of The College of UNIVERSITY OF CALIFORNIA SILAGE, SILAGE CROPS and SILOS FRANCIS L. SMITH LOREN L. DAVIS CALIFORNIA AGRICULTURAL Experiment Station Extension Service CIRCULAR 411 This is a silo and so is this This circular tells how to make silage out of many forage crops and the crop by-products of the farm, and emphasizes the importance of good silage as a supplemental feed when green forage is unavailable. It lists the factors, both good and bad, that affect the ensiling process. Three types of storage are described — the tower silo, both permanent and temporary, the pit silo, and the trench silo. The costs of producing and storing both corn and alfalfa silages are also given. THE AUTHORS: Francis L. Smith is Associate Professor of Agronomy and Associate Agronomist in the Experiment Station, Davis. Loren L. Davis is Associate Agriculturist, Agricultural Extension, Davis. The tower silo is built of reinforced concrete, brick, tile, stone, steel, or wood. Its round shape withstands internal pressure better than any other type of silo. The pit silo, with its thin cement walls, costs less to build. Wall strength depends upon the surrounding earth being free of water seepage. The trench silo also is inexpensively built. Wall strength here, too, depends upon the ground being free of water seepage. A hillside location could provide natural drainage and aid in filling. and this. CONTENTS Page Silage offers certain advantages 4 Converting forage crops into silage 5 Factors affecting silage-making 6 Moisture content 6 Length of chopped sections 8 Exposure to air 8 Supplemental aids 8 Silage as a feed 10 Important silage crops 10 Forage plants 10 Other materials 15 Build silo to fit needs 15 Tower silo 16 Pit silo 19 Trench silo 21 Costs of silage production 22 SILAGE, SILAGE CROPS and SILOS Francis L. Smith Loren L. Davis Oilage is fermented forage plants. When its quality is good, it is a succulent and nutritious feed that can be used when green forage is not available. The meth- ods by which it is made were developed from a nineteenth century German proc- ess for making sour hay. The first silo in the United States was built in Maryland in 1876. There are three methods of harvesting forage plants: pasturing, haying, and silage-making. Pasturing is the least ex- pensive and most efficient method, but this is not always possible and even when it is, forage plants grow faster in the spring and early summer than normal pasturing can remove them. The next most efficient method of harvesting forage plants is haymaking, but this requires drying weather, a condition not always dependable. Ensiling, on the other hand, which can be done in periods unfavorable to the field-curing of hay, is an efficient method for the conserving and storing of green feed for use as supplemental feed when necessary. SILAGE OFFERS CERTAIN ADVANTAGES It conserves nutrients; provides emergency feed; and uses crop by-products. Converting roughages into silage has certain advantages over haymaking. One of the most important is the saving of a greater proportion of nutrients. In hay- making, some losses are caused by bleach- ing and shattering and by rain; in ensil- ing, these damages are avoided. The caro- tene content also is better preserved by ensiling than by haymaking. When coarse roughage is converted into silage the en- tire plant is made palatable, but when dried for hay the stemmy parts of many plants are not readily eaten. The feeding value of good-quality si- lage is about the same as that of an equal quantity of the same crop made into good- quality hay and is superior to poor-qual- ity hay. Palatability encourages animals to consume more roughage and, hence, to produce more milk or meat. Silage is an especially good way in which to store feed for emergency pe- riods. A number of by-products can be stored in this way. For instance, pea vines from canneries and sugar beet pulp from beet-sugar factories, which cannot be readily and profitably dried, can be preserved by ensiling. Silage requires less storage space than hay and creates no fire hazards. Still another advantage of the ensiling process is the killing of weed seed so that cattle feeding on silage do not scatter viable weed seed. [4] CONVERTING FORAGE CROPS INTO SILAGE The fermentation process in ensiling must be understood to reduce the hazards in producing and storing silage. From the time green forage is put into the silo until it becomes sour, aromatic silage, it undergoes a succession of bio- logical changes in which certain factors predominate at different times. Respiration — a continuation of one of the activities of all living tissue — is the first process. In respiration, free oxygen from the air oxidizes the carbohydrates to carbon dioxide and water and releases energy. Respiration ceases when the cells die. Enzyme activity is the second proc- ess. Certain enzymes present in the green feed begin to digest the carbohydrates and reduce them to sugars. Other enzymes reduce proteins to amino acids. Mold, yeast, and bacterial activ- ity represents the third process. When the cells die, these organisms begin to multiply and feed on the available sugars. Their activity diminishes as the oxygen supply becomes exhausted and is re- placed by carbon dioxide. This gas, which is heavier than air, settles like a blanket over the surface of the silage. In air pock- ets or around the outside where air is not excluded, these organisms continue to multiply and, if not checked, will produce poor-quality, moldy feed. The temperature of the material may rise as high as 100° F in the first two days. This is caused by the activity of various microorganisms. As the exhaustion of oxygen slows down biological activity, the temperature gradually declines. De- cline is not rapid because of the slow dis- sipation of heat in the tightly packed mass of feed. The cells collapse at death, and the whole mass settles to a surprising extent. Anaerobic bacterial activity repre- sents the fourth process. When the activ- ity of the molds and yeasts declines as the air is exhausted, certain bacteria that are able to thrive in the absence of air begin to act. The action of these anaerobic bac- teria is important in silage-making. It breaks down the sugars to alcohol, then to acids — mainly acetic acid (the acid in vinegar) and lactic acid (the acid in sour milk). As anaerobic bacterial activity continues, the acid content rises until it is sufficiently strong to kill the bacteria which produce the acid. The ensiling process is now complete. This usually requires about a month. The feed, if left untouched in the silo, will re- main unchanged indefinitely; if exposed to air, with opening of the silo, or through air pockets, the mold organisms again will become active. If the principles of fer- mentation are understood and the proc- esses of ensiling carefully followed, the hazards of producing and storing silage are greatly reduced. Corn is being chopped into silage at the barn for storage in the silo. [5] FACTORS AFFECTING SILAGE-MAKING These are moisture content; length of cut; and need of supplemental fermentation-aids. A number of factors affect silage qual- ity. Some are favorable to the making of good silage, others are detrimental. Moisture Content One of the most important factors to consider in silage-making is moisture con- tent. Forage plants used for silage should be harvested at the same stage of matu- rity that