EMERGING TECHNOLOGIES IN FOOD SCIENCE
GENETICALLY MODIFIED ORGANISMS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a drop in productivity of the land by more than 10%, leading to desertification
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a build up of nutrients, leading to increased levels of erosion
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a build up of salts in the soil, leading to salinization
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decreased phosphorus and nitrogen, leading to eutrophication
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Detailed explanation-1: -Most irrigation waters contain some salts. After irrigation, the water added to the soil is used by the crop or evaporates directly from the moist soil. The salt, however, is left behind in the soil. If not removed, it accumulates in the soil; this process is called salinization (see Fig.
Detailed explanation-2: -Salinization of soil results from a combination of evaporation, salt precipitation and dissolution, salt transport, and ion exchange (Shimojima et al., 1996).
Detailed explanation-3: -As the water is taken up by plants through transpiration or lost to the atmosphere by evaporation, soil water salinity increases because salts become more concentrated in the remaining soil water. Thus, evapotranspiration (ET) between irrigation periods can further increase salinity.
Detailed explanation-4: -Under sprinkler irrigation, the salinity buildup occurs in the subsurface soil (Fig. 4.1). Thus, the SI system is highly effective in leaching salts from the surface and providing a soil environment which is conducive for seed germination and early stage of plant growth.