Introduction
The change of climatic conditions across the globe has necessitated partial shift from the over-reliance of natural rainfall for crop production, to the application of irrigation for production of food and other types of crops. The need to continually produce food crops to feed the rising global population has placed special demand on the water used for irrigation because adverse climatic conditions have pushed more people to engage in irrigation. Water management and handling has had a considerable contribution to the global carbon emissions. There is need to reconsider the manner in which irrigation is administered in our farms and ensure that loopholes that lead to rise in energy consumption in irrigation are sealed. Areas of interest include the pressure employment of pumps in irrigation, efficiency of systems (Gilley, James & Darrell; cited in Hardin, & Ronald, 89) and the possibilities of reduction of water used for irrigation purposes.
Carbon Footprint and Irrigation
Water processing and handling systems involving heating, moving, and treatment contribute to at least 290 million metric tons of carbon footprint per year. Of all the U.S carbon emissions, “5% is embedded in the country’s water” as Carbon Dioxide (Bevan, & Wendy, 1). The carbon footprint in water for irrigation has been aggravated by the fact that people have been adopting technologies that favor usage of pressurized systems that raise energy consumption (up to 163%) even though they present opportunities for saving water in surface water irrigation (“by between 10% and 66%”) (Cawood). Furrow irrigation also makes soil produce more Green House Gas. However, although drip irrigation may be used to achieve reduction of carbon footprints, care must be taken not to apply nitrogen fertilizers that may increase production of Nitrogen Dioxide in the soil. About 32% of all the water used in the United States is for irrigation purposes. This water amounts to 128389 Mgal/day. Water for irrigation contributes to energy usage by 25,639 MkWh and to carbon emission by 15,813,624 Metric Tons every year in the United States.
The amount of water used to irrigate crops may also disrupt the balance within the soil and the structure and thus affect the normal production of green house gas from the soil. It has been argued that 25% of all the carbon emission emanates from agricultural activities. These activities also result in the emission of 65% of methane and 90% of nitrous oxide. The impact of water irrigation in production of Nitrogen dioxide has been captured in that microbes may produce either more of it or less depending on if moisture is high or low respectively. Thus irrigation with water will influence the levels of carbon emission from the soil. One strategy that could reduce the production of Nitrogen dioxide from the soil is the application of frequent and low-volume irrigation. Decomposition of organic matter and microbial activity in the soil increase emission of carbon dioxide. The emission is increased by the soils being wet. Storage of carbon in permanent structures and the growth of vines which can be encouraged by increasing irrigation can help offset Green House Gas emissions. The impact may be great if these vines have prolonged life according to Practical Winery & Vineyard.
Climatic change has played an important role in the increase of carbon footprint in water because it has led to limited availability of clean water and cheap energy. The increased risk for increased Carbon footprint as relates to agricultural activities has been captured in the fact that overuse of groundwater (say for any usage) up to a average fall of 10 feet in the level, may increase energy demands by approximately “1.1 million MWh per year” because of the increased pressure needed to pump this water. Some of the impacts of the increase in the energy consumed in irrigation include the decrease in the water pumped (Moore) among others (Bevan, & Wendy, 33; see LePori & Ronald; cited in Hardin, & Ronald, 89)
Reduction of Carbon Footprint for Irrigation Water
Research ahs captured the impact of drip irrigation in the reduction of the amount of carbon foot print in water for irrigation, in addition to reduction of the amount of water to be used. The preparation of land for drip-irrigation is more easier because it requires a tractor to pass through a particular size of land only about two times as compared to six times passage to prepare a land that is for flood irrigation. This reduces the amount of vehicle emissions as well as the amount of fuel used (Giampaoli, quoted in California Tomato Farmers). The amount of carbon footprint can be reduced by a number of strategies including Low Impact Development (LID), reuse, efficiency and water conservation. There is need to exploit opportunities such as those for reduction of energy use and water used in irrigation, through the use of pressurized micro-irrigation systems where irrigation is carried using groundwater. This is because of the lesser amount of water to be pumped (Cawood). In particular, observation has pointed to a reduction of up to 44% of energy consumption according to the aforementioned author. The carbon emission for drip irrigation for a 12m lift is about 22%-33% as compared to 15%-23% for center-pivot type of irrigation. The corresponding emissions for 35m lift are 2.12%-5.52% and 2.82%-8.48%.
Water management techniques may be applied to address the problem of carbon footprint by eliminating the unnecessary procedures and waterways during irrigation. The fact that water management techniques can improve on the amount of carbon released points to the concept that companies and governments can introduce regulations requiring the disciplined use and handling of water for irrigation. The opportunity and the potential for reduction of carbon emissions need be well understood by policy-makers and water managers. These policies must focus on reuse, efficiency in the water usage and promote water conservation, among other techniques. The fact that the efficiency of the systems being used in the irrigation sector can affect the carbon footprint levels touches the importance of efficient technology use in irrigation.
