A YEAR'S PROGRESS OF EXPERIMENT AND RESEARCH The following brief reports present only the more practical aspects of the principal lines of work done by the Wisconsin Agricultural Experiment Station during the past year. Full discussions of all completed work are issued in the bulletins, either Regular or Research, as the results justify, but the fol lowing reports of progress present a general idea of the purposes and scope of these Station activities. CHEDDAR CHEESE FROM PASTEURIZED MILK The need of uniformity in cheese-making is one of the most important in the development of the industry. The varying quality of the milk makes it necessary that the cheese-maker use good judgment in handling his raw material. Any method which would tend to unify these conditions would be helpful. For several years, cooperative investigations have been in progress between this Station and the Dairy Division of the United States Department of Agriculture, in which the problem has been studied from the chemical and biological, as well as the practical point of view. The attempt has often been made to manufacture cheddar cheese from pasteurized milk. The early experiments in this direction were quite unsuccessful, but more recently, the method of handling curds made from milk heated in a "continuous flow" pasteurizer to 155 degrees has been so improved by Professor Sammis, that excellent results have been secured. The cheese made has been very uniform in quality, of a clean, mild flavor, and an almost perfect texture. During the past summer such cheese has been sold under ordinary commercial conditions to test its keeping quality. The process of pasteurizing destroys the great majority of organisms in the milk, so that the addition. of properly selected pure cultures gives a degree of uniformity with reference to the types of organisms present that renders conditions much more uniform than with the old process. ORIGIN OF FLAVOR IN RIPENING OF CHEDDAR CHEESE This exceedingly complex problem has attracted the attention of cheese investigators for many years, and numerous theories have been advanced to account for the peculiar changes produced. Heretofore attention has been directed mainly to the decomposition changes which occur in the casein, as accounting for the ripening of cheese, but Professors Hart and Hastings have shown for the first time that the non-nitrogenous elements take part in these changes in a most important manner. The by-products formed in cheese, or in milk, by some of the lactic acid bacteria, are able to produce what are known as volatile esters and fatty acids, which give the characteristic cheese flavor. This is an important advance step in our knowledge of the complex changes which are necessary to convert green cheese into a well ripened and palatable product. CREAMERY SEWAGE PURIFICATION Investigations made by the dairy department on the purification of creamery and cheese factory sewage have been continued with good results this year, and the indications are now such as to lead to the conclusion that such sewage can be thoroughly reduced or decomposed in a closed septic tank if the reservoir is built large enough to hold the material for a sufficient period of time. The decomposition processes in the tank do not completely purify the sewage, but render it sufficiently soluble so that the resulting materials are easily purified by turning them on to sand or soil. Such discharges, however, must be intermittent, rather than continuous, so that conditions are favorable for the complete decay of the organic matter. BALANCED RATIONS FROM VARIOUS GRAINS. The experimental work on the value of chemically balanced rations for cattle derived from single plant sources, wheat, oats, corn, and a mixture of all three, has now been in progress for three years, and the results obtained by Professors Hart, McCollum and Humphrey are opening a most interesting field of study. The animals in this experiment have been reared from calf· hood on a ration, balanced in accordance with the regularly accepted standards, but while the rate of growth has not been greatly dissimilar, the physical condition of the different groups has varied widely. The lot fed on the products of wheat alone have shown low vitality, low milk production and weak, undersized calves, while those fed corn and its products have continued thrifty and have given large, strong calves. The oat lot have. given results more nearly like the corn lot, while the lot fed equal parts of corn, wheat and oats, resembled more nearly the wheat-fed animals. The causes of these differences in the effects of these feeds have not yet been discovered. Differences in the nature of the mineral elements may be partly responsible; difference in the effect of the food nutrients based on their distinct chemical natures; or possibly the presence of poisonous substances may contribute to the conditions observed. Animals matured on these somewhat restricted diets cannot be changed successfully to those rations producing low vitality. Contrariwise, transfers can be made to rations producing the more vigorous development. A mature corn-fed animal cannot change to a wheat ration without resulting shortly in death. A wheat-fed animal, however, can pass to a corn ration with improvement. The peculiar effect of the ration is much more rapid with the mature animal than with young growing stock. These experiments indicate that there is a value of one ration over another irrespective of the balance and supply of energy, as shown by the chemical analysis. INFLUENCE OF SULPHUR ON WOOL PRODUCTION The sheep is the only farm animal producing a product particularly rich in sulphur. For most classes of farm animals, the ordinary protein feeds furnish sufficient quantities of sulphur for ordinary needs. The practice