Agriculture Reference
In-Depth Information
rate. The 20th century saw the population doubling rates drop to <40 years, lead-
ing to an exponential growth of the world's population, which has now exceeded
7 billion. The ever-growing population continues to exert pressures on the land and
soil resources of the world, which are finite. Although modern technologies, such
as fertilizers, synthetic pesticides, and mechanization of agriculture, have boosted
the production, the global food supplies are stretched to meet the ever-increasing
demand. Clearly, with arable land being limited, we are left with no option but to
cultivate the existing land more intensively in order to feed the masses. Thus, the past
few decades have witnessed agricultural intensification in various forms (Carswell
1997; Dahal et al. 2008).
Agricultural intensification can be regarded as any change in the cropping or
livestock-rearing practices that make use of a fixed area of land more frequently or
intensely than previous traditional or conventional practices did. Thus, an increase
in the number of crops grown per annual cropping cycle, increase in the stocking
rates of livestock grazed on a parcel of land, or change in types of crops grown and
the sequence in which they are grown (e.g., intercropped or relayed) are all forms
of agricultural intensification (Boserup 1965; Carswell 1997; Dahal et al. 2008).
Agricultural intensification can have both beneficial and adverse consequences on
the environment and human societies. While intensified production systems provide
higher yields, and therefore returns, it is often achieved through the use of chemical
fertilizers and synthetic pesticides, which have far-reaching and long-term conse-
quences for ecological balance and human health. However, it is not necessary that
intensified cropping will inevitably lead to land and environmental degradation as it
generally requires a greater degree of care and meticulous planning, which may, in
fact, result in an overall improvement of land and soil quality. Thus, while it is evident
that the demand for food and pressures on the land resource base will continue to
increase into the foreseeable future, fueling the need for agricultural intensification,
farmers can choose to adopt sustainable and environmentally friendly approaches
to intensified production to avoid the vicious cycle of degradation (McCalla 2001;
Dahal et al. 2008; Bajracharya and Dahal 2012). The possible outcomes of different
pathways chosen to increase global production on limited agricultural land are sche-
matically illustrated in Figure 6.1.
6.2 IMPACTS OF AGRICULTURAL INTENSIFICATION
ON THE ENVIRONMENT
Traditional agricultural practices of the past were done under circumstances of low
demand on the land resource base and with minimal technological inputs, and thus,
had small impacts on the environment as well as low output. However, with the
onset of the Green Revolution and the development of chemical fertilizers along
with a wide variety of pesticides, modern agriculture experienced a major shift in
production practices. Coupled with large-scale mechanization of farming, the ever-
increasing use of agricultural inputs (agrochemicals and improved hybrid varieties
of crops) led to a dramatic increase in outputs; however, impacts on the environment
also began to magnify in scale and intensity. In South Asia, the shift in agricultural
pattern to high input, intensified cropping was somewhat delayed and progressed at
