New Soil. Need Amendments.

13 years ago

I just completed my first soil test for pH, Nitrogen, Phosphorous and Potassium and am looking for advice on amendments for my soil.

I'm working with a clay soil. I've added about an inch of compost from my local city facility and plan to add more to help with soil structure. My tests show I have a slightly acidic soil (somewhere between 7 and 6) and virtually no nitrogen, phosphorus or potassium.

This will be my third year raising a vegetable garden on the mentioned ground. I've got powdered lime to lower my pH. My question is should I add a mixed fertilizer or should I seek out soil amendments for each specific nutrient?

Thanks in advance!

Sort by:Oldest

Comments (3)

gardengal48 (PNW Z8/9)
13 years ago
This was a home soil test kit, right? I am making that assumption because a professional test would be more specific with respect to the test results PLUS it would make recommendations to address any deficiencies.

Home test kits for nutrient levels are notoriously inaccurate - you might as well just throw that out the window! You could have a professional soil test done if you feel the need (your county extension service can help you out with that), but it may not be necessary.

Piedmont soils tend to be quite fertile and relatively acidic. I might retest for pH, as that could be a limiting factor. Home test kits for that are pretty good as long as you use distilled water in the testing solution. And you should be able to come up with a tighter range - a full 1.0 swing represents a 10-fold change in acidity and with pH, that's a lot. A good target for the vast majority of plants is 6.3-6.8 but I wouldn't bother liming unless it registered much less than 6.0. Above 7.0, I'd consider applying sulfur to lower pH.

How have the plants grown in this area in previous seasons? If you've had problems, then a professional soil test may be appropriate and it will indicate what types of amendments you will need to apply. If they have done OK or relatively well, then I'd just add more compost (2-3 inches more) and call it good. Compost will improve the soil structure, help with better drainage, stimulate populations of soil organisms, moderate soil pH and increase fertility.
lightningbug
Original Author
13 years ago
Thanks for the advice.

I did test with a home kit. I was very surprised by the results. Based on the past two growing season the ground seemed fertile; last year we bagged 30+ quarts of beans, though the tomatoes, potatoes, and onions didn't grow as well as in the previous year. According to my test kit the soil seemed like it was nearly void of any nutrients; which didn't match up with the past two growing season's yield.

