Archives for posts with tag: soil sampling

It would be hard to tell from this blog (because I have posted so few real-time entries since mid-fall, 2014) but I decided not to send any soil out for testing this year (well, technically speaking, last year).

During the previous three seasons (2011, 2012, and 2013), I collected soil samples in late September or October (see October 19, 2013, part 2 for the most recent account) and sent them off to the Rutgers Soil Testing Laboratory. Two weeks after that, the lab sent me via e-mail me a report of our soil’s properties (see February 14, 2014 for discussion of the October, 2013 results).

It was a worthwhile endeavor—information is power, and all that—and we made some adjustments that I am sure were of benefit to the vegetables. Probably the most significant factor that the tests brought to our attention was soil pH. Initially, it was too high and the following year (2012), we added Sulfur to bring it down.

But after that first year, we did not learn anything new. Our soil’s pH has stabilized within the optimal range and both the macro- and micronutrient levels have remained constant. The soil appears to have reached a healthy equilibrium and as a result, there have been no recommendations for change. And as they say, if it ain’t broke, don’t fix it.

This year, the vegetable plants themselves are telling me everything I need to know. Almost all are very happy so the soil must be okay.

After returning home from running errands this afternoon, I was surprised to find a voicemail message from the soil testing laboratory.  This is the third year I’ve sent them soil for analysis and I did nothing different this year compared to the previous two years.  What could the issue be?

I gave the lab a call back and learned that they were concerned that the tests I requested might not be appropriate for our soil.  Based on a brief visual assessment of the soil samples and their labels (“East Planter”, “West Planter”, “Ground Level”), and without checking the type of planting for which the soils would be used (as I had indicated on the back of the soil test questionnaire), the lab scientist thought that perhaps I worked for a mall and was checking the soil from its indoor flower beds.  I’m not sure whether to be flattered (or not).

It turns out that the basic soil tests I commissioned are intended for mineral-based soils and use acids to extract the nutrients of interest.   This method is efficient and quick and yields reliable results for total nutrient content.  However, for soils that have very high concentrations of nutrients in mineral form, the observed values may not represent how much of the nutrients are actually available to plants.  For example, a clod of partially decomposed ore may be rich in iron but spinach still won’t grow well in it.

Alternatively, for compost and other soils rich in organic matter, extraction by water solubility is usually employed.  Apparently, this method takes longer and is somehow more complicated (I infer, because it costs much more) but produces values that are closer to what is readily available to a plant’s roots.  I explained our soil’s situation—it is used for a vegetable garden—its composition—it is a mix of compost, peat moss and native soil—and its history—she looked up the previous years’ reports—and weighing this information, she decided the basic tests would be okay.

The soil scientist said that many people are (and here she groped for a politically appropriate word) enthusiastic about adding organic matter to their soil, by which I believe she meant to imply that they add too much.  Looking at our previous reports, however, she saw that although some of our nutrient levels are high (“above optimum” is the lab’s term), the values are not off the charts.  I think she concluded that the total and available concentrations of nutrients in our soil should not be too different.

Looking more closely at our previous analysis results, she liked that our soil pH was in the green zone (6.20 to 6.80) last year and noticed that in our first year (the east planter only, in 2011), our pH was high.  I reported that based on the report, we adjusted the pH by adding elemental Sulfur and that was probably why we were at the proper acidity by the end of the 2012 season.  She was happy to hear that someone actually followed their recommendations.

The lab will start the soil testing tomorrow and I hope to hear back from them next week.

It’s that time of year again (past time, actually):  Time to send the soil out for testing.

Why is it that time?  Because the growing season is over and the soil is as depleted as it will get this year.  Now is the time to add supplements or nutrients that the soil may need before the new season starts in spring.  And I won’t know what to add without an assessment of what is—or is not—there.  Also, the planters are (almost) bare so it is convenient to take samples.

Testing is becoming less critical for the east planter, which has just completed its third year of service.  Its soil needed adjustment after the first year (to increase its acidity) but received no amendments last year.  We did add a small amount of compost (to bring the soil surface higher) and may do so again this year.  Otherwise, I don’t expect that the soil’s properties have changed much.

