Nitrogen balance in response to dryland crop rotations and cultural practices

摘要: Abstract Nitrogen balance provides a measure of agroecosystem performance and environmental sustainability by taking into accounts N inputs outputs retention in the soil. The objective this study was to evaluate based on soil sequestration after 7 yr response five dryland crop rotations (two 4-yr stacked two alternate-year one monocropping) cultural practices arranged split-plot design northern Great Plains, USA. Stacked were durum ( Triticum turgidum L.)-durum-canola Brassica napus L.)-pea Pisum sativum L.) (D-D-C-P) durum-durum-flax Linum usitatissimum (D-D-F-P). Alternate-year durum-canola-durum-pea (D-C-D-P) durum-flax-durum-pea (D-F-D-P). Monocroppping continuous (CD). Cultural traditional (conventional till, recommended seed rate, broadcast fertilization, reduced stubble height) ecological (no-till, increased banded height). Total annual input due pea fixation, atmospheric deposition, N, nonsymbiotic fixation lower CD than other rotations, regardless practices. output grain removal losses denitrification, volatilization, plant senescence, leaching, gaseous (NO x ) emissions, surface runoff D-F-D-P D-C-D-P D-C-D-P, D-D-C-P, D-F-D-P. rate at 0–125 cm from 2005 2011 ranged 40 kg N ha −1  yr for D-D-F-P 52 kg N ha CD. −39 −36 kg N ha with compared 9–25 kg N ha both Because reliance external removal, flow, surplus, legumes, nonlegumes, oilseed crops rotation can be productive environmentally sustainable monocropping,