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matter makes the soil drier, while if it had rotted either before or after being put on the soil, it would have increased the soil moisture. (286) The system of piling manure in the field and subsequently spreading it, while having the merit of securing substantially uniform distribution per acre, has fallen into disuse. It was found to be wasteful of labor and if the piles were left to stand for a considerable time, to cause unequal local distribution of the fertilizing elements. The manure is now usually spread from the wagon with a fork, or spread by means of a manure spreader. The latter are quite satisfactory so far as their work is concerned, but the amount of work required of a spreader is such as to cause those at present manufactured to lack durability.
288. The Use of Commercial Fertilizers for the production of maize has been the subject of field experimentation in at least twenty-six stations, principally in regions east of the Mississippi River. Many of these stations have found but very small increases from the use of commercial fertilizers, and most of them have not found profitable returns, especially west of the Alleghany Mountains. Practically all agree that the maize plant does not respond as readily to the use of commercial fertilizers as do the smaller cereals which are sown broadcast and thus have so many more plants to the acre, and which grow during a cooler portion of the year.
Where the soil requires it, from twenty to sixty pounds of phosphoric acid and from five to twenty pounds of nitrogen may be applied to the acre. Generally speaking, however, the best practice will be found to consist in relying upon the overturned sod and stable manure, with lime where needed to grow the maize and applying the commercial fertilizers to the wheat both to increase the yield of the latter and to promote the new seeding.
289. Relative Importance of Fertilizing Constituents.—The behavior of maize towards the different constituents of fertilizers appears to be much the same as that of wheat. (i 21) In fact, so far as the cereals are concerned, the influence of the several ingredients of commercial fertilizers appears to be more dependent upon the soil than upon the crop. The following table gives the average yield of maize cut green for silage during fourteen years at Ottawa, Canada, when grown continuously on the same plats:1
No. of plats Treatment Tons of green fodder
2 Unmanured 8.02
3 Phosphorus 9.04
2 Nitrogen 11.40
a Potassium ........ 9.02
2 Phosphorus and nitrogen 11.01
2 Phosphorus and potassium 11.03
5 Phosphorus, nitrogen and potassium . . . n-97
2 Barnyard manure (mixed horse and cow) 12 tons . 14.32
Fertilizers applied each year from 1888 to 1898 or 1899. No fertilizer used since. Clover sown in 1900 in place of maize and plowed under in May before maize was planted.
290. Methods of Applying Fertilizers.—While commercial fertilizers may be applied broadcast, this method is not generally advisable. Some maize planters have fertilizer attachments which apply the fertilizer with the seed. Where a wheat drill is used for drilling maize, it is a common practice to drill the fertilizer through the hoes on each side of the hoes drilling the maize, thus placing the fertilizer in the soil seven inches on each side of the maize row. (305)
291. Influence of Season on Efficiency of Fertilizers.—At the .
Illinois Station where maize was raised continuously for twenty years on manured and unmanured plats (284) in certain seasons of deficient rainfall the unmanured plat gave greater yield than that receiving annually stable manure. At the Indiana Station2 both stable manure and commercial fertilizers used continuously for five years gave the best yields during seasons of high rainfall
1 Canadian Experimental Farms Rpt. 1902, p. 34.
2 Ind. Bui. 55, p. 29.
and the least returns during a season of low rainfall, the commercial fertilizer causing a decrease in yield. Other things equal, the best results from the use of fertilizers may be expected in regions or seasons of high rainfall.
292. The Use of Lime.—In those sections where lime is used, it is generally applied to land intended for maize, this appearing to be the best place in the rotation for its application. Wheeler has reported, however, that the use of lime may be injurious to the growth of maize where the nitrogen in the soil is principally in the form of nitrates, but where the soil is very sour and nitrates are not employed its use immediately before this crop may prove of great service.1 In ordinary rotation the lime would be applied to sod land, although sometimes applied to oat stubble, or even maize stubble, where maize follows maize. Usually the best results follow its use upon sod land of rather long standing.
