CHAPTER XVIII

SANDS AND THEIR MANAGEMENT

SANDY soils include four important classes, namely: (1) Coarse and medium sand; (2) fine sand; (3) sandy loam, and (4) fine sandy loam. The last two classes are generally recognized as excellent soils, and their management requires no special attention when due consideration is given to the maintenance of their fertility. When depleted they require about the same treatment in their improvement as do loams and silt loams. The medium

sands and the fine sands, on the other hand, have certain characteristics which necessitate a special knowledge for their successful management.

The fine sands are much more desirable soils than coarse sands. This fact is usually indicated by the character and size of the undergrowth of cut-over lands or by the original vegetation which they are supporting or have supported. Heavy growth and hardwoods usually indicate the presence of more fine material in the soil and a higher content of plant-food elements, which mean more favorable cropping possibilities.

Dune or shifting sands (Fig. 205), being of little or no agricultural value, are not considered in this chapter.

Advantages in Farming Sands.-There are several advantages to be considered in farming sands, namely: (a) They are warm and quick soils; (b) they are especially well adapted to the growing of small fruit, early vegetables and such crops as strawberries,

melons and pineapples; (c) they are easy to till; (d) they can be worked readily during wet seasons or when wet; (e) they respond quickly to proper fertilization; (f) they are profitable in proportion to their valuation.

Sand Problems.-The main problems encountered in cropping sands may be summarized as follows:

Problems in Sand Management and How to Solve Them

Problems

Low in nitrogen and organic matter
Soils usually acid

Deficient in phosphorus and potassium
Too loose seed-bed
Moisture supply uncertain

Subject to wind-action

Solution

Apply manure; grow legumes
Lime the soil

Apply mineral fertilizers

Roll the land; increase organic matter Conserve moisture; increase organic matter

Wind-breaks; proper field management

Nitrogen and Organic Matter.-The need of nitrogen and organic matter is of the greatest importance in sand farming. For this reason, the growing of legumes such as soybeans, cowpeas, velvet beans,1 mammoth clover, etc., should be given the greatest attention. Many times sands are so poor that winter rye is the only crop that can be grown. This rye should be plowed under in the spring, and soybeans, mammoth clover or some other suitable legume planted. The entire legume crop should be plowed under when still green. Following this a short rotation may be put into practice, not only to provide an income, but to improve the soil as well.

Increasing the organic matter and maintaining it constitutes a big problem. The whole program in sand farming should center on this problem. Agricultural lime, manure, commercial fertilizers, and green manure crops should be used particularly to increase the growth of clover and other legumes, these being necessary to assure good yields of other crops.

Manure for Sands. Since sands are usually deficient in the three important plant-food elements, manure is an excellent fertilizer to use. When well decomposed, its application as a topdressing on plowed ground into which it is disked seems to give best results for corn. It is advisable, however, to apply much of the manure as a top-dressing on the clover fields.

1 Velvet beans and cowpeas are important legumes for soil improvement in the South.

NITROGEN FERTILIZERS

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Manure alone does not supply the full needs of sands. Phosphate and often potash fertilizers are necessary to develop properly balanced soils.

FIG. 207. From poor to productive sand in three years.
Same soil as shown in Figure 206.

Lime and proper fertilizers.

Nitrogen Fertilizers. (See index.) The low supply of organic matter in these soils necessarily means a low nitrogen supply, hence the urgent need of nitrogen. However, the use of commercial nitrogen fertilizers, such as nitrate of soda and ammonium sulfate, as the main sources of nitrogen in general farming on sands is not recommended, since these fertilizers cannot take the place of

legumes and manure in supplying the much-needed organic matter (see index).

Liming Sands. For most sands lime may be regarded as the second important need in their improvement. This is necessary, not only to supply available calcium for crop needs, but to render the fertilizing elements in the soil more available as well (Figs. 206 and 207).

Without sufficient lime alfalfa cannot be grown on acid sands. Mammoth, medium red, crimson and Japan clovers are much benefited when sands of slight to medium acidity are limed.

FIG. 208.-A good crop of soybeans on sandy soil.

Soybeans (Fig. 208), cowpeas, and velvet beans grow very well on sands having slight to medium acidity, but when the soils are strongly acid liming is necessary for best results (p. 229).

Phosphorus and Potassium Needs. Some sands, especially those of slight to medium acidity, require phosphorus as second in importance to nitrogen and organic matter. On most sands, however, phosphate and potash fertilizers are indispensable; the potash being of most value during the first few years of improvement.

Of the phosphate fertilizers, acid phosphate and steamed bone meal are most commonly used. Best results in the use of these fertilizers are secured after the nitrogen and organic matter have increased, and acidity has been reduced by liming. Acid phosphate may be applied at the rate of 300 to 500 pounds to the acre, applied as a top-dressing and disked in. This application should be made to benefit the legume crop, and may be repeated at least once in a three-year rotation.

THE MOISTURE SUPPLY

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One hundred twenty-five pounds of muriate of potash should also be applied with the phosphate. Additional amounts of 50 to 100 pounds of the potash fertilizer may be applied per acre for corn and potatoes, respectively.

For more permanent soil improvement rock phosphate (see index) may be used instead of acid phosphate, but not until the soils have been well enriched with organic matter.

Use of Mixed Fertilizers. Many have found it profitable, in addition to the use of manure and special fertilizers, to use from 125 to 200 pounds of mixed fertilizers per acre for corn, applied in the hill or drill and about 500 pounds for potatoes.

Usually, it is advisable, in the spring, to apply a light topdressing of manure to the rye to increase the yield and especially to benefit the clover seeding. When manure is not available, an application of 400 to 500 pounds of a 2-8-1, or a 4-12-0 mixed fertilizer (NPK) may be substituted. A mixture of 100 pounds of dried blood and 300 pounds of acid phosphate per acre gives good results. The fertilizer should be mixed with the soil through disking or harrowing. Harrowing grain on sand in the spring does not injure the crop, but greatly improves it.

The Seed Bed.-Much care should be given to the preparation of the seed bed. Firmness is desired (see Tillage, in index). This can be accomplished through good plowing, thorough harrowing and by using a corrugated roller or cultipacker (p. 155). The importance of close contact between the soil and the seed (Fig. 21) and, later, between the soil and the young roots should always be kept in mind in preparing a seed bed on sand, and in planting and sowing. The presence of a good supply of organic matter is an important factor in preparing a proper seed bed.

The Moisture Supply. The water-holding capacity of sands is low (see index). Moreover, this moisture is easily secured by crops and thus this comparatively small amount of moisture, if not replenished by rains, is soon used up. Crops on sand, therefore, frequently suffer for want of moisture during dry periods. To lessen this injury, moisture conservation and control should be given special attention. Soil mulching is important. Disking and "dragging" winter rye in the spring is good practice. Sowing such legumes as soybeans and cowpeas in rows to permit of cultivation is advisable. In case of potatoes, endeavor to grow thrifty vines to shade the ground. When the subsoil is sand, subsoiling or deep spring plowing should never be done.