Corn Hybrid Interactions with Soil Nitrogen Level and Water Regime (original) (raw)

Corn (Zea mays L.) producers are interested in quantifying interactions of hybrid, fertility and water regime production practices as they relate to grain yield and quality. This study was conducted to determine the interaction effects of corn hybrid with soil N level and water regime (WR) on grain yield, protein content (GP), kernel breakage susceptibility (KBS), kernel density (KD), and N use efficiency (NUE). In 1987 and 1988, a splitsplit plot designed experiment with six commercial corn hybrids, six soil N levels, and two water regimes (irrigated and nonirrigated) was conducted at Mead, NE, on a Sharpsburg silty clay loam soil (fine montmorillinitic, mesic Typic Arguidoll). In the low rainfall year of 1988, grain yields increased linearly for hybrids 442,688,488, and 692 as soil N levels increased, while hybrids 629 and 212 grain yields increased quadratically and peaked at 185 to 235 Ib/acre soil N levels. Increasing soil N level decreased KBS of all hybrids, but hybrid response was inconsistent across WR and years. In 1988, irrigation resulted in denser kernels by 0.0400 to 0.0475 g/ml, except for hybrid 442, whose KD was only 0.0273 g/ml greater. In 1987, GP of hybrids 442, 629, 692, 212, and 488 increased linearly as soil N levels increased while the GP of hybrid 688 peaked at the 235 Ib/acre soil N level. In 1988, GP of hybrid 688 was similar across WR while all other hybrids had 1.9 to 2.5% higher GP on nonirrigated plots. In 1987 and on irrigated plots in 1988, NUE differences were greater at soil N levels below 85 Ib/acre with hybrid 442 having the highest NUE. Producers considering use of low fertilizer N rates must recognize importance of corn hybrid selection for high grain yield and NUE, and that low N levels reduce grain quality as measured by KBS, KD, and GP. C ORN PRODUCERS are interested in the interactive nature of production practices, especially as it relates to grain yield and quality. In the western Corn