Calcium lime (CaO) is generally used and is to be preferred, although magnesian lime (MgO) is also used to a considerable extent with apparently satisfactory results. Besides increasing the per cent of calcium in the soil, lime makes adhesive soils more friable and granular, perhaps by causing a rearrangement and cementing together of the soil grains; makes sandy soil more retentive to organic matter; corrects the acidity of the soil in case any exists, thus creating a favorable condition for the growth of nitrifying organisms; may make potassium and phosphorus more available; hastens decomposition of organic matter; and while making the nitrogen in organic matter more available, may cause a more rapid loss of total nitrogen;—there is an old proverb, "Lime enriches the father but beggars the son." Where it is necessary to use lime, it should be accompanied by a liberal use of stable manure.
293. Indications of Need of Lime.—The need of lime may be 1 R. I. Bui. 46, p. 95.
indicated (i) by the per cent of lime (CaO) present;1 (2) by the acidity of the soil, which may be determined in quite sour soils by bringing the moist soil into contact with neutral litmus paper under proper precautions;2 (3) by the excessive adhesiveness of clay soils; (4) by the character of the vegetation, or a change in the characteristic vegetation, or (5) by the persistent failure of certain crops, such as clover and beets. The most satisfactory method, however, of determining the need of lime is by applying it under conditions which make it possible to tell whether there is any increase of crop due to liming.3
294. The Application of Lime.—The equivalent of from one to four tons or from twenty-five to 100 bushels of quick lime (CaO) may be applied to land intended for maize. Ordinarily the amount should not exceed fifty bushels.4 (122)
The freshly burned (quick) lime may be applied directly to the field, where it soon slakes, after which the land may be plowed, care being taken not to plow too deep. Unless it is ground, however, it is difficult to spread quick lime evenly. In order to reduce it to a fine powder the lime may be put in piles of two or three bushels at any convenient time in the fall, where the air, rains and moisture from the soil slake it. Better results will be obtained if the ground is scraped off down to moist soil where the lime is placed and the pile covered with moist soil. If the soil is dry, a half pail of water may be added to each pile. As soon as possible, the piles should be spread with a shovel and the land plowed. Although more laborious, it is better to apply the slaked lime to the plowed land in the spring and
1 For agricultural crops, 0.2 per cent is usually considered the minimum requirement. This can be determined only by chemical analysis.
2 R. I. Bui. 46, p. 100.
8 For full discussion on the use of lime, see The Agricultural Use of Lime in Pennsylvania. By Dr. William Frear, 6th Ann. Rpt. Penn. Dept. of Agr. (1900), PP- '93-353
* The legal weight of a bushel of lime varies in different States from seventy to eighty pounds.
harrow it in. It takes less lime, the lime is nearer the surface, and, if water-slaked in a large pile, it is in a much finer powder. While there is a difference of opinion as to the practical differences between the causticity of quick lime (CaO), -water-slaked lime (Ca(HO)2), and air-slaked lime (CaC03), all seem agreed that fineness is a positive advantage. The slaked lime may be spread from a wagon with a shovel, or a manure spreader with lime attachment may be used. Finely ground quick lime is now placed upon the market, and may be applied with a grain drill or a lime spreader.
295. Irrigation.—While alfalfa, wheat, potatoes and many fruits and vegetables have been abundantly raised by irrigation in America, maize has nowhere been extensively grown by this means. The yields of maize in the arid region under irrigation so far as reported do not compare favorably with yields in humid regions without irrigation.
The Wisconsin Station' has studied the influence of irrigation in the humid region. During eight years, ending 1901, the average yield of maize silage containing thirty per cent of dry matter was 17.2 tons with irrigation and 12.3 tons without irrigation, on land of moderate fertility. Wherever comparisons were made the increase in grain was greater than the increase in total dry matter. The average amount of water added per year was five inches. King concludes that "well managed irrigation in climates like that of Wisconsin may increase the yield of maize silage 40 to 45 per cent, and that of ear corn from 50 to 60 per cent as a general average." On coarse sandy soils in Wisconsin, water alone produced much better results than stable manure alone, but both together had much the greatest effect. * In 1902, the yield during a cold wet season without irrigation was greater than on comparable plats in the hot dry season of 1901 with irrigation. It was also found that the yield was greater on land that had not been irrigated the previous year, the reduction being greatest on manured land.8
1 U. S. Dept. of Agr., O. E. S. But. 115, p. 315. « U. S. Dept. of Agr., O. E. S. Bui . 119, p. 326. 8 Wis. Rpt . 1902, p. 187