By: Julianna Grant
Plants, like all living beings, need access to water in order to survive.[i] Any house plant owner may be painfully aware of this fact if they have seen their efforts in caring for a plant fall on deaf leaves; too little or too much water can be the difference between a happy, healthy plant and a failed attempt at plant ownership.[ii] Plants grown in mass production environments are no different.[iii] Farmers must carefully monitor and provide their crops with the correct amounts of water to gather a maximum yield.[iv] Implementing irrigation systems in large-scale agriculture has been invaluable to farmers’ ability to supply food to countless consumers.[v] Considering widespread concerns of climate change, there is speculation that the practice of irrigation may need to increase in order to keep up with demand.[vi] However, along with the increased need for irrigation systems, the use of freshwater reserves is bound to increase.[vii] It is estimated that global agricultural production will need to increase 70% by 2050 in order to keep up with the needs of consumers.[viii] To comply with this growing demand while not draining the globe of precious resources, agricultural irrigation practices will likely need to restructure their methods of gathering water.[ix]
Traditional field crop agriculture calls for farmers to supply their plants with water in congruence with rainfall, which can be done through many techniques.[x] Several methods include the use of sprinkler systems, such as center-pivot systems (placed in the middle of the field in need of irrigation), where water is dispersed from a rolling “tower” and covers a circular area.[xi] Other methods of application target the plant from below, adding water either at the soil level or directly to the root.[xii] Through these methods of irrigation, farmers are able to maintain the health of their crop and thus supply consumers.[xiii] However, water used for irrigation must come from somewhere.[xiv] Mainly, water for agricultural irrigation systems is drawn from ground and surface water.[xv] In 2015, agricultural irrigation totaled forty-two percent of total freshwater withdrawals in the United States.[xvi] When considered on a current global scale, this number increases to 70%.[xvii] This percentage is not insignificant, and with worldwide concerns regarding the overuse of natural resources, the discussion of how to conduct agricultural irrigation more efficiently has begun to take root.[xviii]
One proposed solution for restructuring irrigation systems is to collect and use rainwater rather than draw from ground, and surface water reserves.[xix] AppHarvest (a new agricultural initiative started in Kentucky) has structured their greenhouse facilities to do just that.[xx] Concerned with the estimated need for increased production in agriculture in the future and dwindling natural resources, AppHarvest sought to structure their irrigation systems to be supplied exclusively through retained rainwater.[xxi] This new model of irrigation was accomplished by the development of a “10-acre retention pond.”[xxii] This pond holds a vast amount of water, estimated by AppHarvest to be the equivalent of approximately 70 Olympic sized swimming pools.[xxiii] Water is collected through rainfall, aerated through “nanobubble” technology, then double-filtered through sand and UV processes.[xxiv] The irrigation technology itself is implemented in two ways: exact drip application and misting.[xxv] Not only does this method of irrigation eliminate the dependence on freshwater reserves, but it also results in no harmful agricultural runoff, another unfortunate side effect in traditional agriculture.[xxvi]
AppHarvest’s use of recycled rainwater is a monumental step in the right direction in the agricultural sector, as it combines high-yield production with sustainability.[xxvii] The essential question remains whether their methods are applicable to general field crop agriculture rather than greenhouse production.[xxviii] While there is not yet an answer to this question, extensive research is available on implementing rainwater irrigation in large-scale agriculture.[xxix] Research points towards the importance of rainwater use for the reasons echoed by AppHarvest: increased need for production combined with decreasing freshwater resources.[xxx] Additionally, the use of rainwater adds a multitude of other benefits to farmers.[xxxi] Gathering rainwater can improve the quality of crops being produced by traditional field crop methods by diverting substantial rainfall away from areas where crops would be damaged.[xxxii] Rainwater is also typically softer than other sources, meaning it will not have adverse effects on plants, nor will it cause buildup on irrigation equipment. [xxxiii] Lastly, rainwater (since it is soft) can be used for other purposes in farming, such as watering livestock and cleaning farm equipment.[xxxiv]
The continuance of large-scale agriculture is necessary for the wellbeing of countless lives and communities.[xxxv] However, it cannot be forgotten that some must be given back with all that is received from the earth. Ground and surface water reserves are not limitless and are needed for various purposes other than agricultural production.[xxxvi] The solution to challenges in irrigation may not be diverting all methods of drawing water away from natural reserves, but to the extent that gathering rainwater is feasible, it is one possible avenue. The benefits are numerous, multifaceted, and allow farmers to provide for communities while respecting the finite nature of our natural resources.[xxxvii]
[i] Mary Jane Duford, Why Do Plants Need Water?, Home for the Harves, https://www.homefortheharvest.com/why-do-plants-need-water/
(last viewed Oct. 4, 2021) [https://perma.cc/5R8W-WWHQ].
