EFFECT OF SOIL TYPE, SOIL MOISTURE, AND NITROGEN FERTILIZER ON THE GROWTH OF SPRING WHEAT

Abstract

Spring wheat was grown in the greenhouse on two soil types with nitrogen rates of 0, 30, 60, and 90 pounds per acre and at three moisture levels. Significant increases in yield of grain and significant decreases in percentage protein were obtained with increasing soil moisture on a loam soil but not on a loamy sand. Apparently, the difference in plant growth between soils may be attributed to the greater changes in moisture tension of the loam soil within the moisture ranges studied. The loam soil was also watered less frequently and the high moisture tensions were of longer duration.Both soils showed significant increases in yield of grain with increasing nitrogen fertilizer, but significant increases in percentage protein were obtained on the loam soil only. The largest yield increase per unit of nitrogen was obtained on the loamy sand. The growth of wheat on the loam soil was significantly superior in all respects except for the roots to that on the loamy sand. This is explained on the basis of differences in the original fertility of the two soils before treatment.