Assessment of the nitrogen management strategy using an optical sensor for irrigated wheat

摘要: Blanket fertilizer nitrogen (N) recommendations for large irrigated wheat tracts lead to low N-use efficiency due field-to-field variability in soil N supply and seasonal yield. To achieve high use efficiency, a site-specific management strategy using GreenSeeker™ optical sensor was evaluated. We conducted seven field experiments during 2004–2006 at three locations define relationships between in-season measurements yield of know whether response can be estimated by measurements. During 2005–2007, four were assess the sensor-based work out prescriptive followed prior applying sensor-guided dose. observed robust estimates Feekes 5–6 7–8 stages actual yields. Response defined highly correlated with harvest index. Sensor-guided applications resulted levels efficiency. Application 90 kg ha-1 planting or two equal doses crown root initiation stage appropriate management. This study reveals that achieved replacing blanket recommendation an consisting moderate amount dose wheat.