produces the best quality of hay. The best moisture content for success- ful silage production is between 60 and 70 per cent. Any great variation either above or below this average may be detri- mental to silage. Corn is at its best when the kernels are beginning to harden and the lower leaves of the plant are turning brown. At this time the moisture content of the whole plant is between 65 and 70 per cent. Corn Corn that is this near the upper limits of mois- ture content will make good silage. at this stage can be ensiled without any unusual precautions. The moisture content of alfalfa or pas- ture clippings at prime condition is 80 per cent or even higher. To ensile such material properly, it is advisable to re- move some of the water by allowing the forage to wilt, either in the swath or the windrow, before putting it into the silo. Forage too moist. If feed to be en- siled is stored too wet, bacterial action will produce organic acids, such as bu- tyric — present in sour butter — which make the silage unpalatable. The break- down of the mass of green material also is greater if the moisture content is too high. This produces large quantities of water that cause the silage to become soggy and often unfit for feed. The water seeping downward through the silage makes the bottom part especially poor. Even though bottom drainage of the silo is provided there will be a considerable loss of soluble materials that drain out with the water. In general, forage with a high moisture content makes a sour silage. A corrective measure is to mix with the silage 5 to 20 per cent dry straw or hay. The acids in solution of excessively wet silage cause deterioration in the walls of the silo. Research at Beltsville, Maryland, dis- closed a remarkable increase in the pres- sure on silo walls with an increase in the moisture content of the silage. This is shown in graph 1. In a silo 12 feet in diameter the pressure on the walls at a 30-foot depth was 180 pounds per square foot for silage at 64 per cent moisture. In a silo of the same dimensions, silage at 70 per cent moisture exerted 260 pounds pressure; at 74 per cent moisture, 360 pounds pressure ; and at 78 per cent, 580 pounds pressure. [6] Forage too dry. Forage that is too low in moisture content will also produce poor-quality silage. It does not pack well. Air pockets are trapped and around these the silage becomes moldy. Low moisture content can sometimes be corrected by adding water. Corn that is too dry to make good silage can be improved by adding water during the silo-filling process. Test for moisture content. Moisture content can be determined by a number of methods, but the cheapest and most direct is the oven method. This method utilizes heat to drive off the moisture from the plant matter. While the method is rela- tively slow, it does have the advantage of using equipment usually available on any farm. The time required to complete a test will vary with the moisture content, but usually will be less than an hour. Required equipment: Ordinary kitchen scales with capacity for weighing 25 pounds. Ordinary kitchen oven, preferably ther- mostatically controlled. Wide, shallow, metal containers to hold samples. Procedure: 1. Preheat oven to 275° F. 2. Weigh metal container. 3. Spread cut forage in thin layer in container. 4. Weigh container and forage. 5. Subtract weight of container to ob- tain green weight of forage sample. 6. Place container and sample in pre- heated oven. If oven has no vent, leave door slightly open. 7. When plant material appears to be dry, weigh and return it to oven. Repeat at 5- or 10-minute intervals until weight remains constant. Record final weight of dry forage and pan. 8. Subtract weight of the container to obtain dry weight of forage. 9. Obtain water content of sample by subtracting dry weight from green weight. 10. Moisture per cent is weight of water lost (no. 9 above) divided by the green weight of forage (no. 5 above). 600 500 o 400 2 300 200 100 4Er 70^££ ^A^ 10 25 30 35 15 20 Depth of silo (feet) Graph 1. Grass-silage pressure on walls of a 12-foot silo at different moisture contents. [7] 40 These specimens of corn are ready for the silo. They represent approximately Length of Chopped Sections The length of the cut sections has an important bearing on the packing of the ensilage and, hence, the quality of the si- lage. The most efficient length varies with the crop that is being ensiled. Silage made of corn and sorghum is cut into sections % inch to 1% inches long. Grass and legume silage material is cut into short sections, and the drier the crop the finer it should be cut. United States Department of Agriculture scientists at Beltsville recommend that at 75 per cent moisture, the feed should be cut into pieces %- to %-inch long; at less than 70 per cent moisture, y± to % inch long. Wilted grass silage material should be finely cut — not exceeding *4 inch — for several reasons: to pack tighter, to get more feed into a given space, and to re- duce air spaces. The average length of fine-stemmed material is longer than % inch. This is the result of many stems going through the chopper parallel with the cutter blades. This occurs less often with a field chopper than a stationary chopper; there- fore, the cuts may be slightly longer on the field chopper. With either type the knives should be kept sharp. Dull knives tend to shred the material. Exposure to Air Spoilage sets in the moment silage is exposed to air. Therefore, after a silo is opened for use, feed should be removed daily. Even a two-day interval between the removal of feed gives molds oppor- tunity to develop. As a result, both feed- ing value and palatability deteriorate. In an opened silo, at moderate temperatures, about 3 to 4 inches of the surface should be removed daily to prevent spoilage. Supplemental Aids Carbohydrates. Corn, abundant in fermentable sugars that assure preserva- tion, is ideal for silage production. The organic acids are produced by fermenta- tion of sugars that were formed by the breakdown of starches. In corn, the grains are high in starches, sugars, and other carbohydrates. Cut at the proper stage, it will make good silage unaided. Legumes, however, such as clover, al- falfa, soybean, et cetera, contain lower percentages of fermentable sugars than either corn or sorghum. In the absence of the acetic- and lactic-acid formation, other reactions take place between bac- teria and the media from which butyric and other objectionable acids are formed. These make undesirable silage. [8] the smallest and the largest sizes that corn should be chopped for silage. A solution to the problem is to add a relatively cheap feed, high in carbohy- drates, and let the natural forces break the carbohydrates down to acids. Black- strap molasses is often used for this pur- pose. It is high in fermentable sugars that are readily attacked by the bacteria to form the preserving lactic and acetic acids. The amount needed depends on the material. Usually 40 to 100 pounds of molasses are used per ton of silage. The higher rates are used if the silage is made of immature grass and legume plants. Legume silage made with molasses does not need further treatment before feeding. Ground corn, barley, and wheat, all rich in carbohydrates, also are used as adjust- ments. Inorganic acids. Since the acids pro- duced during anaerobic fermentation are responsible for preserving forage, a num- ber of more