Agriculture faces a big challenge

World's population is growing quickly, and we're not only talking about adding more people, we're talking about more people with better lives. 

Agriculture faces a big challenge, it has to produce food to feed 9 billion people by 2050. Experts say that there will be no enough resources to provide food for our population. Moreover, some aquifers under the surface are going down the drain. 

Farmers can't grow corn without irrigation, or it wouldn't be the kind of irrigation production that they're used to using. While dryland corn averages 24 bushels an acre, irrigated corn averages 200 bushels an acre. So the risk with dryland is important. The loss of irrigation would mean less income, fewer business, a decline in land values...

The answer is not shutting off every center pivot. Farms and irrigation communities will never accept to stop watering with machines that make their local agricultural production be sustainable.

Pivot irrigation in Georgia

In Southwest Georgia there are more than 6,000 center pivots used to water peanuts, cotton and corn. Farmers have control over how much water the irrigation nozzles spray as they pass over fields. Small fields can vary in topography and soil types, with some places wetter or drier than other places in the same field.

VRI technology

The concept is simple: apply water when and where crops need it. Don't apply it where they don't. VRI technology uses computer maps, global positioning systems, soil sensors and software to control where and how much water the nozzles on a center pivot spray on crops.

Growers want to irrigate more precisely, but don't have the time or level with higher-tech gadgets. The more time-consuming technology steps have been eliminated to make the system easier for farmers to use.

Instead of having to create computer maps of fields, this system has a simple "push-button" feature. A farmer can start the center pivot over a field. When it gets to a location he doesn't want to apply water, the farmer pushes the button to train the system not to water that area. Once the system passes this area, he pushes the button again to resume watering only the crop. This can be done in as many as 8 locations in the same field.

The water efficiency of VRI has been tested on farms in Georgia and found it can reduce the water use in a field by as much as 15% annually without sacrificing crop yield.

What's so great about Pivot irrigation?

Benefits to irrigating crops with a center Pivot

Flying across the USA, passengers notice green circles and half-circles, on the ground below. Those circles are created when a farmer waters his crops with Pivot irrigation.

There are two major benefits to a Pivot system. The first is simply that plants receive water on a regular, consistent basis. Pivot irrigation systems allow plants to receive water every 3 days, on average. This allows the water to soak into the ground, promoting deep root growth which in turn encourages healthy plants.

The second benefit to a center pivot is that water loss because of evaporation and drifting in the breeze is minimized. Pivots allow the sprinkler heads to be lowered to just inches above the tops of the plants, thus ensuring that most of the water reaches the crop and doesn't blow away in the wind. Water conservation is a serious concern today. Evaporation and wind drift are a concern also because many farmers are allowed a limited amount of moisture to get their crops to harvest.

Varied Terrain is Okay for Pivot Irrigation

Center pivots offer the ability to irrigate fields that have surface slopes that make it impossible to irrigate with surface methods. Many crops benefit from this type of watering system: alfalfa, corn, soybeans, sunflowers and more do very well with Pivots.

Center-Pivot systems and lateral move irrigation machines

Center pivots are a form of sprinkler irrigation consisting of several spans joined together and supported by trusses, mounted on wheeled towers with sprinklers positioned along its length. The machine is fed with water that comes from the Pivot pad.

Center-Pivots are typically less than 500 metres in length (circle radius). To achieve uniform application, center Pivot systems require a continuously variable emitter flow rate across the radius of the machine. Nozzle sizes are smallest at the inner spans to achieve low flow rates and increase with distance from the pivot point.

Most center pivot systems now have drops hanging from goosenecks attached at the top of the pipe with sprinkler heads that are positioned a few feet above the crop, thus limiting evaporative losses and wind drift. Pressure regulators are typically installed upstream of each nozzle to ensure each is operating at the correct design pressure.

Crops may be planted in straight rows or are sometimes planted in circles to conform to the travel of the center pivot.

