We got our soil test reports back a couple of weeks ago, but due to schedule craziness, this is the first chance I’ve had to share them with you. As I expected, the results are quite interesting.
I sent in 7 samples. I sent in two samples of just the sand (load 1 & load 2). Then I sent in two samples of just compost (load 1 & load 2). Then I send in two mixed samples. The first soil mix sample was load 1 of sand and load 1 of compost. The second soil mix sample was load 2 and load 2. The seventh sample was from the bagged raised bed mix.
For your reference as we go through the results, vegetables prefer a pH of 6.3-6.8 (slightly acidic), phosphorus of around 100 ppm, and potassium of around 250 ppm. Low Exchangeable Sodium and Electrical Conductivity are good, high is bad.
Here are the results by the numbers:
pH = 8.3
Organic Matter = 0%
Nitrogen = 1 ppm (parts per million)
Phosphorus = 4 ppm
Potassium = 21 ppm
Exchangeable Sodium = 0.50%
Electrical Conductivity = 0.44 mS/cm
pH = 8.6
Organic Matter = 0%
Nitrogen = 1 ppm
Phosphorus = 4 ppm
Potassium = 31 ppm
Exchangeable Sodium = 0.07%
Electrical Conductivity = 0.40 mS/cm
As you can see, the two sand samples are very similar, both with astronomically high pH levels (yikes!), very little in the way of nutrients (not a big deal once we see the compost numbers), and very low sodium and salinity rankings. Since I was concerned about the sodium levels, I’m relieved that they are very low.
pH = 8.0
Organic Matter = 13.0%
Nitrogen = 12 ppm
Phosphorus = 585 ppm
Potassium = 2,110 ppm
Exchangeable Sodium = -5.81%
Electrical Conductivity = 6.05 mS/cm
pH = 7.8
Organic Matter = 13.0%
Nitrogen = 4 ppm
Phosphorus = 385 ppm
Potassium = 1,740 ppm
Exchangeable Sodium = -4.81%
Electrical Conductivity = 4.31 mS/cm
With the compost, we are still seeing a very high pH. I was rather surprised to see that, and I’m definitely not thrilled at that situation. You can probably guess what the pH of the soil mixes is going to be. The available nitrogen is very low, but the purpose of compost is that the organic matter breaks down and releases nitrogen slowly throughout the summer and in future years. The organic matter percentage is only an estimate because of the nature of testing compost. The phosphorus and potassium levels are astronomically high, which does counter-balance the extremely low results from the sand a bit. Excess of these nutrients isn’t usually considered a problem, we just don’t need to add more, probably for many years.
I’m not really sure what a negative exchangeable sodium means, but I’m not going to be concerned about it, since it certainly isn’t high. Unfortunately, the electrical conductivity is higher than I’d like to see. Not too surprising though, given the amount of nutrients.
Soil Mix #1:
pH = 8.2
Organic Matter = 6.0%
Nitrogen = 3 ppm
Phosphorus = 228 ppm
Potassium = 980 ppm
Exchangeable Sodium = 1.18%
Electrical Conductivity = 4.84 mS/cm
Soil Mix #2:
pH = 8.1
Organic Matter = 7.0%
Nitrogen = 3 ppm
Phosphorus = 223 ppm
Potassium = 820 ppm
Exchangeable Sodium = -1.33%
Electrical Conductivity = 5.83 mS/cm
The two mixes ended up being pretty similar as far as results go. That highly alkaline pH of 8.2 and 8.1 means we certainly have a lot of work to do on our pH. We will also be planning to use some supplemental nitrogen all year as needed. The available nitrogen should increase as the compost breaks down, but with our very sandy soil and the watering and drainage system, we will probably lose it to leaching pretty quickly. The phosphorus and potassium levels are down in a more reasonable range, but we certainly won’t need fertilizer for awhile. The sodium levels are still low, which is good, but the electrical conductivity is still in a damaging range, so we may see some problems from that until some of the salts leach out. (There is a benefit to that sand and the drainage system!)
So far, we have been using a water soluble fertilizer formulated for acid-loving plants to help in the zone right around each plant. This fall, we will probably incorporate quite a bit of sulfur. The recommendation is to start with 3 lbs sulfur per 100 sq. ft. on a sandy soil with a pH of 8.0. I think we’ll do that this fall and then continue testing our soil pH regularly for a couple of years and add more sulfur as needed.
Now for the other interesting result, the bagged Raised Bed Mix!
pH = 7.7
Organic Matter = 13.6%
Nitrogen = 3 ppm
Phosphorus = 692 ppm
Potassium = 6,200 ppm
I have to say that I was really surprised by these results. Usually bagged mixes are somewhat pH balanced! 7.7…wow! It’s a little bit better than our sand-compost mix, but not by much. Sulfur will be in order here too. I shouldn’t have been so surprised at the organic matter percentage, because the coconut coir was really prevalent in the mix. The phosphorus and potassium levels, again…WOW! They are even higher than the straight compost we got! It seems like a waste of nutrients to put into a bagged mix. I’m now very curious how they developed this mix…if they developed the mix to meet a certain soil texture and structure without regard to nutrient levels, or if these levels were intentional. I’m all in favor of adequate fertilization, but this goes well beyond adequate.
So, now we know where we’re starting from. It will be very interesting to see how our garden does this year, how things change as we continue to amend the soil in the next couple of years, and if we notice a difference over time.
