Soil systems nutrient uptake

Galvez L, Douds DD, Drinkwater LE, Wagoner P (2001) Effect of tillage and farming system upon VAM fungus populations and mycorrhizas and nutrient uptake of maize. Plant Soil... 

York and New England are devoid of fish due to the effects of acid rain. Indirect effects of the low pH values associated with acid rain also affect organisms. As noted in Table 13.1, one of the properties of an acid is the ability to dissolve certain metals. This has a profound effect on soil subjected to acid rain. Acid rain can mobilize metal ions such as aluminum, iron, and manganese in the basin surrounding a lake. This not only depletes the soil of these cations disrupting nutrient uptake in plants, but also introduces toxic metals into the aquatic system. 

This chapter reviews the distribution, mechanism and impact of mineral tunnelling by soil ectomycorrhizal fungi (EMF). Most trees in boreal forests live in close relation with EMF (Smith Read, 1997). These EMF mediate nutrient uptake they form an extension of the tree roots. In turn they obtain carbohydrates from the tree. Over the years ectomycorrhizal (EM) research has a strong focus on nutrient acquisition by EMF from organic sources (Read, 1991). In boreal forest systems, however, minerals could also be an important nutrient source, especially for calcium, potassium and phosphorus (Likens et al, 1994, 1998 Blum et al, 2002). Recent developments in EM research suppose a role for EMF in mobilizing nutrients from minerals (see Wallander, Chapter 14, this volume). 

Dunbabin, V. M., McDermott, S., and Bengough, A. G. (2006). Upscaling from rhizosphere to whole root system modeling the effects of phospholipid surfactants on water and nutrient uptake. Plant Soil 283, 57-72. 

In natural soil-plant systems, equation 5.41 is often the relevant one, so that nutrient uptake acidifies the soil in the vicinity of the roots. However, to the extent that these nutrients are returned to the soil (as plant residues), there may be little long-term acidification on balance. In agricultural systems, harvesting can remove much of the plant material, leading to permanent acidification. 

As discussed earlier, most of the phosphorus entering wetlands accumulates within the system. Surface soils in nutrient-impacted wetlands are often enriched as a result of recent accumulation, decomposition processes, and remobilization of phosphorus from subsurface soils to surface through plant uptake and deposition as detritus material. Thus, total phosphorus content of surface soils is higher than that of subsurface soils. Similar total phosphorus profiles have been seen for many wetlands and aquatic systems. In the impacted site, subsurface total phosphorus content can also represent the background levels of phosphorus for these soils, assuming that the surface material is the result of recent accumulation. Much of this phosphorus accumulation is due to organic matter accretion (detrital matter deposition) associated with phosphorus sorption to particulate matter. 

The nutrient uptake by vegetation contributes to nutrient reduction in the soil profile with time. In low-nutrient systems, plants can sequester nutrients from the subsurface soil layers and deposit them on soil surfaces through detrital accumulation and increasing the connectivity of nutrients with water. Vegetative water uptake and transpiration can increase the solute flux from water column into the soil (Figure 14.30). For example, Martin et al. (2003) showed a greater reduction of surface water nitrate concentration in experimental Typha mesocosms with greater rates of evapotranspiration. 

Multiple additions of phenolic acids were used because phenolic acid concentrations in soil decline rapidly after each addition of phenolic acids (Blum et al. 1987 Blum and Gerig 2006). This was due to microbial metabolism, physical breakdown, root uptake, and/or soil particle sorption. Recovery of seedling processes, although considerably slower than in nutrient culture, also occurred in seedling-soil systems (Blum et al. 1987 Blum and Gerig 2006). To maintain inhibition for extended time periods multiple additions of phenolic acids were required. 

If seedling-microbe-soil systems have different or stronger sinks (e.g., microbial utilization, root uptake, and soil sorption), slower root growth, and reduced root contact with simple phenolic acids (e.g., resistance of movement for simple phenolic acids through soil capillaries, and slower root growth) than occur in nutrient culture... 

Lee, S., et al. (2014). Comparison study on soil physical chemical properties, plant growth, yield nutrient uptake in bulb onion from organic conyentional systems. HortScience, 49(12), 1563-1567. 

The normal atmospheric abundance of N is 0.366% for uptake experiments fertilizers are enriched with 5-10% N. Another advantage of N-labeling is that the amount of fertilizer-derived nitrogen retained in soil, and potentially assimilable in the future, can be also measured this makes it possible to calculate the overall retention of the nutrient in the crop-soil system and to establish the true loss from the agroecosystem. 

As mentioned before and in Chaps. 4 and 6, the concentration of rhizode-position decreases as the distance from the rhizoplane increases, whereas the opposite generally occurs for the concentration of any plant nutrient in soil. In this context, the role of rhizospheric soil, rather than that of the bulk soil, is crucial for plant nutrition. It has also to be considered that very different situations can occur depending on the type of nutrient (24) and the nutritional status of plants (see Chap. 3) furthermore, different portions of the root system are characterized by differential nutrient-specific rates of uptake (25). All the above statements point to the necessity of reconsidering the concept of plant nutrient availability giving more importance to the situation occurring in the soil surrounding the root. 

Soil solution is the aqueous phase of soil. It is in the pore space of soils and includes soil water and soluble constituents, such as dissolved inorganic ions and dissolved organic solutes. Soil solution accommodates and nourishes many surface and solution reactions and soil processes, such as soil formation and decomposition of organic matter. Soil solution provides the source and a channel for movement and transport of nutrients and trace elements and regulates their bioavailability in soils to plants. Trace element uptake by organisms and transport in natural systems typically occurs through the solution phase (Traina and Laperche, 1999). 

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