We propose several measures to reduce water consumption in agriculture. As far as livestock farming is concerned we believe the most effective solution is to for people to reduce the amount of beef they eat. A less drastic yet still effective alternative is to consume less water intensive meat such as chicken rather than beef.
Our solution with regard to crops is based in both economics and technology. Water consumption in agriculture will be reduced by a combination of methods including switching subsidies from water intensive crops to water conservation measures, encouraging the already occurring crop shift to low water use crops and assisting in expanding the use of more efficient irrigation technologies and irrigation scheduling systems. We also support a more widespread use of crops which have been engineered to be drought resistant.
To effectively deal with the water crisis, centralized federal control of the water resources is needed. The government should be responsible for determining the sharing of water since they can direct it to areas where it could be most productively used.
In order to most effectively address the water needs of individual areas, irrigation districts should be established with boundaries decided by minor watersheds, as is already the case in many parts of the country. Each board will consist of representatives of every group concerned with the water (farmers who irrigate, municipalities, industries, fisheries, conservationists) and will be responsible for local water issues, such as sources of water, operation and maintenance of water use /conservation schemes and funding of said schemes. A system of full time employees will also be required to deal with day to day running of administration. Each board will be open to the public and encourage public involvement; newsletters will keep districts updated on each others' plans (Johnston, 1987).
The following basic federal guidelines will govern the operation of irrigation districts. The government will not provide subsidized water to areas since it encourages farmers to over use water. Users of federally supplied water will instead pay more to match the cost of supply. The government should also be careful about allowing irrigation districts to borrow large amounts of money for district projects and require a thorough investigation into their repayment abilities before approving loans, decreasing the likelihood of ineffective projects being put into place. Basic water qualities standards will be set by the government. As competition for water increases, users will require either a historic right to the water or a licensed contract for the water. Few new major projects are likely to be built due to the high cost, new knowledge about environmental degradation and the fact that the most justifiable ones have already been built (Johnston, 1987).
Isolating only American beef production, approximately 6.9 billion pounds of beef were produced in 1992 (Beckett, 1993, 824). However, the amount of beef produed has remained relatively constant even though the industry size has declined (Background of Beef Production, 2007). Since one kilogram of boneless beef requires on average 3,682 liters of water (Beckett, 1993, 818) approximately 3 trillion gallons of water is used annually to produce boneless beef. So if we cut production by 10%, we would be saving 300 million gallons of water annually. However, Americans consume 64.4 pounds of beef on average annually, and since the U.S. population is estimated to be 301,139,947 people (CIA Factbook, 2008); Americans are consuming 26.3 million acre-feet of water in beef annually, which is almost equal to amount of all freshwater withdrawals in Texas (USGS, 2000). So alongside decreasing production, consumption must decrease as well in order to make a significant dent in water usage related to beef.
This goal will largely be accomplished by large-scale public awareness campaign throughout the US. This campaign will include advertisements on television, radio, and in print media about the water intensity of meat products, especially beef. The campaign aims to encourage people to make small changes in their lives, beginning with eating 2-5 fewer meat meals a week. Restaurants and television shows will also hopefully join the campaign, seeing it as a popular way to increase business and interest. Alternatively, people could replace beef with less water-intensive meat, such as chicken.
We are choosing not to legislate or zone against meat production in hopes that we can create general public agreement with the campaign. By enacting legislation that forces people to cut down on meat or greatly increases prices consumers are likely to adopt largely negative opinions of the entire movement to conserve water, associating it solely with lifestyle changes that have been forced upon them. We want to work with, not against, the general public in making a move towards more sustainable food sources.
Crop shifting will contribute in part to the solution of water use in agriculture. There are two situations where it would be necessary. The first type of shift is from low income, high water use crops to high income, low water use crops. This will in part occur automatically with a subsidy shift. That is, if the government were to stop subsidizing those field crops which are have a low economic value and a high water intensity, farmers would voluntarily plant more economical plants. Since the gross production value of field crops in general is $524/acre, while it is $3,134/acre for fruits and nuts and $5.171 for vegetables (Cooley, 2008), this would mainly result in shift away from field crops. Fortunately the US currently has a surplus of such crops (See Table 1).
