Kans. State Agric. College Bul. 127: 207-209 (June 1904)
The Roots of Plants
A. M. Ten Eyck

KAFIR-CORN ROOTS

In plate 5 is shown a sample of Kafir-corn roots taken July 28, seventy days after planting. The Kafir-corn was planted adjacent to the corn, in hills three and one-half feet apart, and received similar cultivation to that given the corn. In this sample, which is the Blackhulled White variety, the stalks stood about four feet high and were well covered with leaves. The plants appeared to be thrifty and in good growing condition.

The roots of Kafir-corn are finer and more fibrous than the corn roots. At this stage, a few of the roots had reached a depth of nearly three feet, but the greater part had not penetrated below eighteen inches. The root system is similar to that of corn, but the vertical growth seems to be much less strongly developed in the Kafir-corn. The root-crowns are large and fibrous and the lateral roots are well developed. The depth of the main lateral roots averaged about the same as in the corn, but above the main lateral growth the soil was filled with great numbers of very fine, surface-feeding roots, more noticeable in this sample than in the corn. Compared with corn, Kafir-corn is evidently much more of a surface-feeding crop.

The root development of the matured Kafir-corn is shown in plate 6. This sample was taken October 10, 144 days after planting. The seed had been ripe some time, but the stalks and leaves were green and growing when the sample was taken. The roots in this sample do not extend so deep as do those of mature corn. Some roots were found growing at a depth of three and one-half feet, but the greater portion stop at three feet, and these are much less in number than the roots of corn at the same depth. However, the upper eighteen inches of the soil, as shown by the sample, was very completely filled with a fine, wiry, fibrous network of roots. Some of the main lateral roots lie within four inches of the surface midway between the rows, and from these numerous fine, fibrous branches spread out in all directions, feeding to the very surface of the ground. From the top of the rootcrown radiate several large, rather short roots, apparently similar to the brace roots of corn. It was observed that all the roots were tough and wiry; in fact, the whole plant gives an impression of hardiness and vigor.

The drought-resisting qualities of Kafir-corn are well established. That this character is not due to the deep feeding of the roots is evident, since the plant is even more of a surface-feeder than corn. It is the experience of many farmers that Kafir-corn is a “hard crop on the land.” Crops following Kafir-corn are often less thrifty and less productive than the same crops following corn or other crops, and sometimes the injurious effect is observed for several seasons. No exact experiment has been recorded at this Station to prove this report, but there is little question but that the facts are as stated, and the study of the root system of the plant, together with other characteristics of the crop, offer a reasonable explanation of the facts observed. Kafir-corn is a great producer, yielding in an eleven years’ trial at this Station more fodder and grain per acre than corn. The crop draws the plant-food and water required to produce this large growth mainly from the surface eighteen inches of the soil, and, growing late into the fall, it gives the land little chance to accumulate water or develop available plant-food in preparation for next season’s crop. Thus the soil is apt to be left with insufficient moisture and soluble plant-food, hard in texture, and altogether unfavorable for starting the crop planted on the field the same fall the Kafir-corn is harvested, or the following spring; and without proper tillage and favorable weather, the unfavorable condition of the soil may continue for more than one season, resulting in poor crops.

MOISTURE CONDITION OF KAFIR-CORN versus CORN LAND IN 1903.

In a comparative soil-moisture study made at this Station last season little difference was observed in the moisture content of the soil of the Kafir-corn and corn plots up to September 7, but between September 7 and 28 the Kafir-corn ground lost a much larger amount of moisture than the corn ground. The following table shows the moisture condition of the soil in the two plots when the crops were removed:

Moisture in the soil. Samples taken September 28, 1904.
  First
foot
Second
foot
Third
foot
Fourth
foot
Fifth
foot
Sixth
foot
Corn plots
Kafir-corn plots
20.28%
16.16
22.07%
19.09
20.75%
18.50
21.21%
19.42
20.53%
17.59
19.79%
16.57
Differences 4.12 2.98 2.25 1.79 2.94 3.22
Average difference 2.88 per cent., in favor of corn plots.

The results indicate that Kafir-corn rapidly exhausts the soil moisture in the latter part of the season, leaving the ground drier than does corn. This condition is especially noticeable in the surface soil. The season of 1903 was exceptionally wet. In a season of less rainfall the drying effect of Kafir-corn on the soil would doubtless be more marked than was observed in the above trial.

If the rainfall is not sufficient to supply the normal amount of moisture before winter sets in, Kafir-corn ground will be deprived of a portion of the loosening benefits of winter weathering which result from the expansion and contraction of the soil by means of the freezing and thawing of the soil moisture. Thus the soil may be left in a physical condition unfavorable to the absorption of the spring rains and the development of the roots of the succeeding crops. This study suggests that Kafir-corn should be followed the succeeding year by late-planted crops, in order to allow the soil to regain, previous to planting, its normal amount of moisture and fertility. It was observed late in the fall that the soil of the Kafir-corn ground was apparently firmer and more compact than that of other plots, which observation was supported by the fact that the determination of the weight per cubic foot of the soil in the several plots showed that the dry weight of the first foot of soil in the Kafir-corn ground was greater than the weight of the soil to a like depth in other plots tested. The results of the moisture trial this spring, given below, also indicate that the rains have not percolated so readily into the soil of the Kafir-corn plot as into the soil of the corn plot.

Moisture in the soil. Samples taken March 15, 1904.
  First
foot
Second
foot
Third
foot
Fourth
foot
Fifth
foot
Sixth
foot
Corn plots
Kafir-corn plots
25.69%
25.91
30.33%
28.13
26.86%
23.78
24.44%
20.73
24.05%
20.08
24.26%
15.84
Differences .22 2.20 3.08 3.71 3.97 8.42
Average difference 3.53 per cent., in favor of corn plots.

Compared with the samples taken last fall, it will be seen that the Kafir-corn ground has not gained so much water as the corn ground, which indicates a less absorption of the rains, also that in the Kafir-corn ground a large proportion of the water has been collected in the first two feet of soil and the moisture percentage decreases rapidly as the depth increases, while in the corn ground the percentage of moisture is about the same in the lower four feet of soil.

Table 5   Table 6
 
Showing the growth of the roots of Kafir-corn, seventy days after planting.
Kafir-corn root system at maturity.