Row spacing effects at different levels of nitrogen availability in maize

• PABLO A. BARBIERI, HERNÁN. R. SAINZ ROZAS, FERNANDO H. ANDRADE, HERNÁN. E. ECHEVERRÍA. 2000

AGRONOMY JOURNAL

ASA

Lugar: Madison, WI; Año: 2000 p. 283 - 288

0002-1962

No tillage maize (Zea mays L.) grown without adequate N intercepts less than 95% of the incident radiation at flowering. Reducing the distance between rows could increase radiation interception and grain yield. A 2-yr experiment was conducted at INTA Research Station, Balcarce, Argentina, (37° 45 ´ S; 58° 18 ´ W) to study the effect of row spacing and N availability on intercepted radiation, kernel number and grain yield of no-till maize. Treatments consisted of a factorial combination of row width (0.35 and 0.70 m) and N (0 and 120 or 140 kg ha-1 each year) at a constant plant density. Low N decreased kernel number and grain yield. Narrow rows increased significantly kernel number per unit area and grain yield. Average increases in response to narrow rows were 14.5% and 20.5% for kernel number and grain yield, respectively. However, relative increases in response to narrow rows were greater at low N. A close association between kernel number and intercepted radiation at a period bracketing silking was observed. Relative grain yield responses to narrower rows decreased as crop radiation intercepted at flowering with conventional rows spacing increased. A decrease in row distance when N was limiting, partially offset the negative effects of N deficiency on grain yield. Our results indicate that 27 to 46% increases in grain yield can be obtained in response to narrow rows in N deficient maize crops.