P U B L I S H ED F I VE T I M ES Y E A R LY BY O . M . S C O TT & S O NS CO., M A R Y S V I L L E, O H IO D I S T R I B U T ED F R EE TO L O V E RS OF B E A U T I F UL T U RF Number 48 E L E V E N TH Y E AR February 1938 LIMING ACID SOILS The value of lime as an aid in pro- ducing bigger crops on some soils has been recognized by farmers for many years. This is not because lime is valu- able as a plant food, but because it neutralizes soil acidity. A large percentage of lawns and other turfed areas do not require lime, the soil condition being such that noth- ing would be gained by liming, and some harm might even result. When actually needed, lime may prove of great benefit to grass. Lime is a corrective of soil acidity or sourness. It assists in making certain food ele- ments available to grass, and, in addi- tion, it is a direct source of calcium and magnesium, which turf plants need in small amounts. Lime should not be considered as a substitute for fertilizer. It does not pro- vide those food elements that are of such vital to grass and which are in practically all soils, namely, nitrogen, phosphorus and potassium. importance lacking Soil Acidity According to the theory of electro- lytic dissociation, the relative propor- don in the soil of positive hydrogen ions and negative hydroxyl ions deter- mines its acid or alkaline character. If they are equal, the soil is neutral; if the positive is acid; if the negative, it is alkaline. ions predominate, it For simplicity's sake, chemists have devised a scale for designating hydro- gen ion concentration or intensity of acidity. The unit of measurement is known as pH. The neutral point on the scale, indicated by 7 is the pH value of distilled water. Values lower than pH 7 indicate degrees of acidity while those higher indicate degrees of alka- linity. The pH values represent inten- sity of acidity or alkalinity and not quantities of acid or alkali present. Fortunately, lawn and turf grasses will grow over a wide range of soil acidity and alkalinity, although the moderately acid soils varying from pH 6.0 to 6.5 probably are best. If the acidity is more intense than pH 6, lime will be needed. Soils can be too alka- line for grass but this is rare. Excessive acidity hinders the growth of grass. It interferes with the activity of certain bacteria which change raw plant food elements into forms usable by grass. Undue acidity, preventing decay of organic matter, may mat the turf with dead roots which will dimin- ish the circulation of air and water in heavier soils. A turf on an extremely acid soil may be subjected to frequent attacks by fun- gus diseases since the causal fungi gen- erally grow better in an acid medium. Indications of Acidity The appearance of grass as an indica- tion of soil acidity is not to be trusted. There is some evidence of the need of lime in a shallow grass root system, the appearance of certain weeds, as sheep sorrel, and otherwise unaccountable C O P Y R I G H T. 1 9 3 8. BY O. M. S C O TT & S O NS CO lack of response to fertilizer. Several causes connected with food supply, soil texture and drainage, may produce similar appearances. The sure way to know if lime is needed is to learn the pH value by a laboratory test. Putting greens and other areas that have been much stimulated by ammo- nium sulfate or other acid producing fertilizers are often very acid, especially if the soil has a natural tendency to- ward acidity. The growth of moss may be the re- sult of an acid soil but is more likely to result from a deficiency in plant nu- trients, poor drainage or excessive shade. To use unneeded lime on a soil is wasteful and may be harmful. If a laboratory test of the pH value of the soil shows that lime is needed, it should be applied properly, in the best form, at the best time, and in the required amount. When to Lime Lime is most effective when mixed with the soil to the normal depth of the grass roots. On an established turf where only surface application can be made, penetration is best accomplished during periods of alternate freezing and thawing. Therefore, it is best to make application in the late fall, win- ter, or early spring. In case of a newly prepared seed bed, lime can be raked or disced into the upper six inches. The season is of no consequence except that application is best made even months before seeding. several weeks or Lime may be applied after plowing under a green manure crop or a heavy stand of grass and before preparation of the seed bed. This will stimulate the bacteria that break down the organic matter and liberate plant food. Theory to the contrary, it seems safe to apply lime and fertilizer at the same time. They even may be mixed, but if so, should be broadcast immediately to avoid hardening and caking. It is best not to apply lime and lead arsenate at the same time. At times the efficiency of the lead arsenate as a poison for grubs and earthworms mav be impaired. Forms of Lime The term lime, referring strictly to calcium oxide, has been broadened to include various commercial compounds of calcium and magnesium which are commonly soil acidity. In most localities the only suit- able forms are ground limestone anH hydrated lime. to overcome used Ground limestone is native limestone crushed to an effective degree of fine- ness. For overcoming soil acidity, it should contain about 50 per cent of calcium oxide and fine enough so that about 75 per cent will pass through a 100 mesh screen and all through a 20 mesh screen. should be Hydrated limestone to such a lime is made by heating tempera- ground ture that the carbon dioxide and water are driven off. This makes burned lime, which is very caustic. By slaking the with a fine spray of water as burned through a is blower, hydrated is formed. A good quality tests about 75 per cent calcium oxide. forced lime lime in Other materials available some sections have more or less neutralizing value. Finely ground oyster shells, marl or bog lime, and dolomitic lime- stone may be used if their cost, on the basis of the calcium oxide present, com- pares favorably with that of other avail- able forms of neutralizing materials. largely in agriculture, while a source of calcium, is incapable of neutralizing soil acids, and is not recommended. formerly used Gypsum, In localities near steel producing cen- ters, blast furnace slag may be consid- ered, but it should be used only after comparing the price delivered and the complete analysis with the cheapest available form of lime. On the