So far as soil management is concerned, tillage is the most important operation in vegetable gardening. Both yield and quality are largely determined by the character of the tillage operations. The objects of tillage are as follows: (1) To modify the physical conditions; (2) to regulate the soil moisture content; (3) to modify soil temperatures; (4) to aerate the soil; (5) to provide proper conditions for the action of friendly bacteria; (6) to destroy weeds; (7) to prevent surface erosion; (8) to cover humus-producing materials, as manure and green crops.
The value or efficiency of tillage depends upon character, thoroughness, and timeliness. Both the character and the thoroughness of tillage count for much in vegetable gardening, for in growing crops of high cash value gardeners should be certain that tillage operations should be of the right kind and be fully completed before work is discontinued. Timeliness is of primary importance, for to plow, harrow, cultivate, hoe and weed at just the right time may make the difference between profit and loss. Conditions may be satisfactory for plowing today, while rain tomorrow may fill the soil with too much moisture for the most effectual plowing, and so much rain may fall that plowing, harrowing and planting may be delayed a week or more. Such delays often result in reaching the market too late for the best prices. The failure to cultivate a field at the right time frequently results in the weeds taking possession, a situation causing unnecessary expense in hoeing and hand weeding, and in addition producing later maturing crops and reduced yields. There is a proper time in vegetable gardening for every tillage operation and fortunate is the man who not only knows when to till but who usually does the work when most advantageous.
The increased price of land, labor and supplies makes it imperative for the gardener to use labor-saving implements, with which the work can usually be done better and cheaper than by any hand method. In the purchase of tools and implements for vegetable gardening, the following factors should be considered: (1) The efficiency of the tools and the adaptation to the work to be done; (2) the rapidity with which the work may be done; (3) the ease of operation to team and workmen; (4) durability; and (5) cost.
The walking mold-board plow is most commonly used among vegetable gardeners. Sulky gang and sulky disk plows are seldom used, but are becoming more popular.
Fall plowing is practiced extensively by vegetable growers. It is considered especially desirable on the heavier types of soils. The following advantages may be enumerated: (1) If the land is hilly or rolling, rough unbroken furrows will collect more water than when plowing is deferred until spring, and if harrowing is done as soon as possible, there will be a maximum supply of soil moisture to meet the needs of spring crops; (2) the physical composition of many soils is improved; (3) vegetable matter plowed down in the fall becomes better decayed and more valuable to the spring crop; (4) land plowed in the fall may be harrowed and therefore planted earlier in the spring; (5) some fall plowing often relieves the pressure of the spring work, and makes possible the starting of all crops earlier; (6) fall plowing exposes many insect enemies to destroying agencies and thus reduces ravages from this source. Fall plowing in the North, where the land is sealed by frost during the winter is regarded as more desirable than in the South, where the loss from leaching must be considered. It is especially advantageous to plow heavy sod lands in the fall.
When plowing is deferred until spring it should be done at the earliest possible date. This is important from every standpoint. No greater mistake can be made, however, than to plow before the ground is dry enough. Every experienced farmer well knows the evil effects of such a practice. In order that the soil may be dried out early and that plowing may begin as soon as possible, many gardeners prefer not to spread stable manures until the ground is ready to plow, because such a mulch greatly retards the evaporation of soil moisture.
Most garden crops thrive best in soils which have been ameliorated to a considerable depth, so that deep plowing is favored by successful vegetable growers. No soil should be plowed deeper, however, than the character and depth of the top soil will permit. The intermingling of a large portion of unproductive subsoil is always detrimental to garden crops.
The subsoiling of garden soils has been advocated by many writers, but it is seldom practiced and is of doubtful utility.
In making preparation for sowing or transplanting, harrowing follows plowing. The harrow is also used sometimes by truckers in cultivating after the crops have been started. When used in this manner it is often effective in providing the proper tilth and in destroying small weeds.
Spike-tooth harrows are used more generally than their efficiency justifies, for they are scarcely comparable to some other types in their pulverizing action; their teeth do not run to great depth, and their tendency is to push the clods aside rather than to break them. Smoothing harrows are most valuable, perhaps, when used as weed-ers after a crop like potatoes or sweet corn has been started. The spring-tooth harrow is an important tool among gardeners, being especially well adapted to stony-ground. It is also an excellent pulverizer and leveler. Disk and cutaway disk harrows are exceedingly valuable implements as pulverizers, and are especially useful for clay soils and for reducing heavy sods. When heavily weighted they cut to great depth. Disking is sometimes practiced before plowing. This preliminary operation is regarded by some as being of special value in truck farming. Manure can be applied, and then chopped up and worked into the soil before plowing. This method results in fine soil to the full depth of the plow furrow, if harrowing after plowing is done as thoroughly as it should be. The disk harrow is unquestionably the best pulverizing tool for the heavier soil types and is far superior to the spring-tooth harrow in most soils. The Acme harrow is prized by many vegetable growers because it not only pulverizes to a considerable depth, but it has also good leveling action. The Meeker smoothing harrow, which has 58 disks mounted on four rollers, is practically indispensable in vegetable gardening as a finishing harrow and should be used exclusively for this purpose. It does the work of a steel garden rake, though better and more economically, and not only pulverizes to the depth of 3 or 4 inches, crushing even the smallest clods, but by an adjustable plank running across the middle of the harrow it also levels and leaves the soil in the smoothest possible condition for sowing or transplanting. It is an old harrow, but not as generally used as it should be.