large proportion of land under such management has suffered seriously from lack of sufficient cultivation to make available an amount of the plant food elements required for even normal crop yields.

Perhaps these represent the two extremes in soil treatments, yet in my work over the state these two principles are brought out most forcibly in practically all sections. The item of extensive farming has distinct advantages over the working of small tracts in many ways, but with reference to the maintenance of the soil fertility on these farms there are presented a number of facts which, though disregarded by many, are, however, approaching more nearly every year a limit to profitable operations.

A word might be in order here with reference to the importance of a proper balance of the plant food elements, and also the elements more susceptible to depletion. Just as in the proper feeding of our farm animals rations must be properly balanced to insure the most economic returns, and, as in the human family, rations must be diversified to insure the health of the individual, so in the feeding of our farm crops there must be furnished to them at the proper time and in the proper amounts food for their development. The failure of any one of these elements being present in sufficient amount in an available form will limit the producing power of such a soil to that extent.

The factors of primary importance in our Iowa soils are: First, nitrogen; second, humus; third, lime; fourth, phosphorus. Their mere presence in the soil as determined by chemical analysis means little except that it may indicate whether or not there is a pronounced shortage, for by such analysis no account can possibly be taken of the percentage of such elements found being in a form in which the plant can make direct use of it. Chemical analysis indicates only the total amount present, whether that be available or unavailable.

Nitrogen, which in the larger number of cases proves the limiting factor in crop production in this state, may be purchased in a variety of forms. As such it is very expensive and, aside from cases such as forcing work in market gardening and greenhouse work, it has no place in agriculture. Fortunately, there is a means by which nitrogen may be very readily and economically secured. The life cycle of certain soil bacteria bearing symbiotic relation to the plants of the leguminous family, such as alfalfa, medium red and crimson clover, sweet clover, cow-peas, soy beans, vetch, etc., has to do with the securing of free nitrogen from the air, in which there is an abundant supply, and, by means of its life process, changing the free nitrogen gas thus secured into a combination of nitrogen and hydrogen. In this form it is still further changed by definate classes of bacteria into nitrates, in which form it is stored up in the small nodules on the roots of the host plant, from which the plant is able to draw for this particular item in its diet.

The humus content of any soil is directly proportional to the amount of organic matter returned to the soil plus the accumulated roots of crops grown. Its function is not to act as a direct fertilizing material. As soon as any refuse is plowed under it absorbs moisture from the surrounding soil grains and decomposition sets in.

Among the most important decomposition products are a number of the organic acids. Now, most of the plant food elements are locked up in the soil grains in a form not usable to the plants. These acids set free from decaying vegetable matter attract these unavailable substances [and, by their digestive action, set free such substances] or, in other words, convert such inert materials into forms which may be directly used by the plants. The much discussed abandoned farms of our eastern states have disregarded the return of waste materials to the soil, and by continuous cropping they have gradually removed practically all traces of humus in these soils. It is not so much the depletion of actual plant foods as it is a matter of the plant food within the soil having no means by which it can be made usable to growing crops. The most successful line of procedure in this reclamation work has been the addition of liberal amounts of organic matter, either as dry material, stable manure or green manure.

Previous to the last two years little work was done toward a study into the effect of too great accumulation of acids within the soil. The value of the study of such conditions fiirst came about in the state through the use of some form of calcium on ground recently put into alfalfa. Bacteriological studies revealed the fact that bacteria such as are found on the roots of alfalfa cannot attain their maximum efficiency in the soil which gives an acid reaction. Surmising that other species of bacteria growing on other members of the legume family might be similarly affected by the presence of acids, work was started on areas growing the clovers with much the same results obtained as in the case of alfalfa. So important has this work grown to be, and so pronounced are the results being obtained, that the work has been carried to almost all parts of the state. Decided preference has been given to the ordinary finely ground lime rock since the ordinary air slacked burned lime produces a caustic effect upon the organic matter within the soil. [Although most of the lime rock within the state does not yield a high content of calcium carbonate, yet this fact is more than offset by the inert form of the material when placed within the soil. The stone is quite readily disintegrated both by the leaching action of the soil water and by the acid present within the soil.]

The fourth factor, and the one most recently under investigation, is phosphorus. A plant food survey of the state recently completed, covering approximately five hundred samples in as many different locations, has revealed the fact that almost without exception our farm lands that have been farmed for any length of time are becoming seriously deficient in this element. The amount and texture of the seed produced is largely dependent upon the amount of usable phosphorus present in the soil. For the remedy of such a deficiency there is no short cut. Fortunately, there is available, however, a number of materials which carry a moderately liberal amount of element phosphorus. Ground bone, a refuse from the packing houses, ground raw rock phosphate from the southern states, an acid treated rock phosphate, slag from the steel mills, and numerous other materials may be used in the restocking of soils deficient in this element.

As a result of personal observation in the course of my work two things have stood out above all others as being points worthy of consideration in the improvement of our soil conditions:

First, the need of reducing the number of our cultivated acres and concentrating our best efforts on the cultivation of the land. By this I do not mean cutting down the size of our farms but, rather, either increasing the working force already employed or reducing the cultivated acreage, and devoting additional space to such lines as live stock propagation.

