Agriculture Reference
In-Depth Information
5.7 CONCLUSION
Enhanced productivity and production of rice and wheat in the Green Revolution
era prevented the cultivation of marginal lands and also led to the emergence of
the nontraditional rice-wheat cropping system as the primary production system
in many irrigated areas. The higher productivity of the rice-wheat system has been
apparently due to better land, water, and crop management practices; timely avail-
ability of needed agri-inputs; and market support from the local state governments.
Long-distance transport of irrigation water through canal networks almost doubled
the cropping system intensity in many areas in the northwest Indo-Gangetic plains.
However, these developments also led to land degradation as manifested by second-
ary salinization, reduced biodiversity, lower factor productivity, multinutrient defi-
ciencies, water scarcity, and pollution of groundwater aquifers. Large “management
yield gaps” in cereal crops have been observed in the eastern Gangetic plains of
Nepal, India, and Bangladesh. In high-rainfall districts located between 78.83° and
86.13° north longitudes, there seem to be some nexus between low agricultural pro-
ductivity and poverty due to recurring droughts and floods and technology fatigue.
Conservation agriculture (CA) practices, because of their potential to produce
more at less costs and ability to bridge “management yield gaps,” are increasingly
being seen as the panacea of many ills of modern agriculture. It seems that South
Asian farmers can produce enough additional food by practicing timely planting,
relay cropping, and by adopting appropriate technologies for lowland wet soils and
“rice fallows.” Yield gain can be further consolidated by developing cultivars able
to harness genotype-tillage-cropping system interactions under new microenviron-
ments resulting from the adoption of CA and use of vernalization genes for develop-
ing wheat varieties suitable for early seeding in residual soil moisture of rice fields.
This calls for some added efforts for setting up special crop-breeding programs. It
appears that manipulation of vernalization genes can prove helpful in adjusting the
planting times of crops in cropping systems having short turn-around times and the
added challenge of climate changes.
Green Revolution technologies improved food production in the developing world
through enhanced production and productivity of intensely irrigated intensive crop-
ping systems such as rice-wheat systems in the Indo-Gangetic plains. This, in turn,
induced land degradation, low factor productivity, multinutrient deficiencies, and a
number of other second-generation problems. Besides providing goods, sustainable
land management in agricultural landscapes must focus on key ecosystem services
linked to life support (e.g., soil formation, nutrient cycling, flood control, and pol-
lination) and services derived from the regulation of ecosystem processes (e.g., cli-
mate regulation, disease control, and detoxification). Crop production systems on
CA platforms are closer to natural ecosystems, and hence, if applied properly, can
help South Asian farmers to produce enough additional food for the teaming popu-
lations. Stupendous gains in crop productivity in South Asian countries were the
result of improved crop production environments for high yielding varieties induced
by “better-bet” land and crop management practices. Higher yields being realized
in different cropping systems through CA can be further consolidated through the
development of cultivars appropriate for the conservation agricultural platforms. It is
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