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Tillage, Cropping Sequence, and Nitrogen Fertilization Influence Dryland Soil Nitrogen

Author:
Sainju, Upendra M.
Source:
Agronomy journal 2013 v.105 no.5 pp. 1253
ISSN:
1435-0645
Subject:
Hordeum vulgare, Pisum sativum, arid lands, continuous cropping, conventional tillage, crop rotation, cropping sequence, denitrification, emissions, fallow, fertilizer rates, greenhouse gases, leaching, losses from soil, malting barley, nitrogen, nitrogen content, nitrogen fertilizers, nitrous oxide, no-tillage, nutrient content, peas, soil depth, soil nutrient balance, soil nutrients, volatilization, Montana
Abstract:
Management practices can reduce N losses through N leaching and N2O emissions (a greenhouse gas) by increasing soil N storage. The effects of tillage, cropping sequence, and N fertilization rate were studied on N contents in dryland crop biomass, surface residue, and soil at the 0- to 120-cm depth, and estimated N balance from 2006 to 2011 in eastern Montana. Treatments were no-till continuous malt barley (Hordeum vulgaris L.) (NTCB), no-till malt barley-pea (Pisum sativum L.) (NTB-P), no-till malt barley-fallow (NTB-F), and conventional till malt barley-fallow (CTB-F), each with 0 to 120 kg N ha-1. Biomass and surface residue N increased with increased N rate and were greater in NTB-P or NTCB than CTB-F and NTB-F in all years, except in 2006 and 2011. Soil total nitrogen (STN) at 0 to 60 cm decreased from 2006 to 2011 at 254 kg N ha-1 yr-1, regardless of treatments. At most depths, soil NH4-N content varied, but NO3-N content was greater in CTB-F than other cropping sequences. Estimated N balance was greater in NTB-P with 40 kg N ha-1 than other treatments. No-till continuous cropping increased biomass and surface residue N, but conventional till crop-fallow increased soil available N. Because of increased soil N storage and reduced N requirement to malt barley, NTB-P with 40 kg N ha-1 may reduce N loss due to leaching, volatilization, and denitrification compared to other treatments.
Agid:
56967
Handle:
10113/56967