This week we officially kicked off the garden renovation. There’s no turning back now!
This is as things were winding down yesterday morning. All the rest of those bricks and blocks are gone now. All that’s left is some of the trash lumber, the wheelchair height bed, the table, and the compost area. And a whole bunch of dirt.
Note to self: raised beds do NOT need 2-3′ long pieces of rebar to secure them to the ground. Really, they don’t. Not even in Kansas.
It was pretty cool to see the root remnants of the plants we pulled on Tuesday. This root system is from the pepper garden. I guess we did a decent job of watering, because the roots seem to go all the way to the bottom of the raised bed area and even a little deeper.
We also realized just how important (and nice) all the drainage work is as a component of the renovation. After not having rain for ages, then 2″ over the weekend, there was water standing in the packed clay 12-24″ inches below the surface. When we pulled the demonstration table out, we saw it had literally been standing in water. Yuck!
Can you believe that it’s the weekend before Thanksgiving? I won’t make any promises about posting next week, but maybe I’ll post a recipe or something if I get to it. Just what you need, more food during Thanksgiving!
We were donated about 30 bags of duck poop compost, so that got emptied into our wheelchair height garden, since the soil level had dropped about 6 inches this summer. We make compost too, but we don’t have enough bins to meet all of our compost needs every time!
One of the few things in the garden that is still looking great after several colder days and nights is the Texas Tarragon. It was kind of hidden amongst the basil for part of the summer, but now it is really showing off.
Here’s the Temperature Data from this week:
Outdoors: Min=34, Max=62
Fabric Bed: Min=36, Max=70
Plastic Bed: Min=40, Max = 105
Outdoors: Min=36, Max 64
Fabric Bed: Min=38, Max 70
Plastic Bed: Min=37, Max 105 (afternoon data, so lost previous day’s max)
Outdoors: Min=42, Max 64
Fabric Bed: Min=40, Max 72
Plastic Bed: Min=44, Max 115 (vented at this point)
Outdoors: Min=27, Max=55
Fabric Bed: Min=31, Max=72
Plastic Bed: Min=32, Max=94 (vented one end in pm)
Outdoors: Min=35, Max=61
Fabric Bed: Min=34, Max=61
Plastic Bed: Min=34, Max = 82
The numbers are pretty random right now. I know part of it is because the wind loosens the row covers a bit, so they aren’t as airtight overnight as they maybe should be to keep the temps higher. That being said, we’re having trouble keeping the plastic bed appropriately vented so it doesn’t get scorchingly hot during midday on sunny days.
It’s about 32 degrees out in the garden right now. Finally!
I did end up covering one of our two raised beds, but I only used the very lightest row cover fabric. A quick peak at the thermometer inside the cover shows that it is about the same temperature under the cover as outside, so apparently it isn’t doing much good. I don’t know if that’s because I didn’t put it on until noon yesterday or because it isn’t very airtight. After all, bricks and duct tape don’t make for a very tight row cover.
Yes, I said duct tape. I realized when I started putting the row cover on that I had 3 pieces of the lightweight fabric and none of them were long enough for the whole bed. In order to get it to stay on, I resorted to duct tape. Most of the tape is inside on the hoops, but I had to put a couple pieces on the outside. I may have to buy new row cover now, after the duct tape adventure. I’ll also have to put the heavier cover on before next weekend, when it looks like the forecast is predicting more seasonably cool/cold temperatures.
The Bachelor Buttons started blooming just in time for it to freeze. Luckily, they don’t really care about 30 degrees. They will probably still bloom for another couple weeks. Oh yeah, and they’re edible too!
Our compost committee was busy this week, as we had a full bin of plants that we’d pulled out of the garden, as well as some leaves from around the grounds and the straw mulch from several of the beds. The three big bins are full, as well as 3 smaller bins. We’ll have lots of great compost come spring!
Here’s a sneak peek inside the row cover after I put it on yesterday. You can see that we have some bare spots. For some reason, we didn’t have great germination on things this fall. I don’t know if that’s due to the seed, the generally dry weather, or just not enough TLC. I’m suspicious that we didn’t keep the beds moist enough when the seeds were trying to germinate.
It’s supposed to be a beautiful weekend! Get outside and enjoy it!
I think the garden, by and large, is enjoying the warm weather this week, especially the fact that it hasn’t rained! The strawberries are pretty much done for the time being, but the other fruit is hot on their heels. I’ve posted the handout & recipe for this week’s Lunch in the Garden, featuring Lemon Balm, on the Lunch in the Garden page.
Don’t these look luscious? They are just starting to ripen, so I seem to get too impatient and end up eating a not-quite-ripe and a little bit tart berry every third one or so. The black raspberries are an unknown variety that was mislabeled as a ‘Chester’ Blackberry when I started working here. The red currants are ‘Cascade,’ and this is the first year that the plant looks really good and has a decent number of fruit on it. Unfortunately, our plants are rather too close together, so I’m sure I’m missing some fruit.
The Chinese Long Beans haven’t been bothered by the Bean Leaf Beetles, and they love the heat! They have finally really taken off, and I think they are growing at least 3-4″ up the trellis each day. The best part is that they are finding their way up the trellis all by themselves, without any assistance!
A pair of Mallard Ducks have decided that our compost bins are the best place to build their nest. The mama duck has been dutifully sitting on the eggs for several days now. I’m glad she found a relatively safe nesting site, but it does rather hinder our efforts to make compost.
Have a great weekend!