Deserts – Key to Feeding Future Global Population

Food crop production must expand into land areas considered to harsh, wet, or dry RDO-Water

Author: Lee Allen, Western Farm Press

Merle Jensen may not walk on water, but he knows a lot about it – the water part anyway.

He says, “Farming’s future is totally dependent on the availability of good water for crop production and the proper placement of that water for higher yield. The whole future of growing crops is dependent on the best method of irrigation and fertigation, and farmers would be wise to consider adapting the concept of drip irrigation now – or they might find themselves out of business.”

Jensen, a retired professor Emeritus plant scientist at the University of Arizona (UA), spent his career growing vegetable crops in harsh desert climates over the world – from Mexico and Latin America to Asia, the Middle East, and North Africa.

“There are over 20,000 miles of desert coastline in the world that, if made habitable, could feed millions of people,” he says, strongly recommending drip irrigation for plants grown in sand.

In most cases, edibles are seeded directly into leached beach sand and once growing are put on constant liquid-feed solutions of commercial-grade fertilizer applied through the irrigation system.

With a United Nations estimation that the world’s population will grow by an additional 4 billion to 11.2 billion by 2100, there’s a major concern by food scientists about where food will be grown.

“Vast areas of prime agricultural land are being taken out of production each year and we’re losing farmland and rich river valleys,” Jensen says.

“Production of food crops will have to expand into land areas always thought as too harsh, too wet or dry. If we are to successfully increase our supply of food, we must increase the output our land is producing.”

He adds, “Growth in food production will not keep pace unless we extend agriculture into new areas. And toward that end, the day will come when the world’s deserts must be cultivated.”

That day is here thanks to a variety of issues that work in conjunction toward a common goal, including trickle irrigation where measured amounts of a water and nutrient mix drip onto plants from a narrow hose running the length of the furrow, using whatever soil is available, including sand in Iran, Morocco, Jordan, Israel, and the American Southwest.

A People magazine feature on horticulture quoted Jensen saying, “Year-round growth can give yields 10 to 40 times greater than standard open-field production.”

Another publication, Horticulture magazine, cited “the outlandish world of Merle Jensen” who “has a penchant for blending Buck Rogers with Rube Goldberg for futuristic desert farming.”

Well, the future is now.

According to scientists with degrees from Cal Poly, Cornell, and Rutgers, the pro versus con formula is pretty simple. Over the short term, the negatives include a higher cost to implement along with salinity hazards and an increased sensitivity to clogging.

Jensen replies, “Expensive, yes, but the future alternative is you’re either in production or out of it, and you won’t be in production if you don’t find a way to conserve water.”

Advantages tend to outweigh negatives – maximum use of water maximizes crop yield, less weed growth or soil erosion, relatively low labor and operational costs, less evaporation compared to surface irrigation, and decreased tillage.

AgricultureGuide.com notes, “One of the most important aspects of this method is that the watered zone is only along the plant line, leaving the rest of the field dry – using the least amount of scarce and/or costly water possible. Because the watered zone is shadowed by the plant itself, evaporation is minimal, consumption is lowered, and the required moisture level in the root zone is maintained. Additionally, fertilizers can be used via the drip system, thus reducing that volume needed.”

Jensen proved the efficacy of drip irrigation at the UA’s Environmental Research Laboratory.  Time magazine, in 1967, reported on Jensen’s experiments in the integrated production of vegetables, electricity, and desalted water in the soil-poor desert of Arabia’s Abu Dhabi.

They termed the growing of food in Sadiyat, a sandy, essentially barren, uninhabited island, ‘sand culture.’ And they proved it would work in an area with strong prevailing winds and rainfall that averaged less than two inches per year.

The facility and a previous prototype in Puerto Penasco, Mexico were intended to make a coastal desert agriculturally productive.

In Sonora, plants were seeded in separate plots of beach sand or sphagnum peat moss/vermiculite and grew equally well in either drip-irrigated medium. Once the efficacy of the concept literally bore fruit, it expanded to other countries throughout the world.

Another strong proponent of subsurface drip irrigation (SDI) is fellow Arizonan Howard Wuertz of Sundance Farms in Coolidge, the 2016 winner of Netafim USA’s Award for Advancement in Microirrigation – http://www.westernfarmpress.com/irrigation/wuertz-honored-subsurface-drip-irrigation-pioneer.

