Soil Analysis From A Chemist's Standpoint
( Originally Published Early 1900's )
PROF. A. J. PATTEN, AGRICULTURAL COLLEGE.
Mr. President, Ladies and Gentlemen—The subject which has been assigned to me at this meeting I have tried to treat in a popular way, and if you will pardon me, I will read what I have, because I fear if I trust to my memory, I omit saying some thing that I very much want to say. There is so much to be said on this subject, that I do not want to miss saying some of the things that I particularly wish to say at this time.
There exists today two distinct views of the soil. The one considers the soil simply as a place in which plants may grow and from which they receive their food. In this view of the soil the supply of plant-food, available for plant use is considered as fixed for any given soil and that its productive capacity is entirely governed, under good farm practice, by the amount of plant-food contained in the first few inches of the surface soil and the demands made upon this supply by the crops grown. Infertility has generally been attributed to an actual deficiency of plant-food in the soil or a lack of available plant food. In this discussion, it should be remembered that by plant-food is meant nitrogen, phosphoric acid and potash.
It may be said that this view of the soil originated with the famous German Scientist, Liebig, popularly known as the "Father of Agricultural Chemistry." About the middle of the 19th century Liebig presented to the world his views as set forth in the following four laws :
First. "A soil can be termed fertile only when it contains all the materials requisite for the nutrition of plants, in the required quantity, and in the requisite form."
Second. "With every crop a portion of these ingredients is removed. A part of this portion is again added from the inexhaustible store of the atmosphere; another part, however, is lost forever if not replaced by man."
Third. "The fertility of the soil remains unchanged, if all the ingredients of a crop are given back to the land. Such a restitution is effected by manures."
Fourth. "The manure produced in the course of husbandry is not sufficient to maintain permanently the fertility of a farm; it lacks the constituents which are annually exported in the shape of grain, hay, milk and live stock."
The promulgation of these views had a great influence upon the agricultural practice of the time which has extended even down to the present and placed an added emphasis on the value of the mineral plant-food constituents. It was believed that with the results of a chemical analysis of a soil it would be possible to determine its crop-producing power and likewise its fertilizer requirements. This as you will readily see, makes the question of soil fertility a simple problem in mathematics. Knowing the percentage of plant-food constituents in any given soil, it is only necessary to apply the multiplication table to find out the total amount of plant-food contained in one acre, to any given depth. Likewise, knowing the amount of plant-food removed by the crops grown, also revealed by chemical analysis, the multiplication table will tell us how many years our soil should be able to support a crop and also what amounts of plant-food should be returned to the soil each year that the fertility may be indefinitely maintained. Could anything be more simple? As you will readily perceive this view of the soil makes the amount of the mineral plant food element (nitrogen, phosphoric acid and potash) the index of fertility and they have very naturally been considered by many as the very foundation stones upon which successful agricultural practice rests. No doubt every one of you have heard these three plant-food elements, many times, extolled as the tripod of agriculture. Consequently the scheme of practically all investigations, until comparatively recently, has been with a view to ascertaining the amounts of these elements in the soil and the amounts removed by crops.
With this view of soils it becomes quite imperative that we have some standard by which a soil may be judged as good, bad or indifferent. Many persons have attempted to establish such a standard, but strange to say, the various standards fail to agree. The one most generally referred to is that proposed by a German chemist.
The only serious objection to such a standard is that the facts, as revealed by actual experience do not, in a great many cases, conform with these figures. It is also very evident that the man who proposed this standard failed to recognize the fact that some crops are especially adapted to certain kinds of soil, and that they will do far better upon the particular kind of soil fitted to their needs, by nature, regardless of its plant-food content, than upon any other kind of soil.
According to this classification the great majority of the agricultural soils of Michigan would be classified as good or rich, although we know from actual experience that many of them are not up to, what we may call, their normal productive capacity.
