Some Ways To Save Water: 7 Tips for Irrigation
1. Drip, or Micro-Irrigation
Drip irrigation delivers water (and fertilizer) either on the soil surface or directly to the roots of plants through systems of plastic tubing with small holes and other restrictive outlets. By distributing these inputs slowly and regularly, drip irrigation conserves 50 to 70 percent more water than traditional methods while increasing crop production by 20 to 90 percent. The water and fertilizer are also more easily absorbed by the soil and plants, reducing the risks of erosion and nutrient depletion.
Usually operated by gravity, drip irrigation saves both the time and labor that would otherwise be needed to water crops, leading to larger harvest yields. Small systems on timers can easily be set up by the home gardener, too.
This technology must be innovated and tailored to the crop and conditions. For example, some systems are now solar powered and tubing materials have changed. There are many styles of drip inserts which can be incorporated into the hoses and soaker hose segments can also be used. Instead of using plastic tubing, ceramic can be used as it is more porous.
Small stream diversions, water collection tanks, or holding ponds can be used to provide a gravity water supply for drip irrigation systems. Hand or peddle powered pumps or elevated buckets can also be used.
These micro-irrigation systems, while affordable, are less suitable for major rice growing areas or for staple grain growing. They are more suitable for high value vegetable gardens. Care should be taken to avoid the build-up of salts in drip-system soils.
Within the last two decades, the area irrigated using drip and other micro-irrigation methods has increased more than six-fold, to over 10 million hectares. The adoption of drip irrigation in more areas holds much hope for growing more food with less water.
2. Bottle Irrigation and Pitcher (Olla) Irrigation
Buried clay pot (olla) irrigation is an ancient technology that uses a logical idea. By burying a porous clay pot up to its neck, and filling it with water, a gardener has a 70 percent efficient watering system. Water weeps slowly out of the pot and moistens an area about one-half the diameter of the olla. Since soil is not saturated, the environment created is very healthy for the plant roots, which form a mat around the olla. (Many modern gardeners kill plants by overwatering.)
A perfect olla has a thick wall, is fired at a high temperature, has rough surfaces, and holds one quart to two gallons of water. After burying the pot and filling it with water, the top can be covered with a rock to keep it clean and prevent evaporation.
Depending upon the crop and the rainfall, filling the pots two to three times a week may be adequate.
To use an olla, place it in the middle of several plants so that the plants draw moisture from the center and grow outward onto dry land. This uses the space and the water very efficiently. Smaller ollas may be used to water containers or patio pots.
If the pots lose flow after many years of use, they can be soaked in vinegar to reopen pores. Always use clean or settled water and don’t add fertilizer so as not to clog the clay’s pores.
USING RECYCLED BOTTLES FOR MICRO IRRIGATION
Above is one of many possible designs to aid in using a recycled bottle as a slow release pot or plant waterer. Wine bottles, plastic bottles, and almost any bottle will work. Holes can be tapped into plastic sides or lids, or commercial plastic spikes can be purchased which the bottle can be inserted into. Or, a bottle can simply be filled with water and inverted next to a plant into moist soil. Here is the source link for the wine bottle waterer: http://www.gardeners.com/ .
3. Zai Pits
Zai planting pits are hand dug holes about ten inches wide, ten inches deep, and three feet apart (25cm x 25cm holes one meter apart). They are used to trap water and increase soil fertility, especially in arid regions with degraded, crusty soils. The pits are planted with a mixture of crop residues, manure, and seeds, and covered with a mulch of grass or leaves.
When digging the pits, the excavated soil is used to make a small ridge around the pit to help capture rainfall.
The pits can be reused if silt and sand are removed annually.
This simple technique can increase the amount of crops that smallholder farmers produce by 50 percent after just three years.
4. Drought Tolerant Crops and Seeds
Grow the right crop for the growing region. Regions which suffer water shortages are wise to plant crops which are more tolerant to drought. These include finger millet, pearl millet, Guinea millet, cowpea, teff, lentils, amaranth, fonio, emmer, various sorghums, African rice, Ethiopian oats, irregular barley, mung beans and many grasses. Ideally, researchers would be working with all of the crops on this list to improve the seeds for our crop requirements of tomorrow.
For example, researchers have improved cassava varieties over the past four decades which can increase yields two to four-fold over traditional varieties.
Traditional millets require little water and can grow in poor soils without any synthetic fertilizers. Millet is a heat resistant crop which has high calcium and fiber content as well as essential amino acids.
In addition, drought tolerant crop seeds are available both through biotechnology and from native seed varieties. Examples of drought tolerant seeds available today include corn, rice, and cotton. Just as importantly, there are flood resistant rice seeds available. Having the right, reliable, and quality seeds in hand for a new planting season is of utmost importance.
6. Ripper-Furrower Planting System
In northern Namibia, farmers are using a ripper-furrower to rip 60 cm (2 feet) deep and form furrows which function to harvest rainfall. The crop seeds are planted into the rip lines with fertilizer and manure. When it rains, the water is funneled by the furrows to the crop roots.
Tractors are used the first year to start the ripped furrow system. After the first year, farmers plant crops directly into the rip lines using an animal drawn direct seeder.
This practice is being used to plant drought tolerant millet, sorghum, and maize. Farmers using the system are encouraged to practice crop rotation with legumes.
These practices together lengthen the growing season and improve the soil’s structure, fertility, and moisture retention. They improve crop growing in both droughts and floods. Average maize yields have increased from 300 kg/hectare to 1.5 tonnes/hectare, or five-fold in Namibia since using this system.
This method of rainwater harvesting especially aids in regions where soil is dry, solid, and crusty. Whereas the rain previously ran off, now it soaks into the ground right where it is needed to grow the crop.
7. Acequias
The above photo is a wooden aqueduct near Las Trampas, New Mexico on the High Road to Taos. The aqueduct spans a deep gorge at an approximate elevation of 8,000 feet above sea level.
This is an example of an acequia, which is a historical engineered canal that carries snow runoff or river water to a distant field. Acequias are commonly ditches, and need to be planned, maintained, and overseen by groups of cooperative farmers. Acequia water law requires that all persons with irrigation rights participate in the annual maintenance of the community ditch including the annual spring time ditch cleanup.
Acequias originated in Spain and were built later in the Spanish-American colonies.
