What are mycorrhizae?
The associations between roots and fungi are called mycorrhizae. These symbiotic arrangements have been found in about 90% of all land plants, and have been around for approximately 400 million years. Plant roots are hospitable sites for the fungi to anchor and produce their threads (hyphae). The roots provide essential nutrients for the growth of the fungi. In return, the large mass of fungal hyphae acts as a virtual root system for the plants, increasing the amount of water and nutrients that the plant may obtain from the surrounding soil. A plant that forms an association benefiting both the fungus and the plant is a "host." Large numbers of native desert plants are hosts to these fungi and would not survive without them.
Mycorrhizae are soil fungi that benefit the soil in many ways. A healthy soil is important for a water-wise landscape. Organic matter, drainage, and plant nutrients contribute to the fertility and health of the soil and plants found therein.
Mycorrhizae literally means “fungus root” and describes a mutualistic association between fungus and plant roots that exists in almost all plants. The plant supports the fungus by providing carbohydrates needed for fungal growth, while the fungus helps the plant by increasing its root surface area.
Nutrients and water
Mycorrhizae are essential in areas where soils are deficient in water and certain nutrients - conditions that are found in the desert. Even when there is an ample amount of a nutrient, it may not be readily accessible to the plant. A dramatically larger root system (or
mycorrhizae) permits the plant to obtain additional moisture and nutrients. This is particularly important in uptake of phosphorus, one of the major nutrients required by plants.
Potential Benefits of Mycorrhizae:
- Enhanced water and nutrient uptake
- Enhance flowering and fruiting
- Reduction of irrigation requirements
- Reduction need for fertilizer
- Increased drought resistance
- Increased pathogen resistance
- Increased plant health and stress tolerance
- Higher transplanting success
Soil structure refers to soil particle aggregation as well as pore spaces. The maintenance of soil structure is of critical importance to the preservation of soil functions and fertility. Mycorrhizal fungi play a major role in soil aggregation through hyphae networking and glomalin (biological glue) production. Therefore, their presence in the soil is essential to maintain physical soil properties. Better soil structure results in:
- Greater water infiltration and water holding capacity
- More permeability to air
- Better root development
- Higher microbial activity and nutrient cycling
- Better resistance to surface sealing (crusts)
- Better resistance to erosion (water/wind)
- Better resistance to compaction