461894.fig.004a
(a)
461894.fig.004b
(b)
Figure 4: Soybean grain yield response to K-fertilizer additives (%N-%P2O5-%K2O-%S) of 3-18-18-0 ( , ), 0-0-25-17 ( , ), 5-0-20-13 ( , ), or 0-0-62-0 ( , ) applied alone to weed-free plots (a) and with glyphosate to weedy plots (b) for 3-18-18-0 ( , ), 0-0-25-17 ( , ), 5-0-20-13 ( , ), and 0-0-62-0 ( , ) at Malden in 2004 and 2005. Data were combined over years, and comparisons between figures are valid. The nontreated, weed-free, and glyphosate plus nonionic surfactant plus diammonium sulfate grain yields were 3230, 3660, and 3570 kg ha−1, respectively. There were no significant differences among treatments ( ) at this location.