Online tool helps farmers make decisions that save water

Central Coast farmers can cut back irrigation water by 50 percent over the course of the lettuce or broccoli growing season and still harvest the same yield using an online decision tool developed by UC Cooperative Extension.

Michael Cahn, UCCE advisor in Monterey County, developed CropManage and is now conducting field trials comparing crop water use and nitrogen use under standard growing practices and the recommendations made by the web-based tool. So far, research results are in for lettuce and broccoli, showing dramatic reductions in both water and fertilizer use when the computer aids decisionmaking. Current crops supported by CropManage are romaine and iceberg lettuce, broccoli, cauliflower and cabbage. Additional crops will be added in the near future.

Cahn described and demonstrated the computer program in a 25-minute video that is part of the UC California Institute for Water Resources online video series. The series consists of presentations featuring UC and other experts speaking on topics aimed at helping farmers and all Californians better understand and cope with drought.

Very efficient use of water minimizes the amount of water that will leach below the crop's rootzone, where it can't be used by the plant and can contaminate the water table. Factors that must be considered in achieving such efficiency include the rooting depth of the crop, the plant's stage of growth, the amount of water stored in the soil, the irrigation system uniformity, the water application rate, the salinity in the water source and the weather.

“That requires a lot of calculations in developing irrigation scheduling,” Cahn said.

CropManage gathers much of the information and does the calculating for farmers. CropManage automatically pulls up weather data from weather stations operated by the California Department of Water Resources, soil data from the UC Davis Soil Web, and research data from UC Cooperative Extension. The farmer adds information about the crop, field, and type of irrigation system being used.

“The computer program takes this information and running it through models can make water and fertilizer recommendations,” Cahn said.

The system also stores all the data for farmers, allowing growers to track their practices and demonstrate they are managing nutrients and water efficiently.

View the 25-minute below:

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