The climate is one of the main natural factors that determine which crops could be planted. It defines which crops to be grown in each area. As well, climate is a key factor to the composition of different types of soils and the degree of their fertility. The most important elements affecting crop production are:
2. Rain level;
6. Snow fall;
1) Temperature: temperature determines the duration of growth season and the type of vegetation. The temperature is of great importance when it comes to determining the production of some crops and obtaining the best economic results. This has led to the phenomenon of agricultural specialization and the dependence of crop on temperature whereas the higher the plant's ability to withstand varying temperatures the more widespread it becomes.
During the growing season, temperature must not go below the minimum degree needed for a particular crop. Each crop has an optimal temperature to grow and minimum and maximum degrees below and above which it does not grow. The nearest the degree is to the optimal temperature the better the results and if the degree remain below its minimum level during the growth period, crops would not ripen.
Usually, growth rate remain slow when necessary temperature levels are at their minimum, and if the temperature exceeded the maximum necessary temperature crops would be harmed. The rate of crop growth increases whenever the air temperature increases by ten degrees Celsius. This increase above the minimum temperature required for the growth of crops happens along the season, which is known as heat accumulation. Growing season becomes shorter as we head north or south from the sub-tropical regions since all year long is considered as growing season in the tropics if necessary factors where provided for the cultivation, such as water and good soil...
2) Rain: rain has a significant impact on the growth of crops because it is the main source of fresh water that the plant needs and therefore the amount of rain affects the crop production. The amount, season, and frequency of rainfall determine the crops that can be planted or livestock that can be raised in the region. During summertime, rain falls over most of the tropical wet region; therefore summer crops such as rice are planted in this region. Benefiting from winter rains winter crops are planted in the Mediterranean region, such as wheat.
The amount of rain does not indicate the success of agriculture, as it is more important that the rain falls at the right time, the growth season, during which the plant’s need to water is the highest. Also, are taken into account other conditions that control the utility of rain, such as the regularity of rainfall, the temperature, the evaporation rate, the soil structure, and the vegetative cover. The amount of 100 mm of rain may be convenient for cultivation in temperate regions but not sufficient in tropical regions due to the high rate of evaporation in the tropics.
Plants’ need of water differs according to the type of crop and depending on the regions in which these plants are grown. As rain can be helpful to agriculture, sometimes it can be harmful, as it happens in the case of wild floods.
3) Wind: wind has positive as well as negative impacts over agriculture and crop production. Some of these positive impacts are that it transfers pollen, turns on windmills and turbines of electricity generation that provide groundwater extraction pump with energy. As well, it helps some crops to ripen. In contrast, some of its negative impacts are that its high speed may cause to break some of the weak plants stalks as well as its role in soil erosion, especially in dry areas. Anyway, the wind’s impact over agriculture is shown in the evaporation rates and plant transpiration. As well, wind plays a major role in the pollination process as well as in operating wind turbines in order to extract water from wells. High speed wind could cause fruits and grains to fall as well as it may cause soil erosion. Some types of wind can harm agriculture, for example wind loaded with dust, which may negatively affect vegetables, flowers, citrus, and some fruits. As a result, quality of these crops may decrease whereas prices may increase. As it occurs in the case of sand drift that needs to be stabilized in order not to harm nearby areas. Sometimes, wind can prevent insects from accomplishing their duty of pollinating flowers, however it transfers grains and germs of some fungal diseases. Dry wind may affect vegetative cover; low wind can increase evaporation, thus plants lose their humidity conserved in leafs.
4) Light: light has its impact over photosynthesis, thank to which salts and solvents absorbed by the plant from the soil are transformed into nutrients that help the plant to grow. The impact of such phenomenon is clear especially in high cold regions in which day hours become very long during summer, thus plants grow faster, restoring the impact of temperature decrease.
The impact of light differs from one crop to another. Some crops actually need long day hours in order to well bloom and fruit, thus these crops are called long day crops, even if they vegetative growth is high during short day hours. Moreover, some crops need short day hours in order to bloom and fruit, and contrarily to the previous type, their vegetative growth needs long day hours, and thus these crops are called short day crops. Some crops are not much affected by the day hours and hence are considered neutral and as a result they were named day neutral crops, whereas their propagation is not affected by day hours; if these were appropriate, they bloom in different latitudes all year round.
Types and classes of crops differ when it comes to suitable day hours needed for vegetative and fruity growth; day hours may affect the nature of a certain crop’s growth or even its adaptability. The abundance of light helps the process of branching, and to increase the firmness of stalks, the overall plant weight, the number of grains, and the weight of each grain. As well, light can increase the ratio of roots to the overall crop, and can reduce the ratio of straw to the overall crop.
5) Humidity: humidity has an important impact over crops. In fact, atmospheric humidity affects the quantity of water lost from earth surface through evaporation, which may affect the growth of plants, and increase or even decrease transpiration. All these factors may affect the growth, considering the plant’s need to water available in the soil.
6) Snow Fall: the accumulation of snow and its transformation into ice can kill different types of plants. Snow itself is considered an isolating layer that protects and isolates soil from low air temperature, which may delay deep penetration of frost. In cold areas, snow cover protects grains that bloom during autumn, because it isolates them from frost and dry wind that may cause the death of plants in regions with low humidity, since it results in increasing evaporating rates. Snow, as well, may harm agriculture when it helps in growing some harmful weeds among crops planted by Human.
7) Frost: frost is considered the most dangerous climate factor over plants. Frost occurs in the result of the transformation of water vapor immediately from gaseous state into solid state without passing through the liquid state. The danger of frost increases when it occurs during autumn; the first phase of plant growth, when this latter still unable to overcome intense cold. Moreover, frost may end up dangerous if it occurs during late spring; the season of harvest, thus it may harm fruits. In such case, the harm may result from soil frosting, which is why agricultural engineers look to create new breeds that ripen within short times, so that they would not be affected by frost. Such step could provide further opportunities for agriculture. In fact, frost affects agriculture in high areas, while low areas, affected by cold wind, are subject to frost. Meanwhile, slop feet are rarely affected by frost, which makes them ideal for planting fruits, since their crops are very sensitive against frost.