The science of soil taxonomy and classification is interesting! I forget how many different soils there are estimated to be in the US, alone....as much as 50,000 though! The term 'type', as in 'soil type' really does refer to the texture of the soil, only. When discussing texture, we mean the particle size of the mineral content of a soil...that would be your sand, silt, and clay. Each of those 3 terms, technically speaking, refers to a precise range of mineral particle size. 'Loam' refers to any soil with a somewhat balanced ratio of sand, silt, clay, and organic components. As the ratio tilts one way or another, we use such terms as sandy loam, or clay loam, etc. Those terms make no reference to the mineral source material. Kinds of soils differ in their make-up depending upon a zillion different things, but the make up of the parent material (rock) is probably first. Just think of all of the different mineral sources and combinations! Rock deposits vary enormously. Here is a link that might be useful: Click here!

Interesting: This is the most level portion of my property (exactly 1/2 or three acres) near the road and my home sets back off of the road and up on a small bluff. From the road it slopes about 150 feet to the lowest point...quite an elevation change. And while that slopes, I have rolling hills running perpendicular to the sloping hills. In other words my property is wavy and sloping and surrounded by hills - very similar to a football stadium where the bleachers are the sides of my property and people doing "the wave" lol ;-) Flat (kind of, lol) Mercer County, Illinois 675B�"Greenbush silt loam, 2 to 5 percent slopes Map Unit Setting Elevation: 360 to 1,020 feet Mean annual precipitation: 32 to 40 inches Mean annual air temperature: 47 to 54 degrees F Frost-free period: 150 to 180 days Map Unit Composition Greenbush and similar soils: 95 percent Description of Greenbush Setting Landform: Ground moraines, till plains Landform position (two-dimensional): Summit, shoulder, footslope Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Loess Properties and qualities Slope: 2 to 5 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: About 48 to 72 inches Frequency of flooding: None Frequency of ponding: None Available water capacity: High (about 11.5 inches) Interpretive groups Farmland classification: All areas are prime farmland Land capability (nonirrigated): 2e Hydrologic Soil Group: B Typical profile 0 to 6 inches: Silt loam 6 to 17 inches: Silt loam 17 to 75 inches: Silty clay loam 75 to 80 inches: Silt loam ------- then: Mercer County, Illinois 8D2�"Hickory silt loam, 10 to 18 percent slopes, eroded Map Unit Setting Elevation: 350 to 1,200 feet Mean annual precipitation: 32 to 40 inches Mean annual air temperature: 48 to 54 degrees F Frost-free period: 150 to 180 days Map Unit Composition Hickory and similar soils: 90 percent Description of Hickory Setting Landform: Ground moraines Landform position (two-dimensional): Backslope Down-slope shape: Linear Across-slope shape: Linear Parent material: Loamy till Properties and qualities Slope: 10 to 18 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 25 percent Available water capacity: High (about 10.2 inches) Interpretive groups Farmland classification: Farmland of statewide importance Land capability (nonirrigated): 3e Hydrologic Soil Group: B Typical profile 0 to 6 inches: Silt loam 6 to 51 inches: Clay loam 51 to 60 inches: Loam Elevation: 360 to 1,020 feet Mean annual precipitation: 32 to 40 inches Mean annual air temperature: 47 to 54 degrees F Frost-free period: 150 to 180 days Map Unit Composition Greenbush and similar soils: 95 percent Description of Greenbush Setting Landform: Ground moraines, till plains Landform position (two-dimensional): Summit, shoulder, footslope Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Loess Properties and qualities Slope: 2 to 5 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: About 48 to 72 inches Frequency of flooding: None Frequency of ponding: None Available water capacity: High (about 11.5 inches) Interpretive groups Farmland classification: All areas are prime farmland Land capability (nonirrigated): 2e Hydrologic Soil Group: B Typical profile 0 to 6 inches: Silt loam 6 to 17 inches: Silt loam 17 to 75 inches: Silty clay loam 75 to 80 inches: Silt loam Good for Hickories (score!) and... there are a lot of Walnut groves planted in my neck of the woods. People from Chicago have been buying up the land and planting these Walnut groves. Cheers, thanks! Dax

Softmentor - You are very right on the many number of factors that determine cold hardiness (others we did not mention: acclamation to cold and overall health of the tree)...there is certainly no "magic number." I have found that upper 20's for a few hours are fine for oranges, grapefruit, and meyer lemons. Other lemons, citrons, limes, etc. wouldn't like that I am sure. From my understanding, Trifoliate orange rootstalk actually does add some protection because it is the only citrus that goes completely dormant in the winter. According to John Panzarella (a local citrus guru for Southeast Texas), "PT goes dormant in the winter, so reduces the water flow to the scion and gives the scion a few degrees of cold protection. PT will not start growing and producing tender new growth with a few days of warm weather in the winter." The last sentence is especially important for Texas, as in the winter we have frequent gulf breezes battling arctic cold fronts. So far, here are my unprotected lows for my varieties: Rio Red Grapefruits (2 trees planted at the same time by previous owner)- 26 F (4 years old, south side of house, pine trees overhead) -- tree was covered in snow (maybe insulated it a bit??), I was very surprised that there was no damage. Okistu Satsuma - 29 F (planted fall 2008, north side in the yard, no overhead protection at all) Meyer Lemon - 28 F (planted spring 2007, north side of house, no overhead protection) Moro Blood Orange - 28 F (planted spring 2007, in yard with no protection) Lakeland Limequat - 29 F (planted fall 2008, north side of house, 2 feet from brick exterior of house) As you can see, this is a very small sample size and only a brief history of data. Last winter was pretty warm, as has this winter so far. I wish I had a better way of measuring the length of the freeze and other variables.

Az-very interesting, but I think I have this quite well figured out. For the home gardener with a mixed bag of crop - it's all worthless The item that caught my attention was your reaction to the figures I put up from Brian & Darren and the comparison to Bernie. When compared to the ref. for Wiki, and the information that it contained, the figures varied. What I see - the base sat. MAY be of value, but only to specific crop. All the research was on a singular and certainly did not take into account all the possible variables but all came up with a 60-80Ca./0-20mg. Where did the Hefty's come up with 65-85 and 6-12? I am guessing that it may be the figures for corn & soy as it's fairly far off the academic consensus and if so, it had to be obtained by trial & error. Maybe they know something? Whatever the case as I grow corn,lettuce,cukes,tomatos,sweetpotato,chives,peppers,onions,tobacco,& on occasion, others - it's useless on my part. In June I am 24 years retired and my only goals these days are to TRY to get some of the local small part time farmers and hay field people to stop tossing money. These people do not do any kind of testing and do as "been doing". Yup, the guys doing hayfields & pasture use 19-19-19 and the other bcast AFTER they till. I use the heading " you are tossing money" and nothing else. It does get some attention - skeptics abound. Again, thanx for the followup but it's been my results in my backyard that has gotten the initial attention. Garden is 3,000 sq.ft.