Residual Effects of Novel versus Traditional Organic Amendments for Rain-fed No-till Barley: Yield, Nutrient Uptake, and N₂O Emissions

ABSTRACT

Organic amendments recycle nutrients, but N₂O emissions are both environmental and agronomic concerns. We conducted a 4-year field experiment to determine no-till barley (Hordeum vulgare L.) yield and nutrient uptake and soil N₂O emissions following a single application of six amendment treatments: (1) no amendment (Check); (2) synthetic N fertilizer (Fert); (3) fresh beef cattle feedlot manure (ManureF); (4) beef cattle feedlot manure compost (CompostR); (5) beef cattle feedlot manure composted with cattle mortalities (CompostM); and (6) separated solids from anaerobically digested cattle feedlot manure (ADM). Barley grown in Year 1 (2006), Year 2 (2007), and Year 4 (2009) (with Year 3 (2008) under fallow) had higher grain yields from ManureF (4.73 Mg ha⁻¹) in Year 2 and ADM (6.30 Mg ha⁻¹) in Year 4 (p < 0.05) than other treatments. The grain N and P contents were not affected (p > 0.05), but N uptake over 3 years (112.8 kg N ha⁻¹ yr⁻¹), and P uptake in Year 1 (19.1 kg ha⁻¹ yr⁻¹) and Year 2 (14.3 kg ha⁻¹ yr⁻¹) from ManureF, were higher (p < 0.05×) than other treatments. The cumulative N₂O emissions from ManureF in Year 1 (1.488 kg N ha⁻¹) and from ADM in Year 2 (1.072 kg N ha⁻¹) were higher (p < 0.05) than other treatments while the fraction of applied N emitted as N₂O was small (0.00 to 0.79%) and not affected by treatment. However, the percentages of applied N emitted as N₂O from compost and ADM were similar to synthetic fertilizer and livestock manure.

Acknowledgments

The authors gratefully acknowledge the dedicated technical assistance of Brett Hill, Greg Travis, Pam Caffyn, and Andrew Olson in carrying out field and laboratory work. Special thanks to EcoAg Initiatives Inc., High River, Alberta for providing cattle manure and composts and Himark Biogas Inc. (formerly Highmark Renewables Research), Vegreville, Alberta for providing the separated solids of anaerobically digested manure. This paper is Lethbridge Research Centre contribution no. 38715050.