The Effect of Starter Fertilizer on Soybean Performance in North Dakota.

Soybean production acres have doubled within the last five years and soybean has become a major crop for rotation systems in North Dakota. The objective of this study was to determine the effect of starter fertilizer rates on soybean stand establishment when fertilizer was placed in the seed furrow and to assess the impact of seed size on potential injury due to fertilizer salts. Three soybean varieties were selected based on contrast of seed size. The trial was planted at 7-inch row spacing in mid May, 2005 and 2006. Starter fertilizer (11-52-0) was placed in the seed furrow with the rates of 0, 6, 12, and 18 Kg ha^-1.   Any amount of starter fertilizer placed with the seed resulted in significant reduction in stand establishment and stand reduction increased as starter fertilizer rates increased. However, soybean yields tended to increase with starter fertilizer application up to 6 Kg ha^-1 and soybean yield decreased above 12 Kg ha^-1 of starter fertilizer applied. Soybean responses to variety were due to the variety rather than seed size. Our study showed that higher rates (≥12 Kg ha^-1) of starter fertilizer application in the seed furrow could reduce stand establishment and seed yield.