The reasons for food shortage are quite complex and the major problems are production shortfalls. Production is one of the important problems because it is the one determinant of food shortage. Generally food shortage is critical on the global level but it can be decisive for some regions and countries or communities. The potential of production varies across the countries, natural factors like climate, water, soil, food species, pests etc. Other cultural factors like including technology and investment strategies also play an important role. Climate plays an important role and temperature and rainfall are critical elements as in when to decide when and how the crops can be sown.
Weather Conditions Ruin Harvest
There are some countries in Asia where harvests are carried out three times in a year but in tropical zones and during winter in temperate areas production comes to complete standstill. Extreme weather conditions like heat will be escorted by high ultraviolet radiation and frosts can ruin harvests. These weather conditions are bad for all types of crops and especially bad for certain kind of crop varieties. In most parts of the world drought is the most common threat to food production. Droughts destroy crops but the infrastructure remains intact, but drought prevents planting if the rains arrive late and soil becomes too dry for planting.
Failure of the regular rains also reduces harvests. Excess rains can also harm agriculture production especially if there is a flood. Flood kills the crop by displacing or submergence and also slows the growth making cultivation and harvesting difficult. Crops after harvest will also suffer when there is excess rain. The rain can leave the crops susceptible to rot. The crops damaged by the insects can be avoided by breeding resistant varieties and with mixed planting strategies. This increases the growth of that particular species from the characteristics pests and chemicals that kill the target population. The pest can be controlled by biological control which involves predators or pathogens of the species of the pest.
An integrated pest management which combines chemical, biological and some local mechanical strategies like removing the insect eggs before hatching can be done and these methods are carried out worldwide for better production of food. These are better ways to decrease the use of chemical and increasing the burden on the environment. Human labour also plays an important part in controlling other kinds of animal damage like the rodents, birds, livestock etc. Human labour is used to scare the birds and livestock.
Rodent pest are physically killed, chased or poisoned by the humans and larger animals are also prevented by tending the areas where there is threat of bigger wild animals. Irrigation systems can be used in the case of short or irregular rainfall. The irrigation systems enhance the productivity during dry seasons by holding over water from the rains. Simple earthen dams can also be made for irrigation and elaborate canals and pumps can be used for the distribution of water. The irrigation systems apart from the terracing will also limit soil erosion and also help to maintain soil fertility in the flood plains.