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Abstract
In the last decades, many countries have been characterized by soil conservation concerns
since agricultural land management local practices led to soil impoverishment and
destructuration. Argentina, recently, has been hardly hit by these phenomena of soil
degradation that, depending on the specific region concerned, show up in different forms
of soil erosion. The research tries to give an answer to the questioning concerning the
relationship between agricultural land management and wind erosion occurrence in one
specific area placed within the province of Còrdoba. The research results from an ample
review of the literature and a period of field study in the relevant area, where interviews
with local farmers and experts were carried out.
The research revealed an agricultural system, which in the last 20 years has fully joined
the no-tillage farming practices focused on soil conservation. Whether on one hand, no-
tillage actually reduced erosion, on the other hand it brought to a widespread use of
genetically modified soybean (and to a lesser extent maize) which require increasing
levels of herbicides also due to the spread of resistant weeds, which is mostly caused by
the common practice of sharing harvesters and other machineries. Despite this diffusion
of soil conservation methods, the research reveals how soil erosion still represents a threat
for the province of Cordoba. However, the study also discovered that erosion occurs
differently within the province (in some places mainly as water erosion, in others as wind
erosion) depending on human factors, concerning land management, and natural ones.
Among the human factors, an unbalanced crop rotation, but especially the peanuts
cultivation (due to the particular tasks required for cultivating this crop) have been
identified as the main causes of wind erosion.
It has been noticed, however, as the underlying problem lies both in the absence of legal
constraints aimed at reducing the risk of wind erosion occurrence with peanuts and in the
presence of higher taxes and limitations for the export of certain agricultural products.
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1. Introduction
The Republic of Argentina has an area of 280 million hectares, of which 25% is humid,
15% corresponds to a semi-arid climate and the remaining 60% have dry features. Totally,
the 75% of the country’s surface, 48.000.000 ha, is potentially susceptible to erosion
because of aridity and soil composition (Buschiazzo et al., n.d.).
The 40% of the territory is actually affected to some extent by phenomena of physical,
chemical or biological degradation (Michelena, 2011). According to INTA data
(Michelena, 2011), in the Pampas, economic losses caused by soil erosion amounted to
700 million dollars annually, 1000 million including all the phenomena of soil
degradation.
Among several possible phenomena of land degradation, the most important are probably
water and wind erosion. The term water erosion encompasses all those processes of
erosion due to the action of rainfalls and surface runoff. While the process of blowing
away and transportation of soil particles from the land surface is known as wind erosion
(NSW, 2014).
Wind erosion processes in Argentina affect much of the agricultural land, about 50
million hectares according to Michelena (2011). The lands more severely subjected to
this phenomenon are those located in the Pampas, hereby included the province of
Cordoba, where the current research is placed. The risk taken by a soil to be wind-eroded
depends on climatic conditions of the regions: the threat is higher in areas characterized
by intense rainfalls concentrated in short lapses, great wind intensity matching with dry
periods, high temperatures and high rates of evapotranspiration. Moreover, a low
vegetation cover and a use of agricultural technologies not suitable for the area, further
increase the damages of wind erosion (Buschiazzo et al., n.d.).
In fact, although the phenomenon is a serious threat for the region affected, it has real
importance when it occurs in areas undergoing agricultural exploitation; here an
“accelerated wind erosion” takes place (Instituto de Suelos y Agrotecnia, 1948) especially
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because agricultural lands tillage breaks up soil into finer particles highly susceptible to
be blown away.
Indeed, the soils of arid and semi-arid regions, especially those under agricultural (and to
a lesser extent breeding) use are more susceptible to soil erosion caused by wind-blown
since generally little developed, coarse-textured and slightly structured (Buschiazzo et
al., n.d.).
Hence, this phenomenon has serious economic implications especially in the Pampas
because these plains are the most important regions of the country for livestock breeding
and agricultural goods production (especially grains such as corn, soybeans, wheat,
sunflower and sorghum) (Michelena, 2011).
The few lines above already suggests a clear link between soil degradation and land
management: agriculture practices has always been a key component for the welfare of
the rural areas as well as of the adjacent urban ones. Therefore, in places where fields are
commonly laboured, land management is inevitably characterized by the use made of the
soil by the agricultural sector.
Surely, this argument can be applied to the region around Córdoba, where in recent
decades, intensive agriculture heavily influenced the appearance and the characteristics
of the wide cultivated plain within the province (Seifert et al., 2011). Here, the
implementation of various practices related to farming over the years has been leading to
various troubles not only for the people working in the sector, but also for the entire
resident population in the area.
A typical example of negative externality of farming, which is commonly considered a
historical problem for the area in question, is wind erosion (Instituto de Suelos y
Agrotecnia, 1948; Prosdócimo, 2013; Cisneros, 2014), a phenomenon doubly linked to
management of agricultural land. In fact, on one hand it is due to bad land management
in case of particular geophysical conditions; on the other hand, it is affecting the choices
of local farmers and, in a broader perspective, also the decisions of agrarian policy of the
institutions concerned.
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In this study, it will be shown how, in the target area, the impoverishment of the soil had
peaks and dips depending on the agricultural techniques adopted over the years. In
reference to the last decades, it will be investigated the profound positive impact towards
the conservation of the soil, brought by the diffusion of Siembra Directa.
SD (also called No-tillage, zero tillage, sod seeding or direct drilling) is a set of
agricultural techniques that consists in planting of crops or pasture from year to year by
direct seeding, without disturbing the soil through plowing. Besides reducing soil erosion,
SD has been proven to increase the amount of water that infiltrates into the soil, organic
matter retention and cycling of nutrients in the soil (Siembradirectacorp, 2013).