[ii] 4 Sings you are Overwatering Your Plants, BrightView (Mar. 20, 2017), https://www.brightview.com/resources/article/four-signs-you-are-overwatering-your-plants#:~:text=When%20plants%20have%20too%20little,in%20soft%20and%20limp%20leaves [https://perma.cc/K786-YUAV].
[iii] Biodiversity Food and Farming for a Healthy Planet, Convention on Biological Diversity, https://www.cbd.int/ibd/2008/youth/farmers/ (last updated Apr. 7, 2021) [https://perma.cc/4DGZ-5SNR].
[iv] Id.
[v] Irrigation Water Use, U.S. Geological Surv., https://www.usgs.gov/special-topic/water-science-school/science/irrigation-water-use?qt-science_center_objects=0#qt-science_center_objects (last visited Oct. 9, 2021) [https://perma.cc/HC5C-5TAZ].
[vi] Evan H. Girvetz, Robert I. McDonald, Two Challenges for U.S. Irrigation to Climate Change: Increasing Irrigated Area in the Wet States and Irrigation Rates in Dry States, PLOS ONE (June 5, 2013), https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0065589 [https://perma.cc/FWC2-2496].
[vii]See id.
[viii] Water in Agriculture, The World Bank, https://www.worldbank.org/en/topic/water-in-agriculture#1 (last updated May 8, 2020) [https://perma.cc/U8K2-BKUX].
[ix] Id.
[x] Irrigation Methods: A Quick Look, U.S. Geological Surv., https://www.usgs.gov/special-topic/water-science-school/science/irrigation-methods-a-quick-look?qt-science_center_objects=0#qt-science_center_objects (last viewed Oct. 1, 2021) [https://perma.cc/6Z88-9V5K].
[xi] Id.
[xii] Id.
[xiii] See id.
[xiv] Irrigation vs. Rain-Fed Agriculture, Cent. for Disease Control and Prevention, https://www.cdc.gov/healthywater/other/agricultural/types.html (last updated Oct. 11, 2016) [https://perma.cc/7U68-U2DY].
[xv] Irrigation & Water Use, U.S. Dep’t Agric. Econ. Res. Serv., https://www.ers.usda.gov/topics/farm-practices-management/irrigation-water-use/ (last updated Aug. 27, 2020) [https://perma.cc/3TXD-56LX].
[xvi] Id.
[xvii] Water in Agriculture, supra note viii.
[xviii] Id.
[xix] Stormwater and rainwater harvest and use/reuse combined, Minn. Stormwater Manual, https://stormwater.pca.state.mn.us/index.php?title=Stormwater_and_rainwater_harvest_and_use/reuse_combinco (last updated May 15, 2017 6:52 PM) [https://perma.cc/VEZ3-YQ4D].
[xx] Here’s How it Works, AppHarvest, https://www.appharvest.com/agtech/ (last visited Oct.1, 2021) [https://perma.cc/4C4P-8YLR].
[xxi] Id.
[xxii] Id.
[xxiii] Id.
[xxiv] Id.
[xxv] Id.
[xxvi] Id.
[xxvii] Id.
[xxviii] Id.
[xxix] Irrigation Water Use, supra note v.
[xxx] Juan F. Velasco-Muñoz, José A. Aznar-Sánchez, Ana Batlles-delaFuente, & Maria Dolores Fidelibus, Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research, Molecular Diversity Preservation Int’l., (June 26, 2019) https://www.mdpi.com/2073-4441/11/7/1320/htm [https://perma.cc/77UG-P67P].
[xxxi] Zakari Ajia, Rainwater Harvesting for Sustainable Agriculture, Permaculture Res.Inst. (May 29, 2017), https://www.permaculturenews.org/2017/05/29/rainwater-harvesting-sustainable-agriculture/ [https://perma.cc/A2CQ-SG6W].
[xxxii] Id.
[xxxiii] Id.
[xxxiv] Id.
[xxxv] Irrigation Water Use, supra note v.
[xxxvi] Jane Braxton Little, The Ogallala Aquifer: Saving a Vial U.S. Water Source, Sci. Am. (Mar. 1, 2009), https://www.scientificamerican.com/article/the-ogallala-aquifer/ [https://perma.cc/HSB3-GQMS].; Stuart Orr, Anton Cartwright & Dave Tickner, Understanding Water Risks, World Wide Fund for Nature (Mar. 2009), https://awsassets.panda.org/downloads/understanding_water_risk_iv.pdf [https://perma.cc/3Q42-4GW6].
[xxxvii] Irrigation Water Use, supra note v