Some areas of the world can survive on natural rainfall, but for most of us we have to give nature a hand with a little well-planned irrigation. Watch as we demonstrate a variety of water-saving irrigation methods along with some ways to improve your soil so that it'll retain more water.
Featured Expert: Dr. Frank Williams, BYU Professor of Plant and Animal Science.
Click on a topic below to view additional information.
The goal of irrigation is to get the water into the root zone. Good soil can help make this easier and conserve water in the process.
Properly prepared soil will hold water better. If you have good soil the plants will not need to be watered as often.
Proper soil preparation provides the basis for good seed germination and subsequent growth of garden crops.
This web site describes garden soils and their management, including organic matter, efficient irrigation, nutrients and fertilizers, soil testing, and soil amendments.
See this site for a fun way to understand the important components of soil.
Organic matter is the key to getting water to the root zone.
Organic Gardening emphasizes the use of organic soil amendments to improve the nutrient content and physical characteristics of the soil.
You should have 8-10% organic matter worked into the soil.
Organic matter can be any green, leafy matter-grass clippings, leaves, manure, pea vines, apple peelings, or anything vegetative.
Soil that has been improved with organic matter can drain sufficiently and retain moisture
In dry regions where there is just 1-2% organic matter in the soil, it takes more water because the soil can't hold as much moisture and you get more runoff.
In wetter climates, the organic matter helps to aerate the soil and promote drainage.
Organic gardening differs from "conventional" gardening mainly in the areas of fertilization and pest control.
Mulch, by definition, is a layer of bark, sphagnum peat moss, muck peat, compost, pine needles, gravel, plastic, or any similar material uniformly spread on the surface of the soil under plants.
Mulching is a long-time practice of gardeners to prevent loss of moisture and to control weeds.
Organic mulch needs to be applied to a depth of 2-3".
Grass clippings do not make good mulch because they prevent air getting through to the plant and cause the water to run off.
Organic mulches add nutrients and humus to the soil as they decompose.
Plastic Mulch
Some examples of inorganic mulches are black, clear, or red plastic and newspaper.
Clear plastic is warmer in temperature for the plant but it does allow weeds to grow.
Black plastic is cooler for the plant. Weeds cannot grow under it and it conserves moisture.
Some of the advantages and disadvantages of using plastic mulches are outlined in this site.
Tips on soil from Frank Williams
Healthy fertile soil is a mixture of water, air, minerals, and organic matter.
Organic matter or compost is any plant or animal matter that has decomposed.
Organic matter helps keep the soil from becoming compacted.
If you want to improve a clay soil by adding sand make sure it is very course sand. The best soil is to have a mixture of organic matter (45%), clay (45%), and sand (10%).
Find out the contents of your soil by having it tested at a University Extension office.
A soil test tells you the amount of clay, sand, and organic matter in the soil, as well as the ph (a measure of the acidity or alkalinity).
The natural soil in a hot dry climate usually only has about 1% organic matter.
The natural soil in a very wet climate can have up to 50% organic matter.
Larger pieces of organic matter such as leaves or small pieces of wood will have a longer lasting effect on the soil because it takes longer for those to break down. Peat moss breaks down very quickly so the results do not last as long.
Mulching is very important for water conservation.
Mulch made entirely of grass clippings may prevent air from getting to the roots and may cause excessive run off.
Mulch with larger pieces is more effective, but may not look as neat.
Clear plastic mulch is used to heat the soil up and conserve moisture. It is good to use in the spring when you want to heat the soil. Clear plastic allows weeds to grow underneath.
Black plastic blocks the weeds from growing and does not heat up the soil as much, because it blocks the suns rays at the surface of the soil
Green plastic mulch also warms the soil by allowing infrared rays to enter.
Red plastic mulch encourages higher yields by reflecting light into foliage.
Xeriscape is a concept of water conservation that may be applied to landscapes of any style, from traditional to English, Japanese, Southwestern, and others.
Garden Hose
The garden hose is a good way to water because it forces you to be out in the garden so you observe every day what is going on.
When you use a garden hose you control the amount of water by monitoring the needs of the plants and providing the appropriate amount of water for the climate conditions.
A garden hose is a good way to practice flood & furrow irrigation. For this method you make a furrow between the plants and allow water to run slowly down the rows.