Therefore, after the analysis of the local land management, the following steps needed in
order to accomplish the purpose of the research is to investigate the actual magnitude of
wind erosion in the target area, its cause-effect relationship with the land management
and, at some extent, its economic impact.
This research is part of the larger plan “Coroado”, a collaborative project for specific
cooperation actions dedicated to international partner institutes, mainly aimed at
supporting small and medium scale research projects finalized at assessing and
implementing energy saving and resources optimization plans in Latin America
(Coroado, 2014). In particular, this fieldwork study have been possible thanks to the
collaboration between Wageningen and Córdoba universities since only the
intermediation of the latter allowed the involvement in the research of local agricultural
associations, without which it would have been impossible to achieve the results obtained
by this study.
The present research was born from the need of obtaining missing information about the
Córdoba province. More specifically, the research was required, to collect data about: the
local agricultural practices; the places where wind erosion occurred with greater severity;
and the reasons for phenomenon arising, in order to provide a reliable background of
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information and constitute a starting point for more in-depth future researches under the
same project Coroado.
Precisely due to this previous lack of specific information regarding the region, the area
selected for the research changed during the investigation. In fact, while, initially the
purpose was to analyse the land management and wind erosion in the North Eastern part
of the province of Córdoba as the presence of wind erosion in this region was extremely
low, the research area was moved towards southern departments where wind erosion is
an actual problem.
This paper is divided into two basic sections: a first one related to the agrarian issue and
the soil conservation topic and a second related to wind erosion in all its facets. However,
it will be shown in the following chapters how the two units are bound together by strong
ties of mutual influence and, in some cases, causality.
The common thread between these two issues is represented by soil impoverishment and
destructuration since soil degradation is at the same time both a consequence of a bad
land management and a causative factor for soil erosion. Moreover, by highlighting those
elements specifically leading to wind erosion, the research investigate why soil erosion
occurs in different ways depending on the geographical position of the area investigated
within the province. In particular, within the target area was identified two subareas in
which the phenomenon shows up with remarkably different intensities. This comparison
between a northern area (characterized by a low presence of wind erosion) and a southern
one (characterized by a high presence) plays an important role in this thesis, since it
allows the identification of the main human and natural factors causing the occurrence of
the phenomenon in the region.
The next lines will be now specifically referred to the text structure. In the early chapters,
the main issues arising out of local agriculture will be addressed: the mechanisms, the
techniques, the actors, but also the problems that have arisen in recent years and the
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challenges of the future. In particular, this section is composed by an introductory part
about the events that have affected local agriculture during the last century in order to
justify the arrival to the production techniques of today, followed by a section devoted to
the current prevailing method of production, i.e. Siembra Directa. In fact, the
comprehension of this technique is fundamental to correctly understand the local land
management and comprise the problems that the new techniques solved in recent years
and those that they are generating.
Nevertheless, this first unit is not an end in itself. In fact, the wind erosion dissertation
discussed in the second section finds its foundation especially in the agricultural land
management. Therefore, the explanation of the causes, consequences and solutions to the
phenomenon that will be addressed in later chapter, is closely linked to the agrarian
question initially treated.
Within this second part of the paper, it will be presented the results of the research that
describe a different spread of the phenomenon of wind erosion inside the research area.
These statements will then be justified relying on the outcomes obtained through various
methods of investigation used in the data collection phase (perceived risk and contingent
valuation) and motivated. Finally, it will be shown the legal solutions adopted so far and
the personal impressions and suggestions for resolving the wind erosion issue by the
researcher, developed on the base of the data collected and observations made.
This study aims to answer a General Research Questions, composed by a series of
Specific Research Questions:
GRQ: “To which extent is land management liable of wind erosion in the Central-
Southern part of the Province of Córdoba?”
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Four sub-questions help to answer the first main research question:
SRQ 1: “What kind of land management exists today in the target area and which path
did it follow to get there?”
Background information on the development of agriculture in the province of Córdoba
up to the present are reported in chapter 3. In the same chapter, is also highlighted the
historical link existing in the region between agricultural land management and soil
degradation. An explanation of the current land management, which is practically
identified with Siembra Directa, is instead presented and discussed in chapter 4.
SRQ 2: “Is wind erosion perceived as a real threat in the target area?”
The topic is widely discussed in chapter 5 where occurrence and perception of wind
erosion are presented and analysed. Here a distinction is made between two sub-areas (a
northern and a southern one) characterized by different levels of affection by wind
erosion, detected using an economic assessment of the possible damage caused (WTP)
and a measurement in absolute terms of the degree of concern about the problem.
SRQ 3: “Which human and natural factors are responsible for different levels of wind
erosion in the target area?”
This issue is also addressed in chapter 5 (subchapter 5.3), where, besides the long list of
natural factors, also human factors responsible for wind erosion are reported and
discussed in detail. Hence, emerges how land management is directly linked to the
occurrence of the phenomenon since the research demonstrates how certain crops and
practices significantly increase the probability of wind erosion to arise. Even in this case,
the discussion will rely on the previously detected distinction between the two subareas.
The different impact of wind erosion will in fact be justified on the basis of dissimilarities
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in climate / soil composition, but also a differences in land management within the two
locations.
SRQ 4: “How can wind erosion be curbed in the target area?”
This specific research question, which is discussed in the chapter 6, concerns the gaps in
the current legal system and the recommendations proposed by the author in order to curb
wind erosion basing on the existing land management practices. It emerges how,
nowadays, viable solutions to wind erosion are available at low costs; nonetheless, in the
province still lacks an adequate legal system capable to push farmers to implement such
virtuous practices of soil conservation and to resolves the controversies caused by blown
away soil.