Amounts of fertilizer elements removed by peas at three stages of growth
1945
Wolf, B.
A study of two fields of canning peas (Thomas Laxton variety) in 1943, yielding 4,300 and 2,400 pounds of shelled peas, respectively, revealed that. 1. The high-yielding crop removed 81 pounds of N, 37 pounds of P(2)O(5), and 70 pounds of K(2)O as compared to 45 pounds of N, 20 pounds of P(2)O(5), and 37 pounds of K(2)O for the smaller crop. 2. From 55 to 59% of the dry matter was produced and 47 to 58% of the N, 60 to 65% of the P(2)O(5), and 24 to 45% of K(2)O were absorbed in the last 14 days of growth. 3. The two crops utilized approximately 1.90, 0.85, and 1.55 pounds of N, P(2)O(5), and K(2)O, respectively, to produce a hundred pounds of shelled peas. 4. The shelled peas contained only about one third of the N, two fifths of the P(2)O(5), and one fourth of the K(2)O necessary to produce the crop. Returning the vines and pods to the field would be an important factor in maintenance of the soil fertility. 5. Soil and plant analysis can be used to advantage in studying the nutrient status. Specifically in these studies, soil and plant analysis revealed (a) that N and K(2)O levels dropped markedly as the season progressed, while P(2)O(5) remained fairly constant; (b) the 60 pounds of N supplied by the mixed fertilizer was exhausted in producing the 4,300 pounds of shelled peas; and (c) the 120 pounds of K(2)O supplied by mixed fertilizer was inadequate for the 2,400 pound yield. Reserves of K(2)O in this field were evidently too low for this crop yield.
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