Grassland cultivated

C. A. Cambardella and E. T. Elliott, Carbon and nitrogen dynamics of soil organic matter fractions from cultivated grasslands soils. Soil Sci. Soc. Am. J. 58 123 (1994). 

Mosier A., Schimel D., Valentine D., Bronson K., and Parton W. (1991) Methane and nitrogen oxide fluxes in native, fertilized, and cultivated grasslands. Nature 350, 330-332. 

Carbon. Most of the Earth s supply of carbon is stored in carbonate rocks in the Hthosphere. Normally the circulation rate for Hthospheric carbon is slow compared with that of carbon between the atmosphere and biosphere. The carbon cycle has received much attention in recent years as a result of research into the possible relation between increased atmospheric carbon dioxide concentration, most of which is produced by combustion of fossil fuel, and the "greenhouse effect," or global warming. Extensive research has been done on the rate at which carbon dioxide might be converted to cellulose and other photosyntheticaHy produced organic compounds by various forms of natural and cultivated plants. Estimates also have been made of the rate at which carbon dioxide is released to soil under optimum conditions by various kinds of plant cover, such as temperature-zone deciduous forests, cultivated farm crops, prairie grassland, and desert vegetation. 

Cambardella CA, Elliott ET (1992) Particulate soil organic matter changes across a grassland cultivation sequence. Soil Sci Soc Am J 56 777-783... 

However, there are differences between the various soil and climate types, the ways of utilisation and the crop species (Freibauer et al. 2004 Smith 2008). Depending on the species, the cultivation of annual crops causes a loss of 280-1,300 kg C ha-1 year-1, while grasslands and other conventional perennial crops do not cause a loss but a growth by 600-800 kg ha-1 year-1, and SRCs by even 400-1,600 kg ha-1 year1 because these fields are not tilled (Table 5.8). 

Control of NH3 loss during grassland production presents many problems. The most readily manipulated loss is that arising from land application of slurry. Injection effectively eliminates NH3 loss, as discussed above, and is sometimes reflected in increased efficiency of utilisation of the N applied (29). On grass/arable farms, application of slurry prior to ploughing or cultivation also increases N recovery by the following crop. However, the speed with which NH3 loss can occur requires that cultivation takes place almost immediately after application (29). 

As far as biodiversity of domestic floral species is concerned, research results concentrate on measuring the parameters crop rotation diversity, number of cultivated crops and grassland composition. Hausheer et al. (1998), evaluated crop rotations on 110 organic, integrated and conventional farms in a Swiss pilot farm project and determined the following situations on organic farms. 

Steenwerth, K.L., Jackson, L.E., Calderon, F.J., Stromberg, M.R. and Scow, K.M. 2003. Soil microbial community composition and land use history in cultivated and grassland ecosystems of coastal California. Soil Biology and Biochemistry 35(3) 489-500. 

Ellis, F.B., Mercer, E.R. Milbourn, G.M. (1968) The contamination of grassland with radioactive strontium - II Effect of lime and cultivation on the levels of strontium-90 in herbage. Radiation Botany, 8, 269-84. 

Figure 11.11 Canonical variate plots showing increases in discrimination among three visually similar topsoils as soil attributes (analyses) are combined. A is a cultivated podzol/improved pasture B is a brown earth/improved pasture and C is a brown earth/seminatural grassland. Four replicate values sampled 4 m apart plus 90% confidence ellipses.

Table 6.1. Length of extraradical AM fungal mycelium in field soils, expressed per unit weight of soil. Note values are rounded to the nearest whole number. Where original values were expressed per cm of soil these were expressed per gram of soil assuming a typical bulk density of 1.32 g cm for cultivated mineral soils ( ) and a typical bulk density of 1.10 g cm for permanent grassland ( ). Modified from Leake et al. (2004)...

The revolution spread far beyond the United States. Europe, especially the densely populated Netherlands, became home to some of the most intensively cultivated fields on earth. Even the beloved grasslands of England, where bird-watchers rambled along paths through the countryside, were force-fed a diet of nitrogen. A typical acre of English pasture now receives around 160 pounds of nitrogen annually, as much as North American cornfields. 

Drop in temperature. Monoliths. Advanced beads. In Africa, burning of grassland to cultivate tubers. 

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