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Fertilizer and Soil Nitrogen Use by Corn and Border Crops in a Strip Intercropping System
Author(s) -
Ghaffarzadeh Mohammadreza,
Préchac Fernando García,
Cruse Richard M.,
Harbur Matthew M.
Publication year - 1998
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1998.00021962009000060007x
Subject(s) - agronomy , intercropping , tillage , stover , loam , fertilizer , mathematics , nitrogen , crop , chemistry , soil water , biology , ecology , organic chemistry
Corn ( Zea mays L.) has greater yield potential when strip‐intercropped than when monocropped, but this potential may be compromised by a failure to understand how N requirements change with row position and the possible N competition of adjacent crops. A four block, completely randomized, split‐plot experiment was conducted on a Haig loam soil (fine, smectitic, mesic Vertic Argiaquolls) in southern Iowa, to determine crop utilization of N fertilizer pointinjected into corn rows. Nitrogen fertilizer uptake was evaluated in (i) corn rows injected with labeled N fertilizer; (ii) corn rows adjacent to the injected rows; and (iii) plants at the edge of the adjacent soybean [ Glycine max (L.) Merr.] and oat ( Avena sativa L.)‐alfalfa ( Medicago saliva L.) strips. Main treatments consisted of three tillage systems: conventional tillage (CT), reduced tillage (RT), and no‐till (NT). Subplot treatments consisted of point injection of l5 N‐enriched NH 4 NO 3 (67 kg N ha −1 ) in‐row at three row positions within the corn strips. Grain and stover yield, Kjeldahl N, and isotope composition of plant materials were determined. Corn yield and labeled‐N recovery differed with tillage to the extent that tillage affected early and total season moisture availability. Labeled‐N recovery in labeled rows did not differ with row position. Labeled‐N recovery in unlabeled rows or crop borders was typically less than 5% of that recovered by labeled rows. Nitrogen is primarily recovered by the row to which it is applied; therefore, row‐by‐row precision applications seem to be an appropriate management tool.