“SDI delivers many benefits and we encourage growers to take measures to ensure the sustainability of their farming operations for generations to come,” says Wuertz.

“Successful farming in the desert is not only about using water more efficiently, but about being productive with the resources we have and subsurface drip irrigation has allowed us to boost our productivity per acre with less water than traditional irrigation methods.”

The Wuertz family estimates a reduction in water usage up to 50 percent on their 3,200-acre farm.

While Wuertz has been referred to as “the father of subsurface drip irrigation,” Jensen claims some of that parentage too due to his longevity in drip cultivation trials throughout the globe.

Former colleague Hassan Elattir, Morocco’s first horticulturist, worked with Jensen to initiate drip irrigation there. Elattir praises the growth since their first drip irrigation experiments in 1975.

“By 2020, there will be more than 500,000 hectares of crops under drip irrigation,” Elattir says.

And that’s good news as the estimation is that more food will needed in the first half of this century than was produced in the previous 100 centuries combined.

Jensen isn’t one to generally say ‘I told you so,’ but in this case, he does.

“The projects we’ve been involved with have demonstrated it is possible to produce vegetables in many sandy areas of the world where almost nothing now grows,” said Jensen.

Full article shared from Western Farm Press website.

10 Tips for Rodent Control

Strategies to ward off rodents in drip and SDI systems Gopher-Control

Author: Danilu Ramirez, RDO Water

Rodents are a major concern for all growers, including those who run drip and SDI systems. Pests like mice, voles and gophers, when not properly managed, cause yield loss and crop damage. However, drip and SDI systems have several unique aspects and natural defenses to efficient and effective rodent management.

 

Because there is no one, “magic” solution for controlling pests, those looking to employ a drip or SDI system and successfully manage rodents need to build an integrated plan with these Top 10 tips.

 

Pre-Plant Planning

The first line of defense in the war on rodents is to identify areas of high rodent concentration, not only in the proposed drip or SDI field, in surrounding areas as well. Then, the following steps should be taken in each area.

 

  1. Create a buffer zone surrounding the field by eliminating weeds, ground cover and litter
  2. Cultivation and/or weed control is advised to destroy runways and weed roots, and kill existing rodents
  • Bonus: This also fosters healthier soil, one of the best baseline defenses against rodent as well as insect infestation
  1. Deep rip the soil to destroy burrows and disrupt the gopher’s habitat needed for survival
  • Note: excludes minimum tillage operations

 

Control While You Grow

After proper pre-plant steps have been taken to control rodents, the integrated plan continues with best practices throughout the growing season.

 

  1. Bait for a week, then set traps after bait has been continually taken
  2. For best success with gophers, set traps on both tunnel entrances then check back within 48 hours
  • Note: traps not visited within 48 hours should be moved and tested in a new location
  1. Burrow fumigates, both aluminum phosphide and carbon monoxide-producing machines, are an effective alternative to traditional chemicals and common poisons
  2. Consider a product that addresses rodent control within the system; for example, Netafim USA has developed a product that can be injected into the dripline to irritate rodents and drive them to the surface where they’re more vulnerable to predators

 

Post-Cutting and Crop Rotation

Add these final strategies to complete the thorough pest management plan.

 

  1. After harvest (or each cutting for alfalfa growers), closely monitor the area for any burrowing activity and take immediate action if needed
  2. Consider rotating in a cover crop like beans or legumes to enrich the soil and provide good organic matter
  3. Ask for help – seek out the advice of fellow growers who operate drip or SDI system, as well as pest management experts and local extension agents.

 

There Is No Good Luck – Only Good Planning

With proper planning and ongoing best management practices, rodent threats can be minimized in drip or SDI systems, leaving growers to enjoy benefits of higher yields, and greater WUE and RUE.

 

 

About The Author
Danilu Ramirez, CCA, PCA is a Water Quality Consultant for RDO Water, based in Santa Maria, CA. Contact her at 805.345.5418 or dramirez@rdowater.com.

 

Additional contribution to this article provided by Netafim USA and Toro Micro-Irrigation.