TABLE 1: US AGRICULTURE EXPORTS
2006. Crop Summary, Retrieved November 24, 2008, from USDA, National Agricultural Statistics Services website: www.nass.usda.gov
TABLE 2: AGRICULTURAL WATER USE
(US Census of Agriculture, 2002), (Australian Bureau of Statistics)
The shift will likely be to vegetables rather than orchards or vineyards since the former are more flexible and can be adapted or the fields easily fallowed if climate or markets change. Table 2 details the available information about the amount of water used by different major crop types, and the area under irrigation in the US as a whole.
It can be seen that switching crops from, for example, cotton to vegetables could be highly profitable for the farmer as well as being good for water conservation, since despite the fact that a larger percentage of vegetables are irrigated, they use nearly half the amount of water that cotton uses per hectare. This change of subsidies is already starting to take place. The 2008 Farm Bill gives Environmental Quality Incentives Programs 1% of the farm budget ($1.2 billion) in funding. In distribution of the money the bill requires that priority be given to conservation measures and to farmers who use more efficient irrigation measures which reduce water use, and who promise not to use the saved water to irrigate new lands. This is just a beginning however and the amount of money invested in such a cause should be increased greatly.
The second type of shift would be a movement of crops from dry regions of the country to regions with more water. We also recommend that lands which have been degraded should be taken out of production and purchased by the state government. They could be turned into parks or, if the money to fund a park is not available, they could be left alone as general conservation areas. Once lands have been severely degraded the yield and the economical returns become very low, so there will be less opposition from farmers than otherwise would be expected. One can however expect some opposition from any move of this sort. A more temporary solution, along less drastic lines, is to fallow fields in time of surplus or drought. Fallowing fields takes them out of production temporarily, cutting water use since they do not need to be irrigated. Fallowing in time of surplus would probably require government control. There is another factor to consider with crop shifting: employment. Field crops are not very labor intensive, whereas vegetables and fruits are. In California, field crops supply 5% of average monthly crop production related employment, while vegetables and nursery crops are responsible for 22% each, and fruits and nuts are 42%. So while crop shifts will result in increased labor costs, they will also result in increased employment (Cooley, 2008).
There are three types of irrigation system, each of which has its advantages and disadvantages. Table 3 illustrates each major irrigation type.
TABLE 3: IRRIGATION TYPES
The first method is flood irrigation, which results in a large surface area of water since furrows between crops will be filled with water. It is simple, relatively cheap, requires little energy and can use lower quality water than other systems. However, it is also much less efficient in water use than other systems, inflexible in terms of management and requires that fields be finely leveled. As can be seen from the table below, conventional furrow systems are only 60% efficient in water absorption by the plants and surge flow systems are only 75% efficient.
Sprinkler systems use spray nozzles and pressurized water and can either be movable (such as center pivot) or fixed. Movable sprinklers waste more water than other sprinklers but can be transferred between fields. The most efficient systems are Low Energy Precision Application (95%) and Low Elevation Spray Application (88%) sprinklers. They are an adaptation of center pivot irrigation in which the nozzles extend right down to the ground so the water is supplied only and exactly where it is needed and can be applied at low pressure. This saves water as less is lost to wind or evaporation from the foliage and energy as well as preventing soil erosion caused by runoff of excess water. They also do not require much labor. On the down side sprinkler systems are expensive to install and may become less efficient when it is dry or windy, and they may damage crops by frequently wetting non-root areas.
Thirdly there is drip irrigation. This is where water is supplied at very low pressure, very slowly, directly to a plant's roots from plastic tubing. It is the most efficient form of irrigation at 97%, results in very little erosion and can save labor if it is automated. However it is also the most expensive form of irrigation (Cooley, 2008).
TABLE 4: IRRIGATION SYSTEM EFFICIENCY
Source: Amosson, S. H., New, L., Almas, L., Bretz, F., & Marek, T. (2002).Economics of irrigation systemsNo. B-6113). College Station, TX: AgriLife Extension Texas A&M University.]
TABLE 5: INVESTMENT COSTS OF ALTERNATIVE IRRIGATION SYSTEMS
*Half-mile center pivot.
