Irrigation

Agriculture is the main consumer of water. Studies show that 70% of all freshwater used goes to crops instead of people. Currently 1.1 billion people lack access to water and another 2.7 billion suffer from water scarcity for at least one month throughout the year.

Current methods of Watering:

Surface- flooding surface of farm with water either manually or by natural forces
Sprinkler- using large systems that dust fields from a high distance with water
Drip/Trickle Irrigation- using pipes that run across fields that pushes water directly to roots of the plant
Subsurface Irrigation- underground system that pushes water up through the ground to plants

Current Regulations for being labeled "Organic":

None.

The regulations necessary to be labeled "Organic":

Fully irrigated farms, farms in the West, and farms in the mid-west would need to use drip irrigation.
- Drip Irrigation is a method of water distribution that uses pipes going down rows of crops to administer water straight to the roots. It decreases runoff, evaporation, and other wastefulness of water.
Farms in the East (regions with 30+ inches of water- see Image 1) would be allowed to use some sprinklers but at least 65% of water used would have to be through drip irrigation systems.
Irrigation systems MUST be covered to prevent evaporation

Timing of watering:
- No watering between 11am and 3pm when evaporation is highest.

Location of where certain crops can be grown:
- Water intensive crops should be grown to the East of the country, while water non-intensive crops should be grown to the West.
- There could be exceptions for the regions of Washington, Oregon, and California that get +60 inches of rainfall annually.
- (see Image 1)

Setting limits on how much water is allowed to be used in each region: Three Options
Option One: Root Depth
- Maximum water depth needed for plant roots in the west is 3 feet.
- Crops that need deeper roots will be planted in the east.
Option Two: Water use in million acre-feet per year
- Maximum water allowed for plants in the West is 2 million acre-feet per year.
- Maximum water allowed for plants in the East is 5 million acre-feet.

Option Three: Water use based on rainfall (Most Effective)

Looking at Image 1 highlights how much rainfall per year each region receives. Comparing inches of water needed to grow crops to inches of rainfall received in each region, enables farmers to match crops to the respective regions that receive that much rainfall. There will be a 5 inch/ year margin for each crop. (This is explained in the case study and solution).

Water use depends on soil type:
- Fine soils can hold water better than large, grainy soils. Depending on location some areas should plan for crops that do not need as much water and they should use a method of watering more frequently, but using small amounts of water each time to decrease runoff.
- Example: Water runs through sand more easily than silt and runs through silt more easily than Clay.
- (see Image 4)

No-till farming
- In regions that receive less than 40 inches in rainfall each year (see Image 1) should use the method of no-till farming to keep moisture in the soil, prevent evaporation and erosion, and reduce work goes into production of crops.

Case Study 1: Alfalfa and Corn across the United States

Alfalfa:

Mostly grown in the North West and West but is widespread throughout the US.

Alfalfa is a water intensive crop but is grown in the driest regions of the country (as seen when comparing images 1 and 5). It needs 33 to 58 inches of water annually. There is a big variation in how much water is needed because of the conditions in which alfalfa is grown.

For example, it takes more water to grow alfalfa in the South East region of Oregon than it does to grow it in the North West region of Oregon because the South West has a less rainfall and more evaporation (see Image 1). However, more alfalfa is grown in the South East than the North West (see Image 5). Because of this, more irrigation is needed, and because there are no regulations on irrigation farmers upriver are causing farmers downstream to have a shortage of water.

Corn:

Mostly grown in the Middle of the US around the great lakes.

It is not a water intensive crop. It needs roughly 20-30 inches of water annually depending of evaporation rates, soil quality, and other weather and climate conditions.

Corn is being grown in places that have good weather conditions (see Image 6) but to make room for plants that need more water it would make more sense environmentally to move corn into the North East and through the middle of the country (North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas). Corn is already grown in some of these areas but if we capitalized on growth here then productivity would rise. It would be beneficial to stay away from the South East region of the US because more water intensive crops should be grown here (see Image 1).

Solution: Grow corn in the middle of the country where the rainfall is 15-35 inches/year and grow alfalfa to regions of the country where rainfall is 28-63 inches/year.

This could be done for all crops. Finding how many inches of water they need per year and then matching them with regions of the country that match this amount. Because rainfall varies, farmers would be allowed to plant their crops in regions that have (+/-) 5 inches of rainfall annually than the average of what their crops needs.

Example: If a crop needs 20 inches of rainfall annually, they could plant this crop in regions that get 15 to 25 inches of rain annually.

Case Study 2: Ogallala Aquifer (see Image 7)

Also known as the High Plains Aquifer because it is located directly under the high plains and that is where most of the water goes.
Over 90% of the water taken out of the aquifer goes towards watering crops
It irrigates somewhere between 20-30% of America's crops (decreasing because of the decreasing water supply)
Water is being taken out at a high-speed rate and is being put back in slowly.
Effects of the aquifer going dry include: Loss of jobs, food, resources, money, and not to mention the impacts it will have on the natural environment that surrounds it.
The groundwater level has dropped over 150 feet since WWII. Many farmers have had to reroute their systems to find water.
At peak use, water was being taken out at a rate of 8,250,000,000 m^3/year.

Solution: Stop using the Ogallala Aquifer. It is not sustainable to use water that has been filling up for millennia at this rate. Even if they cut back water will still be taken out faster than it can be restored because the aquifer still needs time to refill.

To keep moisture in the soil, regions with 40 inches or less of water annually should use the method of no-till farming.

To use less water use Option Three of the water conservation.

Main Takeaway:

Covered Drip Irrigation:

Covering irrigation systems so that water is not lost to evaporation. Using drip irrigation so that water goes directly to roots instead of running off or evaporating. Also, get water from sustainable sources.

Comparing rainfall to water needed to grow crops:

Planting water intensive crops in areas with high rainfall.

Planting water non-intensive plants in areas with less rainfall to make room for plants that need more water.