The Effects of Liming On Soil Chemistry at Loch Fleet, Scotland

An experiment to investigate how the water quality of acid lakes can be improved by liming the surrounding catchment was begun at Loch Fleet, Scotland in 1984. the effects on the soils of three sectors of the catchment where limestone was added in 1986 are reported here, following analysis of soils sampled in 1987, 1988 and 1991. the effect of the lime on soil chemistry was still evident in 1991, with about 15% of free lime remaining in the hydrochemical reaction zone of sectors IV and VI and nearly 50% in sector VII. However, this free lime appeared to be dissolving too slowly to maintain large amounts of exchangeable calcium in the soils, indicating that the treatment is starting to become less effective. the fall in the mean exchangeable calcium in the reaction zone between 1988 and 1991 was mirrored by a drop in mean soil pH over the 5 years post-liming from 6.1 to 5.6 on sector IV and from 5.9 to 5.4 on sector VI, whereas mean pH remained constant at about 6.0 in the limed areas of sector VII. Using soil data to predict longevity suggests that the exchangeable calcium remaining on the catchment at the end of 1991 will maintain target water quality in the loch until sometime during 1994. the soil pH is likely to fall to between 5.2 and 5.3 by this time. If the region of hydrochemical reaction is assumed to extend to a depth of 20 cm rather than 5 cm, target water quality is predicted to be maintained until the end of 1995. When the free lime remaining on the catchment is included as a source of acid neutralising capacity, calculations show that treatment may remain effective until around the year 2000.     

Amelioration of Streamwater Acidity by Catchment Liming-Response of Podzolic Soils to Pasture Improvement

The effects of agricultural improvement by cultivation, re-seeding, lime and fertiliser additions on the soil solution chemistry of acid podzolic soils have been investigated in a field experiment in a mid-Wales catchment. the treatment resulted in an increase in the pH, alkalinity and calcium content of soil waters from the surface, organic-rich horizon. in the year following treatment, soil waters in the mineral horizons became more acid and had higher aluminium concentrations than observed at the control site. This response is ascribed to soil water acidification resulting from increased nitrification rates following liming and cultivation. in subsequent years, soil water acidity in these lower horizons was neutralised by lime-rich water percolating from the surface. No changes in stream water acidity and calcium content were observed in the catchment containing the area of agriculturally improved soils. This suggests that the selective treatment of moorland catchments to improve agricultural productivity may not always be accompanied by amelioration of acid stream water.     

The Chemistry of Throughfall, Stemflow and Soil Water Beneath Oak Woodland and Moorland Vegetation in Upland Wales

The chemistry of bulk precipitation, throughfall, stemflow and soil waters beneath an oak wood (Quercus petraea) canopy and soil waters under moorland vegetation were measured at two sites on acid brown podzolic soils near Llyn Brianne in rural mid-Wales, UK. Between March 1986 and November 1988, precipitation was 4354 mm and annual interception losses from the oak canopy averaged 13% of incident precipitation. Throughfall and stemflow were more acid and concentrations of most solutes were increased 2- to 4-fold compared with bulk precipitation. Nitrate was the only solute retained within the tree canopy. Throughfall collected beneath patches of bracken on the forest floor was less acidic but contained substantially higher concentrations of major ions than bulk precipitation and oak throughfall. the moorland soil was more acidic, contained more exchangeable calcium but less exchangeable aluminium and potassium than the woodland soil. Soil waters beneath both vegetation types were acidic (mean pH range 4.5-4.9) and dominated by sodium and chloride. with the exception of calcium, soil water solute concentrations were greater beneath oak. These differences are ascribed to larger atmospheric inputs beneath the oak canopy compared with the shorter grasses, combined with the effect of differences in nutrient dynamics and water fluxes. Variations in soil water aluminium chemistry are explained in terms of ion exchange and podzolisa-tion processes. the water quality implications of increased upland afforestation of moorland by broadleaved trees are discussed.     

