Agriculture Reference
In-Depth Information
developed under the influence of the predominant climate of these regions (alternat-
ing drought and humid conditions); steppe vegetation (mainly from perennial grasses
[
Stipa
]) and the characteristic fauna, including animals; local landscape (relief); and
granulometric and mineralogical characteristics of parent materials. Anthropogenic
activities did not influence soil formation under natural conditions.
Degradation of these soils, similar to most Chernozems from East European
regions, began with the deforestration of the territory and plowing of the steppes.
Globally, Chernozems cover a wide region of some 240 million hectares (Mha)
of the middle-latitude Eurasian steppes and North American prairies. In the for-
mer Union of Soviet Socialist Republics, the total area under Chernozems consisted
of 190 Mha on 79% of the world total. The area under typical Chernozems in the
Republic of Moldova is 817,000 ha.
Sustainable development of agriculture of Chernozems can be achieved by mod-
eling agroecosystems similar to the attributes of natural ecosystems. Indeed, the
industrial model of agricultural intensification has strongly influenced Chernozems,
especially during the last 50 years since the 1960s. Krupenikov (2008) mentions
>40 types of Chernozem degradation. One of the integrated indices of soil fertility
is SOM concentration. The SOM stock in Chernozems has decreased strongly since
Docuceaev's earlier estimates of 100-150 Mg/ha.
The awareness regarding the state of Chernozems has been enhanced by the
classics of agronomy (Docuceaev 1952; Kosticev 1885, 1940; Villiams 1950-1952).
Kovda (1983), in the topic
Russian Chernozem: 100 Years After Docuceaev
, has
pointed out that Chernozems have been changed significantly since the 1960s.
The long grass fallow at the turn of the 19th century has been replaced by inten-
sive row cropping, and by taking soil for granted as a natural resource according to
a typical consumerist attitude. The globally successful intensive row crop system
developed after the Second World War by the industrial model of intensification is
popularly called the “Green Revolution.”
However, the initial increase in yield caused by the heavy inputs (mineral fertil-
izers, pesticides, etc.) masked the adverse effects of decline in SOM and soil health.
The problem cannot be solved without adopting a holistic approach to the farming
system.
Long-term field experiments at Selectia RIFC have provided useful data. These
experiments include crop rotations, continuous monocultures, different systems of
soil tillage, irrigation, and fertilizer use. The data indicate that separate application
of modern factors of agricultural intensification cannot compensate for the annual
losses of SOM (Boaghii and Bulat 2013; Boincean 2013a; Boincean et al. 2013a,b)
and the attendant decline in soil quality. Only a combination of the three main fac-
tors of each farming system (e.g., crop rotation, system of soil tillage, and nutrient
management for the specific crop rotation) with regular input of fresh organic matter
(OM) can restore soil quality. It is only through the adoption of a holistic farming
system approach that would make it possible to drastically reduce soil tillage, and
decrease the amount of nitrogen (N) input from mineral fertilizers by a more effi-
cient use of biological nitrogen fixation from leguminous crops and FYM. The holis-
tic approach can also reduce the use of pesticides by increasing the diversity of crops
within every field and landscape (Boincean 2013a; Cassman 1999; Krupenikov et al.