of good shepherds is, however, to supply certain feeds very rich in sulphur, and this usage has suggested the possibility of a causal relation existing between the form and amount of sulphur supply and its relation to the growth of wool. In the cooperative experiment now in progress between the departments of Agricultural Chemistry and Animal Husbandry, four lots of sheep are being fed different rations: Lot 1 receives as low a sulphur supply as is possible to make from the natural grains and clover hay; Lot 2 receives the same ration plus a low sulphur succulent, as sugar beets; Lot 3 receives the same ration, plus a high-sulphur succulent, as turnips, rutabagas, cabbages, etc., and Lot 4 the same ration, plus a mineral sulphate, as calcium sulphate. Different lots of sheep have been fed succulent root crops that are exceedingly high in sulphur, such as rutabagas, and likewise those peculiarly deficient, such as sugar beets, with dry grain rations supplemented by mineral sulphates. This work requires the complete analysis of the wool, to make a separation of the true fiber, suint and yolk. The first analytical work, already performed, shows that our farm feeds contain greater quantities of sulphur than has hitherto been supposed, the low results which have been previously reported in standard texts being due to faulty analytical methods. This raises the important problem of the removal of sulphur from our soils, which, according to Professor Hart, is much greater than agronomists have heretofore believed. On the basis of existing analyses, it has been considered that a 100 bushel corn crop would remove only about one-fourth of a pound of sulphur per acre, whereas, the improved analytical methods, which have been devised in this work, show that the actual loss is about eight pounds. MINERAL REQUIREMENTS OF GROWING ANIMALS The cooperative work between the Agricultural Chemistry and Animal Husbandry departments on the question of the ash requirements necessary for the growth of farm animals has been continued during the current year, principally along the line of the influence of the lime supply on the development of the skeleton of the progeny. The indications at present are that the skeletal development of the young as to lime content, as well as size, is maintained in the pigs, regardless of the character of the lime supply present in the food. It has been shown that pigs can use mineral phosphorus in the form of floats or ground rock phosphate in place of phosphorus fed in grains. Normal rations used by farmers contain ample supplies of phosphorus. It has been shown that pigs fed grain alone do not get enough lime to meet the needs of the body for the growth of the skeleton. In these experiments lime has been supplied in the form of ground lime stone (calcium carbonate), as floats (calcium phosphate), and in ground alfalfa, since the clovers contain a large proportion of phosphates. The floats has proved superior to the ground limestone. The latter does not serve so well in making bone or in retaining the phosphate fed in grains and clovers. A farther test of clover is in progress. Brood sows have been fed additional lime in the form of limestone floats and alfalfa to determine the effect on the skeleton of their pigs. The skeletons of pigs from litters born this year were analysed immediately after birth and no difference in bone weight or composition was cbserved. This experiment will be conducted through several generations to confirm these findings. In an experiment made three years ago a cow was fed a ration lacking in lime, and it was found that she took lime from her skeleton to put into her milk to keep it up to the average composition. Her skeleton was seriously weakened as a result of this peculiar nutritional process. LOSS OF PHOSPHORUS IN HEAVY MANURING Professor Whitson and Mr. Truog have continued their studies on the loss of phosphorus from heavily manured soils, as is especially found in tobacco, asparagus, and cabbage culture. Marked losses in the leaching of soluble phosphates have been observed, indicating that the excess of phosphorus in such heavy manuring does not accumulate in such soils. Such leaching seems to be more pronounced on soils of open texture, as those of a sandy type. This work has an important bearing on the application of barnyard manures, inasmuch as a moderate application of manure will give relatively greater returns than where excessively large applications are made. CONDITION OF PHOSPHORUS IN THE SOIL Studies on the forms of phosphorus in the soil have been carried on by Mr. P. P. Peterson of the Soils department. These show that nearly one-half of the soil phosphorus is bound up with organic matter in such a way as to render it insoluble. Methods have been devised which permit of the differentiation of the soluble from this insoluble phosphorus, and so make possible the determination of the supply which is capable of being utilized by the plant. SOIL MANAGEMENT INVESTIGATIONS The work at Sparta on the use of peat as a source of nitrogen fertilizer on very light sandy soils indicates the availability in course of time of this cheap source of fertility. Soil plots which have received two applications of peat supplemented with phosphate and potash in five years gave this year a considerably larger yield of corn (grain) than plats receiving two applica tions of barnyard manure, although the yield of stover was not quite so great. The changes in physical texture of the heavy red clays at the Superior and Ashland farms are becoming more and more marked each year. By careful attention to drainage and ploughing under of barnyard and green manure, these soils have been reduced from a stubborn heavy type that can be worked only with considerable difficulty, to most excellent tilth. Not only |