or less futile attempts have been made to supply acids artificially as the silo is being filled. The sources of inorganic acids are sul- furic and hydrochloric. Some workers have tried phosphoric acid, believing that its addition would correct the known phosphorus deficiency in silage. However, addition of acids to silage leads to a num- ber of other problems. One is the difficulty of adding the acid in uniform amounts while filling the silo. Another is the very sour condition in which the silage is pre- served, without fermentation, causing an unnatural odor. To counteract the acidity and make the silage palatable to stock, considerable lime must be added. A further objection to the use of in- organic acids is their destruction to the masonry of the silo. Organic acids, natu- rally produced, cause less injury to ma- sonry. Not only have inorganic acids added in silage-making generally proved unsatisfactory, but they also have in- creased expense ; therefore, they have not been used extensively. Urea. This substance is high in nitro- gen — about 46 per cent. It has been used as a protein supplement in concentrate feeds. Experiments in Mississippi indi- cate that urea considerably improves the feeding value of sorghum silage when added at the rate of 10 pounds per ton, which is equivalent to about one pound of cottonseed meal concentrate in a daily ration of 35 pounds of silage. The pres- ence of urea did not materially affect the fermentation of the silage. Its use to for- tify the protein content of silage will de- pend on its relative cost and the cost of protein-rich feeds. [9] SILAGE AS A FEED Its nutritional value is almost 50 per cent that of good hay. Feeding experiments on fattening cattle and lambs indicate that the nutritional value of good silage is nearly 50 per cent that of hay. Added to the feed of dairy cows, at a time when hay and grain ration is poor, it increases milk production. Good silage, properly fed, does not injure the quality or odor of milk, although si- lage fed too near milking time may cause a slight odor or taste to milk. Silage made with corn and sorghum is widely used for both dairy and beef cattle. It is more palatable than corn fodder and is therefore eaten more readily. Its slightly laxative effect often is an advantage where legume hay is not included in the ration. Moldy silage should not be used. It is especially harmful to sheep in causing digestive disturbances. IMPORTANT SILAGE CROPS These include cereals, alfalfa, soybeans, cowpeas, pea vines, sunflowers, and Sudangrass. Potatoes and almond hulls also are discussed. Any forage crop that is palatable when grazed or when fed green or as dry hay will also make palatable silage; and any crop that is unpalatable in the green stage or as hay will make unpalatable silage. These forage crops include cereals, al- falfa, soybeans, cowpeas, pea vines, sun- flowers, Sudangrass, and other plants. The crops ensiled most often in California are discussed in the following paragraphs. Certain materials other than forage plants can be ensiled. These materials in- clude potatoes and almond hulls, both of which are discussed in this section. Forage Plants Under favorable drying conditions hay ordinarily is produced more economically than silage. Grass silage is a term used to designate silage made of grasses and legumes that ordinarily are considered hay crops. There are times when satisfac- tory drying is not possible. Then good silage probably can be made, and good silage is better feed than poor hay. Many conditions on the farm may make ensiling a more practical method of han- dling a crop than haying. The first cut- ting of weedy alfalfa may be chopped and ensiled to make palatable feed. Dry, hard, and piercing beards of many grasses in hay are dangerous to animals, but by the process of ensiling they become soft and harmless. Also, the curing of clippings for hay on a permanent pasture may not be convenient. For instance, an operator may want to clear the ground immediately for irrigation. Under these conditions the wilted forage could be ensiled profitably. Weather is another condition to con- sider. Occasionally the oats-vetch winter growth comes into the hay-harvesting stage in weather that will not permit proper drying. If a silo is available at the time, the forage can be made into palat- able silage instead of being wasted or made into inferior hay. This is true in making forage-grass and legume silage. In making grass silage certain princi- ples should be kept in mind. First, the quality of the silage is best when the plants are cut at a stage that makes the best hay. Second, green forage as it is cut may contain as much as 85 per cent mois- ture. To ensile this material, part of the moisture should be removed. This is done [10] by allowing the cut forage to dry in the swath or windrow until it is wilted. When its moisture is reduced to 60 to 70 per cent it can be ensiled. In satisfactory dry- ing weather, two hours are sufficient time for drying. In poor drying weather, longer periods are required. The greater cost involved in making silage instead of hay is in transportation of the wilted material from the field to the silo and in chopping it in the silage cutter. A farmer hauling wilted silages moves 60 to 70 pounds of water per 100 pounds of feed. In handling hay he moves only 10 to 20 pounds of water per 100 pounds of feed. Loosely packed silage spoils. Forage material therefore should be firmly tramped and the -sunken places leveled out during the settling. The feeding value and palatability of grass and grass-legume silages made of immature plants may be improved by adding molasses at the rate of 40 to 80 pounds per ton of silage. If the silage is mostly grass the 40-pound rate should be used. The amount of molasses should be increased in proportion to the amount of legumes in the ensiled material. Corn. This widely grown crop pro- duces good forage yields that are utilized most efficiently as silage. The yields are generally estimated at five to seven times the yield of shelled corn. In 1950 at Davis, 15 hybrid varieties were tested for both green weight and grain yields in the same field. The range of the ratio of dry grain yield to total green weight was 1:4.4 to 1 :7.0, with an average of 1 :5.4. The ratio was wider on the late varieties, narrower on the early ones. In general, if the corn crop is intended for silage, choose a variety maturing 10 days to two weeks later than a variety grown for grain. The maturity dates of the new hybrid corn varieties are more precise than those of the old, open-polli- nated varieties. The best variety for any locality is the latest to mature to the silage stage in the available growing season. In the silage test mentioned above, all 15 varieties were planted on April 19. Corn is being chopped into silage in the field and blown into the truck for transporting to the silo. [ii] Their silking dates ranged from 75 to 90 days after seeding, with the average 83 days. Each variety was harvested 40 days after silking. At that time each variety was in its best condition for silage. There was a high, positive correlation between the number of days to silking and yield, the earliest yielding the least and the latest the most. Green weight yields per acre ranged from 13 to 19 tons, with an average of about 16 tons. The re- lationship between maturity dates and yield was so close that 0.4 ton of green matter