The Chemistry of Throughfall,Stemflow and Soil Water Beneath Oak Woodland and Moorland Vegetation in Upland Wales

The chemistry of bulk precipitation, throughfall, stemflow and soil waters beneath an oak wood (Quercus petraea) canopy and soil waters under moorland vegetation were measured at two sites on acid brown podzolic soils near Llyn Brianne in rural mid-Wales, UK. Between March 1986 and November 1988, precipitation was 4354 mm and annual interception losses from the oak canopy averaged 13% of incident precipitation. Throughfall and stemflow were more acid and concentrations of most solutes were increased 2- to 4-fold compared with bulk precipitation. Nitrate was the only solute retained within the tree canopy. Throughfall collected beneath patches of bracken on the forest floor was less acidic but contained substantially higher concentrations of major ions than bulk precipitation and oak throughfall. the moorland soil was more acidic, contained more exchangeable calcium but less exchangeable aluminium and potassium than the woodland soil. Soil waters beneath both vegetation types were acidic (mean pH range 4.5-4.9) and dominated by sodium and chloride. with the exception of calcium, soil water solute concentrations were greater beneath oak. These differences are ascribed to larger atmospheric inputs beneath the oak canopy compared with the shorter grasses, combined with the effect of differences in nutrient dynamics and water fluxes. Variations in soil water aluminium chemistry are explained in terms of ion exchange and podzolisa-tion processes. the water quality implications of increased upland afforestation of moorland by broadleaved trees are discussed.     

施石灰对新垦赤红壤化学性质和作物生长的影响

本文采用pH4.8、交换性酸2.8cmol kg~(-1),交换性Ca0.8cmol kg~(-1)的花岗岩赤红壤(荒丘),进行盆栽试验和田间试验,研究施生石灰对土壤化学性质及花生、甘薯生长的影响。结果表明,大田施用相当于交换酸60％的生石灰,可使土壤pH值在9个月内保持在5.8以上,但就提高花生产量来说,石灰用量以中和交换性酸30％为宜。土壤中Fe、Al的固P能力远比Ca大,即使施用高量的石灰,新形成的Fe-P、Al-P各为新形成Ca-P的2倍以上,同时亦有大量的O-P形成。各水平的石灰处理均显著改善花生的经济性状和品质,但产量的提高却以低水平石灰处理为显著。     

红壤中交换性铝调控条件的研究Ⅱ.有机质和CaCO_3对交换性铝的影响

研究了有机质和ＣａＣＯ３。对发育于花岗岩和第四纪红色粘土母质上的红壤的交换性铝的影响。结果表明,在用Ｈ２Ｏ２去除土壤中的有机质后,交换性铝的含量随有机质的降低而降低,但降低的速度不均匀,由慢到快似有一个“突跃”。而在向土壤中添加有机质的研究结果则表明,交换性铝的含量随有机质的增加而增加;在增加的过程中由快到慢,达到极点后,有机质含量再增加,交换性铝反而下降。在相同的土壤环境中,由于作物品种不同,施用等量的ＣａＣＯ３（或石灰粉）对土壤交换性铝的含量及作物产量的影响不同,而且差异显著。     

Aluminium in tea plantations: mobility in soils and plants, and the influence of nitrogen fertilization

