Agriculture in arid lands refers to the use of agricultural products as a result of soil erosion and moisture loss from groundwater sources. In this type of agriculture, crops are grown primarily for their yield, with small amounts of forage used for animal feed. Some forms of arid lands agriculture are dependent on groundwater recharge and some on surface runoff. Since the source of moisture is usually limited, crop production is typically for a short period each year.
Crop rotation is a practice of crop cultivation designed to improve the productivity of an area by replacing grasslands with crops that require less water. The practice can be implemented both to reduce the quantity of water used for irrigation and to enhance the soil structure. It is sometimes used to replace grasslands with timber for recreational purposes. Timber is planted to replace grass in areas of arid lands that are unsuitable for grazing because they are too wet or have poor drainage. Timber is not suitable for most crops, however, because it does not drain well and does not evenly spread over the land.
In some cases, an area may have more moisture than other areas. This is called a condition termed “wetland”. Wetland areas tend to have lower yields than arid lands because the plant roots cannot pull enough water from the soil for a thriving growth. An area that is commonly referred to as “irrigation belt” has an adequate supply of water for crop cultivation but has high precipitation. The term “semi-arid” refers to areas where the moisture level is between that of the wetland and semi-arid conditions.
Agriculture in arid lands is divided into two major categories: cropland and croasis. Cropland is the permanent inhabitant of a nature-arid landscape, composed of plant seeds and grass that grow for a particular season. Typically, this vegetation is found in flat, open areas and tends to be sparse, resulting in less plant diversity. The most fertile areas of arid lands are typically low in arable soil types, with a short history of plant life.
Crop rotation is the practice of planting different crops in regions with a similar climate and moisture level. For example, in Central America, corn is planted around Panama City to ensure a bumper crop during the hurricane season, while in Southern California, rice is planted around Mono County to improve the country’s hunger ranks during the four seasons of the year. Biomass crop rotation is similar to crop rotation, except that the plant life is not altered. Instead, the biomass crop is planted in an area where it would otherwise not thrive. This type of crop planting allows farmers to benefit from the natural variation in the climate and moisture level of the land without introducing unnatural species.
Irrigation systems are used on arid lands to bring water to plant life. These are either surface-based or ground-based systems that use a pump or suction system to draw water from the land to replenish the moisture level. Surface-based irrigation systems can provide direct moisture to plant roots, while ground-based irrigation systems pull water in through soil pores and into the ground. Both methods are more effective when combined with other practices such as proper tillage, which aids in keeping the soil moist but prevents compacting of the soil.
Plant nutrients are vital for plant growth and survival, and soil is depleted of these nutrients as a result of soil compaction and heat. Adding organic matter, or humic acid, to the soil helps retain moisture and increases fertility by improving the pH of the soil. Increasing the nitrogen, potassium, and calcium in the soil helps improve the nitrogen storage capacity of the soil and improve the structure of the root system. Potassium and phosphorus, two of the most important nutrients, are both lost in the process of crop cultivation. Therefore, plant nutrition and management on arid lands are focused on increasing these three nutrients for improved crop production and increased farming profitability.
In rural areas, where agriculture is the primary source of income, improving water quality can help improve the income level of the people who till the land. Improved irrigation systems improve water usage efficiencies, reducing water loss through wasteful practices such as excessive use of water, improper disposal of water, or over-watering the land. In some cases, introducing livestock into the arid lands can also be an option for ensuring food production and employment. Whether an individual grows his own food or sells food products from his farm, having improved water and soil management systems can give him an advantage in the market.