per acre was added per day. In these tests, therefore, a difference of one week in silking increased the production by 2.8 tons of green forage. In the same test the weight of husked ears was recorded. The ear weights were about one third of the total weight for all varieties. In total digestible nutrients, however, the ears contributed more than half the total. In a plant-spacing and fertilizer-appli- cation test for grain corn at Davis, the most efficient plant spacing was 9 inches apart in 40-inch rows. The other spacings used were 6, 12, and 15 inches. The spacings of plants in the row for silage probably should be 9 to 12 inches, or even farther apart on poorer soils. Many of the fertile river-bottom lands would be expected to yield more silage at spacings of 8 to 10 inches. The planting rates for silage should be regulated to produce as many plants as possible with good ears. The most efficient fertilizer application for grain yields was 100 pounds of nitro- gen per acre. This is equivalent to 500 pounds of ammonium sulfate with 20 per cent nitrogen. The rate can be calculated easily for any nitrogenous fertilizer if the per cent of nitrogen is known. Greater yields were made with higher rates of ni- trogen, but the increases were not profit- able. Since ear weight is also an important factor in silage, the same principles apply. Corn is a prodigious user of nitrogen. Even on soils producing heavy yields, an application of 50 to 100 pounds of nitro- gen may be beneficial if enough irrigation water is available. Corn should be cut for silage when most of the grains are dented and three fourths of them are past the soft-dough stage. In the Sacramento Valley this is about 40 days after silking. In the cooler coastal regions this period will be longer. At this time the lower leaves may be turn- ing brown. The moisture content is 65 to 70 per cent. If a long harvest period is expected, it is best to begin harvest a little earlier. If cut too soon, the corn will be too high in moisture, and the silage will become sour and soggy and will require drainage. If cut too late, the forage will be difficult to pack solidly enough in the silo to prevent mold. When corn is ensiled too dry, add water to aid in packing, but even then, silage made from ripe corn lacks aroma and palatability. Sorghum. In the United States, as a whole, sorghum is second in importance to corn for silage. Sorghum is dangerous to graze after a drought or frost because of the presence of prussic acid. But sor- ghum made into silage is free of this poison. Sorghum is usually cut for silage when the seeds are hard. It may be cut earlier, however, with little loss in feeding value if it is allowed to wilt before ensiling. At younger stages, the water content is more than 80 per cent, which is too high for successful ensiling. The grain content of sorghum is lower than that of corn, because the ratio of grain to total weight is less. Generally, sorghum silage is no more acid than corn silage. In case of drought, sorghum often is cut before heading. Under these conditions, the si- lage is more acid than corn silage unless the plants are allowed to lose some of their moisture before ensiling. In California, sorghum varieties are sometimes used for silage because of their drought resistance and their efficient use of small amounts of water. The sorgo va- rieties are most commonly used. These [12] _::-■: These sugar beet tops are stacked for silage. A stack of this type will have a considerable amount of spoilage on sides and top. sorghums with sweet, juicy stalks are high in grain yield. In sorghum silage there is some loss of grain passing through the animal undi- gested. Grain loss in hard-seeded Kafir has been found to range from one third to as high as one half. Feeding value of sor- ghum is utilized more efficiently as silage than as dried stover. The feeding value of sweet sorghum or cane sorghum is less than that of the Kafirs, but in many areas the difference in yield more than balances the nutritional deficiency. Sorghum silage is often stored in trench silos for feed in dry years. Sugar beet pulp and tops. These two by-products of the beet-sugar indus- try furnish feed for cattle and sheep. Pulp is often ensiled at the factory and fed out either by the refining company or by neighboring farmers. After fermentation it is also dried and sold for feed. Sugar beet pulp has a water content of about 90 per cent, considerably higher than the optimum required for silage. This probably accounts for the strong odor of beet pulp silage, but in spite of this, it is a palatable feed, used extensively to fatten steers and lambs. Feeding lots are near the beet-sugar factory to eliminate costs of long-distance hauling. In beet pulp silage the losses from breakdown of the nutrients to acids con- tinue longer than in silage with a lower moisture content. The total digestible nu- trient content is about half that of good corn silage ; therefore it is very important to supplement beet pulp silage with con- centrate feeds. Sugar beet tops can also be ensiled, and their use as silage will probably be in- creased by recently developed harvesting machinery that mechanically separates the tops from the beets. The tops are esti- mated to be about one tenth of the beet yield on the dry basis. The state average yield of beets was 15 tons per acre for the period 1936-45. This is the equivalent of 1.5 tons of dry beet tops or 5 tons of fresh beet tops at 70 per cent moisture. Ensiled sugar beet tops have a number of advantages over tops that are pastured in the field or are air-dried. The losses from tramping under are greatly reduced. [13] The feeding quality of silage is preserved through all kinds of weather, while in the field it deteriorates rapidly with winter rains. The silage process softens the beet crowns and reduces the danger to live- stock from choking. There are two drawbacks to the use of sugar beet tops as silage. A serious prob- lem is the dirt clinging to the crowns. Not only does dirt reduce the quality of the silage, but it may cause mud to pack in the animals' stomachs. The second prob- lem is the high oxalic acid content of the leaves — a chemical uniting with calcium to form insoluble calcium oxalate crystals. Ensiling reduces oxalic acid somewhat, but to counteract it, excessive amounts of calcium, either as lime or ground oyster shells, are given to animals feeding on this kind of silage. The tops are usually ensiled in trench silos or in stacks. For correct ensiling, the leaves should be allowed to wilt to reduce the moisture to 70 per cent or lower. The general practice is not to chop them into short sections. If not chopped, beet top silage after curing will have to be removed with the aid of a hay knife or some other cutting tool. The average production of beet tops is 5 to 6 tons of green weight per acre., of which 40 per cent is in the crowns and 60 per cent in the leaves. Pea vines and lima bean vines. The recent development of quick-freezing of peas and beans in the green stage has increased interest in using the by-prod- ucts — the vines and empty pods. The moisture content of the green material as it comes from the viners is high — about 87 per cent — higher than generally con- sidered good for satisfactory ensiling. Drying the material before ensiling, how- ever, is impractical. These by-products of the canner or freezer are considered to be too cheap a