Originally, most center pivots were water-powered. These were replaced by hydraulic systems and electric motor-driven systems. Most systems today are driven by an electric motor mounted at each tower.

For center pivot to be used, the terrain needs to be reasonably flat; but one major advantage of center pivots over alternative systems is the ability to function in undulating country. This advantage has resulted in increased irrigated acreage and water use in some areas.

Linear/Lateral Move Irrigation Machines

The above mentioned equipment can also be configured to move in a straight line where it is termed a linear move or lateral move irrigation system. In this case the water is supplied by an irrigation channel running the length of the field and positioned either at one side or midway across the field width.

The motor and pump equipment is mounted on a cart adjacent to the supply channel that travels with the machine. Farmers may opt for linear moves to conform to existing rectangular field designs such as those converting from furrow irrigation.

Lateral moves are far less common, rely on more complex guidance systems and require additional management than compared to centre pivot systems.

Cruise control for center-Pivot irrigation

Valley Irrigation introduced a new software that they have called 'Pivot Cruise Control', which allows producers to be more precise with chemigation and fertigation.

This product is a good demonstration of company's dedication to meeting customers' needs through innovation.

The irrigation industry was asking for a product like this. Now producers can program a center pivot irrigation machine to automatically adjust its speed, based on completing a defined number of degrees in a specific amount of time.

This feature will help producers more precisely manage chemigation and fertigation through their center pivot irrigation equipment. If a center pivot travels too fast during chemigation, it won't be applied enough chemical. If it travels too slowly, the product runs out and a part of the ground goes untreated.

It's a very easy to use product, so simple to operate.

The Nebraska pioneer of center pivot irrigation has died

Robert B. Daugherty was a Nebraska businessman who helped transform the rural landscape into a patchwork of circular fields by popularizing an irrigation system that used a pipe on wheels pivoting around a central point. He died on Wednesday at his home in Omaha, he was 88.

Mr. Daugherty’s company, originally called Valley Manufacturing, started out making agricultural implements. Now known as Valmont Industries, it became an international manufacturing giant. The breakthrough for Mr. Daugherty came in 1953, when he bought the rights to manufacture a new irrigation system, the brainchild of a Nebraska farmer, Frank Zybach. The new system came to be called center-pivot irrigation. It involved a long pipe on wheels that rotated around a point at the center of a field, spraying water as it went.

Engineers working for Mr. Daugherty improved the system, but he had difficulty at first persuading farmers to try it. By the 1960s, however, it began to take hold. Today, about 42% of irrigated farmland in the United States uses center pivot machinery or similar mechanized systems. Its prevalence can perhaps be best recognized from the air, where travelers on cross-country flights can see the landscape converted into a polka dot pattern of irrigated circles inside square fields.

Before the center pivot, farmers would typically irrigate their fields by allowing water to run downhill in furrows. But the center-pivot system allowed for a much more efficient use of water. It also requires less labor and can be used on uneven or hilly terrain where traditional methods of irrigation may not be an option. It is now used around the world and is credited with expanding the acreage of irrigated land and increasing farm productivity.

Mr. Daugherty, who retired from the company in 1996, left a large part of his fortune to a foundation he created. In April the foundation pledged $50 million to the University of Nebraska to found the Global Water for Food Institute, a center for research and policy analysis related to the use of water for agriculture.

Irrigation and Energy Conference

Farmers work consistently to reduce operating costs while maintaining and improving crop yields. Energy and water use are two operating costs that farmers can control.
The California Association of Resource Conservation Districts will host a one-day conference to help farmers reduce energy use and increase water use efficiency. It will be held at the AgTAC Energy Center in Tulare.

The conference will provide information and practical experience on numerous innovative precision agricultural technologies. It will highlight recent successful introductions of mechanized irrigation systems.
The morning program offers an overview of emerging "hot button" issues in air and water quality that the agriculture industry faces. These will include groundwater pumping and cost-sharing funds from the USDA. Air and water quality specialists will offer updates on ag-related air and water quality regulations.
Guest speakers will discuss an overview of precision agriculture technologies.
Further discussions will cover mechanized center pivot and linear overhead irrigation systems. These systems are being adopted because they offer high application uniformity, increased automation, and low reliance on labor.

