How Does a Farmer know it’s Time to Irrigate?

When to water and how much to water is always a question on the farm.  Especially when you have a large mix of fresh crops like squash, green beans, peas, etc.  These crops take anywhere from one to six irrigations (waterings) depending on the weather, time of year they were planted and when they will be harvested.  Irrigation is no exact science on our farm, but I want to say we are getting closer.

Irrigation timing has always been something that heavily relies on “rules of thumbs”.  For instance if the squash is wilting by 3pm, they need water.  Or on the beans, “Just go every 10 days with about an 3/4-1″ and you should be fine.”  And there is always the tried and true, stick a shovel in the ground and just plain play in the dirt and squeeze some soil to see what is there for moisture.

A field of squash that we are getting ready to irrigate.

This year however, with the help of the Natural Resource Conservation Service we were able to get some funding to help us pay to install sensors in the ground that allow us to monitor how much moisture is in the soil.  This type of technology can get pretty fancy, ours however are very basic.  The electrodes are installed into the ground in the row of the crop, you can see this in the photo below.  Ours are installed at 8″ and 18″ deep. 

Next you hook up the reader using two alligator clips and it reads the moisture saturation in the soil at each level.  The higher the number the lower the saturation of moisture in the soil.

Here is a video of me checking the electrodes.

As you can see it doesn’t take much time to get the information that we use.  This information is then put into a graph on my computer so I can monitor where the fields are on a day to day basis.

It’s been a learning curve mashing together our old rules of thumb with these new readings to give us the best timing for irrigation.  I would say that the best thing it’s done is given us a number to fall back on when we’re triaging which irrigation to start up and when.  It’s a quick way to see which crops need to be irrigated first, and which can probably wait a day while the others get a drink.  Farming has always been a mix of old traditions and new technology, this is just another way that our farm is moving forward with both the past and present ideologies working together.