Precision N Management: Developing Science-Based Practices.

Increasing N use efficiency (NUE) with precision technologies (e.g. GPS,

remote sensing, yield monitors, VRT) will require increased scientific understanding of

landscape-scale processes and their impacts on decision-making. We are assessing

yield-water-NUE relationships among diverse environments to elucidate site-specific

processes that regulate the environmental and economic performance of wheat-based

cropping systems. This effort will produce grower-oriented site- and time-specific N

management monitoring, decision-aid and evaluation tools required to formulate N

efficient and environmentally sound conservation strategies. We are pursuing these

goals through the integration of crop (e.g. yield monitoring), soil (e.g. apparent electrical  conductivity), remote sensed (e.g. Rapideye satellite imagery) and economic

data using field-scale studies at the WSU Wilke Farm, WSU Cook Agronomy Farm and

on-farm locations. Here, we are: (1) measuring site-specific wheat performance and

related  variables (yield, protein, economic return, N status, N use efficiency, soil

organic matter and inorganic N) required for precision N management decisions; and

(2) developing and testing site- and time-specific decision-aid and evaluation tools

including an economic assessment required by growers to formulate and assess

science-based precision N recommendations. Our expectations are to develop

science-based decision aids that improve the application of precision N management

strategies in wheat.