Author
LUTCHER, L - Oregon State University | |
SCHILLINGER, WILLIAM - Washington State University | |
CHRISTENSEN, N - Oregon State University | |
Wuest, Stewart | |
WYSOCKI, DONALD - Oregon State University |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/10/2010 Publication Date: 3/15/2010 Citation: Lutcher, L.K., Schillinger, W.F., Christensen, N.W., Wuest, S.B., Wysocki, D. 2010. Phosphorus Fertilization of Late-Planted Winter Wheat into No-Till Summer Fallow. Agron. J. 102:868-874. Interpretive Summary: Delayed plant growth and reduced grain yield associated with late planting in no-till fallow might be offset by P fertilization. We conducted field experiments during nine site-years to evaluate effects of 0, 5, and 15 kg ha-1 of P fertilizer on plant P concentration, dry matter accumulation, P uptake and yield. Soft white winter wheat was planted during the third week of October. Phosphorus fertilizer was placed below and beside the seed while planting. Application of P fertilizer increased P uptake in the plants, and increased the number of spikes formed. There was no effect on kernel size. The 5 kg ha-1 P treatment increased overall grain yield by 4.4%. The corresponding increase from the 15 kg ha-1 P treatment was 7.9%. Grain yield response to P application, across sites, ranged from 2.2 to 14.5%. Improvement in P nutrition and increases in SPU and GY were consistently observed at sites where initial soil test P levels were less than 12 mg kg-1. Technical Abstract: Winter wheat (Triticum aestivum L.) is planted in low precipitation (< 300 mm) areas of north-central Oregon and east-central Washington after 14 months of tilled fallow. No-till fallow (NTF) is an alternative to the tillage-based method. The disadvantage of NTF is the loss of seed-zone moisture and inability to plant early. Delayed plant growth and reduced grain yield (GY) associated with late planting in NTF may be offset by P fertilization. We conducted field experiments during nine site-years to evaluate effects of 0, 5, and 15 kg ha-1 of P fertilizer on plant P concentration (PPC), dry matter accumulation (DMA), P uptake (PU), spikes per unit area (SPU), 1000 kernel weight (KW), kernels per spike (KPS), and GY. Soft white winter wheat was planted into NTF during the third week of October. Phosphorus fertilizer was placed below-and-beside the seed while planting. Application of 5 and 15 kg ha-1 P increased PPC and/or DMA and enhanced overall PU by 0.6 and 1.6 kg P ha-1, respectively. Corresponding increases in SPU were equal to 31 and 47 spikes cm-2. Phosphorus application had no effect on KW or KPS. The 5 kg ha-1 P treatment increased overall GY by 4.4%. The corresponding increase to the 15 kg ha-1 P treatment was 7.9%. Grain yield response to P application, across sites, ranged from 2.2 to 14.5%. Improvement in P nutrition and increases in SPU and GY were consistently observed at sites where initial soil test P (STP) levels were less than 12 mg kg-1. |