The levels of extractable aluminum (Al) in soils of tea plantations, Al concentrations in tea leaves and the impact of nitrogen fertilization on these two parameters were investigated. In addition, the properties of soils from tea plantations were compared to those from soils of adjacent non-tea fields to evaluate the effect of land use conversion (from non-tea soils to tea soils). Exchangeable Al (extracted in 1 mol l⁻¹ KCl) ranged from 0.03 to 7.32 cmol_c kg⁻¹ in 94 tea fields and decreased rapidly with increasing soil pH. In comparison with non-tea soils, tea soils had a significantly lower pH and exchangeable Mg²⁺ concentration but higher organic matter contents and exchangeable K⁺ concentration. Contents of extractable Al were not different (P > 0.05) between these two soils. The concentrations of Al in mature tea leaves correlated significantly with exchangeable Al in soil samples taken at a depth of 20–40 cm and with exchangeable Al saturations in soil sampled at␣depths of 0–20 and 20–40 cm. In the pot experiment, nitrogen fertilization significantly increased extractable Al levels but decreased soil pH and the levels of exchangeable base cations. Nevertheless, the levels of Al in mature leaves and young shoots were significantly reduced by the application of large amounts of N fertilizer.     

石灰氮对镉污染土壤中镉生物有效性的影响

以石灰作对比,在大田条件下研究了不同石灰氮用量对镉污染土壤中镉生物有效性的影响。结果表明,一定量石灰或石灰氮处理均能显著提高酸性土壤的pH值,降低污染土壤中有效态镉质量分数及水稻茎叶和糙米中的镉质量分数。与不施改良剂的对照相比,石灰施用量达到1 200 kg.hm-2时土壤pH值显著提高,土壤有效态镉质量分数降低12.6%（P〈0.05）,水稻茎叶和糙米中镉质量分数分别降低25.5%（P〈0.05）和28.3%（P〈0.05）;石灰氮施用量达到600 kg.hm-2时,土壤pH值显著高于对照,土壤有效态镉质量分数较对照降低10.9%（P〈0.05）,水稻茎叶和糙米中镉质量分数分别降低36.8%（P〈0.05）和33.0%（P〈0.05）。等量条件下（600 kg.hm-2）石灰氮对降低土壤镉有效性及水稻累积镉的效果相对优于石灰处理。因此,石灰氮与石灰一样可用于酸性重金属污染土壤的修复与改良,是一种极具潜力的土壤改良剂。     

施用碱渣对茶园土壤酸度和茶叶品质的影响

开展田间小区试验研究了不同施用量条件下碱渣对酸化茶园土壤的酸度和茶叶品质的影响.结果表明,施用碱渣可以显著提高土壤pH、土壤交换性盐基和盐基饱和度,降低土壤交换性酸和交换性铝含量,并使土壤中钙、镁养分保持合理比例.施用碱渣提高了茶叶中茶多酚、儿茶素、咖啡碱、氨基酸和叶绿素含量,降低了茶叶中铅含量,使茶叶品质得到改善.碱渣施用量为4 500 kg·hm-2时,可将土壤pH值调节至5.51,达到最适合茶树生长的酸度条件,该条件下生产的茶叶品质也最佳,茶叶茶多酚、儿茶素、咖啡碱、氨基酸和叶绿素含量分别比对照提高22.5%、27.8%、34.9%、69.0%和52.1%,而Pb含量下降51.2%.     

A Critical Appraisal of Field Evidence From A Regional Survey for Acid Deposition Effects On Scottish Moorland Podzols

Samples have been collected from major horizons of 34 podzol profiles distributed throughout Scotland, all developed from granite or granitic tills and under Calluna moorland. the pH in water and calcium chloride pastes, exchangeable cations and cation exchange capacity, and extractable aluminium of the soils collected have been measured, and the results studied in relation to reported atmospheric deposition of H⁺, non-marine sulphur and nitrate. for all horizons, significant positive correlations were found between soil pH and rainfall mean pH, as might be expected when the critical load of H⁺ deposition is exceeded. Acidifying pollutant deposition also apparently increased soil extractable aluminium concentrations in the B and C horizons. However, exchangeable base cation concentrations tended to increase, rather than decrease, with increasing precipitation acidity. This effect was attributed to increases in biogeochemical cycling of base cations, increases in leaching inputs of base cations from overlying A/E horizon soils, and increases in the inputs of base cations leached from upslope. the results suggest that the simple steady state mass approach to the quantification of critical loads, as often applied, may be an oversimplification.     

