How far down will plants go for moisture?

[vvalk]

Just wondering how far down different crops can Go to bring up moisture? I realize hot windy weather, it doesn't matter but just in general. We are getting dry to 2.5 ft. Decent moisture from there to 3 feet and then good moisture below that. Heard canola can bring from 4 ft with normal temps. Not sure about barley.

[farmaholic]

Crops here are progressing, but slow. It BETTER be rooting because its not growing in leaps and bounds above the ground. Spraying is finished and at this point it was still worth doing. Let's see what it looks like in a couple of weeks. I honestly believe potential is being lost with each passing day without rain. It may take more than a measly half inch to wet the top enough to meet the moisture below, likely an inch to wet everything well and it could very easily take it. The few very sandyspots we have are kinda hooped.

I am beginning to lose my patience watching radar. Systems coming our way and they dissipate before they get here. Seems like they run out of fuel or no fuel along the way to keep them going. Then there's the wall....the systems push up against It and just sit there and dump rain. Seems we are in a dome of dryness. Last year I would report that we dodged alot of bullets (excessive rain events but got reasonable rains). We've been luckier in the pas tand always seemed to sc**** something off. Looks like it could be one of those years of scraping.

Doesn't look promising for us again tonight. Even if I could buy rain, they would probably be sold out. Getting discouraging. My sympathies to those worse off than us and congrats to those better off.

Take care....

[freewheat]

Crops of course vary in how deep and efficient they are:

Peas use water very efficiently, but do not root a whole lot below the top two feet.

Canola can root to four easily. In my experience, blooming during heat is not an issue, if it is humid and if there is soil moisture. If dry on both counts, look out.

Wheat will go to four feet too.

Flax roots to 39 inches about, but uses most of it's water in the top 28, so it is more suited to moist areas.

In the U of S Ag building they have glass cases with carefully dug out plants, with the intact roots on display. It is incredible how deep an annual plant will root to.

If your soil is in good shape with no hardpan, or solonetzic areas, roots go deep.

But then the other kicker: What is the temperature? In hot conditions, obviously plants transpire far more. I know in the canola manual, at peak times, canola can use up to a THIRD OF AN INCH OF WATER A SINGLE DAY!!! Depending on temp of course. I think you have time, not a lot, especially if it gets warmer.

[riders2010]

All those numbers depend on what soil you have.
And how hot and windy it is. Have seen lots of crop not tiller and head out at a foot with lots of moisture down below when she s hot for too long.
The disaster is already here. Take a look at how many fields you drive anywhere and you don t know what is seeded there and it's June 18?

[farmaholic]

After 'several' years of adequate to excessive moisture for a large part of the Prairies, maybe this just feels like a drought...yeah right, fire away. I'm getting nervous too!!

[vvalk]

Would barley be similar to wheat?

[AlbertaFarmer5]

I realize every soil is different, but I have never yet found an annual plant with roots into the subsoil here. When the topsoil runs out, that is it. Alfalfa and Dandelions are able to penetrate the subsoil in certain places only, everything else stops at that point. I'm trying subsoiling to see if it will help. Will be digging holes this year to see if it is working. Grass here rarely goes below a couple of inches, unless on worked ground.

In our organic/peat soil, I find roots of grass/reeds etc all the way down and even into the subsoil, and the deepest peat I've found is 11'.

[mcfarms]

http://www.soilandhealth.org/01aglibrary/010139fieldcroproots/010139ch8.html



Barley (Hordeum vulgare) is grown either as a summer or winter annual. The root system is very much like that of oats and spring wheat. Manchuria barley was grown in experimental plots in both upland and lowland silt loam soil at Lincoln. Root habit was studied several times during the development of the crop.

Early Development.--When 3 inches tall and in the second-leaf stage, a maximum depth of penetration of 10 inches was attained on the upland. Unbranched laterals 0.3 to 1 inch in length were fairly abundant except near the root ends. The general root habit as regards fineness of roots, branching, and lateral spread was almost identical with that of spring wheat and oats, being somewhat intermediate.

