Agriculture’s Troubled Waters

Growing up in New England and being exposed to the wilderness as a young Boy Scout, I thought all streams had soap suds in them. I believed nobody could drink water from a stream but only from a faucet. It was taken for granted that polluted streams were a necessary byproduct of the expansion of manufacturing during the previous decades.

Since that time, rivers and streams have gotten cleaner in New England and in the U.S. due to the Clean Water Act of 1972 which regulated point source pollution. In the subsequent decades, other laws were passed at both the federal and state levels to address non-point sources of pollution and to set water quality standards.

Today, most attention is focused on the Total Maxi­mum Daily Load (TMDL) of permitted contaminants in water, especially in the context of watershed management. States are being tasked to implement remediation plans in response to their TMDLs for pollutants. Since the agricultural lands are non-point sources, they have come under intense scrutiny because of fertilizer practices that introduce nitrogen, potassium and phosphorus into ground water.

In recent years, water quality has gotten more attention in many states due to the practice of “hydraulic fracking,” which uses large amounts of water, sand and chemicals in the deep drilling for natural gas. Because of our nation’s past experience with water quality and industrialization, questions have been raised about the long-term effect of fracking near streams and other water bodies.

I started this article talking about pollution because water quantity has never been a big concern in the past in the U.S. Yes, there have been significant droughts affecting parts of the country.  But the affected regions always bounce back over time to normal precipitation patterns.

That said, there have been number of disquieting trends in weather and water usage that, when coupled with pollution issues, present a number of future challenges to agriculture. Before addressing these challenges and possible solutions, a few facts may be in order to put everything in context.

Weather is on the forefront of everyone’s mind because of the extreme events being experienced this winter not only in the U.S. but around the world. An unusually dry winter is contributing to persistent dry conditions in the Southwestern U.S., while the Midwestern and Northeastern parts of the country have been dealing with frigid cold and above normal moisture. Weather terms like “polar vortex” are becoming part of the everyday lexicon. In recent years, warmer summers are becoming the norm for most of the country.

The drier conditions have resulted in record fires and declining snowpack in the Rocky Mountain States, while recurrent, high frequency moisture has both hindered and helped the Northeastern states. Globally, the story is the same. While Brazil is baking in the Southern Hemisphere, Great Britain is experiencing widespread flooding and China is facing its coldest winter in decades.

All these extreme weather events are occurring at a time when the global population is rapidly increasing along with its competition for water, energy and food resources. It is not hard to understand that if the snowpack declines in the Rocky Mountains, then there are less seasonal headwaters to feed rivers and reservoirs. With diminishing water resources, distribution must be prioritized among people, manufacturing and agriculture. Historically, this competition for resources results in people needs coming first, followed by protecting manufacturing because of jobs, and, lastly, agriculture.

The snowpack also affects the long-term viability of aquifers located beneath states east of the Rocky Mountains. Since it takes many years to replenish aquifers with snow melt and seasonal rain, these water reserves, like the Ogallala aquifer, can be viewed as a non-renewable resource. The intense mining of these reserves through irrigation has put certain productive agricultural lands at risk of having no water in the future.

Besides quality concerns and the competition for quantity, there is water usage. Since there are varying kinds and amounts of natural and manmade chemicals and particulate matter, water may be safe for one type of use, such as watering a lawn, but not for another, such as drinking.

The World Health Organization (WHO) has addressed usage head on by developing indices that range from 0 to 100 where the low end is poor and the upper end is excellent. Examples of usage indices are the Drinking Water Quality Index (DWQI), a Health Water Quality Index (HWQI), and an Acceptability Water Quality Index (AWQI). The purpose of each index is to give the public some relative measure of quality for a particular type of use, such as drinking.

Separating sources of water based on their usage can be helpful for a community. Recycled water leaving a wastewater treatment plant can be safely used for irrigating vegetation. The recycled water saves money for a landscaper and at the same time reduces the demand for drinking water. While salinity and alkalinity are commonly tracked in irrigated agricultural soils, an unknown number of exotic and unreported chemicals may be present in some underground water. Over time, agricultural usage of water will come under increased scrutiny by discerning consumers, who will want to know where crops are grown and with what water source.

The water challenges facing agriculture are on several fronts. First, growers near populated areas have to compete with people and businesses for water resources. This is especially true in regions experiencing prolonged dry conditions. Second, in high competition areas, growers may have to settle for recycled or brackish water as sources for irrigation. Third, as farmlands are targeted as sources of non-point water pollution, especially in sensitive watersheds, growers may be enlisted to participate in control programs. Fourth, changing weather patterns, whether short or long term, that result in excessive heat and/or drought conditions may force growers to scale back their operations or switch to less productive crops.

Lastly, downstream processors and consumers who are conscious about where and how crops are grown may demand records of production practices including the source, amount and quality of water.