A Critical Appraisal of Field Evidence From A Regional Survey for Acid Deposition Effects On Scottish Moorland Podzols

Samples have been collected from major horizons of 34 podzol profiles distributed throughout Scotland, all developed from granite or granitic tills and under Calluna moorland. the pH in water and calcium chloride pastes, exchangeable cations and cation exchange capacity, and extractable aluminium of the soils collected have been measured, and the results studied in relation to reported atmospheric deposition of H⁺, non-marine sulphur and nitrate. for all horizons, significant positive correlations were found between soil pH and rainfall mean pH, as might be expected when the critical load of H⁺ deposition is exceeded. Acidifying pollutant deposition also apparently increased soil extractable aluminium concentrations in the B and C horizons. However, exchangeable base cation concentrations tended to increase, rather than decrease, with increasing precipitation acidity. This effect was attributed to increases in biogeochemical cycling of base cations, increases in leaching inputs of base cations from overlying A/E horizon soils, and increases in the inputs of base cations leached from upslope. the results suggest that the simple steady state mass approach to the quantification of critical loads, as often applied, may be an oversimplification.     

四种改良剂对Cu、Cd复合污染土壤中Cu、Cd形态和土壤酶活性的影响

以黑麦草（Lolium perenne L.）作为修复植物进行田间试验,研究了石灰、磷灰石、蒙脱石、凹凸棒石4种改良剂对铜镉复合污染土壤中Cu、Cd形态和土壤酶活性的影响。结果表明,改良剂提高了污染土壤pH,降低了土壤可交换态（EX）Cu、Cd含量;改良剂提高了土壤脲酶、酸性磷酸酶和过氧化氢酶活性,每种改良剂对土壤酶活性增加幅度随其添加剂量增加而增大;土壤酶活性与土壤EX态Cu、Cd含量呈显著或极显著负相关关系,与土壤pH呈显著或极显著正相关关系;高剂量石灰（石灰占污染土壤耕作层质量的0.4%）和高剂量磷灰石（磷灰石占污染土壤耕作层质量的2.32%）处理钝化污染土壤中Cu、Cd及提高土壤酶活性效果最好。     

Seven Years of Change Following Liming of Sphagnum Communities in Sector Vii of the Loch Fleet Catchment

In 1986, application of lime within the upper wetland area of sector VII of the Loch Fleet catchment initiated numerous unscheduled small-scale experiments on the vegetation of this heterogeneous terrain. Vegetation changes and erosion were monitored in permanent or relocated plots established in 1987 and 1989 and re-surveyed in 1993, seven years after liming.

The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris.     

Evaluation of lime requirement tests for minesoils

Evaluation of twelve minesoils collected from restored or abandoned surface mines in eastern Kentucky with six standard lime requirement procedures showed that one of the procedures accurately forecasted long term lime requirements. The minesoils were then evaluated for potassium choloride-extractable aluminum using the Yang exchangeable acidity procedure. When the extractable A1³⁺ was multiplied by a factor of 2.24 it was found to also be an accurate measure for longterm limestone requirements. To bring the minesoil to pH 5.5 the results obtained using the modified Yuan procedure indicate that for each MEQ Al³⁺ extracted per 100 grams of minesoil 2.24 Mg of calcium carbonate (CaCO₃) equivalent lime per hectare be applied. Application of lime based on this procedure and one of the standard lime procedures resulted in pH stability of the minesoils for forty months.     

