Experiment Station Record, 2: 724-726 (1891)
Kentucky Station, Bulletin No. 33, April, 1891 (pp. 15).


These experiments are a continuation of those begun two years ago, and were made on the same plats. For a description of the land used (a "blue-grass" soil) see Experiment Station Record, Vol. II, p. 143. "The season was unfavorable to corn."

Effect of the leading elements of plant food used in various combinations, on the production of corn.—This is a report of the third year's experiment on this subject. The results of the two previous years are recorded in Bulletins Nos. 17 and 26 of the station (See Experiment Station Record, Vol. I, p. 61, and Vol. II, p. 143). The fertilizers used on the 9 tenth-acre plats were nearly the same as in 1889, i.e. nitrate of soda, muriate of potash each 160 pounds per acre, dissolved boneblack, and acid black 320 pounds, used singly, two by two, and all three together; two plats remained unmanured. In 1889 each plat was divided in two halves to compare the effect of sulphate and muriate of potash; in 1890 the same fertilizers were applied to both halves. "The plats receiving no fertilizers the past years received none this year, and likewise the plats receiving fertilizers during the past years received the same kind in each case this year."

Field notes, the yield of corn and fodder, and the financial results are given for each plat. The yields of ear corn on the two uumanured plats were respectively 34 and 40 bushels per acre; on the three plats receiving fertilizers containing no potash, from 33 to 36 bushels; and on those receiving potash fertilizers, from 65 to 76 bushels, the largest yield being with the combination of potash and nitrogen.

  1. In those plats where potash was one of the ingredients of the fertilizers used there was a marked increased yield [ranging from 28 to 39 bushels of corn per acre] both in corn and fodder.
  2. Where a fertilizer was used without potash there was scarcely any increase in yield over those plats containing no fertilizer.
  3. The greatest increased yield was made by using a combination of potash and nitrogen [39 bushels per acre].
  4. The use of muriate of potash alone resulted in a marked increased yield [30 bushels per acre] over the plats receiving no fertilizers.
  5. There was a profit in the use of fertilizers in every instance where potash was one of the ingredients, the largest net profit arising from the use of the mixture of nitrate of soda and muriate of potash.
  6. There was a [financial] loss by the use of fertilizers where potash was not one of the ingredients.

Permanency of effect of fertilizers.—This is a continuation of the experiment commenced in 1888 on 10 tenth acre plats "to test the length of time potash fertilizers will remain in the soil and still be available as plant food." The subsoil of the land used is stated as being "so retentive as to make the soil deficient in natural drainage. In 1888 a mixture of sulphate of potash 160 pounds, sulphate of ammonia 260 pounds, and dried blood 100 pounds per acre, was applied on eight plats; two were unmanured, and the remaining five received respectively cotton-seed-hull ashes 500 pounds, muriate of potash 200 pounds, sulphate of potash 200 pounds, kainit 800 pounds, and tobacco stems 3,000 pounds per acre (See Bulletin No. 26 of the station, or Experiment Station Record, Vol. II, p. 144).

In 1890 the three plats which had received cotton-seed-hull ashes, sulphate of potash, and kainit in 1889 were left without manure, and the two remaining plats received muriate of potash 160 pounds and tobacco stems 2,000 pounds, respectively. Thus of the eight plats originally fertilized three had received no fertilizers since 1888, three others had received none since 1889, and the remaining two were fertilized each year. According to the tabulated results for 1890 the yields of ear corn per acre ranged on the unmanured plats, from 17 to 30.5 bushels; on the plats unmanured since 1888, from 44 to 61 bushels; on those unmanured since 1889, from 44 to 61 bushels; and on those fertilized in 1890, from 59 (muriate of potash) to 71 (tobacco stems) bushels. "It will be seen that the fertilizers applied in 1888 were of benefit to the crop of 1890."

Relation of fertilizer to shrinkage and the proportion of kernel to corn.—"For the purpose of continuing the study of the above question, the corn [from the nine plats of the first experiment], after being husked and weighed, was spread on the floor of the barn loft and allowed to cure. The loft is well ventilated. After curing it was shelled. The tabulated data for each plat show the number of ears of corn per bushel of 70 pounds, the weight of corn when husked and again when cured (February 7), and the weight of the shelled corn from 70 pounds of ear corn. The number of ears per bushel ranged from 112 to 125 on the unfertilized plats and where no potash fertilizer had been used, and from 84 to 91 where the potash had been applied. As in the trial in 1889 (See Bulletin No. 26 of the station, or Experiment Station Record, Vol. II, p. 144), no relation was apparent between the fertilizers used and the shrinkage of the corn in curing or the proportion of kernel to corn.