feed to justify much expense in handling or transportation. The high moisture content can be re- duced by adding straw, but this is not usually done. There will be leakage from the stacks of silage. The spoilage in the stack will extend from the outside to a distance of 8 to 10 inches on the sides and 16 to 20 inches on the top. To aid in shed- ding water, the stack may be domed in the center as it is being built so that it will be well rounded when it is complete. Pea vine silage can be made in trench or tower silos but usually is not. In tower silos, extra costs would be involved in cut- ting the vines into sections short enough to be blown into the silo. Because the ma- terial is high in moisture, great pressure develops in the lower part of the silo — enough to burst the walls of some silos. Losses are lessened if the sides are pro- tected from air. Great care must be taken to provide drainage for the leaking juices. Molasses added will make the silage more nutritious and palatable. Pea vine silage is usually made by stacking the vines, as they come from the viner, in straight-sided stacks 20 to 30 feet wide and at least 20 feet high. The high stacks require less artificial packing. Since the vines are not chopped, they should be distributed evenly to prevent the formation of air pockets. Silage made of pea vines is eaten read- ily by animals. Feeding results generally have been good. Experience with lima bean silage has not been as extensive as with pea vine si- lage. Results from feeding the silage have not been uniform. In some instances the animals did not eat enough to make gains, while in others there seemed to be no dif- ficulty. This difference is probably due to variations in methods of handling. Sunflowers. In the northern and west- ern states, where the growing season is short or cool, sunflower silage is used. In areas in this state, where the altitude is high and the growing season short, sun- flowers may find a place as a silage crop, but sunflower silage is a poor substitute in areas where corn can be grown. It is less palatable than mature-corn silage, with only about two thirds of the feeding value, but its feeding value is favorable when compared with silage made from [14] immature corn. Its feeding value for cattle is about the same as that of oats and vetch silage, but for sheep it is inferior. Sunflower silage is reputed to be some- what constipating. The crop is cut when one half to two thirds of the heads are in bloom. If cut too early the silage is watery and leaks badly. If cut too late the heavy stalks are too difficult to pack. The older plants are decidedly less palatable than the younger. The planting rate recommended for sunflower forage is about 10 to 15 pounds of seed per acre, sown in 30-inch rows with the plants 10 inches apart in the row. Close planting keeps the plants from be- coming too large and woody. Other Materials Potatoes. Occasionally, surplus or cull potatoes are available for stock feed. The feeding value of potatoes stored as silage does not deteriorate as it does under ordinary storage conditions. Raw tubers can be ensiled. However, potatoes contain 78 to 80 per cent moisture and cannot be ensiled alone. To take up the excess mois- ture, dry forage is mixed with the pota- toes, in the ratio of 20 to 25 pounds per 100 pounds of potatoes. The potatoes and the dry feed can be run through the en- silage cutter together for mixing. Two per cent ground corn added will furnish the inoculum of the acid-forming bac- teria needed to produce good silage. Potatoes can also be added to corn or sorghum silage. Under these conditions, the potatoes are added at the rate of 500 pounds per ton of silage. Whole potatoes do not ensile satisfactorily and sprouted or frozen potatoes should not be used. Potato silage must be packed thor- oughly. Trench silos with sloping walls are better than silos with perpendicular walls. As the silage settles in the trench silo, it slides against the walls. In the up- right silo it settles away from the walls near the top, and its excessive weight in- creases the pressure on the walls at the bottom. Adequate drainage should be pro- vided at the bottom of the silo. Almond hulls. Hulls from the almond crop have received some attention as a source of feed for both cattle and sheep. If fed dry, the hulls should be ground. To keep ground hulls from spoiling, the mois- ture content must be about 12 per cent. The moisture content ranges from 10 to 45 per cent when they come from the huller. The expense of drying and grinding may be avoided by dumping the hulls into a trench silo and adding water. The hulls are rich in carbohydrates that form the organic acids needed to preserve si- lage. The experience gained in trials in- dicates that good silage can be made if enough water is added at the time of en- siling to bring the moisture content up to about 65 per cent. BUILD SILO TO FIT NEEDS Size depends upon number of stock to be fed daily. Graphs and tables will help to determine size. The making and feeding of silage de- pend very largely on a farmer's individ- ual problems. Therefore, the silo should be built accordingly. Its type of construc- tion is important. It should be built of material that for him is the cheapest and most efficient, and to a size that fits his needs. Its location on the farm is de- pendent upon two factors: 1) it must be near to the feeding lots because silage is a type of feed that must be consumed soon after it is exposed to air; and 2) it must be near to the fields where the crop is grown, because its bulkiness demands hauling and long hauls are expensive. The most important requirement of any good silo, regardless of its shape, is exclu- sion of air. Its sides must therefore be 15] made as smooth as possible to prevent the formation of air pockets. Where silage is stacked rather than packed in a walled container, the spoilage around the sides ranges from 4 to 20 inches. Feed under these conditions is sacrified for lack of space or of time in which to build the silo so that it will exclude air. The part of any silo most vulnerable to spoilage is the top. Unless air is excluded, the top may be spoiled to a considerable depth. There are a number of ways in which to minimize this loss. Having the last few loads of ensiling material wetter than the average will aid in packing down the material in the silo. The top should be trampled before and during settling, with straw or hay finally placed as a cover. In some silos, espe- cially the trench type, the whole mass can be covered with a layer of dirt several inches thick. The use of dirt as a cover, however, is sometimes objectionable be- cause it is difficult to remove. Oats often are sown on top of the silo to help water- proof it. Paper and plastic covers also are used to waterproof and to exclude air. This circular does not pretend to give detailed instruction on the building of silos. Such information is given in United States Department of Agriculture Farm- ers' Bulletin 1820, entitled "Silos, Types, and Construction." The three general types of silos are tower or upright, pit, and trench. Each type offers advantages and disadvantages. Tower Silo Permanent construction. The tower silo is a cylinder built aboveground. Its round shape withstands internal pressure better than any other type. Diameters vary from 7 to 20 feet. Height should be at least twice but not more than three and one-half