Root-zone mineral nitrogen changes as affected by crop sequence and tillage

Meek, B.D. and Carter, D.L. and Westermann, D.T. and Peckenpaugh, R.E. (1994) Root-zone mineral nitrogen changes as affected by crop sequence and tillage. Soil Science Society of America Journal. 58:1464-1469.

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Abstract

Crop sequence and tillage affect soil mineral N (NH4 plus NO3)
and NO3 leaching below the root zone following alfalfa (Medicago
sativa L.). A 2-yr field experiment was conducted in south-central
Idaho to determine the effect on soil NO3 levels of a corn (Zea mays L.)-
wheat (Triticum aestivum L.) rotation compared with a bean (Phaseolus
vulgaris L.)-bean rotation and to demonstrate improved N utilization
with a corn-wheat rotation. Alfalfa, growing on an irrigated Portneuf
silt loam (coarse-silty, mixed, mesic Durixerollic Calciorthid), was
killed in October 1989 with herbicide. Treatments were: (i) BT-BT:
conventional tilled bean grown in 1990 and 1991; (ii) CNT-WNT:
no-till silage corn grown in 1990, and no-till winter wheat grown in
1990-1991; and (iii) CT-WT: same as CNT-WNT but under conventional
tillage. Similar amounts of soil N were mineralized the first
(275 kg N ha-1) and second (213 kg N ha-1) year after killing the
alfalfa in all treatments. The BT-BT treatment had the highest growing-season
soil mineral N (up to 251 kg ha-1, 0-0.45-m depth) because
the N uptake by bean was lower (187 kg N ha-1) than corn (252 kg
N ha-1, average of CT-WT and CNT-WNT treatments) in 1990 and
later than winter wheat uptake in 1991. Most wheat N uptake had
occurred by late June when bean uptake was just starting. A rotation
that follows alfalfa with corn or a crop with a similar N uptake pattern,
instead of bean, will save N fertilizer, lower soil NO3 levels, and reduce
NO3 leaching potential

Item Type:	Article
NWISRL Publication Number:	0852
Subjects:	Soil > Tillage Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:54
Last Modified:	23 Nov 2016 21:31
Item ID:	630
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/630