This project aims at developing integrated irrigation practices that capitalize on soil health to improve the efficiency of irrigation water and decrease pest pressure and potential N losses of California organic processing tomato production. The current drought has dramatically decreased irrigation water allocated to organic tomato growers and there is an urgent need to test new irrigation strategies that reduce water inputs while maintaining product quality, nutrient supply and high productivity levels. In collaboration with Scott Park, an organic grower located in the Sacramento Valley, we propose to (1) measure the potential of soil health building management strategies to improve water conservation and decrease irrigation water inputs and (2) develop best water management practices that maximize water use efficiency, disease and weed suppression, N retention and tomato quality. We will compare the impact of three different water management scenarios that delay onset of irrigation and/or advance irrigation cutoff on tomato water-use efficiency, yield and fruit quality and monitor shifts in water acquisition dynamics, N leaching and pest pressure over two field seasons. These water management strategies have been partially tested by Scott Park last year by additional monitoring and evaluation is needed. Results will be used to develop applied recommendations for smart irrigation strategies optimized for shifts in soil properties and water uptake dynamic with adoption of soil-health building management strategies on organic farms in Northern California. We will communicate results to a wide audience of conventional and organic, producers, advisors, researchers and the general public though a variety of outreach and education activities. We anticipate that the practices developed will assist organic tomato growers in dynamically coping with irrigation water shortages and increasingly stringent N regulations without hampering the quality of their harvested product.
A final project report will be available upon completion.