Many requests come to the Animal Husbandry Department of Iowa State College for information relating to the literature of the swine industry as well as for the names and addresses of swine registry and record associations. To supply this increasing demand this catalog and directory has been prepared to present information which is concise and up-to-date. The literature on swine husbandry is growing rapidly and many notable additions to the list of publications on this subject may be expected in the near future.

One of the promising seedling apples originated at the Iowa Experiment Station Is now offered to the nurserymen of the state under the label Iowa 403. It is hoped that the nurserymen will assist In making a thorough test of the variety, so that as soon as possible Its value for planting In this region may be determined. The distribution at this time will consist solely of clons. Since the nurserymen, as a class, are prepared to give the clons more skillful attention than other people, this distribution Is to be offered to all Iowa nurserymen whose names appear on the 1914 list of the State Inspector. Later distribution will be made to others who may be Interested In testing this apple.

The major problems that the present depression has forced upon agriculture can be grouped under three heads : 1. Low prices for agricultural products. 2. High fixed charges on mortgage and other indebtedness in relation to income. 3. High truces in relation to income. The gravity of these problems is perhaps not comprehended by those outside of agriculture itself. The average man hears of 10 cent corn and $3.00 hogs, but he does not grasp the significance of these prices; he does not realize the meaning of the events· of the past year for agriculture, nor does he realize what is going to happen to agriculture during the next 12 months if some program of action is not put into effect.

Green manuring puts humus into the soil and that makes it an important farm practice, because humus is absolutely essential for the best growth of crops. Humus may be added in another way, by applying barnyard manure, but that method alone will not keep the soil from losing fertility from year to year. Even though it is saved with the utmost care, the manure produced on the farm will not return to the soil all the fertility removed by the crops. Circular No. 9, "Farm Manures," Iowa Agricultural Experiment Station, shows furthermore, that there are certain unavoidable losses in the storing of manure and that they may involve not only the valuable mineral constituents, but also the organic matter. As agriculture is now generally practiced in Iowa and elsewhere, the soil is being gradually worn out.

It is clear, therefore, that some other means must be employed to keep up the humus content of soils and this may be accomplished by turning under green manure crops.

We have in Iowa two troublesome species of morning glory. One is native and is known as the wild morning glory or bindweed (Convolvulus sepium L.). The other, an introduced European species, is known by many common names, the principal of which are European bindweed, field bindweed, small morning glory and creeping Jennie (Convolvulus arvensis L.). This circular will discuss the European morning glory, which is becoming a serious pest in many states and especially in those west of the Mississippi River. It is reported as the worst perennial weed in Colorado, California and Kansas, and a serious pest in South Dakota, Idaho, Utah and Washington. It is generally distributed in Iowa but is particularly abundant and troublesome in the northwestern part. The European bindweed reduces crop yields, increases the labor costs, menaces the adjoining clean land and finally reduces land values. Every farmer should learn to recognize the European bindweed and eradicate it before it becomes established.

The gross income to Iowa farmers has increased rather steadily since the low point of the depression in 1921. This fact is brought out in the study reported in this circular.

The soil-enriching effect of the growth of clover and other legumes has been recognized from the earliest days of agriculture. Even ancient Roman authors emphasized their \value In regular rotations. Since then the use of leguminous crops to Increase the yields from soils more or less worn out has gradually gained In favor. By the early part of the eighteenth century, clover had replaced the older bare fallow as a means of restoring fertility and It was a very common crop. At that time It was practically the only Important fertiIizer known and It received much attention and many theories were advanced about Its growth and action.

The serious outbreaks of white grubs that have occurred in northeastern Iowa during the past ten years are part of a general outbreak appearing in a number of more or less timbered areas in a belt running from Minnesota and Iowa east to New York, Connecticut and New Jersey. These grubs first appeared in unusual number in 1909, increased in severity in 1912 and reached a climax of injury in 1915. In 1918 the damage was considerably less than in the previous outbreak and it is probable that the parasites and other enemies of the grubs will reduce their numbers to a nearly normal amount by 1921 or 1924 at the latest.

Iowa farmers get from hogs, on the average, $40 out of every $100 of their gross income. Since about 10 percent of all pork products and from 25 to 35 percent of the total output of lard are exported, Iowa farmers arc interested in the foreign outlet for their pork. The price at which pork products are sold abroad has a good deal to do with the price of hogs when sold off the farm.

More than 2,000 years ago it was known that the application of farm manures to soils increased the yields of various crops. Since then the need of putting back into the land in this way some of the fertility taken out by crops has become more and more evident. It was not, however, until the middle of the last century that t much of the mystery as to why the action of manures was beneficial was cleared up by the brilliant researches of Liebig.