Furrow irrigation and N management strategies to protect water quality

IRRIGACION CON SURCOS Y ESTRATEGIAS DE MANEJO DE N PARA PROTEGER LA CALIDAD DEL AGUA

Lehrsch, Gary A. and Sojka, R.E. and Westermann, D.T. (2001) Furrow irrigation and N management strategies to protect water quality. Communications in Soil Science and Plant Analysis. 32(7&8):1029-1050.

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Abstract

N management under furrow irrigation is difficult because nitrate-nitrogen
(NO3-N) is frequently leached to groundwater. Banding
and sidedressing N fertilizer on a non-irrigated side of a row of
corn (Zea mays L.) might increase N uptake and minimize nitrate
leaching potential by reducing the NO 3 -N in soil profiles at harvest,
thereby protecting water quality. For two years in the field,
we evaluated two N placements (broadcast vs. banded), two row
spacings (0.76-m vs. a modified 0.56-m), and two ways of positioning
irrigation water (applying water to the same side or alternating
sides of the row with successive irrigations) for their effects
on N uptake in corn silage and soil profile NO3-N (to the 0.9-m
depth). In southern Idaho, we grew field corn in Portneuf silt loam
(coarse silty, mixed superactive, mesic Durinodic Xeric Haplocalcid)
by irrigating every second furrow nine times in 1988 and
seven times in 1989. We measured N uptake by harvesting whole
plants at physiological maturity and NO3-N in soil samples taken
at two in-row locations in selected plots after each irrigation.
Where irrigating alternating sides of the row, two-year average N
uptake from 0.76-m rows was 131 kg ha- 1 , 15% greater (P<0.001)
than from 0.56-m rows. Where irrigating the same furrow all season,
N uptake from banding equaled that from broadcasting the
first year but was 21% greater (P<0.001) the second. Applying
water to the same furrow decreased profile N by about 170 kg ha- 1
under 0.76-m rows by season's end in 1988. In 1989, irrigating the
same furrow and banding N into an adjacent, never-irrigated furrow
produced season-average profile N of a) 303 kg ha- 1 , the least
under all fertilized 0.76-m rows, and b) 152 kg ha- 1 under 0.56-m
rows, half that under similarly treated 0.76-m rows. Our findings
suggest that corn in 0.76-m rows should be fertilized by banding
N into every second furrow and irrigated season-long using the
remaining, non-fertilized furrows because those practices maintained
or increased N uptake in silage and minimized residual
NO3-N in 0.9-m soil profiles at season's end.

Item Type:	Article
NWISRL Publication Number:	1044
Subjects:	Irrigation > Furrow irrigation > Erosion Water > Water quality > Nutrients Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:50
Last Modified:	14 Nov 2016 17:25
Item ID:	122
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/122