Bucket Watering
Bucket watering is a useful method, especially for areas where water needs to be conserved.
With the bucket method water is applied directly to the plant root zone.
A drip system needs to be taken up at the end of every season in the vegetable garden.
The drip systems can easily get plugged with algae and other debris.
Tips on watering from Frank Williams
Plant your garden in zones with plant needing similar water use placed together.
Using a water can for watering makes for less water waste.
Water enough so the water goes down to the bottom of the root zone.
Clay soil absorbs less than 1 inch of water per hour. Loamy soil absorbs 3 inches of water per hour.
Water slowly to avoid run off and to ensure that the soil is absorbing water.
To water in the root zone try burying a large can with holes punched in the bottom next to your plant roots and fill the can with water.
A sprinkler system can save about 25% more water than the flood and furrow irrigation system.
Drip irrigation systems will use about 50% less water than the flood or furrow irrigation system, and will save 25% over a sprinkler system.
Drip irrigation systems take time to make sure they are assembled properly and that they are working properly.
Make sure to use a good filter with a drip irrigation system to help prevent plugs.
Drip irrigation systems need a pressure reducer because you only want 25 psi.
Water pressure for most hose spigots runs from 50 psi to 100 psi.
You will need a device that prevents back flow. This prevents the small hoses from sucking up dirt and chemicals, which can then flow backwards through the system and end up contaminating the culinary water.
Drip systems are best for trees, shrubs and permanent fixtures in the landscape.
Assembling and maintaining a drip system requires our constant care.
Drip irrigation systems can help reduce some plant diseases such as fungus.
Don't try to make your own soaker hose by poking holes in a regular garden hose. It will not work very efficiently or effectively.
When the plants are small, watering is necessary every day or even twice a day for germination.
As the plant matures watering can decrease.
The best time of day to water is early morning before the temperatures begin to rise. This gives the plants a good supply of water to face the heat of the day.
Some climates get too hot in the summer months so the plant can't take up water fast enough.
In hot climates, we practice "syringing" which is to spray water in an area for 2-3 minutes to cool down the air. This prevents water loss in the plant.
Over watering or under watering
Watering too often or too much is likely to exclude the necessary oxygen from the soil pore spaces. Without enough oxygen, plant roots suffocate and die.
Ninety-five percent of people over-water their gardens.
Signs of under-watering in some plants, may cause leaves to turn from shiny to dull. The color may also change from bright green to blue green or gray green.
Water stressed plants-can look just like an over-watered plant except the soil is dry.
Water Conservation
Using mulches will help prevent evaporation.
Never water below a depth of 3-6".
For efficient water management tips see this site.
Water is a critical component of photosynthesis. Water is one of the many factors that can limit plant growth. We also need to plan how to use water wisely.
The very best time to water is early in the morning.
Studies show that plants use water most efficiently early in the day.
Use syringing to cool the area down in very hot dry climates. Syringing is turning the sprinklers on in the afternoon for about 5 minutes to help cool the air and area down.
In moist climates turning the sprinklers on for a few minutes in the early morning will wash off spores and other things that can cause disease in your plants.
Use a screwdriver or dig down to see how far the water is going into the soil. You can also push your finger into the soil to check for moisture.
Keep the root system wet and after the top 2 inches is dried out apply more water.
The purpose of fertilizer is to provide necessary plant nutrients so that the plant can make its own food through photosynthesis. Choosing and using fertilizer properly will enhance plant growth and protect water quality.
Make and keep a record of your observations and how much fertilizer you use. What growth response do you see in your plants from the fertilizer you apply?
Some plants that require a lot of fertilizer can use a side dressing part way through the growing season. This means you would apply fertilizer along the row about six inches from the plants.
Tips on fertilizer from Frank Williams
Using enough fertilizer can help reduce the need for as much water.
The healthier the plant the better it can withstand not having as much water.
It is best to apply fertilizer in late fall or early spring.
Fertilizer can be applied at a rate of 1 pound per 100 square feet.
If we have prepared our garden properly with mulch and fertilizer and we water deeply, we should only need to water every 7 - 10 days.
The more often your shadow falls in the garden, the better you'll know what it needs.