Similarly, the soil in the west planter was nearly on the mark in terms of pH and nutrient concentrations, as evidenced by its first soil testing last year (see October 4, 2012).  It received the same treatment as the east planter (a minor infusion of compost) and in conjunction with the solid performance of this year’s crops, is unlikely to need any modifications.

The condition of the newest soil in the garden, the mounds where we planted the squashes and cucumbers, is another matter entirely.  We were not particularly careful in designing this soil and simply mixed together roughly equal parts of compost and peat moss.  It looked right and was good enough but apparently only just so.  While the summer squashes performed adequately (especially the yellow crookneck), the winter squashes and cucumbers did poorly (in fact, only one Kabocha and none of the Delicata squashes reached maturity).

Clearly, there is something missing from (or otherwise not quite right with) this soil.  Testing should help uncover what that is.

As in previous years, for each of the planters and the mounds, I dug soil from four locations, mixed it together and dumped it into a labeled zip-top bag.  I slipped each baggie into a larger one (to contain possible spillage) and packed the three sacks into a box for shipping.  To the box I added the testing lab’s forms (one for each sample) and a check to cover expenses.

Next week, I’ll send them to New Jersey and in another week to 10 days, we should have the results.

It’s a happy time of year in the garden.  Everyone is growing with vigor and strength (every one of the vegetables, that is).

Well, almost everyone.  One of the cucumber vines is showing the unmistakable signs of bacterial wilt, having been infected (I presume) by the striped cucumber beetles who arrived in the garden only recently.  The upper third of the vine is completely and irreversibly shriveled.  I snipped off the afflicted section and will see whether the condition spreads to the remainder of the plant.  Based on experience, I’m fairly sure that it will but as my father used to say, hope springs eternal (he usually said this about our always-hungry cat).

Bacterial wilt aside, the cucumbers have not been particularly successful this year.  We are very happy with the varieties—they are the tastiest and have the silkiest texture of any we have ever grown—but the vines are small and weak and there has not been an abundance of fruit.  Whether this is due to the particular cultivars, too little or too much water, the soil (very likely; we dug only small pits for the seedlings), or—who knows?—sun spots is not clear.  It is nearly time to take soil samples for testing and perhaps that will shed some light.

I received, via e-mail, the results of the soil testing from Rutgers this afternoon.  It has only been ten days since I sent them the samples (see September 17, 2012) and I consider that a very quick turnaround indeed.  Nice work, lab technicians.

I tend to approach things from an analytical perspective.  When something is or is not working, I want to find out why and usually look for some measurable or otherwise quantifiable property with which to make an assessment.  This approach applies to the garden daily when I decide whether to water or not and weekly and monthly when I determine when to add fertilizer.

On a seasonal level, this trait manifests itself with my plan to send off samples of the garden’s soil for testing.  I did this last year (see September 13, 2011) when assessing the performance of the first planter and planning the soil composition for the second one.  Based on the results of the test (see September 27, 2011), we added amendments to the existing planter and adjusted the ratio of soil components in the new planter.

This year, I’ll be making similar assessments of each planter’s performance.  But because there are now two planters, one of which is in its second season, I’ll be able to make some comparisons as well.  The first planter did very well this year (despite bouts with harmful insects and plant diseases) while the second planter did not (even though all of the plants were quite healthy).  It is my hope that the results of soil testing will provide information as to why and give me some direction on how to make next year’s garden more productive.  Results for the first planter should also tell me whether our additions in the spring were effective.

So I collected soil samples today.  In each planter, I chose four locations (representative of the entire area but otherwise arbitrary), cleared away the mulch, and removed a trowel or two of soil and set it aside.  Then, from the holes in each planter, I took a scoop of soil from the bottom and combined them in a zip-top bag, one carefully labeled “East Planter” and the other “West Planter”.  (They aren’t the most imaginative names but they are clear and distinctive.)  I made sure to remove the earthworms who were trying to stow themselves away for a free trip to New Brunswick, New Jersey.

I put each baggie into a second, larger one (to prevent accidental spilling and mixing), packed both into a box, included an order form and check and sent everything off to the Rutgers Soil Testing Lab.  When I get the results, which should be e-mailed to me in about two week’s time, I will have the information I need to make my comparisons and should have some recommendations for next year’s planting.