Plant Population and N Application Time for Improved Spring Wheat Production.

Increasing the efficiency of spring wheat production is vitally important to Montana growers’ bottom line, and Montana’s competitiveness on the market. In  semiarid regions of the Northern Great Planes, agronomic practices must aim at maximum capture and utilization of plant growth resources. The key to well-established crop stand is optimal seeding rate, while proper fertilization strategy ensures that the nutritional requirements of the crop are met in order to optimize both yield and quality. Seeding rate and nutrition are among the top factors affecting cereal crops’ grain yield. This study is proposed to develop guidelines for Montana growers focusing on seeding rate and nitrogen (N) management strategy for optimized spring wheat grain yield and grain protein content. The specific key objectives are: 1) To determine how late can N be applied to spring wheat without reducing grain yield and quality; and 2) To determine the most effective combination of seeding rate and N rate and application time for spring wheat dryland production system. Two dryland experimental sites will be established in Montana in the cooperating wheat producers’ fields. Two seeding rates - 60 and 120 lb/ac pure live seed (PLS) will be assessed. Three N fertilizer rates (25, 75, and 125 lb N/ac) along with the unfertilized check will be evaluated. Four N application times will be evaluated - at seeding, early tillering, late tillering- beginning/beginning of jointing, and flag leaf emergence. Statistical analysis will be carried out to evaluate the effect of seeding rate, N fertilizer application rate and application time on plant stand, plant height, spike density, number of seeds per spike, test weight, spring wheat grain yield, grain protein, protein yield, N uptake, and N use efficiency (NUE).