Nitrogen fertilization of wheat no-till planted in alfalfa stubble

Westermann, D.T. and Crothers, S.E. (1993) Nitrogen fertilization of wheat no-till planted in alfalfa stubble. Journal of Production Agriculture. 6(3):404-408.

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Abstract

Conservation tillage practices significantly reduce soil erosion,
improve water distribution, and decrease environmental
concerns in furrow-irrigated fields. Developing optimum N fertilization
practices after legumes in these systems will help their
adoption. We conducted three field studies on a silt loam soil
to determine if N fertilizer is required for furrow-irrigated wheat
(Triticum aestivum L.) planted in herbicide killed alfalfa
(Medicago sativa L.) stubble. Fall regrowth of alfalfa was
sprayed with a mixture of 1 qt glyphosphate and 2 qt 2,4-D/acre.
`Stephens', a soft white winter wheat was planted with a double
disk opener drill in two experiments and 'Bronze Chief', a hard
red spring wheat in a third experiment. Nitrogen fertilizer (ammonium
nitrate) was spring broadcast at four rates from 0 to
200 or 240 lb N/acre. The buried plastic bag technique estimated
available N (EAN); above ground whole plant samples estimated
root zone nitrate-N; and grain plot yields estimated with a combine.
Nitrogen fertilization increased grain yield in all experiments
because sufficient N had not mineralized from soil and
legume residues before uptake needs of the wheat. The wheat
plant at the soft dough growth stage contained about 109 lb
N/acre from N mineralized from soil and legume residue
sources. The apparent N fertilizer recovery calculated by a combined
regression relationship between N uptake and fertilizer
rates was 76%. The average plant recovery of mineralized N
at maximum grain yields was calculated at 78%. Crops planted
in herbicide killed alfalfa should be selected so sufficient
nitrate-N can accumulate from mineralization before maximum
crop uptake and for N uptake ability in late summer. Nitrogen
fertilizer applications should be based on a spring soil test for
nitrate-N in this no-till system. Both practices will reduce the
potential for nitrate-N leaching losses.

Item Type:	Article
NWISRL Publication Number:	0819
Subjects:	Irrigated crops > Alfalfa Irrigated crops > Small grain Soil > Tillage Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:53
Last Modified:	01 Dec 2016 20:58
Item ID:	605
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/605