Browse on keywords: fertility OR soil structure
Search results on 06/19/18
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.
6001. Russell, J.S. and C.H. Williams. 1982. Biogeochemical interactions of carbon, nitrogen, sulfur, and phosphorus in Australian agroecosystems.. IN: J.R. Freney and I.E. Galbally (eds.). Cycling of C,N,S, and P in terrestrial/aquatic ecosystems..
An excellent review article looking at nutrient cycling and gains and losses over time under different agricultural management. Estimates that over 3 million tons C are tied up in soil organic matter additions each year in Australian farmland. SOM levels are higher now than the native condition under systems that have used a legume pasture in the rotation. There was a generally downward trend in the soil C:N over the first 25 yr of OM accumulation. A WWPP rotation slightly increased SOM, while WWWP decreased it slightly, and fallow systems decreased it significantly. Increases in SOM increased the water-stable aggregates in the soil and improved infiltration. Leguminous pastures had an acidifying effect on the underlying soil.