Row Spacing, Landscape Position, and Maize Grain Yield

The use of narrow row spacing for the different landscape positions of a field could punish maize (Zea mays L.) grain yield. Two experiments were conducted (2006/07 and 2007/08) at different landscape positions in the Inland Pampas of Argentina. Hybrid DK190MGwas grown at the commonest plant density used at each landscape position (approximately 5.1 plants/m(2) at the summit, 6.5 plants/m(2) at shoulder-slope position, and 7.6 plants/m(2) at foot-slope position) with three row spacings (0.38m, 0.52m, and 0.38m in a 2 x 1 skip-row pattern). At the silking stage of maize crops, soil water content (0-200 cm depth) and maximum light capture differed (0.05 < p < 0.001) among landscape positions but were similar among row spacings. Differences in grain yield among landscape positions (mean 806, 893, and 1104 g/m(2) at the summit, shoulder-slope position, and foot-slope position, resp.) were related to kernel number/m(2) (r = 0.94), which was closely related (r = 0.90) to light capture around silking. Grain yield reductions (6 to 20%) were recorded when crops were cultivated in rows 0.38m apart. The skip-row pattern did not improve grain yield. Maize grain yield was optimized in rows 0.52m apart along the sandy landscape positions of the fields.