Protecting Crops from Frost with Sprinklers

During winter farmers face the daunting challenge of protecting their crops from frost damage. Frost control through irrigation has emerged as a crucial agricultural technique, offering a practical solution to mitigate the adverse effects of low temperatures on crops. Alvaro Rocca, Rivulis’ Senior Product Manager, shares valuable insights into how irrigation can serve as an effective tool for frost protection and discusses the best practices for optimizing its use.

Understanding Frost Types and Their Impact?

To effectively combat frost damage, it's essential to understand the two main types of frost that can affect crops: 1. Advection Frost: This happens on clear and calm nights when heat from the Earth's surface radiates into space. The absence of cloud cover allows heat to escape, while the lack of wind prevents air layers from mixing. This means the air temperature near the surface drops rapidly, meaning ice crystals form in plant tissues, which can damage cells. Radiation frost tends to be more severe in low-lying areas and valleys. 2. Black Frost: This is less common and happens during a thermal inversion, where a layer of cold air is trapped near the ground with a warmer layer above. Black frost can occur with either clear or cloudy skies and light winds. Even if the air temperature is not extremely low, the thermal inversion traps colder air near the ground, potentially freezing plant tissues. It is not possible to protect against Black frost with sprinklers. ?

How Irrigation Prevents Frost Damage?

The principle behind frost control through irrigation is straightforward yet effective. By applying water before a frost is forecasted, farmers can generate latent heat during the freezing process. As water turns into ice, it releases a small amount of heat, creating a protective layer of ice around the plants. This ice acts as a blanket, helping to maintain a temperature above the freezing point and protecting the plants from severe cold. Latent heat is like a hidden ally in frost control. When water freezes, it releases heat that helps keep plants warmer during cold conditions. This protective ice layer is critical in shielding crops from frost damage.

Choosing the Right Irrigation System

Selecting the appropriate irrigation system is important and the crop type, distribution in the field, water availability, soil type, and the desired temperature for protection need consideration. For fruit tree plantations, sprinklers located under the trees offer valuable protection. Systems like Rivulis’ AquaSmart 2002, Aquamaster 2005, and Rondo sprinklers are suitable for both irrigation and frost protection. These systems are particularly beneficial because they provide a dual function: irrigation and cooling, with limitations noted at temperatures no lower than -2.5°C (27.5°F) to -2.0°C (28.4°F). For a more comprehensive approach, full above-canopy coverage is recommended. This method involves using high-quality, robust sprinklers placed over the plantation canopy to ensure uniform coverage. It helps protect the entire plot, leaving no areas uncovered. An individual sprinkler system for each tree provides targeted protection with lower flow rates and optimal water use. This method is water efficient and ensures frost protection is localized to each tree; this case creates the “igloo effect”. The igloo effect is when a layer of ice forms on the key parts of the tree ensuring the temperature will not go lower than zero degrees Celsius (32°F). ?

The strip method is where the Rivulis Flipper sprinkler, covers narrow strips, such as vineyards, and other row crops, achieving significant water savings. Using individual sprinklers, the Flipper, or full canopy coverage depends on the specific needs of the crop and field conditions. These methods have their advantages, and the key is to choose the one that offers the best balance of protection and resource efficiency. Frost control through irrigation is a valuable tool for managing the impact of low temperatures on agriculture. By understanding the types of frost and applying practical guidelines farmers can effectively use irrigation to protect their crops. With Rivulis’ innovative sprinkler systems, including options for under-canopy and above-canopy coverage, growers can ensure their crops remain safe during frost periods. With the right approach and equipment, frost control through irrigation can make all the difference in preserving your crops and ensuring a successful harvest.

Alvaro Rocca Baruch Barchad Adolfo Levin Matt Clift Moshe Viduta Juan Pe?a Sánchez Jesús Javier Sánchez de la Nieta López Romeo Dragan Annelle Whyte Igor Goldfeld