Irrigation small grain residue management effects on soil properties

Tarkalson, D.D. and Brown, B. and Kok, H. and Bjorneberg, D.L. (2008) Irrigation small grain residue management effects on soil properties. pp. 30-35. USA-ID-Jerome, 2008/03/04. Proceedings of the Idaho Nutrient Management Conference.

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Abstract

The effects of straw removal from fields under irrigated wheat and barley on soil
properties has become a potential concern in Idaho. The demand of straw for animal bedding
and feed, and the potential development of cellulosic ethanol production will likely increase in
the future. This paper reviews published research assessing the effects of wheat and barley straw
removal on soil organic carbon (SOC), and analyzes changes in nutrient cycling within wheat
and barley production systems. Six studies compared SOC changes with time in irrigated
systems in which wheat was removed or retained. These studies indicate that reductions in SOC
due to removal may not be a concern. Soil OC either increased with time or remained constant
when residues were removed. It is possible that belowground biomass is supplying C to soils at a
rate sufficient to maintain or in some cases, slowly increase SOC with time. A separate research
review calculated the minimum aboveground residue required to maintain SOC levels from nine
wheat system studies. Eight of the studies were dryland production systems. The grain yields
required to produce sufficient above ground biomass to maintain SOC levels ranged from 9 to
122 bu acre-1 for wheat and 14 to 185 bu acre-1 for barley. Wheat straw contains approximately
15, 3.4, and 33 lbs nitrogen (N), phosphorus (P2O5), and potassium (K2O) ton-1, respectively.
Barley straw contains approximately 12, 3.9, and 38 lbs N, P2O5, and K2O ton-1, respectively.
The calculated total economic value of the N, P2O5, and K2O in one ton of wheat and barley
straw is $17.91 and $18.18, respectively, based on average nutrient costs in the Pacific
Northwest in 2007. Rotations including wheat and barley in the irrigated agriculture of Idaho
and many other states in the Pacific Northwest are much different than what was reported in the
reported studies. There is very little reported data that can be directly related the irrigated
rotations in Idaho that include wheat or barley. To fully understand the impacts of crop residue
removal from soils in Idaho, research projects need to be conducted on crop rotations that
include wheat and barley under irrigated conditions in Idaho. Otherwise the best data available
for dissemination is from research conducted in different environments and systems.

Item Type:	Conference or Workshop Item (Paper)
NWISRL Publication Number:	1266
Subjects:	Irrigated crops > Small grain
Depositing User:	Users 6 not found.
Date Deposited:	13 Aug 2008 20:38
Last Modified:	18 Oct 2016 15:50
Item ID:	1289
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1289