While there are challenges, there are solutions. One solution is the genetic modification of plants to strive in brackish conditions or use less water while maintaining the same amount of growth. A second is to use irrigation equipment and practices, such as schedules, to conserve water. A related third solution is to use soil sensors or imagery to zone irrigated fields for variable rate applications of water. Variable-rate applications may use the same amount of water as applied to a whole field, but deliver less moisture in some zones and more in others based on the pattern of crop growth across a field. A fourth solution is deficit irrigation which is designed to sustain crop yields while saving water.

Solutions outside of irrigation include the use of natural and artificial surface covers to retard soil evaporation and thus conserve ground water. Also, the leveling of land to minimize slope runoff, and the use of basins to catch runoff, may also be employed. There are many other innovative solutions for water conservation on a farm, but choosing them depends on the crop, its geography, surrounding environment, water source and production practices.

All agricultural stakeholders, be they individuals or organizations, can be part of the water solution. ZedX, Inc., my employer, is an information technology company that has been developing information-based products and services for the agricultural community for over 26 years. The company strives to give growers and their trusted advisors a more holistic solution for water management by providing models and decision-support tools that range from multi-county watersheds down to a single irrigation pivot.

By inputting virtual local weather data into a soil moisture budget and coupling it with a crop development model as part of an irrigation schedule, daily recommendations can be made as to how much water needs to be applied to a field. Since precipitation and evapotranspiration are accounted for in a schedule, irrigation can be withheld when ground water is replenished through rainfall. This withholding of irrigation not only translates into a savings of water but also into a savings in dollars for energy and labor.

The graphical output of a simplified irrigation schedule using the water budget approach is shown in Figure 1.

Irrigation Schedule Graph

It illustrates the interplay of precipitation, evapotranspiration and irrigation in the management of crop water requirements. As can be seen in the figure, the available water in a soil is the sum or budget of precipitation minus evapotranspiration plus irrigation. If a budget drops below a certain threshold due to the loss of water by evapotranspiration, then irrigation must be added to the soil. If there is precipitation, then irrigation can be reduced or withheld according to the budget.

The available water can be presented as a fraction of the maximum water stored in a soil. This fraction fluctuates daily as shown in the figure between a preset, crop-dependent, lower threshold of 0.7 and a maximum of 1.0 (field capacity) according to the precipitation, evapotranspiration and irrigation budget. An irrigation schedule begins just before planting and ends just before harvest. The amount of irrigated water is a function of soil texture and rooting depth, crop type, irrigation method and the capacity and efficiency of a system making applications. It is adjusted during a growing season based on root growth, crop stage and canopy size.

A schedule, as a water management tool, not only takes the guesswork out of the timing and amount of an application but also provides peace of mind because a grower knows that the water needs of a crop have been met. When coupled with soil sensors or imagery, a schedule can become a precision agricultural tool for prescribing variable rate irrigations.

The take-home message for this article is although we live on a planet with 71% of its surface covered with oceans, we must never lose sight that our local water sources can be limited and at risk for contamination. By understanding soil properties and crop water needs and employing the appropriate tools and practices, a grower can manage water resources intelligently and sustainably into the future.

WEBINAR ON DEMAND: Take the Challenge: Water Quality and Agriculture

Topics:

