Variable Rate Drip Irrigation for Horticulture: Potential and Challenges.

Horticultural cropping systems including fruit tree orchards are commonly faced with non-uniformity causing water-induced spatial variability in growth, yields and product quality that should/would justify variable rate irrigation (VRI). These crops are typically drip irrigated, making them unique compared to crops irrigated via center pivot sprinklers for which VRI is more established. In this talk the uniqueness and possibilities of and obstacles to VRI for drip irrigation of horticultural crops will be addressed.

The presentation will review relevant literature and bring examples from current research projects and developments. The topics covered will include:

• Comparison and contrast to “traditional” field crop VRI. High value crops in small fields and the importance of product quality. Drip irrigation is already “smart”, allowing high sensitivity to temporal needs. How much can we additionally benefit from spatial precision?
• Technological challenges of VRI drippers/drip systems. Systems of valves and pipes (expensive, rigid) or variable rate drippers (science fiction?)?
• OK, there will be variable rate drippers…now what? What about fertigation? Can sensing, algorithms and decision making adopt the methods being developed for field crops under central pivot systems? Point source (trees) vs spatially continual data bring analysis challenges.
• Wine vineyards as case studies