FORAGE CROPS IN CALIFORNIA

B. A. Madsen, R. Merton Love

OF THE 7,500,000-odd acres of land in harvested crops in California, more than a fourth was cropped to hay in 1945.

It is estimated that 200,000 acres are planted to silage - and annual pasture crops and about 450,000 acres to perennial irrigated pastures. In addition, livestock are grazed in the fall on most of 2 1/4 million acres of grain stubble, bean straw, and beet tops forms of forage that equal a half ton of hay an acre and fill an important gap in the fall from the time cattle and sheep are removed from the mountain ranges until fall rains have started new growths on the lower pasture and range lands.

Alfalfa is the most important cultivated forage crop in California. It is grown in all sections where water and soil conditions permit, and is essentially an irrigated crop. The largest acreage (and the highest production) is centered in the San Joaquin and Imperial Valleys, where water, soil, and growing season are the most favorable. In 1943 a total of 945,319 acres of alfalfa was cut for hay.

Alfalfa is grown on many soil types, ranging from light sand to clay loam. The chief essential is that the soil be deep, friable, well drained, and free from excessive amounts of alkali. Practically all the good alfalfa soils are alluvial deposits of valley fills. The soils least suited to the crop, because of poor water penetration, are the heavy clay adobes and hardpan soils.

Fertilizers have been unnecessary on most of the loam soil, but in some areas (particularly the Imperial Valley, the sandy soils of the San Joaquin, and a few others) phosphorus or sulfur, or both, are necessary for maximum yields.

The yields vary with the soil and water supply and the length of the growing seasons. The average for the State is a little more than 4.5 tons an acre, but in the interior valley in the southern half of the State, where 6 to 9 cuttings are obtained for the season, 8 to 10 tons an acre is common.

The most serious problem is the short life of the stand, due mainly to three serious diseases, alfalfa wilt (Phytomonas insidiosa); alfalfa dwarf, a virus disease peculiar to some sections of California, and crown rot (Stagonospora meliloti). Alfalfa wilt and crown rot are prevalent throughout the State, and reduce the life of the stands to about 4 years. The destructive effect of both of these diseases is aggravated by the common practice of frequent irrigation and early cutting in order to obtain the maximum yield of high-quality hay. Where irrigation is less frequent or where the plants are permitted to reach a more advanced stage of growth before cutting, the course of these diseases seems to be less rapid. The alfalfa dwarf (which is caused by the same virus as causes the Pierce disease on grapes) is most prevalent in the San Joaquin Valley and in some sections of southern California. Its effect on the plants and on the life of the stand is essentially the same as that of wilt. Whether the course of the dwarf disease is influenced by irrigation or the stage of cutting has not been determined.

A breeding program has been under way for a number of years to develop a strain of California common alfalfa resistant to wilt. Considerable progress has been made, and we expect that a healthier strain will be available in a few years. Some work also has been started on the development of strains resistant to crown rot and dwarf, but no strain has been found that shows any appreciable resistance to either disease; progress has been slow. It is quite evident that the only cure for these diseases is to develop resistant strains.

Alfalfa hay as grown in California is usually quite clean and free from grasses and weeds, except for the first spring cutting, which often may be so full of weeds as to be practically worthless. Recent experiments have demonstrated that a late-winter spraying before the alfalfa starts rapid growth, with a mixture of oil and a selective weed spray, may eliminate the weedy grasses and weeds.

Because of the rainless summer weather, damage to the hay is not a problem except along the coast, where high humidity and fogs may prolong the curing process and cause bleaching. In the valleys, where most of the alfalfa is grown, the chief problem is to get the hay put up and baled before it becomes so dry that many of the leaves are lost by shattering. Most growers have mechanized and systematized their practices, however, so that this loss is greatly reduced. Generally hay of excellent quality is put up.

During the warmer periods the alfalfa is usually cut in the morning, raked into windrows in the afternoon, and baled the same night. This procedure varies with temperature, humidity, and curing rate, of course. Most of the crop is cut just before the plants begin to bloom. This produces an excellent soft leafy hay with a protein content of 18 to 20 percent, but it does tend to lower the yield and contributes to the short life of the stands.

California common, a nonhardy strain, is the principal variety grown in California. Numerous tests have shown that for most sections it is superior to other varieties and other strains of common alfalfa. Winterkilling is not a problem in California and winter-hardy strains, which go dormant during the winter, yield less as a rule than the nonhardy common.

Most of the 8.5 to 9 million pounds of seed used here is produced in the State or in Arizona. The 10-year average annual production of seed in California is 3.5 million pounds; in 1946 it was 4.5 million pounds. Yields of seed have been low in recent years, mainly because of damage by Lygus. Dusting the field with DDT just before blooming has proved effective. Experimental results indicate that seed production can be doubled by proper treatment without increasing the acreage.

Other tame hay consists mostly of cereals or cereals and legume mixtures, With a limited acreage of other annual crops. The acreage and production of other tame hay, according to 1945 census, was: Grain hay, 286,877 acres, 415,914 tons; other tame hay, 245,256 acres, 361,724 tons; clover and timothy, 39,099 acres, 69,712 tons. Besides those, 249,646 acres of oats was cut when ripe, and fed unthreshed. Locally it is considered to be hay and serves the same purpose. The principal cereal seeded for hay is oats either alone or in combination with vetch or some other winter legume. Some oat hay is grown in most counties; it has been particularly popular along the coast from Marin County south, in southern California, and in a few areas of the larger valleys.

The principal variety of oats planted for hay, when grown alone, is California Red, which is preferred for its fine, leafy stems. Rust epidemics frequently reduce the quality of the oat hay in some localities. In southern California, particularly, some farmers are replacing California Red with Ventura, a recent development that is more resistant to rust, yet possesses good hay characteristics.

Growing oats for hay is not essentially different from growing oats for grain. The main difference is in a somewhat heavier rate of seeding to increase the yield and produce a finer product.

Oats and legume mixtures, principally purple or common vetch, have been increasing in popularity as a hay crop. Oats and vetch are particularly favored in the coastal valleys where water is not available for alfalfa. Good crops of oats and vetch can be grown there without irrigation and (if the proper mixture is used) will produce a hay only slightly inferior to alfalfa.