Soil survey of the Willits area, California /

"Advance sheets--Field Operations of the Bureau of Soils, 1918."

Soil survey, Auburn area, California /

"In cooperation with the University of California Agricultural Experiment Station."

Soil survey of the Napa area, California /

In cooperation with the University of California Agricultural Experiment Station."

Soil survey of the Clear Lake area, California.

In cooperation with the University of California Agricultural Experiment Station.

Soil survey of the lower Salinas Valley, California /

"Reprinted from the Report on field operations of the Bureau of Soils for 1901."--Cover.

Soil survey of the Sacramento-San Joaquin Delta area, California /

"Report no. 21."

Soil survey of the Visalia area, California /

R. Earl Stories, in charge, and Bruce C. Owen, University of California, and E.J. Carpenter, M.H. Layton and W.J. Leighty, Soil Survey Division, Bureau of Chemistry and Soils, United States Department of Agriculture.

Soil survey of the Modesto-Turlock area, California, with a brief report on a reconnaissance soil survey of the region east of the area,

Mode of access: Internet.

Soil survey of the Yuma-Wellton area, Arizona-California /

Cover title.

Soil survey manual,

"Effective 1952, the Soil Survey was transferred from the former Bureau of Plant Industry, Soils, and Agricultural Engineering to the Soil Conservation Service."

Soil survey--Desert Experimental Range, Utah /

"April 1997."

Soil survey of the Brawley area, California /

U.S. Department of Agriculture, Bureau of Soils in cooperation with the University of California Agricultural Experiment Station.

Soil survey of the Coalinga area, California /

"Literature cited": p. 91.

Soil Influence on Forest Vegetation Productivity and Patterns in the Eastern Cascades of Southern Oregon

Thesis (Master's)--University of Washington, 2016-06

Impact of pre-existing sulfate on retention of imported chloride and nitrate in variable charge soil profiles

In variable charge soils, anion retention and accumulation through adsorption at exchange sites is a competitive process. The objectives of this study in the wet tropics of far north Queensland were to investigate (i) whether the pre-existing high sulphate in variable charge soils had any impact on the retention of chloride and nitrate, derived mostly from the applied fertilizer; and (ii) whether chloride competed with nitrate during the adsorption processes. Soil cores up to 12.5 m depth were taken from seven sites, representing four soil types, in the Johnstone River Catchment. Six of these sites had been under sugarcane (Saccharum officinarum-S) cultivation for at least 50 years and one was an undisturbed rainforest. The cores were segmented at 1.0 m depth increments, and subsamples were analysed for nitrate-N, cation (CEC)- and anion-exchange capacities (AEC), pH, exchangeable cations (Ca, Mg, K, Na), soil organic C (SOC), electrical conductivity (EC), sulphate-S, and chloride. Sulphate-S load in 1-12 m depth under cropping ranged from 9.4 to 73.9 t ha(-1) (mean= 40 t ha(-1)) compared with 74.4 t ha(-1) in the rainforest. Chloride load under cropping ranged from 1.5 to 9.6 t ha(-1) (mean= 4.9 t ha(-1)) compared to 0.9 t ha(-1) in the rainforest, and the nitrate-N load from 113 to 2760 kg ha(-1) (mean = 910 kg ha(-1)) under cropping compared to 12 kg ha(-1) in the rainforest. Regardless of the soil type, the total chloride or nitrate-N input in fertilisers was 7.5 t ha(-1), during the last 50 years. Sulphate-S distribution in soil profiles decreased with depth at >2 m, whereas bulges of chloride or nitrate-N were observed at depths >2 m. This suggests that chloride or nitrate adsorption and retention increased with decreasing sulphate dominance. Abrupt decreases in equivalent fraction of sulphate (EFSO4), at depths >2 m, were accompanied by rapid increases in equivalent fraction of chloride (EFCl), followed by nitrate (EFNO3). The stepwise regression for EFCl and EFNO3 indicated that nitrate retention was reduced by the pre-existing sulphate and imported chloride, whereas only sulphate reduced chloride adsorption. The results indicate that chloride and nitrate adsorption and retention occurred, in the order chloride>nitrate, in soils containing large amounts of sulphate under approximately similar total inputs of N- and Cl-fertilisers. (C) 2004 Elsevier B.V. All rights reserved.