Liming soils

Since most trace elements in soils are at parts per million levels, a separate compound may be not formed. Most likely, trace amounts of these trace elements and their compounds are adsorbed on the surfaces of clay minerals and various crystalline and amorphous Fe/Mn/Al oxides and hydroxides. Curtin and Smillie (1983) reported that the solubilities of Mn2+ and Zn2+ in limed soils were not consistent with the solubilities of any... 

These differences are exemplified in Figure 7.5 which shows the results of an experiment in which Cd +, Zn +, Ni + and Cn + salts were applied on the surface of an acid soil, with and without lime, and the soil leached with 0.01 MCaCF for several hours (McBride, 1994). In the unlimed soil, Cd +, Zn + and Ni moved readily to depth, but Cu + remained near the snrface becanse it was strongly sorbed on soil solids. In the limed soil, with pH 6.5, increased sorption and... 

Clover grows well in poor soil. Fertilizing the lawn will tend to deter it (but see also The value of clover, opposite). Sheep s sorrel can be a problem in acidic soil conditions. Liming soil (see below) can help. Plantain and thistles grow where grass is thin or patchy. Lawn pests include ants, leatherjackets, and moles see the A-Z of Plant Problems ipp.320-341) for advice on these. 

As in pure systems, the adsorption of anions and cations on iron oxides is strongly pH dependent. This has to be kept in mind when an optimum pH is to be obtained with liming. The adsorption of phosphate, arsenate etc. increases as the pH falls below 7, whereas the adsorption of heavy metal cations rises as pH goes up (see eq. 11.18 11.19). Therefore, as soils become more acidic, heavy metals will be released into the soil solution. Conversely, liming soils has the opposite effect. 

Fluorides do nol usually ntnve from the soil lo plants and on to livestock feedstuff s and human foodstuffs ill amounts that are toxic. Injury tu plants from fluoride in the soil has been noted on soils that are loo acid for the satisfactory growth of most plants. On limed soils or soils w ith sufficient calcium for optimum growth, any fluorine added lo the soil reacts with the calcium and other soil constituents to form insoluble compounds, which are not taken up by the plants. Rock phosphate and some kinds of superphosphate fertilizers contain large amounts of calcium fluoride, bul the fluorine content of the plants grown on soils that have been heavily fertilized with these phosphates is nut appreciably increased. Tea and some other members of the Theaeeae family are the only plants that take up very-much fluorine from the soil. 

Gaynor, J.D. and V.V. Volk (1981). Runoff losses of atrazine and terbutryn from unlimed and limed soil. Environ. Sci. Technol., 15 440 143. 

Mn nutrition of wheat was found to be dependent on the P status of soil as well as on its pH and Mn status (Neilson et ah, 1992). Concentrations of Mn were depressed in leaf tissue of plants from lime soils and also in high P soils. The depressed values for lime treatments were explained in terms of depressed soils solution Mn concentrations resulting from elevated pH. It was suggested that high soil P resulted in elevated plant P which interfered in the uptake and/or translocation of Mn. 

Budding material Natural stone Brick Cement Sandrock Lime Soil... 

Estimates of soil texture and measurements of initial soil pH for similar soils from a rather homogeneous geographical area can provide a simpler but less precise estimate of soil lime requirements. Such techniques must be calibrated against one of the more precise lime requirement methods to accurately estimate the amount of lime required. Different limed-soil pH values each require a separate calibration curve. 

The change in ion-exchange specificity with pH (Chapter 8) can also cause opposing trends of K availability in limed soils. Increased availability can be attributed to greater quantities of K in the soil solution, because of Ca replacement of K in the DDL of the soil s colloids. Decreased K availability after liming can be due to greater quantities of K leaching from limed soils. 

The benefits of liming soils with marls and soft chalks was known to the Romans in the first century A.D. Pliny reported that the Ubians, north of Mainz, used white earth (a calcarious marl) to fertilise their fields. 

The ability of lime to dry, modify and stabilise clay soils has been known for many years. However, its systematic use only started in the late 1940s in the USA, when the techniques of soil mechanics testing were applied to lime-soil mixtures. They demonstrated in quantitative terms that lime treated layers could, with confidence, be designed into the construction of roads, runways, car parks etc. 

Six field experiments were conducted in four southeastern states over a 3-year period to determine the responses of soybeans to Mo applications at several soil pH values (Anderson and Mortvedt, 1982). Soybean yields were increased by Mo application rates (as Na2Mo04) up to 800 g ha on relatively acid soils. Soybean yields also were increased by liming soils whose pH values were less than 5.7, with the highest yields occurring near pH 6.0. Yield responses were more closely related to soil pH than to the available soil Mo concentrations. 

Growth and nitrogen fixation by subterranean clover in response to inoculation, molybdenum application and soil amendment with lime. Soil Biol. Biochem. 17 791-6. 

Open field experiments were also conducted at the New Jersey Experiment Station by Lipman et al. (1928) during the period 1908 to 1927. The percent nitrogen recoveries for the 20-year period from limed soils were calcium nitrate 42, ammonium sulfate 42, calcium cyanamide 36, sodium nitrate 33, fish scrap 26, tankage 26, and manure 12. On the unlimed soils the recoveries in the same order were 32, 21, 33, 37, 37, 21, and 17%. 

Liming soils can increase the pH resulting in the formation of calcium carbonate, which can coprecipitate phosphate. Under anaerobic conditions CaC03 amendment can significantly decrease Fe(II) concentration in soil pore water as shown below ... 

Molybdenum - Deficiencies of molybdenum are found on acidic soils and may be corrected by liming soils to pH 6.0. Because the amounts needed to correct molybdenum deficiencies are very low, seed treatment (supplying 60-120 g/ha) is the recommended method [3]. Deficiencies are mainly found in legume crops, because molybdenum is essential for nitrogen fixation. However, some vegetable crops also are sensitive to molybdenum deficiencies. 

High concentration of dissolved NH4 and OH ions in recently fertilized or limed soils may cause the formation of gaseotts ammonia (NH3) ... 

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