Drought is a temporary and natural climate feature caused by a significant decrease in precipitation over a prolonged period. Human activities, such as ground clearance and changes in land use, can exacerbate drought situations. Farmers are usually the first to be affected by drought because of their dependence on stored soil water, which rapidly becomes depleted during extended dry spells.
Effects of Drought on Crops
Prolonged reduction of ground-water supplies can have a devastating effect on a farmer’s crop yields. If a drought occurs soon after seeding, plants may fail to germinate; and during the later stages of development, a drought can cause entire crops to wither. However, as long as there is sufficient moisture in the topsoil to see the seedlings through the early growing stages, yields may not be affected if there is enough water stored in the sub-soil to sustain the plants through the remainder of their growth cycle.
Effects of Drought on Livestock
Drought conditions can make grazing lands and hay fields hazardous for livestock, since lack of water causes increased concentrations of nitrates and prussic acid. Even if the animals are not directly affected, these chemicals contaminate their meat and milk. If livestock cannot graze, they eventually become infertile, and their milk will dry up. Their physical condition will deteriorate, until finally they become so weak that they may die. The farmer's only options are to sell the stock at a low price or to buy feed, which is expensive.
Fire and Other Hazards
Drought greatly increases the risk of fire on a farm because the fields become so dry that they easily ignite, and fire can spread quickly. The dryness of the land also leads to soil erosion. Another problem for farmers is that drought conditions encourage the influx of invasive species, such as weeds and insects, which cause damage to crops and can be difficult to get rid of.
Effect on Farming Strategies
In time of drought, water shortages and economic restraints often drive farmers to improve their stewardship of water resources. For example, they use more efficient watering methods, such as drip irrigation. They schedule their watering based on actual crop needs by monitoring the soil and weather forecasts carefully. They use recycled water -- for example, treated city waste water. Other possible changes that conserve soil moisture include the use of mulches and amendments and planting cover crops in the winter. As drought continues, farmers are also motivated to switch to drought-resistant crops such as sorghum.