Browse on keywords: organic matter OR
Search results on 12/12/18
1033. Bracken, A.. no date. Dry farming.. USU (Logan) Course notes for Agronomy 116.
Describes climatic factors that cause dry lands, the dryland regions of the world, soils of dry areas, organic matter and N relations. Dry farms in northern UT have lost 16% of soil N and 22% of SOM from first foot of soil, after 44 years of cropping.
1632. Dormaar, J.F. and U.J. Pittman. 1980. Decomposition of organic residues as affected by various dryland spring wheat-fallow rotations.. Can. J. Soil Sci. 60:97-106.
8926. Lunt, H.A.. 1923. Some factors affecting soil organic matter decomposition.. M.S. thesis, Washington State College, Pullman, WA.
2918. Idaho Agr. Expt. Sta.. 1950. Annual Report. Id Agr. Expt. Sta. Bull. #280.
T: hay yields, economics
197. Allen, M.C.. 1931. Sequence of activity and effect of certain specific groups of microorganisms.. M.S. Thesis WSC.
Experimental approach to monitor soil microbial activity under different treatments. T: Extensive tables on microbial biomass from Palouse silt loam.
565. Auld, D.L., B.L. Bettis, M.J. Dial and G.A. Murray. 1982. Austrian winter and spring peas as green manure crops in northern Idaho.. Agron. J. 74:1047-1050.
T: organic matter and nitrogen contributions, pea yield.
690. Bear, F.E.. 1931. Soil management.. J. Wiley, N.Y..
A fairly complete text on soil management - fertility, tillage, organic matter, fertilizers; describes proper plow, moisture content, and depth to improve soil tilth; describes weeds as a potential cover crop; field study in England - free living N fixers input ~44 lb/ac/yr (est.). Azotobacter critical pH = 6.4.
906. Blake, J.. 1989. Reading the soil.. Seattle Times p. F1, 7/24/89.
Describes in popular style the highlights of the long-term plots at Pendleton, OR. The importance of organic matter is stressed.
1024. Boyle, M., W. Frankenberger, L. Stolzy. 1989. The influence of organic matter on soil aggregation and water infiltration.. J. Production Agric. 2:290-299.
Describes a conceptual model for soil aggregate formation and stability. Soil organic matter contributes to improvement of soil structure in a number of ways. It enhances microbial action which produces more polysaccharides. Aggregation is the product of such forces as mechanical binding by roots and fungal hyphae, temporary adhesive properties by products of microbial synthesis and decay, and persistent cementing action by resistent humus components. Organic materials that decompose quickly (low C:N) had a rapid but ephemeral effect on soil structure. Plant materials that are more resistant to decomposition are slower but more persistent in changing structure. Soil polysaccharides are more complex and diverse than those derived from plants and microbes. Long-term pastures are ideal for aggregation. Good distribution of OM in soil is achieved from the fine roots of grasses, which can translocate as much as 50% of their photosynthate below ground. Green manuring rarely increases aggregate formation, but may inhibit its destruction. Cereals are similar to perennials in increasing % water stable aggregates formed during vegetative growth, but perennials are superior in maintaining the structure after the growing season. A grass-legume mixture is most effective at maintaining soil aggregation, while cereals and root crops are least effective.
1042. Bradfield, R.. 1954. Organic farming with chemical fertilizers.. J. Agric. Food Chem., 2:1216-1220.
An excellent discussion of soil organic matter and the question of fertilizer use. T: Comparative direct residual effects of manure and chemical fertilizers.