Soil quality

Table 10.11 Selected British Standard methods for monitoring soil quality ...

Soil quality may vary seasonally and such conditions must be carefully considered in the foundation design. No foundation should rest partially on bedrock and partially on soil it should rest entirely on one or the other. If placed on the ground, make sure that part of the foundation does not rest on soil that has been disturbed. In addition, pilings may be necessary to ensure stability. 

Without a solution, formulated mathematical systems (models) are of little value. Four solution procedures are mainly followed the analytical, the numerical (e.g., finite different, finite element), the statistical, and the iterative. Numerical techniques have been standard practice in soil quality modeling. Analytical techniques are usually employed for simplified and idealized situations. Statistical techniques have academic respect, and iterative solutions are developed for specialized cases. Both the simulation and the analytic models can employ numerical solution procedures for their equations. Although the above terminology is not standard in the literature, it has been used here as a means of outlining some of the concepts of modeling. 

Generally speaking, a deterministic or stochastic soil quality model consists of two major parts of modules ... 

The solute module — aiming to predict pollutant transport, transformation and soil quality in the soil zone. 

The above two modules form the soil quality model. The flow module drives the solute module. It is important to note that the moisture module can be absent from the model and in this case a model user has to input to the solute module information that would have been either produced by a moisture module, or would have been obtained from observed data at a site. 

Numerical soil models (time, space) provide a general tool for quantitative and qualitative analyses of soil quality, but require time consuming applications that may result in high study costs. In addition input data have to be given for each node or element of the model, which model has to be run twice, the number of rainfall events. On the other hand, analytic models obtained from analytic solutions of equation (3) are easier to use, but can simulate only averaged temporal and spatial conditions, which may not always reflect real world situations. Statistical models may provide a compromise between the above two situations. 

P cycling, pre chain emissions, animal welfare, economics, biodiversity, product quality, soil quality, and landscape aesthetics [60]. Whole farm model (WFM) uses pasture growth and cow metabolism for predicting CH4 emissions in dairy farms. Also included in the WFM is climate and management information. However, recent reports also suggests that WFMs may incorrectly estimate CH4 emission levels as they do not take into account the DMI and diet composition while predicting the enteric CH4 emission. This low prediction efficiency of WFMs may lead to substantial error in GHG inventories [10,11],... 

Soil Contamination as the Main Threat to Soil Quality. 4... 

Alabouvette C, Backhouse D, Steinberg C, Donovan N J, Edel-Hermann V and Burgess L W (2004), Microbial diversity in soil - effects on crop health , in Schjpnning P, Elmholt S and Christensen B T, Managing Soil Quality - Challenges in Modem Agriculture, CAB International, Wallingford, 121-138. 

Schjpnning P, Elmholt S, Munkholm L J, and Debosz K (2002), Soil quality aspects of humid sandy loams as influenced by different long-term management . Agric., Ecosystems Environ., 88, 195-214. 

Concerns regarding progressive soil degradation and the long-term sustainability of current agricultural practices have lead to the study and assessment of soil quality (Karlen et al. 1997). Soil organic matter is an extremely important attribute of soil quality since it profoundly influences... 

Hot water-extractable C accounts for 1-5% of soil organic C (Leinweber et al. 1995 Sparling et al. 1998 Chan and Heenan 1999) and about 50% of this is thought to be present as carbohydrate (Haynes 2005). Because it is usually extracted from air-dried soils much of the pool originates from desiccated microbial cells but it also includes exocellular polysaccharides, root exudates, lysates and humic material (Redl et al. 1990 Leinweber et al. 1995 Sparling et al. 1998). Both hot water extractable C (Sparling et al. 1998 Chan and Heenan 1999) and hot water-extractable carbohydrate (Ball et al. 1996 Haynes and Beare 1997 Debrosz et al. 2002) have been used as indices of soil quality. 

As noted earlier, total soil organic matter content can be considered as a coarse indicator of soil quality. However, changes in the content of organic C and total N occur only slowly and do not provide an adequate indicator... 

Bolinder MA, Angers DA, Gregorich EG, Carter MR (1999) The response of soil quality indicators to conservation management. Can J Soil Sci 79 37-45... 

Campbell CA, Janzen HH, Juma NG (1997) Case studies of soil quality in the Canadian prairies long-term field experiments. In Gregorich EG, Carter MR (eds) Soil quality for crop production and ecosystem health. Elsevier, Amsterdam, pp 351-397... 

Fenton TE, Brown JR, Mausbach MJ (1999) Effects of long-term cropping on organic matter content of soils implication for soil quality. In Lai R (ed) Soil quality and soil erosion. CRC Press, Boca Raton, pp 95-124... 

Haynes RJ, Tregurtha R (1999) Effects of increasing periods under intensive arable vegetable production on biological, chemical and physical indices of soil quality. Biol Fertil Soils 28 259-266... 

Karlen DL, Mausbach MJ, Doran JW, Cline RG, Harris RF, Schuman GE (1997) Soil quality a concept, definition, and framework for evaluation. Soil Sci Soc Am J 61 4—10... 

Sojka RE, Upchurch DR (1999) Reservations regarding the soil quality concept. Soil Sci Soc Am J 63 1039-1054... 

Values of a soil fertility index (SFI, Moran et al. 2000) or a soil evaluation factor (SEF, Lu et al. 2002) were calculated to quantify the intensity of the land degradation. SFI showed the applicability to measuring soil quality and to predicting succession rate of secondaiy tropical forest (Moran et al. 2000). The following equation was used to calculate SFI values (Lu et al. 2002). 

Originally, SFI was developed to measure quality of soils of cacao fields (Alvim and Rosand 1974). Moran et al. (2000) extended its use in forest soils in the humid tropics, where the climate is classified as Am or Af (Koppen 1931). Recently, Doi and Sakurai (2004) found the applicability of SFI and SEF to evaluating soil quality in the SERS. 

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