Big return in corn

When it came to deciding whether or not to spend $120,000 to install a center pivot in an area where the systems are a rarity, “We had to do some serious thinking,” says John Grant, who farms hill land in north central Mississippi.

John Grant, and his son, Kenneth, say the difference in corn yield over dryland in 2008 helped them pay almost half the cost of installing a center pivot system on a 170-acre field. They’re hoping to recoup the rest of the cost this year.

Drilling wells in the area is an expensive — and often futile — proposition, given the depths required to try and get adequate water to run an irrigation system. Grant and his son, Kenneth, who farms with him, had a go at drilling a well on a field where they planned to grow corn in 2008, but called it quits when they got to 600 feet and still couldn’t get sufficient water to run a center pivot. They weren’t ready to give up on irrigation, though.

“Bogue Creek runs along one edge of the field,” says John. “You can walk across it in most places and not get too wet, and just to look at it, you wouldn’t think there’s enough water flow to support a quarter-mile center pivot. But, it doesn’t go dry in the summer, and when we checked the flow, it averaged 3,000 gallons per minute. The pivot would require only 1,000 gallons per minute.

“We worked with the Big D folks at Greenwood, Miss., to design a Valley system that would pump water from the creek, uphill through an underground line, to the pivot". “We had to pay the electric company $9,600 to run a line to power the pump in the creek and the pivot, but when we looked at operating costs, electricity was much less than diesel.

“We ran the system 16 days last year, and we’ve already used it several times this season. It takes 36 hours to make a full circle on 167 acres, putting down a half-inch of water.”

When harvest time came, says John, any reservations they may have had about the irrigation investment vanished. “We averaged 195 bushels on the field, and the yield monitor on the combine was showing some spots with 230 bushels. On areas outside the pivot, we averaged 54 bushels. With the price we got for our corn, we figure we recouped half the cost of the system in just one year". “If corn prices hold this year, and we’ve already got a lot of it booked, we’ll likely make back the rest of what it cost us. As soon as we get this pivot paid for, we’ll look at putting in another.”

Installation of 23 Center Pivot in Pakistán

The Government of Sindh intends to install 23 Center Pivot Toeable Sprinkler Irrigation Systems, one each of 50 acres, at each district of the province. The list of districts: Hyderabad, Karachi, Thatta, Matiari, Jamshoro, Dadu, Badin, Mirpurkhas, Sanghar, Tando Mohd Khan, Tando Allah Yar, Umer Kot, Nawabshah (Daur), Naushehro Feroze, Khairpur (Nara), Tharparkar, Larkana, Ghotki, Sukkur, Jacobabad, Kambur-Shahdadkot, Kashmore-Kandhkot, Shikarpur.

The firms already pre-qualified / short-listed with the Government under WC & PE-HEIS project would be required to:

• Design and prepare material & cost estimates with the consent of farmers
• Get it authenticated from consultants and approved from the Project Director
• Install the complete system on farmers’ fields with all diesel, electrical and water hook-ups / accessories within this financial year 2005-2009
• Operate the system to the satisfaction of the farmers and line agencies on turn-key basis
• Provide O & M for one year, after the installation within estimated cost (warranty period) and from 2nd year to successive five years at an agreed O & M cost
• The firms would be required to provide training to the farmers

The format for submitting rates can be purchased from the office of the undersigned on payment of Rs.3000.00 during office hours. The firms are required to submit their sealed offers for the cost estimates. The offers will be opened by the Technical Committee of the Department in the committee room of Directorate General, Agricultural Engineering & Water Management Sindh, Hyderabad, in the presence of the representatives of the respective firms, if they so desire.
The Project Directorate, with the approval of competent authority, reserves the right to accept or reject any or all offers without assigning any reason.