times the diameter. Many ma- terials are used for construction; among these are reinforced concrete, brick, tile, stone, steel, and wood. The tower silo is a •2 500 a 300 15 20 Depth of silo (feet) Graph 2. Grass-silage pressure on walls of different-sized silos at 70 per cent moisture. [16] permanent farm structure and, as such, should be constructed to stand long usage. There are several essentials to good tower-silo construction. With a consider- able part of it aboveground it should be strong enough to withstand the hazards of wind and other elements from the outside as well as pressure of the green feed from the inside. The pressure of silage on the walls varies directly with the diameter of the silo and the depth of the silage. The rela- tionship of depth and diameter to wall pressure is shown in graph 2. A large and deep silo must necessarily have very strong walls. Its foundation must be built to stand up on the soil type of the site. The walls need to be plumb — straight and 66 62 58 54 50 8 46 42 S 38 34 30 26 22 18 // ■S-> M . *i 10 30 15 20 25 Depth of ensilage (feet) Graph 3. Effect of depth of ensilage on its density (pounds per cubic foot). [17] 35 40 smooth, with well-made, airtight openings for removing the feed. The ladder rungs must be conveniently spaced and firmly placed. Some authorities think that well- made silage does not require drainage, but serious losses can be avoided by pro- viding ample drainage from the silo. The capacity of a silo is increased by depth. Unpacked silage weighs about 18 pounds per cubic foot. But in the bottom of a 40-foot silo, as shown in graph 3, a cubic foot of silage weighs 67 pounds. Therefore, one tall silo will hold con- siderably more feed than two short silos of the same cubic capacity. The size of the silo is determined by the number of stock to be fed daily. The capacities of silos with various diameters and heights are shown in graph 4. In table 1 are given the volume, amount of feed that must be removed daily, and number of animals that can be fed daily with ra- tions of 40, 30, 20, and 10 pounds per day. This table can be consulted to de- termine the size of silo to be built to feed any number of animals. Typical daily silage rations for differ- ent animals are : Cows, 900-1,200 pounds weight 30-50 pounds Yearling cattle 15-24 pounds Fattening cattle 25-30 pounds per 1,000 pounds live weight Sheep 2-3 pounds If a farmer plans to feed 30 head of dairy cattle at the minimum rate of 3 inches of silage per day, a silo of 12-foot diameter will be required. This will sup- ply a daily ration of 40 pounds per cow. 50 293 \ f7\ 48 f 220 1 279 344 46 209 265 327 44 |Oj 198 251 310 42 144 188 237 293 40 ( 10 ° 1 135 177 224 276 38 93 126 165 209 258 1 36 86 117 153 194 : 34 (*^ 80 109 142 180 a. & 32 51 74 100 131 30 47 68 92 121 28 43 61 84 26 38 55 24 34 49 22 30 20 27 12 ft. 18 ft. 14 ft 16 ft Diameter of silos Graph 4. Capacity in tons of settled silage in silos of varying sizes. 20 ft. [18] Table 1. Relation of Herd Size to Diameter of Silo, Based on 40 Pounds of Silage per Cubic Foot and the Removal of 3 Inches of Silage Daily to Avoid Spoilage Inside diameter Volume per foot of depth 3 inches daily Number of animals that may be fed with a daily ration in pounds per head of silo 40 pounds (number) 20 30 pounds 20 pounds 10 pounds (feet) 10 (cubic feet) 78.5 (pounds) 785 (number) 26 (number) 39 (number) 79 12 113.1 1,131 28 38 57 113 14 153.9 1,539 38 51 77 154 16 201.0 2,010 50 67 100 201 18 254.5 2,545 64 85 128 255 20 314.2 3,142 79 105 158 314 The capacity of a 12-foot silo, 36 feet high, is 86 tons. A silo of this size would provide 1,200 pounds of feed daily for 143 days. If the expected feeding period is shorter, a smaller silo could be built, and silage fed out faster than at the minimum rate of 3 inches per day. Table 1 can be used to determine the minimum rate of feeding from a given silo size. By estimating the number of feeding days, the number of animals, and the daily rations necessary, the correct silo size for individual conditions can be esti- mated. It is often easier and more eco- nomical to build two or more silos if there is a considerable amount of feeding to be done. A silo of 20-foot diameter covers a broad, unwieldy working area that in- creases the labor of digging the material out for feeding. Two smaller silos would probably be easier to operate. Temporary construction. If ensiling is not a yearly enterprise, perhaps some cheaper type of construction for tempo- rary or emergency storage could be used. Upright silos can be constructed of poles, wooden staves, or snow fences, erected in circular form, and lined with tar paper. Because of the relatively weaker walls of temporary structures the height should not be more than twice the diameter. The losses may be greater in a tempo- rary structure, but if it is really airtight, it is just as efficient as a permanent struc- ture. Generally, the greater losses around the periphery of a temporary structure come from the difficulty of making it air- tight. Pit Silo As the name implies, the pit silo is underground. It is cylindrical, with sizes and capacities the same as those for tower silos. Pit silos are used extensively in semiarid climates, where seepage of the soil moisture is not likely to be a problem. In digging the pit, special care must be taken to keep the walls plumb and smooth. Walls should extend 4 or 5 feet above- ground to protect people and livestock from falling in. The cost of construction of a pit silo is less than for the upright type because the walls are lined with only a thin layer of cement. The strength of the walls depends on the surrounding earth. Not only is the pit silo cheaper to build, but, if constructed properly, it preserves silage just as satisfactorily as the tower silo. One objection is danger of water seepage from the surrounding soil in un- seasonably wet weather. There must be adequate air drainage in deep silos, or pit silos, where a dangerous concentration of carbon dioxide gas can collect from respiration of the green forage. This gas, which is heavier than [19] A temporary tower silo can be made of snow fence and fiber tar paper. In this structure the lower section overlaps the upper by about four inches. air, concentrates in the silo at the surface of the silage. A wise precaution is to lower a lighted lantern into the silo and if it goes out, assume that the pit is dangerous to enter. Then replenish the silo with fresh air before entering. The hard work found in using a pit silo is in elevating the feed to the surface. In spite of the fact that a number of elevator devices can be adapted to make feeding easier, pit silos are not popular in Cali- fornia because of this problem. The bulldozer attachment on this tractor will spread and pack the chopped corn, dumped from a truck, in the trench silo. The design of this trench silo could be improved if the sides were smoother and more sloping. Natural drainage was provided for by constructing the trench on a hillside. [20] Trench Silo Like the pit silo, the trench silo can be used only in areas of good drainage, where soil moisture from the outside is not a problem. The walls may or may not be lined, but for the making of good silage they should be smooth. The dirt removed from the trench is piled at the sides. This builds up the sides and reduces the amount of earth to be excavated. The sides of the trench usually