HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Brown, T. T. Articles by Rossi, R. E. PubMed Articles by Brown, T. T. Articles by Rossi, R. E. Agricola Articles by Brown, T. T. Articles by Rossi, R. E. Related Collections Soil Fertility and Productivity Soil pH

SOIL FERTILITY & PLANT NUTRITION

Lime Effects on Soil Acidity, Crop Yield, and Aluminum Chemistry in Direct-Seeded Cropping Systems

^a Dep. of Crop and Soil Sciences, P.O. Box 646420, Washington State Univ., Pullman, WA 99164-6420
^b USDA-ARS, Land Manage. and Water Conserv. Res. Unit, 215 Johnson Hall, Washington State Univ., Pullman, WA 99164-6421
^c John Deere Agri Services, 3665 JFK Pkwy., Fort Collins, CO 80525

^* Corresponding author (richk{at}wsu.edu).

Soil acidification threatens dryland crop production in the inland Pacific Northwest (IPNW). Our objective was to assess the efficacy of lime to lower soil acidity, alter Al chemistry, and increase crop yield in a direct-seeded system. Treatments of subsurface banded fertilizer (120–168 kg N ha^–1 yr^–1) alone or with subsurface banded lime (224 kg ha^–1 yr^–1), or a one-time broadcast application of lime (7000 kg ha^–1) or elemental S (1000 kg ha^–1) were initiated in spring 2002. Grain yield was measured annually from 2002 to 2005 in a spring barley (Hordeum vulgare L.)–spring wheat (Triticum aestivum L.)–winter wheat rotation. Soil was sampled in spring 2004 to assess pH and model Al speciation. Low pH was evident at the depth of fertilizer placement (5–10 cm). Broadcast lime increased pH in the surface 15 cm, although reductions in Al³⁺ activity [(Al³⁺)] occurred only in the 0- to 5-cm layer. Relative to banded N, there was no increase in pH at the 5- to 10-cm depth where banded lime was placed. At the 0- to 5-cm depth, lower pHs were observed with broadcast S (4.6) compared with the banded N control (5.1) or banded lime (5.0). There was no effect of treatment on yield. Modeling suggests that soluble Al is dominated by organic matter–Al complexes (fulvic acid, FA; FA₂Al⁺ and FA₂AlOH⁰). Solid- and solution-phase organic complexes may control (Al³⁺) at pH <5.5. Although acidification is a concern in the IPNW, the high organic matter content in direct-seeded soils may buffer against Al phytotoxicity.

Abbreviations: CT, conventionally tilled • DS, direct seeded • FA, fulvic acid • IPNW, inland Pacific Northwest • NT, no-till