I've never really added a whole lot to the soil, just a little fertilizer or lime here and there. This is the first year I've added compost to the soil. I'm adding compost mostly to loosen the clay in hopes that my root crops will have an easier time growing.
Related Discussions
To amend or not to amend? Clay soil...
Q
Comments (22)
"It seems that it is highly recommended to plant peach trees in raised beds from the experience on this board. Does anyone have a good link or more detailed directions as far as how to do that? What type of soil do I need? How deep do I dig the hole? How high should the bed be?" For my peach trees I use mounds and terraces. It doesn't seem to make a difference how tall the mound is. Some of my mounds are 1' tall, others started out 4' tall (before settling). The peach trees do about the same either way. Some people enclose their raised beds with a raised border of some kind. I think that's fine too. I don't think it makes much difference what soil you use for the raised beds/mounds. Several years ago, I installed drain tiles in the orchard area (The drainage was horrid and I was tired of losing peach trees.) In places we had to excavate to a depth of 4' to install the tile. What we dug out was pure clay. I used this material for some of the mounds. The peach trees have done fine in the clay mounds. Per the above posts, I would only use mounds if the drainage is poor. But since you mention puddling, I strongly suspect you could benefit from raised beds/mounds. Mounds not only provide good drainage, they also loosen the dirt so there is minimal resistance for the roots to spread. Mulching on top keeps the soil moist longer into the growing season, further encouraging root growth. It's hard for peaches not to succeed when they have moist (but not overly wet) loose soil with no weed competition and plenty of sunshine. Here's a picture that's a couple years old. You can see some tall and shorter mounds. Some of the older trees aren't in mounds. The drainage tile helped them. Here's a pic of some terraces I built last fall for planting peaches this spring. By the way, I don't bother with mounds for more water tolerant trees like apple, pear and plum, unless the drainage is really bad.
...See More
Soil Amendment for New Plantings
Q
Comments (7)
Once upon a time somewhere some one used to say "for planting just about anything I guess" dig a hole twice the size of the root ball and amend the soil before planting. In later years it was discovered that (especially in certain soil types and certain climates) this really wasn't so great for trees, large shrubs, and long lived large rooted perennials. In some clay soils what happens is the roots have trouble leaving the nice amended soil and act as if they are pot bound. This might also happen in other soil types that the plant doesn't like as much as the amended soil. Finally, in some climates it is not recomended because the amendments will break down so fast that it is of minimal benefit to the plant for greater expense and disruption to the soil. Something like annuals, Go ahead and give em a nice amount of really good stuff. As to the perennial shrubs and climbers, you are probably better off searching for varietys that will like they type of soil in the location you intend to put them and then use mulching to keep the soil as lively as you can.
...See More
Need help with soil amendment for planting new rose garden!!
Q
Comments (2)
Are you planting in pots or in the ground? If it's in the ground, most of what I add to my clay-loam soil is some additional organic material. I mix in to the native soil about 1/4 or less of cotton burr compost (to lighten the soil a little) and composted manure (for a little nutrition) plus a handful of alfalfa hay (bought at local farm and feed stores, or pet stores for small quantities). I wouldn't worry about a particular topsoil to add if you're in the ground planting. If you mix in known ingredients, you know what you're getting, vs. the possible unknowns of topsoil. The additives don't need to be specific to roses, and unless you have rock-hard clay soils like in the southeast it isn't necessary to add anything if you've already planted them. Some folks do, some don't. If your clay is rock hard, you need to amend the whole bed rather than just around the rose itself, or you'll create a moisture "sink" that retains too much moisture. I don't think that's what you have in the Northwest, but just mentioning that. Cynthia
...See More
Pet bedding in soil killed my plants. Need help amending soil
Q
Comments (7)
Thanks for the replies and advice:) To Embothrium: In hindsight, the bedding used to soak up the pet urine most likely soaked up the water in the soil, wicking away water from the tree roots. That's my hunch since the trees deteriorated in the same manner as when irrigation is turned off in this desert climate that I live in. And you're right, if it ain't broke... but because the soil in that part of the garden usually runs really dry, I somehow thought the bedding would help retain more moisture. Duh, what was I thinking?!?!?! To rifis: In the desert where I live, it takes forever for anything to decompose if I don't water it. Hmmm, I wonder what mobster treasures have been found in the desert out here? :) Anyhow I agree with you. Manually removing 30 cubic feet of bedding with or without the soil will be a lot of work but it might be the most effective option (if the seeds don't grow per toxcrusadr's advice). It took me 30 minutes today to sift a gallon's worth of soil with minimal results. No can do but seeing the rate of (non)decomposition of the bedding and the time-consuming task of sifting, I might have to remove the soil and start over as Embothrium suggested. To toxcrusadr: I live in Henderson, Nevada, an extremely dry desert climate. The bedding contained duckling urine and feces, so I'm guessing it was high in nitrogen. The leaves turned yellow and brown and new growth stopped altogether by next season even after I hand-watered throughout the spring and summer months. I dug through the soil today- dry but bedding is still intact and moist (irrigation has been turned off for a year and last precipitation was 2 weeks ago). I will take your advice and do a test run of the soil with some seeds and will post the results. That's great advice, btw!
...See More
Kimmsr
13 years ago
A soil pH between 6 and 7 is ideal for most all of the vegetables you might grow. That is the range most all soil nutrients are most readily available.
Nitrogen availability is dependant on soil temperature and your soil may not yet be warm enough for the soil bacteria to be active enough to make some available to your plants. A low test result at this time of year means little.
If posssible add enough compost and other oganic matter to bring the humus level up to 6 to 8 percent.
I'd not add anything to that soil until a good, reliable soil test indicated what and about how much should be added. Excess amounts of nutrients can create as many problems as too little nutrients.

New Soil. Need Amendments.

Comments (3)

gardengal48 (PNW Z8/9)

lightningbug
Original Author

Related Discussions

Kimmsr

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

New Soil. Need Amendments.

Comments (3)

gardengal48 (PNW Z8/9)

lightningbugOriginal Author

Related Discussions

Kimmsr

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

lightningbug
Original Author