EFFECTS OF CULTURAL-PRACTICES ON OAT GRAIN-YIELD AND MINERAL-COMPOSITION

Oats (Avena saliva L.) is an important protein and mineral source for humans and animals. Few data exist that relate cultural practices to oat grain nutritional quality. A split-plot design was used to evaluate the influence of the four main treatment seeding rates (36,72, 108, and 143 kg/ha), and four split treatments of N fertilizer applications (control and 56 kg N/ha applied at planting, 4 leaf, and jointing stages) on oat grain yield and mineral concentration in oat grain. The study was conducted at two Ohio locations in 1984. The soil at Columbus was a Kokomo silty clay loam (fine, mixed, mesic type Argiaquoll) and at Springfield was an Ockley silt loam (fine, loamy, mixed, mesic type Hapludalf). There was no significant location effect on grain yield, but a significant location by seeding rate interaction was observed. Location affected grain mineral concentration for all elements except Mg. Location appeared to cause differences for all elements studied except N and K. Significant location by seeding rate interactions occurred for all elements except N, P, Mn, and Zn. Seeding rate affected the concentrations of N at both locations, but the other nutrients (P, K, Mg, Cu, Zn, and Fe) were either unaffected or affected at only one location. Nitrogen application increased grain N concentration at both locations. This effect was enhanced by delaying N application. Significant location by time of N application interactions occurred for all elements except P, K, Ca, and Mg. Time of N application affected the concentrations of P, K, Mg, Fe, Cu, Zn, and Mn for at least one location. Decreased concentrations of Cu, Zn, and Mn, can be attributed to a dilution because treatments also increased grain yield. Some N treatments increased P, K, Mg, and Fe grain concentrations and yield above control values. These studies indicate that it may be possible to design oat cropping systems which allow for increased yield without sacrificing grain nutritional quality.