slope outward at the rate of 3, 4, or 5 inches per foot of depth. This increases the volume of the silo and makes a more solid pack when the silage settles. Where topography permits, the trench silo can be located on the side of a hill. This will lessen the difficulties of filling the silo and provide natural drainage. The feed can be packed by a tractor with a bulldozer attachment in front. This keeps the pile level and makes the material easier to pack firmly. The danger of ac- cumulated carbon dioxide gas in this type of silo is reduced to a minimum. Good drainage is especially essential in a trench silo, not only to preserve the feed but also to aid in the emptying. If the only approach to the open end of the silo is so muddy that equipment cannot be used, efficient feeding is almost impossible. Al- lowing some slope from the head end to the open end of the silo will provide drain- age of the silo and the approach. The size of the trench silo depends, like that of other types of silos, on the number of animals to be fed, the probable length of the feeding period, and the amount of feed available. Silage in a trench silo is removed from the end and not from the top. The minimum rate of silage removal in a trench silo is 4 inches. Because the trench silo is not as deep as other types of silos, the silage is not packed as tightly; Table 2. Relation of Size of Herd to Dimensions of Trench Silos of Different Sizes and Slopes on the Basis of 35 Pounds of Silage per Cubic Foot and the Removal of 4 Inches of Silage Daily to Avoid Spoilage Side slope Depth Width Cross- sectional area Weight of silage Animals that can be fed with a daily allowance per head of: per foot Per linear foot Per 4 inches of depth Bottom Top 40 lbs. 30 lbs. 20 lbs. 10 lbs. (inch) (feet) (feet) (feet) (inch) (sq. ft.) (pounds) (pounds) (number) (number) (number) (number) 3 6 6 9 45 1575 525 13 17 26 53 4 6 7 11 54 1890 630 16 21 32 63 5 6 8 8 13 63 2205 2240 735 747 18 19 24 25 37 37 74 3 6 10 64 75 4 8 7 12 4 77 2695 898 22 30 45 90 5 8 10 8 6 14 11 8 91 3185 2975 1062 992 27 25 35 33 53 50 106 3 85 99 4 10 8 14 8 113 3955 1318 33 44 66 132 5 10 12 10 10 18 16 8 143 156 5005 5460 1668 1820 42 45 55 61 83 91 167 3 182 4 12 12 20 192 6720 2240 56 75 112 224 5 12 14 26 240 8400 2800 70 93 140 280 [21] therefore, artificial packing at the time of filling is important in order to avoid air pockets. Table 2 gives the capacities of several different sizes of trench silos. For ex- ample, a silo 6 feet deep, 6 feet wide at the bottom, and 9 feet wide at the top will contain 1,575 pounds of silage per linear foot. Therefore, for a 60-day feeding period for 13 cows the silo should be 20 feet long, and for a 120-day feeding period, 40 feet long. With a silo 10 feet deep, 10 feet wide at the bottom, and 18 feet 4 inches at the top, each linear foot of silo would contain 4,970 pounds of silage, or enough to feed 42 cows a daily ration of 40 pounds at the minimum feed- ing rate of 4 inches per day. If the size of the herd and the probable length of the feeding period are known, table 2 can be used to estimate the size of the trench silo needed. Increasing the capacity by extending the length of the trench is probably more practical than in- creasing the size of the cross section. The feeding rate then surpasses the minimum silage removal requirement to avoid spoil- age, and lessens the amount of trimming that would be necessary at the edges of the exposed end of the silo. COSTS OF SILAGE PRODUCTION Tables show costs of producing and storing corn and alfalfa silages. Since silage crops are grown under many different conditions of soil, climate, and operating conditions, the cost fig- ures* given here are examples only. The data presented are representative of Cali- fornia conditions, and the costs are those which should be achieved with good man- agement practices. Local variations, such as cost of irrigation water, type of equip- ment available, and yields obtained, will result in variations in costs between areas and between farms. Preharvest costs will be the same whether the crop is harvested for silage, for grain, or for hay. Therefore, the har- vesting costs and the quantity and quality of the feed obtained are the determining factors in deciding whether or not to ensile a given crop. Silage harvesting re- quires rather expensive machinery, which makes a high overhead of depreciation, interest on investment, and to some extent repairs. This results in a high cost of har- * This section was prepared by A. D. Reed, Extension Economist and Associate on the Gian- nini Foundation, University of California, Berke- ley; R. C. Geiberger, Farm Advisor, Sacramento County; and B. W. Ramsaur, Jr., Farm Advisor, Sutter County. vesting, if the machinery is not used to its full capacity. Many owners of silage- harvesting equipment, who have only small acreages of their own, may need to do outside work to make efficient use of the equipment, unless the importance of getting the work done easily and on time overweighs the higher harvesting cost. Cost figures given in tables 3, 4, and 6 cover average conditions. Excessive weed control before planting or wind storms that knock the crop down before harvest naturally would increase the costs. On the other hand, ideal conditions would result in lower costs than those shown here. With overhead making up most of the expense in the operation of field chop- pers, to change the annual hours of use materially affects the total cost per hour. Depreciation is the major item of expense and will be high whether the machine lasts ten or fifteen years. Table 5 shows costs of operating the field chopper. Harvesting costs for hay have been found to be about $9.25 per acre for a one-ton yield, or $18.37 per ton total cost. Alfalfa silage at $6.98 per ton is equiva- lent in feeding value to alfalfa hay at [22] Table 3. Cultural Costs of Producing Corn Silage (Yield of 20 tons per acre) Operation Cost per acre* Labor Tractor Equipment Material $.... 2.00 1.76 12.50 8.00 Total Land preparation : plow, disk, etc. Man, tractor, and equipment — 2.0 hours $2.00 .20 1.00 .25 2.00 4.00 $4.00 .40 .25 2.00 $ .25 .05 .30 .20 $6.25 .65 3.00 15.06 4.20 12.00 Check Man, tractor, and ridger — 0.2 hours Pre-irrigate Man — 1 hour ; water — 0.5 acre feet Plant and fertilize Man, tractor, 4-row planter — \i hour Seed — 8 pounds at 22c per pound . Nitrogen — 100 pounds at 12.5c per pound Cultivate and furrow Man, tractor, and equipment — 2 hours Irrigate four times Man — 4 hours ; water — 2.0 Total $9.45 $6.65 $ .80 $ 24.26 $41.16 Miscellaneous expense : Interest on land, $400 at I > per cent . JtC. . $20.00 4.00 2.00 $ 26.00 $ 67.16 Taxes on land Insurance, office, phone, < Total miscellaneous . . . Total preharvest cost * Cost items: Labor — $1.00; heavy tractor — $2.00 per hour; light tractor — $1.00 per hour; truck $1.50 per hour. Tractor, truck, and equipment costs given are for all costs of operation, including depreciation and in- terest. Irrigation water cost was figured as delivered to the field. ).60 per ton. This is based on alfalfa silage having 21 per cent total digestible nutrients and alfalfa hay having 50 per cent. This gives a cost of about $1.66 per cwt of total digestible nutrients. The first cutting of alfalfa hay is frequently dam- aged by rain, with the result that it sells for only $9.00 to $12.00 per ton when good alfalfa is worth $25.00 per ton. Under