外源铅铜镉在长三角和珠三角农业土壤中的转化

选择了我国经济发达地区的长江三角洲和珠江三角洲10个代表性农业土壤，采用室内培养和化学分级方法研究了加入外源铅、铜、镉在土壤中的动态变化及转化趋势，探讨了碳酸钙、粉煤灰、猪粪和钢渣等土壤改良剂对土壤重金属形态的影响。结果表明，随着土壤重金属负荷的提高，土壤中交换态重金属的比例增大，残余态比例下降，有效性提高，对环境威胁增大。当重金属加入最较低时，重金属优先向氧化物结合态、有机质结合态转化；而当加入最较高时，向交换态和碳酸盐结合态转化的比例明皿增加。pH和土壤组分对重金属在土壤中的转化有显著的影响，土壤pH下降可使交换态Cd、Cu、Pb的比例递增。加入碳酸钙、粉煤灰、猪粪和钢渣等改良剂可显著地降低土壤中交换态重金属比例，增加其它形态的重金属比例。     

石灰、钙镁磷肥对烤烟生产及土壤酸度调节的影响

广东植烟土壤酸度普查结果表明，沙泥田的pH值在3．45～5．75之间，大于5．5的很少。pH值偏低是制约沙泥田烤烟产量、质量进一步提高的主要障碍因子之一。在沙泥田烟区进行石灰施用量及提高钙镁磷肥施用比例的试验结果表明，随着石灰施用量的增加，气斑病、青枯病有下降的趋势；而赤腥病有上升的趋势，而烤烟的产值、均价、上等烟率等都是在石灰施用量1500kg／hm^2时为最高。提高钙镁磷肥的施用比例，烤烟的产量、产值、均价、上等烟率等也相应提高。施用石灰及钙镁磷肥均有提高土壤pH值的作用。建议在沙泥田烟区每公顷施石灰1500kg，全部以钙镁磷肥作为磷的来源。     

石灰性土壤环境中缺锌机理的探讨

作者认为石灰性土壤中锌活性较低的原因,是由于碳酸盐导致土壤pH上升,在较高pH条件下氧化铁对锌的强烈固定,造成了大量专性吸附状态的氧化铁结合态锌及部份碳酸盐结合态锌,使交换态的有效锌含量很低,同时还证明:自然的石灰性土壤中,松结有机态锌与碳酸盐结合态是活性锌的直接给源,外源加入的锌仅为松结右机态锌。此外,石灰性土壤中各主要土壤的化学组份对外源锌的固定量高伛顺序为:氧化铁>有机质>粘土矿物>碳酸盐>氧化锰:对土壤中原有锌的固定作用大小依次为:粘土矿物>氧化铁>有机质>氧化锰>碳酸盐。     

模拟酸雨对红壤铝形态的影响

用动态淋洗试验，研究了不同pH的模拟酸雨对红壤中铝形态和性质的影响．结果表明，酸雨淋洗引起红壤中盐基离子的淋失和土壤铝的溶出．随着酸雨溶液pH的降低，盐基淋矢量和铝溶出量增加．酸雨淋洗影响土壤铝形态的转化，使红壤中交换态铝上升，吸附态羟基铝有所下降．这说明在酸雨长期作用下，羟基铝溶解，并转化为交换态铝和引起铝的溶出，使铝进入环境，危害生态系统．     

Seven Years of Change Following Liming of Sphagnum Communities in Sector Vii of the Loch Fleet Catchment

In 1986, application of lime within the upper wetland area of sector VII of the Loch Fleet catchment initiated numerous unscheduled small-scale experiments on the vegetation of this heterogeneous terrain. Vegetation changes and erosion were monitored in permanent or relocated plots established in 1987 and 1989 and re-surveyed in 1993, seven years after liming.

The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris.     

模拟酸雨对酸性土壤铝溶出及其形态转化的影响

研究了我国南方酸沉降区主要土壤类型在模拟酸雨影响下,土壤中铝离子释放及铝形态转化的特点。结果表明,酸雨淋洗造成土壤中铝离子释放,酸雨pH值越低,铝离子释放量越大;酸雨淋洗还造成土壤中铝形态发生变化,酸雨pH越低,土壤中羟基态铝和腐殖质铝含量愈低,交换态铝含量越高,土壤中铝对植物和生态系统的危害性也越大。