Soils No. 1 and 2 are from newly cleared land in Manistee county. The soil represented by No. 1 was set to peach trees last spring and No. 2 was set, during the spring of 1911, to apples, pears, peaches and cherries. According to the classification previously given, both these soils would be ranked as poor but it would be difficult to find a better or more thrifty looking lot of trees than these were last July. How long they will continue in their present condition without fertilization, is impossible to say but I predict that with good cultivation and cover crops they will continue to make good growth for many years to come. Soils Nos. 3 and 4 also come from Manistee county and represent the so-called Jack Pine sand region. Soil No. 3 was taken in a young orchard set in 1911, which has had a crop each of rye, clover and vetch turned under. While this orchard is not as favorably located as the two just referred to, yet the trees have made good growth and were looking thrifty. Soil No. 4 was taken in a corn field across the road from this orchard and nothing had been done to it further than plowing and fitting for the corn crop. It is needless for me to say that the corn crop was looking very poor and weak. A good illustration of the unadaptability of crop to soil. Soils No. 5, 6 and 7 are from Benzie county. Number 5 was taken in an orchard, which is about 20 years old. This orchard has been well taken care of and has received frequent applications of manure and commercial fertilizers in addition to having cover crops turned under. Number 6 was taken in a pasture adjoining this orchard and so far as is known has never received any manure or fertilizers. Number 7 was taken from the roadside opposite this orchard. The only marked difference in these three soils is found in the amount of phosphoric acid and lime contained in them. This may be accounted for in part at least by the addition of manure and commercial fertilizers; but if we assume that this orchard soil originally contained the same amount of phosphoric acid as the pasture soil then the difference between them now is greater than the amount present in the soil before the orchard was planted. This difference is equivalent to 10,000 pounds of acid phosphate per acre 7 inches, or to an annual application of 500 pounds of acid phosphate over a period of 20 years. Such an amount of phosphoric acid has in all probabilities not been added to this soil. It is more plausible that in taking the sample some recently applied fertilizer, which had not been thoroughly incorporated with the soil, was accidently included or else the natural and unavoidable error of analysis is, in this ease, more pronounced than in the other cases. It may also be true that in this case phosphoric acid is being brought. up from much lower depths by the capillary water faster than it is being used and is therefore, increasing in the surface soil. However, the point I wish to make in this connection is this : This orchard set 20 years ago on soil that would classify as poor from the plant-food stand-point, is today, one of the finest looking orchards in the whole state and I know of no one who would presume to say or even venture the opinion that had the same trees been planted in a soil with twice the amount of plant-food as was contained in this soil No. 5 they would have produced any more fruit. Sample No. S is from a farm in Kalamazoo county. It is of a very different character than the soils previously considered, being a clay loam, and it contains a considerably larger amount of plant-food. The productiveness of this soil has been increased, by the present owner by practicing good methods of farm management and not by increasing the amount of plant-food.
I desire to call your attention particularly to samples 9 and 10, which were taken from adjacent farms in Barry county. These soils would be classified as sand but number 9 was producing in the neighborhood of 30 bushels of wheat per acre while number 10 was producing less than 10 bushels per acre. In seeking for an explanation for this difference it is very apparant that it is not due to a difference in the amounts of nitrogen and phosphoric acid and in all probabilities there is no appreciable difference in the amounts of potash in the two soils.
I regret that I am unable to say what is the cause of the difference in productiveness in these two soils as we have only had time to make the analyses referred to. However, this one example serves to illustrate hundreds and thousands of similar conditions. I presume there is not a farmer within this sound of my voice that has not some places on his farm that fail to produce as abundant crops as the adjoining areas. Such cases cannot, certainly, be explained by any marked differences in the amounts of nitrogen, phosphoric acid and potash. We must seek further for an explanation of these differences.
While it has long been recognized that the organic matter of the soil has a great influence upon the productiveness of the soil it has been looked upon as influencing the physical condition of the soil rather more than the chemical. Though in more recent years the turning under of leguminous crops, as a source of nitrogen, has been receiving more and more attention. During the past few years, however, a critical study has been undertaken in a few laboratories of this country to find out more about the nature of the organic matter of the soils and its influence upon fertility. The result of this work, so far, has been that quite a large number of organic compounds have been isolated from soils and some of them have been found to have a decided injurious effect upon plants while there are others that have as decided beneficial effects. These compounds have resulted from the decomposition, in the soil, of organic matter turned under as green manure or introduced as barnyard manure.
It is not at all strange that these compounds should be found in the soil, but, on the other hand, it would be decidedly strange if we failed to find, at least some, of these compounds, for when these same materials (green manures) are allowed to decompose in the laboratory many of these same compounds are formed. The process of decomposition in the soil cannot be very different from the decomposition in the laboratory for there is present in the soil the very agencies which affect the de-composition under laboratory conditions. I refer to the countless number of microscopic organisms: bacteria, molds, yeasts and fungi. You are all familiar with the work of these organisms on various materials above ground and I need only to call to you minds a few examples, as for instance, the souring 'of milk by bacteria, the destruction of grain by molds when stored in a warm, damp place, the transformation of sugar in apple juice into alcohol and vinegar by yeasts and the brown rot of grapes by fungi. Changes in the organic matter of the soil, of a like nature to these, are going on continually in the soil, when the temperature conditions are favorable, and the result must be the production of- a great many compounds in the soil of which, as yet, we know very little.