Article originally written for Progressive Forage Grower magazine. Full article can be viewed on Progressive Forage Grower website.

6 Must-Ask Drip/Subsurface Drip Irrigation Questions

Questions to ask the design engineer when converting to drip or subsurface drip irrigation RDO-Water-Drip-Irrigation

Author: DuWayne Fritz, RDO Water

With contribution from Eurodrip USA and Toro Micro-Irrigation

Once it has been decided to convert a field to drip or SDI, growers can expect many questions from the irrigation engineer designing the system. It’s equally important growers are proactive and ask questions that ensure a full understanding of the system – how it works and how it affects current operations.

 

The following 6 questions are a solid starting point and put all growers in the best position to reap benefits of greater yields, WUE and RUE that have become synonymous with drip and SDI systems.

 

Existing Field Conditions

The initial questions to ask the irrigation engineer should focus on the present situation. The three major areas to explore:

 

  1. Question: How will the system affect crop rotations?

Answer: A system can be built to accommodate future crop rotations.

 

For example, say the proposed field is primarily a vegetable crop field but will be rotated to alfalfa in the future. A good designer will ensure the system’s infrastructure is designed to support greater water pressure and capacity demands to accommodate the future alfalfa crop.

 

  1. Question: How does soil type affect the system?

Answer: Soil type affects the system’s emitters.

 

Sandy soils need a different flow emitter than a loamy soil. Another parameter determined by soil type is emitter spacing. A soil that encourages the spread of water can have emitters spaced further apart vs. a soil that holds water close.

  1. Question: How are lateral spacing and depth determined?

Answer: Several factors, including crop type, influence these design parameters.

 

As mentioned above, soil type/texture determines approximate emitter spacing – but it’s only part of the story. Crop type plays a huge role in spacing. A crop that requires more water, alfalfa, for example, needs closer-spaced emitters vs. crops like lettuce, cotton or berries.

 

The crop type also heavily influences line depth. Again, let’s look at alfalfa. Because of its deep roots, drip lines must be installed 10 inches or deeper.

 

When depth and lateral spacing are set, lateral flow rate, emitter flow rate and spacing, and lateral wall thickness and diameter can be set. Each step is dependent on the one prior, and is also affected by general characteristics of the field.

 

Operational Changes

Converting a field to drip or SDI greatly affects the day-in, day-out operations of a farm. To be prepared and set up for best success, every grower should ask three primary questions:

 

  1. Question: How do I set irrigation periods?

Answer: There are several options for controlling irrigation periods.

 

A grower may choose daily intervals in which the system is run for a short period of time every day to put out the daily required amount of water. Another option is running the system every few days, for a longer time period, and put out multiple days-worth of water in a single day.

 

Automation systems offer assistance with setting irrigation periods. These systems come with an added upfront cost but offer time and labor-saving benefits. Every grower should analyze the cost/benefit ratio to decide if it makes sense for his/her unique operation.

 

  1. Question: Do I need to change fertilizer?

Answer: It shouldn’t be necessary to change fertilizer.

 

Operations that use fertilizer with higher acidic levels require a system that uses PVC or steel pipe, to ensure acid doesn’t corrode the system – something that a good engineer will ask about early on in the process and specify in the system.

 

  1. Question: How do I maintain the system?

Answer: An integrated, planned approach is advised for all drip and SDI systems.

A few best practices include periodic flushing every 2-4 weeks to rid the system of potentially clogging debris. Periodic filter maintenance is also recommended, as is regular inspection of the piping system for leaks.

 

An ongoing, dedicated rodent management plan is also recommended. Those looking for a place to start can access a best management practices article by Danilu Ramirez, Water Quality Consultant for RDO Water.

 

In regions that shut down systems for winter, it’s advised to either terminate crops or run the system once a week or even every-other week to prevent root intrusion.

About The Author
DuWayne Fritz is the Lead Irrigation Designer for RDO Water, based in Yuma, AZ. Contact him at dfritz@rdowater.com.

 

Additional contribution to this article provided by Eurodrip USA and Toro Micro-Irrigation.

 

Article originally written for Progressive Forage Grower magazine. Full article can be viewed on Progressive Forage Grower website.