Root Development of Vegetable Crops

Sweet Tatorman's picture

This is the title of a book published in 1927 by two researchers associated with the University of Nebraska; John Weaver and William Bruner. If you have ever wondered what your garden plants are up to underground this is well worth a look. I provide a link below to this work which in turn is a collection of links to the individual chapters which excepting the Introduction chapter each provide the research results for a single crop. The Introduction chapter is worth a read to understand their methodology as well as to appreciate the huge amount of work that was expended. I first became aware to this work years ago via a book by Steve Solomon who reproduced a number of their diagrams in one of his garden topic books. I have since referenced the original work from time to time and never cease to be amazed by it. Some of their results are to me counter-intuitive. Taking beets as an example, when I pull these up to harvest they seem to hardly have any roots at all. The reality is the roots can attain a spread of 4 feet from the beet and a depth of up to 10 feet. This is a spread and depth greater that that of sweet corn!
There are many take away conclusions from their data but one is that there generally is less need to obsess about watering if the surface layer of soil is dry since direct seeded plants very rapidly attain considerable root depth. If the seed managed to germinate and emerge it will be rapidly developing roots downwards to where the moisture is.
https://soilandhealth.org/wp-content/uploads/01aglibrary/010137veg.roots...

David Trammel's picture

Perfect timing, I was going to reply to some comments on my "Subsurface PVC Watering System" post. This is helpful.

lathechuck's picture

I just got done digging out a new 3'x5' section of vegetable garden. By that, I mean that I scraped off the few inches of topsoil, then broke up the subsoil of sand, clay, and rocks (mostly rounded quartzite, as if they've been tumbled smooth in some prehistoric riverbed or beach). By the time I get down a foot or so, I'm swinging a pick to loosen it, scooping it out with a shovel, and sifting the stones out (with 1/2" hardware cloth over a 2'x4' frame). Two feet of that is enough for me, but your book describes carrots going MUCH deeper than that! A 6" "carrot" has a taproot going down six feet! I don't think that every going to happen in MY garden!

Sweet Tatorman's picture

LC, your situation sounds similar to mine with the exception that the rocks are mostly rounded sandstone stream cobbles with some angular chert in the mix. Once I get down to a foot or so it is mostly interlocking cobbles with soil existing in the interstices. It would be an all day project to dig a hole down to two feet so I will not be disposing of any bodies in my garden. I would like to think, but have not way of knowing, that at least some roots can actually burrow down in those spaces between the rocks and bring up nutrients and water from depth.

lathechuck's picture

But you know, if some day you DID need to bury a body... a well-dug garden would be just the place for it. I've actually buried the bodies of several local animals in mine. No point in letting the nutrients go to waste!

After I dig down about two feet, I fill the bottom of the hole with sticks (windfall and prunings), to capture the carbon (and other nutrients) and create space for water absorption.