Record yields on rice fields

A production of rice under center-Pivot irrigation systems, located in Missouri (United States) reached record yields. While the majority of fields were well-suited for flood irrigation, one field had sandy loam soils and hilly terrain, which previously made it impossible to produce rice. The kind of soil cannot maintain a flood, so Pivot irrigation is a good alternative. It was the first experience with rice for the producer, but it didn't mean more work than in the corn field. They just ran the center-Pivot more time.

A grower who produces rice with a center pivot can be 5% more profitable than if he had flooded his field. Data collected throughout the years, on traditional and non-traditional rice fields, have recorded cost savings that rice producers have experienced with center pivot irrigation and linear machines versus flood.

Though a rice producer may use more pesticides and herbicides with a center pivot, the fertilizer costs remain the same as with a flooded field. Because a rice field irrigated with a center pivot does not need to be flat, and crop protection products can be applied through the irrigation machine, growers may see a 75 percent or more difference in labor costs, and a 50 percent or more difference in maintenance costs. Compared with a flooded field, fuel costs are also lower for rice produced with a center pivot due to a significantly smaller volume of water that is pumped throughout the growing season.

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.

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.