assessed by Analysis of Covariance (ANCOVA) with time (years) as covariate factor, treatments as group factor and individual scores from Principal Component Analysis (PCA) as responses. Correlated changes in the soil characteristics were detected, especially at the top soil layer. Both carbon and nitrogen contents increased in both GP and ZT systems. An opposite trend was found for CT, which also had a negative impact on salinity. Both land use change and management practices in the Chaco region represent the main human activities that modify the landscape; thus, they should be analysed by recognizing heterogeneity on farming practices and identifying their impacts on a specific site. The results of this work reinforce the utility of soil organic carbon as a single parameter for monitoring land management systems, especially for monitoring large region like Chaco that are subject to continuous transformation processes.



Anderson JPE. 1982. Soil respiration. In: Page AL, Miller RH, Keeney DR, editors. Methods of soil analysis: Part II. Chemical and Microbiological Properties-Agronomy Monograph No. 9. Madison, WI, USA: American Society of Agronomy, Soil Science Society of America. p. 837-871.

Andrews SS, Karlen DL, Cambardella CA. 2004. The soil management assessment framework: a quantitative soil quality evaluation method. Soil Sci Soc Am J. 68(6):1945-1962.

Asner GP, Seastedt TR, Townsed AR. 1997. The decoupling of terrestrial carbon and nitrogen cycles. BioScience 47(4):226-234.

Astier CM, Mass-Moreno M, Etchevers BJ. 2002. Derivación de indicadores de calidad de suelos en el contexto de la agricultura sustentable. Agrociencia 36(5):605-620.

Baumann M, Gasparri I, Piquer-Rodríguez M, Gavier Pizarro G, Griffiths P, Hostert P, Kuemmerle T. 2017. Carbon emissions from agriculture expansion and intensification in the Chaco. Glob Chang Biol. 23(5):1902-1916.

Bird J, Torn M. 2006. Fine roots vs. needles: A comparison of 13C and 15N dynamics in a ponderosa pine forest soil. Biogeochemistry 79(3):361-382.

Bremmer JM, Mulvaney CS. 1982. Nitrogen total. In: Page AL, Miller RH, Keeney DR, editors. Methods of soil analysis: Part II. Chemical and Microbiological Properties-Agronomy Monograph No. 9. Madison, WI, USA: American Society of Agronomy, Soil Science Society of America. p. 371-378.

Bucher E. 1982. Chaco and Caatinga-South American arid savannas. Woodlands and thickets. In: Huntley BJ, Walker BH, editors. Ecology of tropical savannas. Berlin: Springer. p. 48-79.

Cambardella CA, Elliott ET. 1992. Particulate soil organic-matter changes across a grassland cultivation sequence. Soil Sci Soc Am J. 56(3):777-783.

Campitelli P, Aoki A, Gudelj O, Rubenacker A, Sereno R. 2010. Selección de indicadores de calidad de suelo para determinar los efectos del uso y prácticas agrícolas en un área piloto de la región central de Córdoba. Ciencia del Suelo 28(2):223-231.

Conant RT, Paustian K, Elliott ET. 2001. Grassland management and conversion into grassland: effects on soil carbon. Ecol Appl. 11(2):343-355.

Doran JW, Parkin TB. 1994. Defining and assessing soil quality. In: Doran JW, Coleman DC, Bezdicek DF, Stewart BA, editors. Defining soil quality for a sustainable environment. Madison, WI, USA: Soil Science Society of America. p. 3-21.

Duval ME, Galantini JA, Iglesias JO, Canelo S, Martínez JM, Wall L. 2013. Analysis of organic fractions as indicators of soil quality under natural and cultivated systems. Soil Tillage Res. 131:11-19.

Eriksen J, Jensen LS. 2001. Soil respiration, nitrogen mineralization and uptake in barley following cultivation of grazed grasslands. Biol Fertil Soils 33(2):139-145.

Fan LC, Yang MZ, Han WY. 2015. Soil respiration under different land uses in Eastern China. PLoS ONE 10:e0124198.

Ferreras L, Toresani S, Bonel B, Fernández E, Bacigaluppo S, Faggioli V, Beltrán C. 2009. Parámetros químicos y biológicos como indicadores de calidad del suelo en diferentes manejos. Ciencia del Suelo 27(1):103-114.

Frank AB, Liebig MA, Tanaka DL. 2006. Management effects on soil CO2 efflux in northern semiarid grassland and cropland. Soil Tillage Res. 89(1):78-85.

Franzluebbers AJ. 2002. Soil organic matter stratification ratio as an indicator of soil quality. Soil Tillage Res. 66(2):95-106.

Franzluebbers AJ, Stuedemann JA. 2002. Particulate and non-particulate fractions of soil organic carbon under pastures in the Southern Piedmont USA. Environ Pollut. 116:S53-S62.

Franzluebbers AJ, Stuedemann JA, Schomberg HH, Wilkinson SR. 2000. Soil organic C and N pools under long-term pasture management in the Southern Piedmont USA. Soil Biol Biochem. 32(4):469-478.

Galantini J, Rosell R. 2006. Long-term fertilization effects on soil organic matter quality and dynamics under different production systems in semiarid Pampean soils. Soil Tillage Res. 87(1):72-79.

Ganjegunte GK, Vance GF, Preston CM, Schuman GE, Ingram LJ, Stahl PD, Welker JM. 2005. Soil organic carbon composition in a Northern mixed-grass prairie: effects of grazing. Soil Sci Soc Am J. 69(6):1746-1756.

