The lowly shall be great: that has become the destiny of the corncob. It has long been recognized as a useful article for corn cob pipes, as litter for chickens, as feed for pigs, and finally, as a soil conditioner and mulch.
The last high estate was reached after it began to be advocated with a great deal of gusto as a miracle mulch for greenhouse roses.
It had been used for many years as a mulch for outdoor roses and other crops, but the great impetus came from the excellence of roses grown under it by Lou Endres of New Philadelphia, Ohio.
However, this coincided with the effective use of aerosols, so some credit must be given to pest control for greater growth.
Several Ways To Use Corn Cobs
In the first place, they change the structure of the soil, making it more porous, which means more air for the roots, thus greater root development and naturally larger tops and better production.
The sugar in the cobs is leached into the soil and used by bacteria, which affects soil granulation. With this granular structure, more water can be applied to the soil more safely, adding another factor in favor of the corn cob mulch.
However, as the cobs decompose, the nitrogen in the soil is used in the process by various organisms, and starvation of the plant may and often does result.
That means that additional nitrogen must be supplied at the time of corncob application and regularly after that until complete decomposition occurs.
Since such organic fertilizers as blood, tankage, cottonseed meal, soybean meal, and ground leather decompose slowly, they are suggested in combination with cobs.
However, since the first reaction is quick, it is best to use such inorganics as ammonium sulfate or ammonium nitrate at the start to avoid plant starvation.
Later the organic materials may be substituted. Such materials should be added if they do not contain phosphorus and potash. This applies, in particular, to blood.
Tankage contains some phosphorus, while soybean and cottonseed meals have both phosphorus and potassium.
Moisture Retention of Corn Cobs
Corncobs retain a good deal of moisture, so their application to the stems of plants depends on the kind of plant. Thus, three or four inches are used in the case of roses, whereas, in carnations, it would not be safe to apply more than an inch for fear of increasing stem rot.
Even in the case of roses, the mulch will increase any tendency toward canker, and cases of serious damage have been noted.
Under such conditions, the mulch should be reduced in depth, and spraying the lower stems and the mulch with Fermate (two lbs. to 100 gals.) becomes necessary.
A one-inch application is adequate for mums, snaps, stocks, and other crops of short duration. At the removal of the crop, the mulch may be incorporated into the soil, but again, unless it is well-rotted, nitrogen starvation must be watched for.
Corn Cobs As Light Mulch
In addition, fine corncobs may be used successfully as light mulches in flats and benches where seedlings are pricked off to ensure that high nitrates do not prevail during the initial starting period. It has worked particularly well on snaps.
Also, during the winter months, when the danger of overdosage of fertilizers becomes a factor, a mulch of cobs will reduce the nitrates. Thus, the lowly corn cobs have become an integral factor in greenhouse crop management.
Speaking of mulches, others should not be overlooked. For years, peat has been excellent for mums and continues to be such.
Shredded sugar cane will give similar results to corn cobs, containing some sugar. In localities where cottonseed hulls are available, they make excellent mulch.
44659 by I. A. Fight