Some of these compounds contain nitrogen and some contain phosphorus and a great many of the compounds already isolated contain neither one of the so-called plant food elements and I now come to the most interesting and perhaps most important phase of the subject.
It has usually been considered that nitrate is the best form of nitrogen for plants and that it could not be used by plants in any other form. Now we do not find nitrogen in plants in the form of nitrates (with the exception of a few cases) but on the contrary it is in the form of very complex protein compounds. It is very evident then, that if the plant gets all of its nitrogen as nitrate it must expend an enormous amount of energy in building up these complex compounds. Now, as has already been indicated, when these protein compounds are decomposed by bacteria or other agencies, they are split up into simpler but still complex compounds, which are again acted upon by the same or other agencies with the production of more simple compounds. This action may be carried on until a part of the nitrogen originally present in the protein compounds has been changed into nitrate or ammonia. Now, since the plant must transform its food material into these very complex materials what is more plausible than that it may make use of some of these simpler decomposition products before they have been reduced to nitrate.
While I realize that this is decidedly contrary to the time honored theory that plants can only take their food material in the simplest forms but, why not change our views on this subject if the evidence is sufficient? We are now experiencing a similar change in regard to the theory of animal feeding. For a long time it has been supposed that a ration balanced with respect to protein, carbohydrates and fats had solved the problem of cattle feeding, but recent researches have disclosed the fact that there is a great difference in the feeding value of the various protein compounds and indicate that in order to obtain the greatest efficiency we must take into consideration the decomposition products of the protein materials we feed. We must therefore, take into consideration the possibility of the plant making use. of these soil decomposition products as plant-food just as they can use the more simple forms of nitrogen, phosphoric acid and potash.
It has in fact already been demonstrated that plants will use some of these soil decomposition products and even when it has access to the usual forms of plant-food. Then again, some of the injurious compounds formed in the soil appear to be less injurious in the presence of nitrates, phosphates and potash; with some, nitrate gives the best results, with others phosphate and with still others potash has the most influence in overcoming the injurious effects. So it is seen, that the fertilizer have a value, when added to the soil, in addition to their plant-food value.
This new view of soils is well expressed in the following words of Dr. Schriener : "The soil cannot be considered as the dead, inert re-mains of rock and previous vegetation, but must be considered as an accumulation of such material in which the process of formation, alteration and transposition are still at work. In other words the soil in its entirety is not dead or inert, but endowed with functions analogous to those of life itself. In it take place the same processes of solution and deposition that have taken place in past ages, and are taking place today in the geologic processes connected with the action of the water on the rocks and minerals of the earth's crust. In it take place the same physical and chemical interactions as take place in the movement of subsurface waters generally, resulting in ore formations and depositions. In it take place the same processes of fermentation, digestion, or decay of organic materials as take place in animals and plants or in the production of industrial products, such as cheeses; wines and beers, brought about in the soil as in these other processes by means of ferments, bacteria and fungi or molds. In it take place the same processes of oxidation and reduction which play so important a part in all life processes and it has been shown that the nature of the compounds in the soil organic matter is the same as those derived from similar laboratory processes of digestion, oxidation or reduction. Organic matter is very changeable; it is the material which forms the food, as it were, of all the microorganisms of the soil, of the bacteria, of the molds, etc., and influences them favorably or unfavorably, just as the higher plants are affected. In turn these agents are great promoters of these changes in the organic debris of the soil. All of these processes and life forms in the soil are affected by fertilizer salts when added to the soil, and changes are produced in the soil, physical, chemical and biochemical, which influence the soil and affect its potential fertility irrespective of the added plant food.
So, the message which I bring to you today is one of optimism. I have no patience with the man who is continually preaching soil exhaustion and predicting the time when our soils will no longer support our increasing population. The soils of Europe and Asia, which have been under cultivation for centuries are still producing good crops and give no evidence of any decline so long as they are properly handled.
The maintenance of fertility, I admit, is still a big problem with us but it cannot be solved on the basis of supply and demand of plant-food. This has already been well demonstrated for if this were the solution it would have been solved long ago. But the problem is still be-fore us. That it will be solved I confidently believe and I look for the time to come when it will be possible for the chemist with probably the assistance of the bacteriologist, the physicist and the plant physiologist, to examine a soil sample and determine the exact cause of in-fertility and prescribe the remedy. It is going to take time, however, before this is accomplished for there remains yet a great deal to be learned.