Gasparri NI, Grau HR. 2009. Deforestation and fragmentation of Chaco dry forest in NW Argentina (1972-2007). For Ecol Manage. 258(6):913-921.

Gasparri NI, Grau HR, Angonese JG. 2013. Linkages between soybean and neotropical deforestation: coupling and transient decoupling dynamics in a multi-decadal analysis. Global Environ Chang. 23(6):1605-1614.

Gasparri NI, le Polain de Waroux Y. 2014. The coupling of South American soybean and cattle production frontiers: new challenges for conservation policy and land change science. Conserv Lett. 8(4):290-298.

Giménez AM, Hernández P, Figueroa ME, Barrionuevo I. 2011. Diversidad del estrato arbóreo en los bosques del Chaco Semiárido. Quebracho 19(1):24-37.

Hansen MC, Potapov PV, Moore R, Hancher M, Turubanova SA, Tyukavina A, Thau D, Stehman SV, Goetz SJ, Loveland TR, Kommareddy A, Egorov A, Chini L, Justice CO, Townshend JRG. 2013. High-resolution global maps of 21st-century forest cover change. Science 342(6160):850-853.

Imaz MJ, Virto I, Bescansa P, Enrique A, Fernandez-Ugalde O, Karle DL. 2010. Soil quality indicator response to tillage and residue management on semi-arid Mediterranean cropland. Soil Tillage Res. 107(1):17-25.

Karlen DL, Mausbach MJ, Doran JW, Cline RG, Harris RF, Schuman GE. 1997. Soil quality: A concept, definition, and framework for evaluation (A Guest Editorial). Soil Sci Soc Am J. 61(1):4-10.

Lai L, Wang J, Tian Y, Zhao X, Jiang L, Chen X, Gao Y, Wang S, Zheng Y. 2013. Organic matter and water addition enhance soil respiration in an arid region. PLoS ONE 8:e77659.

LeCain DR, Morgan JA, Schuman GE, Reeder JD, Hart RH. 2002. Carbon exchange and species composition of grazed pastures and exclosures in the shortgrass steppe of Colorado. Agric Ecosyst Environ. 93(1-3):421-435.

Mendes Malhado AC, Pires GF, Costa MH. 2010. Cerrado conservation is essential to protect the amazon rainforest. AMBIO 39(8):580-584.

Müller R, Müller D, Schierhorn F, Gerold G, Pacheco P. 2012. Proximate causes of deforestation in the Bolivian lowlands: an analysis of spatial dynamics. Reg Environ Change 12(3):445-459.

Nelson DW, Sommers LE. 1982. Total carbon, organic carbon and organic matter. In: Page AL, Miller RH, Keeney DR, editors. Methods of soil analysis: Part II. Chemical and Microbiological Properties-Agronomy Monograph No. 9. Madison, WI, USA: American Society of Agronomy, Soil Science Society of America. p. 539-579.

Piñeiro G, Paruelo JM, Oesterheld M, Jobbágy EG. 2010. Pathways of grazing effects on soil organic carbon and nitrogen. Rangeland Ecol Manag. 63(1):109-119.

Pittelkow CM, Linquist BA, Lundy ME, Liang X, van Groenigen KJ, Lee J, van Gestel N, Six J, Venterea RT, van Kessel C. 2015. When does no-till yield more? A global meta-analysis. Field Crops Res. 183:156-168.

Poeplau C, Marstorp H, Thored K, Kätterer T. 2016. Effect of grassland cutting frequency on soil carbon storage - a case study on public lawns in three Swedish cities. Soil 2(2):175-184.

R Core Team. 2016. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL: http://www.R-project.org/.

Rowe EC, Evans CD, Emmett BA, Reynolds B, Helliwell RC, Coull MC, Curtis CJ. 2006. Vegetation type affects the relationship between soil carbon to nitrogen ratio and nitrogen leaching. Water Air Soil Pollut. 177:335-347.

Schuman GE, Reeder JD, Manley JT, Hart RH, Manley WA. 1999. Impact of grazing management on the carbon and nitrogen balance of a mixed grass rangeland. Ecol Appl. 9(1):65-71.

Shukla MK, Lal R, Ebinger M. 2005. Soil quality indicators for reclaimed mine soils in southeastern Ohio. Soil Sci. 169(2):133-142.

Shukla MK, Lal R, Ebinger M. 2006. Determining soil quality indicators by factor analysis. Soil Tillage Res. 87(2):194-204.

Soil Survey Staff. 2014. Keys to Soil Taxonomy. 12th ed. Washington D.C., USA: USDA-Natural Resources Conservation Service.

U.S. Salinity Laboratory Staff. 1954. Diagnosis and Improvement of Saline and Alkali Soils. Agricultural Handbook No. 60. Washington D.C., USA: United State Department of Agriculture.

Volante JN, Alcaraz-Segura D, Mosciaro MJ, Viglizzo EF, Paruelo JM. 2012. Ecosystem functional changes associated with land clearing in NW Argentina. Agric Ecosyst Environ. 154:12-22.

Zuccardi RB, Fadda GS. 1985. Bosquejo agrológico de la provincia de Tucumán. Facultad Agronomía y Zootecnia Miscelánea No. 86. Universidad Nacional de Tucumán.