Winter Wheat Yield, Quality, and Nitrogen Removal Following Compost- or Manure-Fertilized Sugarbeet

ABSTRACT

To efficiently use nitrogen (N) while protecting water quality, one must know how a second-year crop, without further N fertilization, responds in years following a manure application. In an Idaho field study of winter wheat (Triticum aestivum L.) following organically fertilized sugarbeet (Beta vulgaris L.), we determined the residual (second-year) effects of fall-applied solid dairy manure, either stockpiled or composted, on wheat yield, biomass N, protein, and grain N removal. Along with a no-N control and urea (202 kg N ha⁻¹), first-year treatments included compost (218 and 435 kg estimated available N ha⁻¹) and manure (140 and 280 kg available N ha⁻¹). All materials were incorporated into a Greenleaf silt loam (Xeric Calciargid) at Parma in fall 2002 and 2003 prior to planting first-year sugarbeet. Second-year wheat grain yield was similar among urea and organic N sources that applied optimal amounts of plant-available N to the preceding year’s sugarbeet, thus revealing no measurable second-year advantage for organic over conventional N sources. Both organic amendments applied at high rates to the preceding year’s sugarbeet produced greater wheat yields (compost in 2004 and manure in 2005) than urea applied at optimal N rates. On average, second-year wheat biomass took up 49% of the inorganic N remaining in organically fertilized soil after sugarbeet harvest. Applying compost or manure at greater than optimum rates for sugarbeet may increase second-year wheat yield but increase N losses as well.

Abbreviations CNS, carbon–nitrogen–sulfur

KEYWORDS:

• Dairy manure
• grain yield
• nitrogen uptake
• nutrient management
• organic fertilizer
• protein
• small grain
• urea

Acknowledgments

We thank Drs. Christopher Rogers, Olga Walsh, and others for reviewing an initial draft of the paper. We also thank Dr. Bruce Mackey, Albany, California, for assisting with our statistical analyses, and Lindsey Balis-Cypriano, Percy Booth, Jim Foerster, Larry Freeborn, Roger Gibson, Paula Jolley, Myles Miller, Philip O’Connor, and John Rawluk for their able assistance in the field and laboratory.

Declaration of Interest

Manufacturer or trade names are included for the readers’ benefit. By including names, the USDA-ARS implies no endorsement, recommendation, or exclusion.