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Search results on 06/19/13
1729. Douglas, C.L., R.R. Allmaras and N.C. Roager. 1984. Silicic acid and oxidizable carbon movement in a Walla Walla silt loam.. Soil Sci. Soc. Amer. J. 48:156-162.
Leachate concentrations and net transfers of silicic acid decreased as long term C additions and soil pH increased; liming reversed this; results in adverse physical properties below the plow layer - decreased hydraulic conductivity, increased cementation.
3392. Johnson, E.C.. 1952. Emphasis on conservation.. WA Agr. Expt. Sta. Cric. #186.
A narrative on historical efforts in soil conservation at Washington State College, including establishment of the Soil Erosion Station near Pullman, WA.
4058. Mann, F.. 1920. Frank Mann's soil book.. Prairie Farmer, Chicago, 180p..
A detailed description of sustainable soil management on an Illinois farm.
7103. Vandecaveye, S.C. and C.D. Moodie. 1942. Occurrence and activity of Azotobacter in semiarid soils in Washington.. Soil Sci. Soc. Am. Proc., 7:229-236.
The Azotobacter population in any of the nonirrigated semiarid soils tested was too small to contribute significantly to nitrogen fixation.
10864. Fitch, B.C., S.K. Chong, J. Arosemena, and G.W. Theseira. 1989. Effects of a conditioner on soil physical properties.. Soil Sci. Soc. Amer. J. 53:1536-1539.
Agri-SC, a soil conditioner, was applied at four rates to a silt loam in Illinois for two successive years. There were no effects of the treatments, but the various physical parameters measured all declined the second year, probably due to the detrimental effects of fallow the land during the study.
178. Alef, K. and D. Kleiner. 1989. Rapid and sensitive determination of microbial activity in soils and in soil aggregates by dimethylsulfoxide reduction.. Biol. Fert. Soils 8:349-355.
Based on the reduction of dimethylsulfoxide (DMSO) to dimethylsulfide (DMS) by microorganisms, a simple, rapid, sensitive and inexpensive method for the determination of microbial activity in soil samples was developed. When DMSO was added to samples, DMS appeared immediately in the gas phase, which was quantitatively analyzed by gas chromatography. The DMS liberation rate was constant for several hours. The reaction immediately starts and its linearity indicate that neither the physiological state nor the number of organisms were changed by the assay. The method is sufficiently sensitive to allow measurements of activity in very small samples.
261. Allmaras, R.R., K. Ward, C.L. Douglas and L.G. Ekin.. 1982. Long-term cultivation effects on hydraulic properties of a Walla Walla silt loam.. Soil Tillage Research, 2:265-279.
Hydraulic properties were significantly changed by 50 years of wheat-pea and/or wheat-fallow rotations. pH was reduced, dry bulk density was increased, more smaller soil pores were produced at the expense of larger pores, in the upper 30 cm soil hydraulic conductivity was reduced 10-fold increasing water runoff and denitrification.
404. Anon.. 1989. Algae: companion crop for reduced compaction.. Journal of Sustainable Agriculture (CA) 2:16..
Soil Technologies Corp. of Fairfield, IA is marketing strains of green algae to reduce compaction and improve soil aggregation. The algae produce polysaccharides which help bind soil particles together. The product Microp is applied in the spring or fall, and must be undisturbed by tillage for 3-4 weeks. Polysaccharides will leach down into the soil. Their field results show a 15% reduction in compaction at 8" depth after the first year. The cost is $6/ac.
651. Bakken, L.R., T. Borresen and A. Njos. 1987. Effect of soil compaction by tractor traffic on soil structure, denitrification, and yield of wheat.s. J. of Soil Sci., 38:541-552.
Tractor traffic on wet soil reduced the pore volume, doubled the percentage of large aggregates (>20mm), reduced the wheat yield by about 25%, and increased the N-loss through denitrification by a factor of 3-4. None of these parameters was affected by tractor traffic at low soil moisture content. The weight of the tractor did not significantly alter the effect of compaction on the measured parameters.
886. Blaikie, P. and H. Brookfield. 1987. Land degradation and society.. Methuen, London, pp.296.
Sections cover: Measuring land degradation; economic costs and benefits of degradation and its repair; etc. The farmer, the state and the land in developed market economics.