Because agriculture is one of the largest uses of freshwater on our planet, it is important that we change our farming practices to conserve water instead of wasting it. Many farmers are already implementing wise water management in their farming operations, and are employing many of the following practices.
- Preserve and build healthy soil
Healthy soil has a structure to it that soaks up water and retains it much more effectively than degraded soil does. By implementing minimal tillage and incorporating healthy levels of organic matter into the soil, the soil will retain its healthy structure and hold moisture effectively.
Hugelkultur is a specialized cultivation technique that involves burying woody materials in soil, such as logs and branches, and then planting in the soil on top of the buried mound. The woody material inside the mound soaks up water like a sponge, and creates productive growing conditions. Hugelkultur is so good at retaining water that a grower may not even need to water at all!
Hugelkultur systems can be implemented on both a small and large scales, wherever there is an abundance of woody debris. Some tree species work much better than others, however.
- Raised keyhole bed gardens with a rainwater and greywater capturing component
In some areas of arid Africa, such as in Lesotho, communities and families are growing food for themselves using raised keyhole bed gardens. These gardens provide a way to produce food in regions that are challenging to grow crops in, and also allow for the capture of compostable organic materials, rainwater, and greywater to enrich and water the keyhole garden.
- More efficient irrigation systems
Irrigation systems should be as efficient as possible, with leaky irrigation lines being replaced to no longer waste water. Drip irrigation can be used to deliver water specifically to crop plants to avoid unnecessary water evaporation from the soil.
- Capturing and storing water
Farmers can create ponds and wetlands that capture rainwater throughout the year that can be used during the dry season. Such ponds and wetlands can also provide habitat for waterfowl and other aquatic wildlife. Building swales on contour offers an opportunity to capture and hold water high on the landscape and to recharge groundwater supplies.
- Irrigation scheduling
Watering schedules can be adapted to allow for watering only when it is necessary. Computer applications are now available to adjust irrigation systems to respond according to precipitation and moisture in the soil.
- Drought-tolerant crops
In order to conserve water, farmers should consider growing those crops that are the most appropriate to the local climate. This means not growing thirsty crops in a very arid region, but instead growing those crops that are naturally drought-tolerant. Crops such as olives, tepary beans, quinoa, Gold Coast okra, millet, sorghum, and Armenian cucumbers are crops that can tolerate drought conditions.
- Dry farming
Dry farming relies only on moisture present in the soil to produce crops when rain is scarce. Implementation of such a method involves implementing specific types of tilling and focusing on microclimates.
- Rotational grazing
If grazing pastures are managed well, they will have increased absorption ability and decreased runoff, which makes them inherently more resistant to drought. Other water-saving features of good grazing management includes increasing organic matter in the soil and forage cover.
- Compost and mulch
When organic matter such as compost and mulch is added to soils, the structure of that soil will improve and has an increased water-holding capacity. Mulch materials such as straw or wood chips are excellent choices because they help to reduce moisture evaporation and also break down and increase the water-holding capacity of the soil. Another common water-conserving practice for farmers is to cover the soil with black plastic mulch covers, which reduce evaporation and suppress weeds.
- Cover crops
Cover crops help to reduce weeds, and increase soil fertility and compaction, allowing for easier penetration of water into the soil and improving its capacity to hold water.
- Conservation tillage
By only allowing partial tillage and by retaining some crop residue on the soil surface, farmers help to increase the water absorption of the soil and reduce problems of evaporation, erosion, and compaction.
- Going organic
It has been found in a study by the Rodale Institute that organic fields not only have higher yields than conventional fields, organic fields retain greater soil moisture, helping to replenish groundwater supplies[sc:1].