those conditions, the crop is worth more as silage than as hay. The cost figures presented in table 7 do not take into consideration any differ- ences in amount of spoilage. About 15 per cent more spoilage in the trench and snow fence silos than in the upright silos would be necessary to make the costs of storage comparable. [23] Table 4. Harvest Costs for Corn Silage Harvesting with field chopper Cost per acre* Labor Tractor Equipment Material $.... Total Cut and chop Man, tractor, and chopper — 2.0 hours $2.00 4.00 4.00 $4.00 6.00 $4.94 4.00 $ 10.94 10.00 8.00 Haul Two men, two trucks — 2.0 hours . . Unload and tramp Two men and blower — 2.0 hours . Total harvest cost $ 10.00 $ 10.00 $8.94 $.... $ 28.94 Harvest cost per ton — 20-ton yield $ 1.45 Total cost per acre $ 96.10 Total cost per tonf . $ 4.80 Harvesting with binder and Cost per acre* stationary cutter Labor Tractor Equipment Material Total Bind Three men, tractor, and binder — 1.5 hours $4.50 4.50 3.00 $1.50 6.75 2.25 $1.40 1.75 $.... $7.40 Haul Three men, three trucks — 1.5 hours Chop Two men, cutter, tractor — 1.5 hours 11.25 7.00 Total harvest cost $ 12.00 $ 10.50 $3.15 $.... $ 25.65 Harvest cost per ton — 20-ton yield Total cost per acre Total cost per tonf $1.28 $92.81 $ 4.64 * Cost items: Labor — $1.00; heavy tractor — $2.00 per hour; light tractor — $1.00 per hour; truck — $1.50 per hour. Tractor, truck, and equipment costs given are for all costs of operation, including depreciation and interest. Irrigation water cost was figured as delivered to the field. t Silage at these costs of $4.64 to $4.80 per ton is equivalent in feeding value to alfalfa hay at about $13.00 per ton. This is based on the fact that total digestible nutrient content of alfalfa hay is about 50 per cent and of corn silage, about 18 per cent. This relationship gives a cost of about $1.30 per cwt of total digestible nutrient. [24] Table 5. Costs of Operating Field Chopper Overhead per year : Depreciation — $3,000 for 10 years $ 300.00 Interest— $1,500 at 5 per cent 75.00 Taxes, housing and miscellaneous — $3,000 at 1 per cent 30.00 Total overhead per year $ 405.00 Overhead per hour (200 hours) $ 2.02 Operating cost per hour : Fuel — 2 gallons at 21c per gallon $ .42 Repairs 03 $ .45 Overhead per hour $ 2.02 Total cost per hour $ 2.47 [25] Table 6. Costs of Producing Alfalfa Silage (Yield of 3 tons per acre per cutting) Operation Cost per acre* Labor Tractor Equipment Material Total Irrigating, five times Man — 5 hours ; water — 2.5 acre feet Miscellaneous upkeep Man and tractor — 1 hour $5.00 1.00 1.00 $.... $ 10.00 $ 15.00 2.00 Miscellaneous expense : Interest on land and alfalfa stand, $412.00 at 5 per cent ... $ 20.60 Depreciation on alfalfa stand, $24.00 for 4 years 6.00 Insurance, office, phone, etc 2.00 Total miscellaneous Total preharvest cost Share to each cutting — 5 cuttings . $ 28.60 $ 45.60 $ 9.12 Harvesting cost per acre per cutting Cost per acre' c Labor Tractor Equipment Material Total Mowing and windrowing Man, tractor, mower — 0.5 hours . . Chopping Man, tractor, field chopper — 1.0 hour Hauling Man, pickup, 2 trailers — 1.0 hour . Unloading Two men and blower — 1.0 hour. . . $ .50 1.00 1.00 2.00 $ .50 1.00 1.00 $ .15 2.47 .20 2.00 $.... $1.15 4.47 2.20 4.00 Total harvest cost $4.50 $2.50 $4.82 $.... $ 11.82 Harvest cost per ton — 3-ton yield $ 3.94 Total cost per acre per cutting Total cost per ton Cost per ton with 80 lbs. molasses at $2.50 cwt $ 20.94 $ 6.98 $ 8.98 * Cost items: Labor — $1.00; heavy tractor — $2.00 per hour; light tractor — $1.00 per hour; truck — $1.50 per hour. Tractor, truck, and equipment costs given are for all costs of operation, including depreciation and interest. Irrigation water cost was figured as delivered to the field. [26] Table 7. Annual Costs of Storing Silage Type of silo Total Per ton Upright ($2,000 for 150 tons) Depreciation — $2,000 for 30 years Interest — $1,000 at 5 per cent $ 66.67 50.00 20.00 $ 136.67 10.00 2.50 16.00 $ .45 .33 .13 Repairs, taxes, etc. — $2,000 at 1 per cent Total annual cost $ .91 Trench ($100 for 200 tons) Depreciation — $100 for 10 years Interest — $50 at 5 per cent .05 .01 .08 $ .14 Repairs and cleaning — man and tractor, 8 hours at $2.00 per hour Total annual cost $ 28.50 Snow fence ($75 for 100 tons) Depreciation — Fence $50 for 5 years 5.00 12.50 1.88 2.25 .05 .12 .02 .02 Paper $25 for 2 years Interest — $37.50 at 5 per cent Repairs, taxes, storage, etc. — $75 at 3 per cent Total annual cost $ 21.63 $ .21 Cooperative Extension work in Agriculture and Home Kcon co-operating. Distributed in furtherance of the Acts of Cong ■s, College of Agriculture, University of Cali of May 8, and June 30, 1914. J Earl Coke 20m-4,'52(9008)M.H. 27] THIS DOOR SWINGS OPEN TO ANSWER COUNTY FARM ADVISOR QUESTIONS Bring your farming questions to your County Farm Advisor— he's an agricultural special- ist with a background of practical experi- ence. And he's there to help you. If he can't answer your question himself, he'll find someone who will. Farm Advisors serve 52 counties in Cali- fornia, with offices in the towns listed below. Get to know yours— make use of his free service. Alameda County: Post Office Bldg., Hayward Butte County: Federal Bldg., Oroville Colusa County: Federal Bldg., Colusa Contra Costa County: Cowell Del Norte County: Post Office Bldg., Eureka El Dorado County: Post Office Bldg., Placerville Fresno County: Post Office Bldg., Fresno Glenn County: 607 5th St., Orland Humboldt County: Post Office Bldg., Eureka Imperial County: Court House, El Centro Kern County: 2610 M St., Baker sf.eld Kings County: 131 E. 8th St., Hanford Lake County: Kelseyville Lassen County: Memorial Bldg., Susanville Los Angeles County: 511 E.AIisoSt., Los Angeles 12 Madera County: Post Office Bldg., Madera Marin County: Post Office Bldg., San Rafael Mariposa County: Fairgrounds, Mariposa Mendocino County: Court House, Ukiah Merced County: County Adobe Bldg., Court House Square, Merced Modoc County: 1621 Main St., Alturas Monterey County: Court House, Salinas Napa County: Post Office Bldg., Napa Nevada County: Memorial Bldg., Grass Valley Orange County: 1 104 W. 8th St., Santa Ana Placer County: 1389 Lincoln Way, Auburn Plumas County: Court House, Quincy Riverside County: Post Office Bldg., Riverside Sacramento County: 315 Federal Bldg., Sacramento 2 San Benito County: Court House, Hollister San Bernardino County: 566 Lugo Ave., San Bernardino San Diego County: 4005 Rosecrans St., San Diego 10 San Joaquin County: 145 S. Amerkan St., Stockton 2 San Luis Obispo County: 997 Monterey St., San Luis Obispo San Mateo County: Half Moon Bay Santa Barbara County: Federal Bldg., Santa Barbara Santa Clara County: 201 Post Office Bldg., San Jose 13 Santa Cruz County: 555 Ocean St., Santa Cruz Shasta County: County Office Bldg., Redding Sierra County: Court House, Quincy Siskiyou County: Court House, Yreka Solano County: County Library Bldg., Fairfield Sonoma County: Court House, Santa Rosa Stanislaus County: Federal Bldg., Modesto Sutter County: Post Office Bldg., Yuba City Tehama County: Federal Bldg., Red Bluff Trinity County: Court House, Weaverville Tulare County: Post Office Bldg., Visalia Tuolumne County: 815 Washington St., Sonora Ventura County: 52 N. California St., Ventura Yolo County: Court House, Woodland Yuba County: Federal Bldg., Marysvillo CALIFORNIA AGRICULTURAL EXTENSION SERVICE • COLLEGE OF AGRICULTURE UNIVERSITY OF CALIFORNIA