This means that the irrigation system must deliver water to the irrigation site in as amount fed into it. Efficiency of machines such as pumps (Hardin & Ronald, 89) may also be impacted by the maintenance of the system because poor maintenance may result to leakages. Leakages contribute to the wastage of energy in that the water leaking is pumped but does not help to achieve the target. It has been found that avoiding leakages for water distribution systems could save the globe about 225,000 metric tons of Carbon Dioxide gas emissions by saving “270 MGD of water and 313 million kWh” of electricity annually (Bevan & Wendy, 2). Among the recommendations posed by the aforementioned authors is the integration of those policies touching energy and water and ensuring they are managed well. One of the measures that can help in the implementation of strategies for reducing carbon footprints is the tracking of the energy emission and the intensity of the water supply for all water utilities. It is important to establish or develop standard methodology which will allow tracking or determination of their energy consumption. All water end-users in the irrigation should be required to report on their usage of water.
Usage of grey water for substituting some irrigation needs such as vegetable or vegetation in the garden can also save on carbon emissions. Grey water is one that has been used to wash hands, for bath and showers and from washing machines. Through specific and suitable designs for the location of the irrigation fields, and properly instituting the drainage system, it is possible to utilize this water flowing from homes to water crops. There is need to rethink the regulations which restrict the usage of such water on the basis of environmental quality. Grey water Usage of grey water is regulated and restricted in some parts of the United States, with a permit for usage of this water being required in Pima and Tucson County. Grey water presents an opportunity to lower energy and chemical use. Other opportunities that may present saving of energy on water for irrigation purposes includes collection and usage of rain water for irrigation purposes.
Some of other techniques that have been thought of as of help in reducing the emission of nitrous oxide, methane and carbon dioxide include poly-cropping and usage of citrosa rather than insecticides and pesticides. There is need to venture more into the research to exploit the possibility of planting crops which use lesser amounts of water to save on the costs of pumping where such is a requirement. Plants being irrigated may also be shaded so as to reduce the chances of draught thus there is lesser need for constant irrigation. Less constant irrigation lowers the amount of harmful gases being released in the atmosphere. There is evidence that reduction of the amount of water pumped for irrigation may reduce consumption of energy in the irrigation sector. These and other previously addressed techniques such as lowering the pressure requirements for water, and improving on pumping efficiency may reduce carbon emission (Condra et al.; cited in Hardin, & Ronald, 89).
Determination of Carbon Footprints
The quantification of carbon footprint/emission also captures human activities that involve energy emissions. These activities include that involving energy release such as refrigeration, power, light and heat. It has been possible to determine the total amount of carbon footprints using tools such as carbon calculators. It is possible to calculate one’s contribution to carbon footprints by the use of tools such as SafeClimate carbon footprint calculator by determination of the amount of energy consumption and usage. The aforementioned tool allows individuals to enter the distance they travel with their car and plane, then describe the energy used at homes and it is possible to track the emissions over time. The quantifying of the carbon footprint control can be synthesized in the fact that it is possible to track, control and quantify the amount of carbon released and energy used during irrigation. It is possible to workout the energy consumed by the water handling systems such as pumps, and estimate on the carbon footprint contributions and thus it is possible to track the improvements on these carbon emissions.
Conclusion
Production of crops through irrigation has partly arisen because of the inconsistent and unreliability nature for rainfall. Shortage of rainfall has partly been a consequence of climatic changes. There is still demand for water for irrigation as population continues to grow, because there is need for enough food to sustain the masses. Water has substantially contributed in the amount of total carbon emitted. There is need to rethink the manner in which irrigation water is currently handled, in order to exploit the opportunities available for reduction of energy consumed in this respect. Energy consumption in water handling increases with raise with the amount of water and the pressure used to pump this water. The opportunities for reduction of energy consumption in the handling of water includes usage of grey water, improving on the efficiency for pumping and other water-handling systems through continuous maintenance, tapping and usage of rainfall water among others.
Work Cited
California Tomato Farmers. Drip Irrigation Means Reduced Water Use and a Smaller Carbon Footprint. Web.
Cawood, Matt. “New light on carbon footprint of irrigation”. 2009. Web.
Condra, Gary, et al. “Texas Econocot System, Upland Cotton Demonstration in Pecos County, 1976”. 1977. Texas Agricultural Extension Service, Texas A&M University, Final Demonstration Report for Pecos County.
Gilley James & Watts Darrell. “Energy Reduction through Improved Irrigation Practices”, pp. 187-203 in “Agriculture and Energy”, William Lockeretz, (ed). 1977. New York: Academic Press, Inc.
Hardin Daniel & Lacewell Ronald. “Implication of improved irrigation pumping efficiency for farmer profit and energy use”. 1976. Southern Journal of Agricultural Economics.
Hardin Daniel, Lacewell Ronald, & Petty James. “The Value of Improved Irrigation Distribution Efficiency with a Declining Groundwater Supply”. Contributed paper. 1978. Annual Meeting of Western Agricultural Economics Association, Bozeman, Montana.
LePori Wayne & Lacewell Ronald. “Impact of Increasing Energy Costs on Irrigated and Agricultural Production”. 1976. Presented at Conflicts and Issues in Water Quality and Use Seminar, The Water Resources Committee and the Resource Economics Committee of the Great Plains Agricultural Council, Denver, Colorado.
Moore, Charles. “Impact of increasing energy costs on pump-irrigated agriculture”. California Agriculture, Web.
Practical Winery & Vineyard. “Irrigation”. 2009. Web.
“The Carbon Footprint of Water”. Web.