1Assumes a marginal tax rate of 15 percent and discount rate of 6 percent.
2Assumes a marginal tax rate of 28 percent and discount rate of 6 percent.
Source: Amosson, S. H., New, L., Almas, L., Bretz, F., & Marek, T. (2002).Economics of irrigation systems No. B-6113. College Station, TX: AgriLife Extension Texas A&M University.
As for expenses of these systems, conventional furrow and surge flow cost the least to install but is more expensive to run and maintain. The spray systems cost more to install but cost less money in water usage and about the same as conventional furrow in running and maintaining it. The subsurface irrigation systems are the most expensive to install but they use the least water and labor. After all of the net investments, LEPA has the greatest benefits with respect to conventional furrow. At about two times the cost, LEPA has benefits on average $600/acre. (USGS, 2000) Also, using larger farms has lower costs per acre - just for LEPA, the gross costs of a quarter mile pivot are $376/acre while a half mile pivot costs $250/acre. (USGS, 2000)
We recommend that farmers adopt the most water-efficient technology possible for their specific crops to maximize efficiency. This switch in irrigation systems will save farmers money in the long run since the price of water will generally be increased to more accurately reflect its actual value.
To promote the more modern irrigation systems the following steps need to be taken:
It is necessary to improve the networks which provide real time information on weather and evapotransporation and on crop water needs. One example is the California Irrigation Management Information System (CIMIS), which consists of automated weather stations throughout California, which provide the real time data needed to calculate the amount of water crops need. The Department of Agriculture and Resource Economics at the University of California, Berkeley conducted a study which showed that using CIMIS increased yields by 8% and reduced water use by 13% on average (Cooley, 2008).
It would also help to promote use of smart irrigation scheduling technologies e.g. plant and moisture sensors, computer models.
Another possibility is to use regulated deficit irrigation, whereby the amount of water supplied to the plants is less than the maximum that could be lost by evapotranspiration. Deficit irrigation is used mainly in orchards/vineyards since for these types of crops quality of yield is more important than quantity, and they also have stages which are less affected by poor environment, which are generally lacked by field crops or vegetables. Regulated deficit irrigation can reduce water consumption by 20% for almonds, pistachios and citrus trees and 39% savings to vines. More specific studies are needed in to the exact effects of this since it is shown to result in greater yield per unit of water, but may have negative effects on the yield over a longer period of time (Cooley, 2008).
Multiple companies are working to develop crops that will retain high yields under drought conditions. Few of these technologies are in practice now in the United States, and it is unclear exactly how much water these technologies will save. Most projects are under development and papers have not yet been published. Scientists researching genetically modified crops have yet to discover a single gene to reduce water consumption, but instead are working with several genes.
The Monsanto Company will introduce in four years a drought-tolerant corn for drier places, such as Nebraska and Kansas, that will increase yields by 10%. Monsanto is also working to make plants that will keep producing when droughts begin so that limited water will not directly hinder production, which is the normal plant response. Tours of the Monsanto facilities and projects to farmers in the western United States have led to positive responses from most farmers, who are eager for a solution to the water problem (Pollack, 2008).
USDA, 2008. www.ers.usda.gov
Several other companies and labs are working on other projects involving drought-resistant crops. Sygenta Company will market a conventionally-bred drought-resistance corn in 2011, and a genetically modified version in 2014. The production of both varieties is likely to appeal to opponents of genetic modification of food crops while the modified version is expected to have even more effective water use. The International Maize and Wheat Improvement Center in Mexico has introduced in Africa a drought tolerant corn that increases yields during drought years by 20-50%, without decreasing yields in good years. Although the center's first priority is to help places such as Africa with a more imminent food shortage, similar technology could be used in North America. Another company, Performance Plants, is working to develop plants that retain water quickly after a drought begins (Pollack, 2008).
Despite controversy over the use of genetically engineered crops, over the last 12 years the use of these crops has increased dramatically to the point where they make up the majority of American acreage of some crops, such as soybeans and cotton. Since, in the less water abundant era to come, every saving will be a boon, it is recommended that research into drought resistant crops continue. Graph 1 indicates the spread of genetically modified crops to a forefront in agriculture.