Satellites have been measuring NDVI over the entire planet for many years, but only recently has the data become accessible to the non-expert with the development of very user-friendly websites. This accessibility to the data has created opportunities for us to apply it in ways that can help illuminate many issues that we deal with in vineyards and other crops. The ability this gives us to "look back in time" is particularly helpful to answer questions today that are a consequence of conditions in the past.

A webinar was held on May 7, 2021 as an introduction to this topic; you can view a recording of this webinar at the following link:

Using satellite NDVI for vineyard...

The following charts are updates of similar ones first presented here in 2015; they now include values through the 2019 harvest. They are helpful to appreciate the divergent paths that the wine grape industries in each county have been experiencing in recent years.

This difference can be explained in large part by the unequal crop options that are available for producers in the different counties. Farmers in much of Santa Barbara County have a large range of potential crops to choose from, including citrus, berries, flowers, cannabis, etc. The notable decline in wine grape acreage in that county in recent years likely reflects the shift in cropping to these other options which may offer better returns currently. Conversely...

This new project is bringing some unique and very useful weather data to San Luis Obispo County. Twenty weather stations are planned for the County; at this writing 12 are installed and operating. An additional twenty stations are also planned for Santa Barbara County, to be installed gradually after the San Luis Obispo network is completed. 

These stations measure common variables of air temperature, humidity, rainfall, solar radiation, and wind speed, plus calculated variables such as the dew point and the reference evapotranspiration. They also have an additional air temperature sensor 30 feet above the ground to be able to measure the temperature inversion. This measurement is very useful to understand frost conditions...

Irrigation frequency and volume

One fundamental decision that a grower needs to make is how frequently to irrigate a vineyard; either applying small amounts of water frequently, or larger amounts of water less frequently. This choice determines how large the soil "flower pot" is that supports the vines, while also having implications for nutrient availability, salinity conditions and potential limitations on water infiltration. Changing from frequent small irrigations to infrequent large irrigations, either as an ongoing practice or as a one-time event, may lead to unanticipated outcomes and thus should ideally be done after ensuring that the conditions are adequate for this practice....