"Is it possible to supply all required nutrients for a tomato plant by wicking water containing a soluble fertilizer such as Foliage Pro up into a container, without any other watering of the container?"

Yes

".... is it an inferior method of supplying nutrients relative to watering (with soluble fertilizer) the top of the container's mix because watering from above allows the draining water to draw a better supply of oxygen into the mix?"

Because watering with a wick tends to leave larger air pores unfilled (with water), gas exchange would probably be somewhat superior (o/a) in a soil that is fine enough to be considered appropriate for wicking, when that soil is watered with a wick vs when the same soil is watered from the top.

When wick watering with a fertilizer solution, there is no way to prevent the steady accumulation of dissolved solids in the soil. Every drop of water that evaporates leaves behind the dissolved solids it held before it evaporated. Unless you flush from the top regularly, the concentration of these solutes continually increases. The nutrient ratio can also become grossly skewed due to whatever solutes are contained in the irrigation water.

Al

Al, thanks for your answers. If I am reading you right, I would not be losing oxygen supply to the plant by using wicks for fertilizing?

I forgot about the buildup of solutes with wicks....So, with plants in 5 gallon containers in a hot climate, how often would I need to flush from the top to keep the buildup from interfering with maximum growth/production?

When you say "the nutrient ratio can also become grossly skewed due to whatever solutes are contained in the irrigation water"....do you mean the water in the resevoir providing water to the wick and also, as a result, in the mix in the container? Irrigation water would be collected rainwater as much as possible, supplemented with municipal water as needed. Maybe you can expand on that for me to understand better...and maybe about what can be done about that skewing to fix the problem(flush out the resevoir also?)?

I'm asking because I'm considering trying to supply nutrients and water via wicks, rather than doing that with a "fertigating" system involving injecting nutrients into a drip watering system, or more labor intensive hand mixing and watering.

Thanks.
Tom

Guessing fertilizing via wicks is not being used by anyone...

yeah I'm really curious about this too! It sure is hard to get answers for things like this. I wish I knew where to look to figure things out when it comes to wick watering and fertilizing.

PC - What are your questions?

I wick-water my african violets, one reservoir for each plant, and I'm wondering how often to flush the soil of each plant so that salts don't build up too much in the soil mix? Is salt build up correlated with the size of the container too? Or no? Then related to chalstonsc's question, if I use half tap water and half distilled water, and wick water AVs, will that still skew the nutrient ratio that they received? They're getting the Dynagro foliage pro fertilizer

I'm wondering how often to flush the soil of each plant so that salts don't build up too much in the soil mix? I'd flush at least monthly. Is salt build up correlated with the size of the container too? Or no? Yes smaller containers have more surface area:volume than containers with larger diameters of the same ht, so there would be more evaporation per soil volumes in smaller pots of a given depth. E.g. a 3" pot 10" deep has 1/4 the volume of a 6" pot 10" deep; so twice the diameter in this case = 4X the volume. This would be for a cylindrical container rather than a truncated cone, but the principle still holds. Then related to chalstonsc's question, if I use half tap water and half distilled water, and wick water AVs, will that still skew the nutrient ratio that they received? Yes, the quality of your irrigation water can make a significant difference in how quickly the ratio of dissolved solids (one to the other) gets skewed (depending on what minerals are dissolved in your tap water), which brings us full circle to why we flush the soil when we water.

If you have a lot of plants and/or buy bottled water, you might consider investing in a RO water filtration system - they make great drinking water.

Al