The Potential for Future Crop Loss Essay

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The Potential for Future Crop Loss

On the subject of potential crop loss there are several variables, which influence drought and plant disease resulting in a loss of crops.

The first variable is that of drought. Drought is a result of shifting weather patterns, which changes the amount of precipitation an area receives. There are three major causes of drought, deficient and unfavorably distributed precipitation, excess heat and warm winds (Nemanishen, 1998, p.35). Historically the grasslands of North America have had a highly varied climate with years of drought immediately followed by years of sufficient precipitation. For example, in the area of the Palliser Triangle in the grasslands of Canada, wheat crop loss has been seen
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Krick identified twelve major North American weather patters which paved the way for long term weather forecasts that are now used universally in farming and crop production (Nemanishen, 1998, p.27). It is understood that migratory cold blows bring moisture to the Great Plains and grasslands it is important to track these cold blows in order to identify wet and drought seasons. Also understood is the effect humans have on the weather patterns. At least two of the past three major droughts have coincided with changes in the general circulation of the atmosphere over the northern hemisphere (Borchert, 1971, p.7). It is undeniable that human use of land has modified atmospheric moisture patterns. Also effecting moisture patterns is solar radiation. For example, in years with high volcanic activity solar radiation was lower because the atmosphere was not as transparent. Higher solar radiation results in less precipitation due to excess heat resulting in drought (Nemanishen, 1998, p.36). It is difficult to deny that drought occurs rhythmically, however, on account of the great randomness of weather we are only able to forecast when the next drought may be and gauge its severity depending on what is known about the previous years.

Another variable resulting in crop loss is that of plant disease, and more specifically late blight. Late blight is caused by the plant pathogen Phytophthora infestans
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