Leave a Reply

State of the Industry Stories

Liquid Fertilizer Storage tanks
State of the IndustryComplex Fertilizer Market Brings Mixed Feelings
January 5, 2016
Declining fertilizer prices and plentiful supplies should be good news for growers facing low crop prices. But they and their Read More
Asmus Farm Supply crop protection products in storage
State of the Industry2016 Crop Protection Outlook: The Guessing Game
January 4, 2016
One would naturally assume that retail sales of crop protection products in a contracted market would themselves be contracted, but Read More
Seed corn bags in storage
Special ReportsThe Outlook For Seed In 2016
January 3, 2016
Among all crop input categories going into 2016, the seed category has as many questions regarding which direction it will Read More
Wilbur-Ellis’ new fertilizer blending facility, located in Mott, ND, was designed by A.J. Sackett & Sons.
State of the IndustryBuying Intentions Survey: Retailers Taking A Prudent Approach In 2016
January 2, 2016
The CropLife® magazine Buying Intentions Survey made its debut last year to gauge current industry trends against the retailer’s plans Read More
Top 100 Articles
Elburn Cooperative
CropLife 100Elburn Cooperative Members Vote To Join CHS
December 28, 2015
With 81% of eligible producers voting, 94% cast an affirmative ballot for Elburn Cooperative, a diversified agricultural retailer based out Read More
West Central Cooperative, Jefferson, IA
CropLife 100Farmers Cooperative-West Central Merger Approved
December 21, 2015
The members of Farmers Cooperative Co. (FC), Ames, IA, and West Central Cooperative, Ralston, IA, have both approved the merger Read More
Wheat Growers Innovation Center, Bath, SD
CropLife 100Wheat Growers Opens Innovation Center
December 21, 2015
Wheat Growers’ commitment in providing its farmer-owners with the latest in technological advancements now has a one-of-a-kind focal point, as Read More
CropLife 100ARA Selects The Andersons As 2015 Retailer Of The Year
December 9, 2015
The Agricultural Retailers Association today named Maumee, OH-based The Andersons as its Retailer of the Year for 2015. The award Read More
CPS Washington Court House John Deere Sprayer
CropLife 100Application Equipment Report: It Is Easy Being Green For Top 100 Ag Retailers
December 5, 2015
On The Muppets television show, Kermit the Frog is famous for singing a song about the troubles he encounters in Read More
Fertilizer Bin
CropLife 100Fertilizer Sales: Another Down Year For Top 100 Ag Retailers
December 4, 2015
In pure number terms, the fertilizer category still dominates all crop inputs/services among CropLife 100 ag retailers. In 2015, for Read More
Latest News
Crop InputsBayer Contests EPA’s Decision On Valuable Insecticide F…
February 5, 2016
Crop Science, a division of Bayer, has announced it has refused a request by the Environmental Protection Agency (EPA) to Read More
Wheat Field North Dakota
Seed/BiotechSyngenta Wins Seed Fraud Suit Against South Dakota Grow…
February 5, 2016
Syngenta has obtained a $25,000 settlement from Paul and John Mayclin, Mayclin Farms, Plankinton, SD, in response to their Plant Read More
ManagementOABA Annual Conference Wraps Up In Columbus
February 5, 2016
More than 300 Ohio AgriBusiness Association (OABA) members and industry professionals were on hand to engage in collaborative learning and Read More
Crop InputsBayer To Contest EPA Flubendiamide Decision
February 5, 2016
Crop Science, a division of Bayer, announced today it has refused a request by EPA to voluntarily cancel the uses Read More
Syngenta
Seed/BiotechNot So Fast: ChemChina Syngenta Takeover Could Draw Nat…
February 5, 2016
State-owned China National Chemical Corp. (ChemChina), which plans to buy Swiss seeds and pesticide maker Syngenta, will promptly start preparations Read More
Rendering of Syngenta Seedcare Institute expansion
Seed/BiotechExpansion Of Syngenta’s North America Seedcare In…
February 4, 2016
As demand for seed treatment knowledge and products grows among farmers, retailers and others in the seed industry, Syngenta is Read More
Soybean Field
Industry NewsArysta LifeScience Strengthens Sales Team
February 4, 2016
Arysta LifeScience North America recently announced three new personnel additions: Jake Cook and Peter White are Territory Sales Managers for Read More
Davor Pisk Syngenta COO
Crop InputsSyngenta COO: Why ChemChina Offer Beat Monsanto’s
February 4, 2016
Syngenta Chief Operating Officer Davor Pisk says he is confident the proposed acquisition by ChemChina will ultimately help preserve choice Read More
Young corn plants in soil
Crop InputsKoch Biological Solutions Invests In Pathway Biologic
February 4, 2016
An affiliate of Koch Biological Solutions, LLC has acquired a minority equity position in, and entered into collaboration with, Pathway Read More
Crop InputsABG: China Signs Off On Monsanto’s Roundup Ready …
February 3, 2016
Monsanto Co. on Wednesday announced it plans to launch its Roundup Ready 2 Xtend soybeans in time for the 2016 Read More
Syngenta headquarters in Basel, Switzerland
Crop Inputs6 Things To Know About The ChemChina-Syngenta Deal
February 3, 2016
After months of rumors and speculation, Syngenta has announced that ChemChina has offered to acquire the Swiss-based company. “In making Read More
FertilizerPhosphorus: Is Band Or Broadcast Application The Better…
February 3, 2016
Is band or broadcast application the better method when it comes to phosphorus? The answer to this question depends mostly Read More
Syngenta Sign
Crop InputsChemChina Nearing Deal To Buy Syngenta For Record $43 B…
February 3, 2016
China National Chemical Corp. is nearing an agreement to buy Swiss pesticide-and-seeds-maker Syngenta AG for about 43.7 billion francs ($42.8 Read More
Herbicides2015 ASA Trials Demonstrate Valent Fierce XLT Herbicide…
February 2, 2016
Valent U.S.A. today announced that new Fierce XLT Soybean Herbicide ranks in the top tier among growers for length of Read More
Crop Protection Products in storage
Paul SchrimpfCrop Input Selling: Return Of The Price List
February 2, 2016
It was a good 15 years ago, shortly after I first started writing for this esteemed publication, that it all Read More
Potash storage at Growmark
FertilizerThe Phosphate And Potash Outlook For 2016
February 2, 2016
Like other commodities, prices of the leading plant nutrient products dropped sharply in 2015. At this writing, the price of Read More
Chesapeake Bay
StewardshipKeeping A Watch On Water Issues
February 2, 2016
During a down cycle in the market, it’s difficult to think about investing for the long term. For retail businesses, Read More
Young Corn Plants
FertilizerNutrient Considerations For Low Corn Prices
February 2, 2016
Corn prices are low and many producers are asking tough questions about their nutrient management programs. Here are some suggestions Read More