e-journal

Effect of Nitrogen Addition and Weed Interference on Soil Nitrogen and Corn Nitrogen Nutrition

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Weeds cause crop loss indirectly by reducing the quantity of resources available for growth. Quantifying the effects of weed interference on nitrogen (N) supply, crop growth, and N nutrition may assist in making both N and weed management decisions. Experiments were conducted to quantify the effect of N addition and weed interference on soil nitrate-N (NO3-N) over time and the dependence of corn growth on NO3-N availability, determine the corn N nutrition index (NNI) at anthesis, and evaluate if relative chlorophyll content can be utilized as a reliable predictor of NNI. Urea was applied at 0,60, and 120 kg N/ha to establish N treatments. Season-long weedy, weed-free, and five weed interference treatments were established by delaying weed control from time of crop planting to the V3, V6, V9, V15, or R1 stages of corn development. Soil NO3-N ranged from 20 kg N/ha without N addition to 98 kg N/ha with 120 kg N/ha added early in the season, but crop and weed growth reduced soil NO3-N to 10 kg N/ha by corn anthesis. Weed presence reduced soil NO3-N by up to 50%. Average available NO3-N explained 29 to 40% of the variation in corn shoot mass at maturity. Weed interference reduced corn biomass and NNI by 24 to 69%. Lack of N also reduced corn NNI by 13 to 46%, but reduced corn biomass by only 11 to 23%. Nondestructive measures of relative chlorophyll content predicted corn NNI with 65 to 85% accuracy. Although weed competition for factors other than N may be the major contributor to corn biomass reduction, the chlorophyll meter was a useful diagnostic tool for assessing the overall negative effects of weeds on corn productivity. Further research could develop management practices to guide supplemental N applications in response to weed competition.

Nomenclature: Corn, Zea mays L. ‘DK589RR’.

Key words: Duration of weed interference, nitrogen uptake, resource acquisition, interplant competition, nitrogen nutrition index, chlorophyll.

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Ketersediaan

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Informasi Detail

Judul Seri

Weed Technology

No. Panggil

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Penerbit

New York : Weed Science Society America., 2010

Deskripsi Fisik

Weed Technology 2010 24:50–58

Bahasa

English

ISBN/ISSN

DOI: 10.1614/WT-09-0

Klasifikasi

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Tipe Isi

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Tipe Media

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Tipe Pembawa

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Edisi

24, January–March 2010

Subjek

PERTANIAN.
ILMU GULMA

Info Detail Spesifik

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Pernyataan Tanggungjawab

agus

Versi lain/terkait

Lampiran Berkas

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