Agriculture Reference
In-Depth Information
mospheric carbon dioxide level will have a fertilization effect on crops with
C3 photosynthetic pathway promoting, thereby, their growth and produc-
tivity. The increase in temperature, depending upon the current ambient
temperature, can reduce crop duration, increase crop respiration rates,
alter photosynthate partitioning to economic products, affect the sur-
vival and distribution of pest populations, hasten nutrient mineralization in
soils, decrease fertilizer-use efficiencies, and increase evapo-transpira-
tion rate. Indirectly, there may be considerable effects on land use due
to snow melt, availability of irrigation water, frequency and intensity of
inter and intraseasonal droughts and floods, soil organic matter transforma-
tions, soil erosion, changes in pest profiles, decline in arable areas due to
submergence of coastal lands, and availability of energy. Major impacts
of climatic change are as follow:
Reduction in crop yield, shortage of water, irregularities in onset of monsoon,
drought, flood and cyclone, rise in sea level, decline in soil fertility, loss of
biodiversity, increasing in diseases, insect pests and weeds may be the prob-
able adverse effect of climate change.
8.3.1 EFFECT OF CLIMATE CHANGE ON VEGETABLE CROPS
Vegetables being rich sources of calories, health-building substances
ensure food, nutritional and livelihood security. Optimum consump-
tion of vegetables lowers incidence of degenerative diseases. Bioactive
compounds besides their health benefits, affects storability of vegetables
that contain them. They also play an important role in senescence of veg-
etables by combating relative oxygen in species (Hodges and Forney,
2003). Therefore, a product with a high concentration of antioxidants is
well protected against oxidation and may thereby retain its quality longer.
Freshness of vegetables, to some extent, is a marker for its food value as
regards the content of bioactive compounds. Climate change may have ad-
verse small and marginal farmers who are mainly dependent on vegetables
(FAO, 2009). Moreover, the cool season vegetables are more sensitive to
adverse weather than warm season. Abiotic stresses like extreme temper-
ature (low/high), soil salinity and drought are detrimental for vegetable
production. Thus, high temperatures and limited soil moisture are the ma-
jor causes of low yields in vegetables. The different development phases
like vegetative growth, flowering and fruit development are significantly