Fifteen days later (May 15), when the plants were 4.5 inches high and possessed 3 or 4 leaves and 2 or 3 tillers, the roots were 5 to 11 in number. The working level was 9 inches but some roots were 2.2 feet long. A maximum lateral spread of 8 inches had been attained. Short secondary branches occurred on some of the older roots. As among the other cereals, the glistening white, deeper roots -often ran' several inches without branching.

Half -grown Plants.--By June 3, when the plants were in the sixth-leaf stage, the area to be occupied by the mature root system was fairly well delimited except in depth. The shallower roots, which spread 5 to 8 inches on all sides of the plants, were somewhat nearer the surface than those of wheat or oats of the same age. Of the 10 to 17 main roots, the shallowest ended in the surface 3 inches of soil. Many reached depths of 1.5 to 2.5 feet and a few were 3.2 feet deep. The best developed branches were in the surface 1.5 feet of soil. Here, often as many as 15 laterals per inch occurred, but they were only an inch or two long and secondary laterals were nowhere abundant. The last 6 to 12 inches of the rapidly growing deeper roots were entirely devoid of branches. The working depth was 1.8 feet.

Mature Root System.--At the time of blossoming, when the plants were 2.3 feet tall and only fairly well tillered, a great tangle of well-branched roots spread laterally from medium-sized plants to distances of 7 to 10 inches and occupied the soil thoroughly to the working level at 2.7 feet. Roots were quite abundant 8 to 10 inches deeper, the longest reaching depths of 4.4 feet. They were more abundant in the surface 3 inches of soil than were those of either wheat or oats. The development of secondary rootlets was very similar to that of wheat or oats. Wheat, however, was more abundantly supplied with finer rootlets than either oats or barley.

When the grain was ripe, 22 days later, the working level had reached nearly 3 feet and the maximum depth 4.7 feet. The volume of soil under the plants was even more completely filled with great masses of finely branched roots, the whole forming an exceedingly efficient absorbing system. On the lowland where the tops were more luxuriant, both working level and maximum root penetration were about half a foot greater. Similar root relations were found during subsequent years.

Other investigations, where barley was grown in large pots, indicate that maximum root development, as regards weight of roots, is reached at about the time that fertilization takes place. Here, root growth culminated with the final stage of preparation of the plant for grain formation. The physiological explanation of this is that during the period of vegetative growth, the plant needs large supplies of nitrogen and ash constituents to aid in building up a strong shoot in readiness for grain formation, and the root constantly increases in order to be able adequately to meet this demand. During the reproductive phase, on the other hand, vegetative development is reduced to a minimum and the whole energy of the plant is diverted towards the grain. Although nitrogen and ash constituents are just as essential as before, the area of supply is increased as migration of these substances from the straw into the grain goes on from the outset. 19 If the water supply is limited, however, these conditions may be somewhat modified.

Root Variations under Different Soils and Climates.--In loess soil in northcentral Kansas, lateral spread of roots and degree of branching were very similar to that at Lincoln, but the depth of penetration was somewhat greater (maximum 6.7 feet). In the short-grass plains, root penetration was limited by dry subsoil to the surface 2 to 2.5 feet. Under these drought conditions, the roots extended even more widely in the surface soils than those of wheat. Great mats of branches occurred in the surface 6 to 12 inches, forming a profusely developed absorbing system on all sides of the plant, even to a distance of 1 to 1.2 feet.

Shoot development and yield were correspondingly reduced with depth of root penetration. It was clearly demonstrated that this shallow root habit was due to lack of moisture in the subsoil and not to soil nutrients. During another season, an unusual amount of soil moisture, partly due to the accumulation of drifting snow, moistened the subsoil. The crop, which was 2.5 feet tall, had a working depth of 4.2 feet and a maximum root penetration of 5.7 feet as compared with a maximum penetration of 2.5 feet in the dry soil.