assump- tion that the slag will have 40 to 50 per cent of calcium oxide and that it will lack the fineness of ground lime- stone, it may be necessary to use twice the amount that would be used of ground limestone. Generally speaking, ground lime- stone is the best form of lime for neu- tralizing turf soils. Usually it is the more economical and, furthermore, it is safer than hydrated lime for treating established turf since it is not caustic and does not cake. Quantities of Lime A prescription for the use of lime cannot be written unless an accurate soil test is made. When the pH and the soil type are known the proper amount of a given form of lime may be calculated. Except in extreme cases, the quantity of ground limestone required will vary from 50 to 100 pounds per 1000 square feet, or from one ton to two tons per acre. For hydrated lime, with its 75 per cent calcium oxide as compared with limestone's 50 per cent, these quantities are reduced one third. In liming established turf areas, not more than 50 pounds of limestone or 30 pounds of hydrated lime per 1,000 square feet should be used in a single application. If more is needed the ap- plication should be divided among sev- eral seasons. In preparation of a new seed bed, the entire quantity desired may be added at one time, but it should be thoroughly harrowed or raked into the upper five or six inches. It is especially difficult to change the reaction of silt or clay that is well forti- fied with organic matter; hence such soils require more lime than a light, sandy soil having the same intensity of acidity. It is far better to lime too little than too much. An overdose may upset the chemical balance of the soil, causing starvation of the grass plants and per- mitting certain weeds to gain control of the lawn. Lime may be broadcast by hand or, better, with a mechanical spreader. Such spreaders are available in small sizes for home use, as well as in large tractor-drawn equipment. is It important to spread evenly since the lime will not move laterally through the ground, but only down- ward. On established turf areas, the lime should be washed or brushed off the grass leaves to prevent burning. Native Limestone Country The need of a soil for lime may de- pend largely upon the nature of its par- ent material, and upon the extent of leaching of alkalies. Soils of the Atlantic Seaboard and New England States are likely to be acid because of their derivation from granites, sandstones or shales. Also, soils in New York State and northern Pennsylvania tend toward acidity, as do those of eastern Ohio. In other parts of the country soils may be alkaline. In southern Pennsyl- vania there is much natural limestone. Beginning in western Ohio and extend- ing through Indiana, Illinois, Wiscon- sin and into the far west, soils are gen- erally of limestone origin. However, it is not safe to infer the acidity or alkalinity of a soil from the fact of its location in any such division of the country. There are many modi- fying factors. Conditions may vary, even on adjoining properties. The maintenance program may cause an alkaline soil to become acid. Or, an alkaline condition may be maintained because of regular sprinkling with wa- ter that is strong in lime, or because of frequent topdressing with soil contain- ing lime. A soil test is the safe guide. Soil Tests Free soil tests for lime requirement and other lawn needs will be made by O. M. Scott & Sons Co. at Ridgefield, New Jersey, and Marysville, Ohio. Address your soil to us at Ridgefield, New Jersey, from any place east of Ohio or any Ohio city affected by the Department of Agriculture Plant Quar- antine No. 48 (Japanese Beetle Con- trol). Otherwise all soil samples should be mailed to Marysville, Ohio. Your co-operation this government regulation will help con- trol the spread of the Japanese Beetle. in complying with To obtain a good sample, make a vertical cut about 4 inches deep with a trowel and take a slice from the face of the cut. Repeat in various spots and mix the soil so obtained. One pint of this mixed soil is sufficient. Mark the package plainly with name and address. Write us separately, giv- ing a brief description and history of the lawn. This service, which includes a report of the soil analysis and a letter of grass growing recommendations, will require about a week's time after receipt of is no charge and no obligation. the sample. There Moles Shy Lead Arsenate At the meeting of the North Cen- tral State Entomologists' Conference at Kansas City, last March, Professor J. S. Houser, entomologist of the Ohio Agri- cultural Experiment Station, spoke of a seeming control of moles with lead arsenate. Here is his statement: "It is interesting to note the mole's behavior in the lead arsenate treated plots. They stop almost at the line where lead arsenate has been used." The directions for using lead arse- nate in grub control were given in the L A WN C A RE issue Number 4 4. The Scott Publications Lawn Care—This issue is No. 48. Subjects featured issues include: 1928 Plantain, Sodium Chlorate. 1929 Compost, Moss, Web Worms, in previous Iron Sulphate, Buckhorn. 1930 Ground Ivy, Yarrow, Earth- worms, Heal-All, Ants. 1931 Speedwell, Creeping Buttercup, Moles, Knotweed. 1932 Sheep Sorrel, Quackgrass, Spurge, Trefoil, Goosegrass. 1933 Nimble Will, Knawel, Terraces, Shepherd's Purse, Ground Covers. 1934 Sedge, Purslane, Spring Seeding, Dandelions, Summer Feeding. 1935 Peppergrass, Shade, Crabgrass, Summer Injury to Turf. 1936 White Clover, Poa Annua, Hen- bit, Fall Seeding, Foxtail. 1937 Honeycombed Seeding, Control of Grubs, Orchard Grass, Soils, Injury from Excess Moisture. If your file is not complete, please be sure to ask for the missing issues. A full set of bulletins in stiff paper bind- ing will be sent for 25c. Binder—An attractive imitation lea- ther ring-binder containing all bulle- tins, index, graph paper for charting your lawn, and with capacity for sev- eral years to come—$1 postage paid. For 20c additional, you may have a name gold-stamped on the cover. Bent Lawns—A practical discussion of the most beautiful of all grasses. Tells how to plant with either seed or stolons. Many natural color illustra- tions. Free. Good Lawns—The amateur garden- er's guide to better lawns. Condensed but very complete information on soils, fertilizing and seeding. Free. O. M. SCOTT & S O NS CO. M A R Y S V I L LE • • O H IO EVERY PACKAGE OF SCOTTS LAWN SEED BEARS THIS TRADE-MARK AND IS SEALED FOR YOUR PROTECTION A A