Phosphorus Nutrition of Soybeans

Abstract

An increase in P from 2 to 10 ppm resulted in soybean plants which were taller and heavier, produced a greater seed yield, and had a higher oil content. A marked difference in varietal response to higher levels was observed. Chief variety responded favorably to P levels as high as 112 ppm, whereas, Lincoln and Illini were severely stunted and produced much smaller seed and oil yields at levels of 50 ppm and above than at lower levels. Leaves of plants supplied with very low levels of P developed an interveinal necrosis which could not be corrected, but spread of which could be arrested by addition of P.