At Fargo, N. D., barley reached depths of at least 4 feet, 186 and at Manhattan, Kan., a root penetration of over 4.5 feet has been found. 204

In the deep, mellow loess soil of southeastern Nebraska, Manchuria barley, when 54 days old, had a slightly greater height growth than 63-day-old plants at Lincoln. The roots were 1.3 feet deeper, and the differentiation of the root system into a shallower and deeper portion was clearly indicated (Fig. 82). The deeply penetrating roots varied from two to four in number, ran vertically or obliquely downward and were profusely branched, sometimes as many as 20 branches occurring on a single inch. On mature plants, the shallow portion was scarcely more extensive than before, extending from 8 to 16 inches on all sides of the plant. The primary root system constituted the part which penetrated deeply. Occasionally, however, a root which had developed later from a node on the stem turned downward and penetrated deeply into the subsoil. Many roots penetrated to over 5 feet and a few were found at 6.3 feet. Branching extended to the root tips and showed that growth was complete.



Fig. 82.--A, Manchuria barley 20 days old; B, 54 days old.

Many investigators have 'found that the presence of fertilizers modifies root development of barley. In containers large enough so that the roots can develop normally and under field conditions, nitrate fertilizers at any level lessen root penetration but greatly increase branching. 225 Potassium salts and phosphates, on the other hand, greatly promote root extent. When liberally fertilized with these salts, plants in moist soil make a more vigorous growth both above and belowground, the roots extending farther into the substratum. For example, at Rothamsted, England, in a very shallow, heavy clay soil in poor tilth, with a compact clayey subsoil, the roots of barley plants were mostly confined to the top 2 inches, and none were found below 6 inches. Deficient aeration was indicated by the decay of some of the roots. But when superphosphates were used, the roots were somewhat deeper, and in the plots treated with barnyard manure, a depth of 9 inches was attained. The plants responded readily to the favorable conditions of penetrability and aeration under pot cultures. They soon reached the bottom of the pots, which were 14 inches deep, where they curved about and formed an extensive growth. 19

SUMMARY
Barley, when grown in rich deep soil, has a root habit very similar to that of spring wheat and oats; the fineness of the roots, degree of branching, and lateral spread often being intermediate. As in these cereals, the soil volume to be occupied is early delimited, except in depth, by the widely spreading roots. A lateral spread of 6 to 12 inches is usual, great masses of well-branched roots frequently filling the soil to a depth of 3 to 3.5 feet and maximum depths of 4.5 to 6.5 feet are frequently attained. Sometimes, the differentiation of the root system into a shallower portion and a deeply penetrating portion is very distinct. Barley roots often occur nearer the surface than those of oats or wheat. The root system is very plastic, and where dry soil prevents normal penetration, lateral spread and degree of branching are greatly emphasized. Poorly aerated, heavy clay soils may cause the roots to be very superficial. Addition of fertilizers promotes root development.

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[hobbyfrmr]

Thank you mc farms that was an education for me.

[furrowtickler]

Yes mc, very interesting

[cottonpicken]

Free,remember those glass cases,I think the wheat may have been ten feet?

If I remember soil science class it's also the soils ability to release moisture to the plant with loam being the worst and sand the the best but then there is soil water carrying capacity which is opposite.

[cottonpicken]

Often think its us and the plants vs everyone

[boarderbloke]

cotton, I also thought I remember that glass case with wheat roots being close to 10', if not more.
I always thought that 'clay' soil texture, had the highest water holding capacity, but also retained more(based on a percentage). Loam will give up virtually everything, while clay will hold back. I suppose science could have changed since I was there, or I could be remembering it wrong too. lol

[farming101]

The last line in McFarm's post,

"Poorly aerated, heavy clay soils may cause the roots to be very superficial. Addition of fertilizers promotes root development."

describes what is happening with this dry spell.
We are finding out how much compaction and salinity are teaming up to inhibit root growth. Plants are having a hard time developing. Growth is noticably slower than it should be.

This crop is not going to thrive even if there is moisture in the soil. We need regular rains. Fresh water from the sky.
That's here anyway. We have moisture in the soil. Some places you can kick the dirt with your boot and the moisture is there.

The article makes me think we need more P and K to promote root growth with these soil conditions. Maybe lots more.

[cottonpicken]

O no your probably right to busy chasing women and drinking to retain much which I regret now.

Did give the red head bitch olfert? A run for her money in econ