Ecological and environmental footprint of 50 years of agricultural expansion in Argentina

Abstract

Agriculture expanded during the last 50 years from the Pampas to NW Argentina at the expense of natural forests and rangelands. In parallel, productivity was boosted through the increasing application of external inputs, modern technology and management practices. This study evaluated the impact of agricultural expansion between 1960 and 2005 by assessing the implications of land use, technology and management changes on (i) carbon (C), nitrogen (N) and phosphorous (P) stocks in soil and biomass, (ii) energy, C, N, P and water fluxes and (iii) water pollution, soil erosion, habitat intervention and greenhouse gas (GHG) emissions (impacts). Based on different data sources, these issues were assessed over $1.5 million km 2 (63% of Argentina), involving 399 political districts during three representative periods: 1956-1960, 1986-1990 and 2001-2005. The ecological and environmental performance of 1197 farming system types was evaluated through the AgroEcoIndex model, which quantified the stocks, fluxes and impacts mentioned above. Cultivation of natural ecosystems and farming intensification caused a noticeable increase of productivity, a strengthening of energy flux, an opening of matter cycles (C, N, P) and a negative impact on habitats and GHGs emission. However, due to the improved tillage practices and the application of less aggressive pesticides, erosion and pollution risk are today lower than those of the mid-20th century. The consistency of some assumptions and results were checked through uncertainty analysis. Comparing our results with international figures, some impacts (e.g. soil erosion, nutrient balance, energy use) were less significant than those recorded in intensive-farming countries like China, Japan, New Zealand, USA, or those of Western Europe, showing that farmers in Argentina developed the capacity to produce under relatively low-input/low-impact schemes during the last decades. [Correction added after online publication 4 October 2010: In the first sentence of the Abstract, NE was corrected to NW.]

Soil Quality Impacts of Current South American Agricultural Practices

“…In general, soybean has expanded at the expense of other crops and through land use change [26], increasing production at an annual rate of 5.9% from 1961-2013. Most of the increase can be attributed to an increase in production area (5%), with an additional 0.8% attributed to increased grain yield.…”

Survey of the vascular plants of Sierra Chica, the untouched area of the Paititi Natural Reserve (southeastern Tandilia mountain range, Buenos Aires province, Argentina)

“…Fire, habitat fragmentation, introduction of exotic species, and high rates of agrochemical application have generated negative impacts on different habitats, and therefore, on the diversity of plants and animals (Frangi et al 1980;Tscharntke et al 2005). The province of Buenos Aires, located in the east-central region of Argentina, due to the advance of the farming frontier, does not escape this phenomenon (Bilenca and Miñarro 2004, Paruelo et al 2005, Viglizzo et al 2011. However, the Tandilia and Ventania mountain range systems disrupt the typical plain landscape of the province, limiting the extent of agricultural fields, and acting as biodiversity reservoirs (Fig.…”

Global Ecosystem Response Types Derived from the Standardized Precipitation Evapotranspiration Index and FPAR3g Series

“…Although [47] attributed the decreased productivity in Argentina to agricultural expansion, our results suggest that droughts may also have contributed to productivity decline. In Australia, the correlation between vegetation responses to SPEI12 anomalies was very strong for most of the continent but trends in FPAR3g were mostly positive (probably due to the extreme wet years in 2010 and 2011, Bureau of Meteorology.…”