UC Cooperative Extension is rolling out a new website for farmers that will help them save money and protect the environment. CropManage contains a wealth of UC research in a format that makes it easy for growers to apply to their farms.

Conceived by Michael Cahn, UCCE farm advisor in Monterey County, and programmed by the UC Agriculture and Natural Resources web team, the free website – ucanr.edu/cropmanage – allows farmers to quickly calculate the precise fertilizer and water needs of their crops.

"It's great,” said Salvador Montes, ranch manager at Corey Ranch in the Salinas Valley, who pilot-tested the software last year on lettuce crops. "It's very accurate in predicting the irrigation times and fertilizer (needs). It actually worked! We didn't see any significant yield reduction using less water and fertilizer.”

By applying only the exact amount of water and fertilizer to optimize plant growth, the new website keeps farmers from using too much. Overfertilizing in the past has resulted in groundwater contamination with nitrate, a serious concern in the Salinas Valley and other farming regions. In coastal areas, overpumping wells can lead to sea water intrusion into the aquifer.

"Besides, fertilizer and water are expensive inputs,” Cahn said. "Applying more than the crop needs is like throwing money down the drain.”

On Feb. 26, Cahn will offer a mini CropManage workshop during the 2013 Irrigation and Nutrient Management Meeting at the Monterey County Agricultural Center, 1432 Abbott Street in Salinas. The meeting runs from 7:45 a.m. and concludes with a pizza lunch at 12 noon. Following lunch, the one-hour CropManage workshop begins. No reservations are required.

"Inspiration for this project,” Cahn said, "came from local growers who expressed a need for software to help them use the quick nitrate soil test and weather-based irrigation scheduling in their farming operations.”

Cahn and his colleagues, Tim Hartz, UCCE specialist in the Department of Plant Sciences at UC Davis, and Richard Smith, UCCE advisor in Monterey County, have been conducting trials for years to determine whether the combination of quick nitrogen testing and weather-based irrigation scheduling could reliably reduce the amount of nitrogen that lettuce growers apply.

"We demonstrated a 30-percent reduction in nitrogen fertilizer application,” Cahn said.

The excitement of such a significant result was tempered by the fact that implementing the research results on individual farms would require some serious math.

"When we introduced farmers to the quick nitrate test, some said they would have to hire someone to manage all the data, keep records and make decisions. I realized that we could make this a lot easier for them by programming software to do the work,” he said.

For example, farmers who wish to use weather data to schedule irrigation for lettuce must sign into CIMIS (California Irrigation Management Information Service) to request an email with reference evapo-traspiration for their locations. The data must be punched into an equation along with the irrigation coefficient for lettuce – a figure that represents how much water the lettuce needs – and the size of the lettuce canopy at the time of irrigation. This time-consuming data collection and manipulation is eliminated with CropManage.

"We've figured out how to facilitate all these calculations,” Cahn said.  

CropManage automatically downloads the CIMIS data. The website pulls soil, crop growth and water needs information from a UC research database. The farmer goes to a simple website, names his or her fields, adds the type of irrigation systems to be used and how much water they deliver per hour.