It is not strange that the older scientists of the time of Liebig should have attacked the greatest importance to the mineral plant food for at that time, organic chemistry was little developed, the science of bacteriology was hardly known and plant physiology was in its infancy.
It is strange, however, that, with our present knowledge of these subjects, their influence in the solution of the problem should be so completely ignored by so many.
The chemical department of the Michigan Experiment Station is in full sympathy with the new view of soils and our soil work is being conducted along those lines.
The Chairman—We must hasten with our program for it is getting rather late. The next topic is "Clearing and Developing of Three Hundred Acres of Land for Fruit Growing," by Mr. J. E. Merritt, of Manistee.
Mr. Merritt—Mr. Chairman. Ladies and Gentlemen : I was quite surprised a few days ago to receive a letter from Secretary Bassett asking that I come down here and tell you something about my experience in clearing up a piece of land for fruit growing.
I replied to him that I feared that 1 might not be able to interest you, but inasmuch as I have had some slides made illustrating our work he asked that I come down and show them, and I have consented to do it. As I was coming down here on the Pere Marquette train you know I would have plenty of time for reflection and I tried to think up some-thing that would be of interest to you, and the more I thought of it the more forcibly there came to my mind a story that was told to me recently of a land and lot boomer, from Wichita, Kansas. This land boomer from Wichita, it seems, was in the habit of going away from home to other states to sell Wichita lots and lands to outside people. One time when on an eastern trip, after he had finished his business, and while waiting for a train, he sauntered around to the suburbs and noticed a fine residence with carriages outside, and a number of people going into the house. So he went in and sat down. He found it was a funeral of the owner of the place, so he sat down and listened to the music and the remarks of the pastor, who was very profuse in the words of praise for the charitable and benevolent character of the deceased. When he was through, this stranger rose to his feet and said : "Ladies and gentlemen, I am a stranger in this town; in fact this is the first time I was ever here. I have listened to the beautiful music and heard the glowing words of tribute from your beloved pastor as to the character of this man here who lies dead, and I am very much impressed with the fact that I have missed a great deal in my life by not having been acquainted with him. But as I do not know anything about him I am unable to say anything in his favor, but if you have no objection I would like to make a few remarks about Wichita."
I relate this story because after talking about my own farm and my own county and showing you pictures which may look like boosting, if you happen to think that I am like this man from Wichita, I wish you would kindly place the blame where it truly belongs, and that is with your good secretary, Mr. Bassett.
In 1909 I wanted an orchard and I secured some wild land in the vicinity of Manistee, and started in to clear it. Along in the spring of 1910 I went up and saw Paul Rose. After getting acquainted he said : "Are you not a little old to start in to raise a young orchard." I probably don't look even as old as I am, but I am not as old as Paul Rose anyway.
Well, I wanted to get this land cleared and I went at it and have been successful in clearing up 310 acres of this land and have 200 acres under cultivation and planted to trees. I have tried to adopt the most improved method used in successful clearing of land on a large scale. One of the cardinal points that I have tried to follow out all the way through is to keep busy all the time. You lose time on account of bad weather any way, but by planning our work ahead and carrying it forward with diligence we have been able to accomplish what many 'seem to think is quite extraordinary.
Our first operation was brushing. I secured two men to cut the brush and then cut the trees down, saw them up, cut off the small stuff like 21/2 inches in diameter, then trim up these tree tops and what could be made into wood use it that way and the other burn. Our next thing was to go in on that land with teams and chains and do what we called snagging, that is, hitch these chains on these stumps and pull them out with the horses. This is the second operation. Then we would take by hand and pile up these roots and burn them up and get them out of the way.
Our idea all the time in clearing this land is to get our table clean ; get the surface free from obstructions.
The third operation is to do the block work; that is, take a block and tackle and fasten on the end of this block, use one block for hitching block and the other for pulley. We used one-half inch cable wire. Hitch one of these blocks on the heavy stump, put a chain around an-other stump and then hitch the horses on and pull these out with this cable. We used 100 feet of cable. You can pull everything around a radius of 75 feet, and then go on and set up your machinery again. These stumps we pile up and burn. Then we have our table cleared ready to use the big machine. The machine I have used is a large lever machine, called the Stalwart. They claim that the machine will lift 500,000 pounds. This machine is set right over the stump, hitch on the team and begin the work and out comes the stump. Sometimes we would not get the large stumps out at one pull, but we have taken out stumps five feet across with roots two feet around.
