Photograph by Bonnie Veblen
A growers' workshop on nutrient and irrigation management featured the Solution Center for Nutrient Management last week in San Benito County. The workshop was funded by the San Benito County Water District and brought together a wide variety of attendees including: growers, seed representatives, consultants, scientists, an operational engineer, an aide to Senator Canella and the President of the San Benito County Farm Bureau. Beginning with a presentation on the latest water quality and nitrogen reporting requirements from the Central Coast Regional Water Quality Board, the topics covered on nitrogen and water management generated lots of dialogue and participation throughout the event. Monterey County UCCE Farm Advisor Richard Smith gave a succinct presentation on nitrogen budgets, illustrating findings from several field trials throughout the central coast of California. The findings highlighted the need to take residual soil nitrogen into account when calculating how much fertilizer to apply, and matching this to crop nitrogen uptake as closely as possible. Smith also presented on several fertilizer technologies for improving nitrogen use efficiency such as slow release fertilizers and nitrification inhibitors. Another Monterey County Farm Advisor, Michael Cahn presented on irrigation management as it pertains to nutrient management. He pointed out that because nitrate will go wherever water goes, good irrigation management is good nutrient management. His presentation covered challenges to achieving high irrigation efficiency such as distribution uniformity in drip irrigation systems. Distribution uniformity is also very important in the distribution of fertilizer through fertigation in drip systems. In his presentation of CropManage, an online decision tool to assist growers with irrigation and nutrient management, he suggested that irrigation scheduling is really about when to irrigate and how much to irrigate when it's time. This online decision tool is aimed at helping growers decided when and how much to fertilize and irrigate taking into account local weather data, soil type, crop and a myriad of other factors. CropManage can also be a great way to keep accurate records of fertilizer application. The workshop concluded with a presentation on the Solution Center for Nutrient Management and its role in providing growers and CCAs with sound resources needed to address the current challenges in nutrient and irrigation management in California. A representative from the Fertilizer Research and Education Program pointed some key resources that FREP has developed such as the Crop Fertilization Guidelines.