If we are to cope with the demand of our soils for decaying organic materials more manure must be produced. If this proves insufficient green manuring crops must be grown and plowed under. Permanent agriculture can only be realized by systematic treatment and feeding of our soils.

Second, the need of a definite plan for farming operations. This means, in short, systematic crop rotation. Under such management first of all we are enabled to distribute systematically over the farm some form of organic matter, looking toward the up-keep of the humus content. The regular change from year to year of the feeding zone of the plant roots affects directly the kinds and amounts of the plant food elements demanded. It is true that most of our insect pests are confined in their operations to some one crop. By moving these crops from year to year a process of starvation eliminates a very large percentage of them. An item of no small importance is the equalizing of seasonal labor. It is possible to so plan the cropping system that the work throughout the year can be definitely planned for, and one year's work may be made to compare in amount very favorably with another. So often rush seasons with their call for extra help are followed by slack seasons with the resultant loss in labor efficiency.

It has been my personal observation in many instances in visiting farms of various types that, almost without exception, the better type of farms follow a very definite cropping system and in every instance attribute the success of their crops to a systematic change of the same. Such a system may be very readily mapped out to suit the varied conditions of each individual farmer. Many rotations cover a period of as high as six or seven years, in which two or three years of hay and pasture are used. Grain crops are worked in as warranted by the farmers' needs.

It must be understood, however, that no systematic rotation, however thorough, can ever be expected to permanently maintain soil fertility. There must be a constant loss in plant food elements even where all refuse materials are carefully cared for and returned to the land, since every bushel of grain sold direct or fed to stock is removed permanently from the land. There must be a return of the elements removed in some form before such shortage becomes a limitation to the crop production of such a soil.

The growing of legumes and the return of the tops, either entire or in the manurial accumulations, will in a large part care for the nitrogen and humus supply. Limestone in its simplest form furnishes calcium and neutralizes any acid condition that may be present. It also encourages very materially an added growth of clover by furnishing a soil medium, in which medium nitrifying bacteria attain their maximum efficiency.

The state is answering the call for more local demonstration of these principles in various parts of the state, there being at present eleven local stations, each one studying carefully the needs of the soil of that locality. Various specialized problems are being worked out under as near known conditions as possible. Definite knowledge of soil improvement can only be gained through a successive cropping on the same area, hence permanent work must be followed. All experimental work in the state is on a four year rotation basis, but the crops used are suited to the local needs.

It is proposed by the Soils Section of the Experimental Station to answer calls for the establishment of local fields where permanency is assured, on which shall be used the materials heretofore discussed. We feel sure that contained in this list of treatments there is embodied one or more problems that are directly applicable to a very large percentage of the farms of the state. It is our purpose to study diligently into specialized soil problems of any considerable importance and meet such demands as promptly as finances and competent help can be secured.

Agriculturally, we stand high as a productive state. We cannot afford to disregard the fundamental principles upon which our crop production is built. The opportunity for improvement is ours, and our farmers are rallying to the call for better methods of soil management on their farms so fortunately situated in this, one of the greatest agricultural states in the union.

THE MANAGEMENT OF DAIRY HERDS AT

STATE INSTITUTIONS.

By L. Eschenheimer, Head Farmer, Mt. Pleasant State Hospital,
Mt. Pleasant, Iowa.

One of the main factors in private dairying on a large scale, such as is practiced by state institutions, is the cost of efficient labor with which to operate a modern dairy successfully. In dairies at state institutions, where we have the chance to give our patients the kind of work mostly desired by them, especially those who come from the farm, we have two opportunities: First, we can adopt a more intensive dairying by running a dairy practically with our patients; second, by studying the nature and ability of a patient and getting him interested in a certain line of work, we can make helpers of great efficiency of mentally defective men. The willingness and accuracy with which these men perform a certain work to which they get accustomed, by having each man do his particular share day by day, is astonishing. For illustration:-We have one man who feeds and takes care of the calves under six months of age, and has done so for the past two years, and the way he attends to his duty is admirable. He follows his instructions as to the ration given them precisely and reports any appearance of sickness immediately, and as a result we can say that we raise calves successfully.

But, it must be remembered that we can get these results from our patients only by being their friend and protector in every way, never getting angry at mistakes, showing them in a cheerful way their work and never changing them until convinced that they are incapable of doing it, then putting them in a pleasant way to some other work until the right place is found for them. Nothing goes farther with insane patients than a pleasant, encouraging word at all times, a good word for their deeds, and a correction in a friendly way of mistakes.

As we know, the most desirable man in a dairy is a good milker. We frequently find that such a man is willing to milk, but has objections to other work. We have had several cases of this kind which came out all right by letting the patients have their own way and inducing them now and then to do little jobs, and in a short time they made worthy helpers in the dairy. The value of the dairy is realized more and more every day for the reason that dairying is profitable not only in itself but because it increases