A Voice-Why did you not use dynamite?
Answer-We do use it but we don't use the dynamite until after the stumps are out, and we do it in order to facilitate removing them into piles.
As this work is quite hard on a team we put one team in the forenoon, and another team in the afternoon.
A Voice—How many stumps can you pull in a day?
Answer—I could not answer that definitely. One day we might pull two or three times as many as another day. In pulling these stumps they are pulled right up straight in the air. We dig holes under the roots of the stump, put the chains under the root and fasten to the lever of the machine by grab hooks, and then as the team goes out on the cable line the stump comes up, then the men with long bladed ditching shovels would cut the dirt loose, and then the team would go forward again until the stump was cleared from the ground.
Question—How do you get rid of these stumps?
Answer—In regard to getting rid of these stumps would say that after we get them on top of the ground we would not do any piling until we had cleared off 40 acres or more. Generally we have 40 acres on hand, and then we would suspend other operations until they were cleared up. Our method of piling these stumps was to attach a long arm or lever which we call a gin pole. It is attached to this machine and raises and lowers. The arm of the machine is thrown sidewise and there is a catch on the end and then the belt holds the stump until from below there is a release of it.
We would start pulling stumps—we would set this machine and pull in a number of stumps with the horses to form a base for this pile and then pile these stumps all together, sometimes as high as they could be made, and the piles would contain hundreds of stumps, and then fire was set to them and burned. On 40 acres we would have about ten such piles, and they would all burn up, either wet or dry.
A great many people said to me "You should not do this, for you will injure your land." At first I did not know but I would, but I wish to state after burning these immense piles of stumps we would go in, before the land was cultivated, with an ordinary road scraper and scrape these piles of ashes out over the land, and I wish to state that where we have planted both cherry and peach trees, some of the best growing trees are growing right where we had these stump piles. I have my own theory about that, and that is, it is the lime in these ashes which benefits these trees. I do not think the burning of stump piles in a clearing of land does any damage, although it may be that forest fires running over land may burn out the humus and do considerable damage.
After these stumps have been piled and burned, we then go over this land with a jumper—it is nothing more than an ordinary sled with wooden runners, that a team of horses will draw, and go over the land picking up the roots and everything on the surface, and haul back together in piles and burn them, and then the land is well cleared. We get in on it to do ploughing in the fall. Then after the land is ploughed we go in with our jumper and pick up everything that has been thrown out on the surface, such as roots, etc., that have been turned up by the plow. After this operation we finish by ploughing, and thus the land and our work is finished all but the planting in the spring. Although in the fall of the year we make a practice of having our land surveyed and set with stakes for the trees. It is cheaper to plant your trees on a large plat by the aid of a surveyor's crew than to line it up yourself. I paid a surveyor for his work $6.00 a day, he paid his helpers $1.75 a day. I took this surveyor and this crew and they surveyed and I found that they could set a good many more stakes than any home made crew that could be had, and then there is the satisfaction of knowing that everything is done right, and then your trees are lined up properly, and especially on rough or rolling land. Another practice which we make is of securing our trees in the fall and heel -them in for the winter. I have a carload of trees now on the way which I expect to heel in as soon as they arrive. Mr. Paul Rose who has been the father of this greenhorn who is now talking to you, has been our inspiration and help through all of our efforts, and it is under his advice that I get my trees in the fall rather than in the spring. I wintered 3,200 peach trees and then out of these 3,200 which I planted in the spring, I lost but 28 trees, which is much less than 1%, but I do 'not think that fruit growers will have a loss of more than 1% if they winter their trees on their own land.
(Following this were shown a number of very interesting lantern slides, illustrating Mr. Merritt's work.)
REPORT OF SPECIAL COMMITTEE.
Your committee appointed to consider plans for the better grading and marketing of our fruit report as follows :
We recommend the establishing of fruit marketing associations where-ever fruit is grown in sufficient quantities to warrant it, and the co-operation of these associations already organized for the purpose of getting uniform marketable grade and for the marketing of the same.
We recommend the adaption of the Sulzer law and the encouraging in every way the adaption and enforcement of the same by all Michigan growers of apples. We recommend that this society,—The Michigan State Horticultural Society, take up the organizing of local societies for the purpose of grading and marketing their products, especially the apples, with a view of a federation of all societies whose object is better grading and more profitable marketing of our fruits.
We ask the hearty support and co-operation of every Michigan fruit grower to help make the Michigan apple a standard of quality, a profit to the grower and as economic food to the consumer, by cutting out all unnecessary expense between the produce and the consumer.