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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 M chemistry, and increase crop yield in a direct-seeded system. Treatments of subsurface banded fertilizer (120-168 kg N [ha.sup.-1][ yr.sup.-1]) alone or with subsurface banded lime (224 kg [ha.sup.-1][ yr.sup.-1]), or a one-time broadcast application of lime (7000 kg [ha.sup.-1] or elemental S (1000 kg [ha.sup.-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 [Al.sup.3+] activity [([Al.sup.3+])] 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; [FA.sub.2] [Al.sup.+] and [FA.sub.2] [AlO[H.sup.0]). Solid- and solution-phase organic complexes may control ([Al.sup.3+]) at pH Abbreviations: CT, conventionally tilled; DS, direct seeded; FA, fulvic acid; IPNW, inland Pacific Northwest; NT, no-till.

Individual soil variables are spatially dependent and the variables are systematically correlated in the landscape. The predominant shrub in the inter-mountain western US, big sagebrush, is related with multiple-variable indicator transform resource islands and adjacent to the big sagebrush. There are maximum chances for encountering zones of above-median resources.