The Machinery of Grain Production - With Information on Threshing, Seeding and Repairing the Machinery of Grain Production on the Farm

By Read Books Ltd.

This is a classic guide to farm machinery, with a special focus on machinery used for producing grain. It provides detained descriptions and explanations of the machinery dealt with, as well as information on repair, maintenance, and operation. Written in plain language and full of helpful diagrams and photographs, “The Machinery of Grain Production” will be of considerable utility to those who use and maintain vintage farming machinery, and it is not to be missed by readers interested in the history and development of modern agricultural equipment. Contents include: “Harvesting and Threshing Methods”, “Types and Development of Combines”, “Flow Path of Material”, “Types and Sources of Seed Loss”, “Cutting and Conveying”, “Types of Threshing Cylinder”, “Rubber Rolls for Threshing”, “Threshing Effectiveness”, “Seed Damage”, etc. Many vintage books such as this are increasingly scarce and expensive. It is with this in mind that we are republishing this volume now in an affordable, modern, high-quality edition complete with a specially-commissioned new introduction on agricultural tools and machinery.

• Language: English
• Publisher: Read Books Ltd.
• Release date: May 31, 2013
• ISBN: 9781473391123

Book preview

Grain and

Seed Harvesting

17.1. Introduction. Most grain and seed crops are now harvested with combined harvester-threshers, commonly known as grain combines. Consequently, the following discussion pertains primarily to this type of machine. Except for differences in the feeding arrangement and the addition of a straw stacker, stationary threshers employ the same principles and include the same basic components as combines.

Although the greatest application of combines is in harvesting the small grains and soybeans, these machines are also used for a wide variety of small-acreage or speciality crops. Thus, although most emphasis in the following discussion will be placed upon grain harvesting, special considerations relating to other seed crops will be mentioned from time to time. The relatively new practice of harvesting corn with modified grain combines is covered in Chapter 18, along with the discussion of specialized corn-harvesting equipment.

17.2. Harvesting and Threshing Methods. For many centuries the procedure for harvesting grain involved hand cutting with a sickle, scythe, or cradle, threshing by the treading of animals or by flailing, and separating the threshed grain from the straw and chaff by hand raking, sieving, and winnowing.

The systems followed in mechanically harvesting grain (and other seed crops) include (a) direct combining, (b) windrowing and combining, (c) binding or heading and stacking, followed by threshing in a stationary machine, and (d) windrowing, picking up the windrows with a field chopper, and threshing in a stationary machine.

Direct combining and windrow combining require the least amount of labor and, in the United States, have largely replaced stationary threshing methods. In 1950, for example, 85 to 95 per cent of the barley, wheat, and soybean crops in the United States were harvested with combines.⁵

The windrow-combine method involves an extra operation as compared with direct combining but is advantageous under certain conditions. Windrowing permits the curing of green weeds and unevenly ripened crops before threshing. The weather hazard to the standing crop is reduced because windrowing can be started several days earlier than direct combining. In tests conducted in Ohio, windrows on grain stubble 9 to 12 in. tall cured more rapidly than standing or shocked grain, regardless of whether or not rain occurred.¹⁹ Heavy vegetative crops, such as alfalfa grown for seed, are often harvested by the windrow-combine method.⁶

In areas having a hot, dry climate, the system of spray curing followed by direct combining is being practiced to an increasing extent for small-seed legumes such as alfalfa and clover.⁶ In this method, general-contact herbicides are applied to kill the top growth. The crop is then direct combined after the leaves are dry but before regrowth starts (usually from 1 to 5 days after treatment). Spray curing is most effective when the stands are uniformly mature, open, and erect.

Stationary threshers are still used to some extent where the fields are small and the conditions not well suited to combine operation. Approximately one-fourth of the 1950 oat and rye crops in the United States were threshed with stationary machines.⁵ Binding or heading the grain prior to threshing provides the advantages of curing of green material and reduction of weather hazards (as with windrowing) but involves a considerable amount of labor. The stationary thresher accumulates the straw in a stack, which is an advantage if the straw is to be saved for future use.

The windrow-field-chopper method, in conjunction with stationary threshing, is a recent development in the Wisconsin area. After the windrowed material has cured, a field chopper picks up the grain, chops it (using a long cut), and deposits it in a wagon. By means of a mechanical unloading arrangement, the chopped material is then fed directly from the wagon into a stationary thresher. This system is most feasible where all of the following conditions exist: (a) the grain should be windrowed because of green material, uneven ripening, etc., (b) the terrain is rolling and not too good for combining, (c) a forage harvester and wagons are already available because of other applications, and (d) the farmer wants to save his straw. Labor requirements are lower than for the binder-thresher method.

17.3. Types and Development of Combines. Although combines were rather common in California as early as 1885,¹¹ the large-scale adoption of these machines in the wheat belt of the Great Plains area did not occur until the 1920’s. The early combines were all large, trailed units (mostly 12 to 16 ft cut, with some as wide as 35 ft or more), and were not adaptable to the small farms of the eastern part of the United States. Small, trailed combines (mostly 5 to 7 ft cut but some as small as 3 1/2 ft) were introduced commercially in 1935. Since that time, the combine has become nationally accepted. More than 95 per cent of the trailed combines built in 1952 and 1953 had widths of cut less than 12 ft.

Self-propelled, flat-land combines appeared commercially⁸ in about 1939. These machines ordinarily have widths of cut ranging from 9 to 16 ft and have the header mounted across the front of the combine (Figs. 17.1 and 17.3). Their popularity has increased rapidly in recent years. In 1952 and 1953, over 60 per cent of the domestic shipments of combines larger than 6-ft cut were self propelled (although self-propelled machines represented only 21 per cent of all combines of all sizes).¹⁸

As compared with trailed machines, self-propelled combines have the advantages of (a) saving of grain in opening up fields surrounded by fences, other crops, levees, etc.,