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1.
Abstract

Information on the redistribution of applied micronutrients into different fractions as a result of lime application is important to predict plant accumulation of nutrients and to select appropriate chemical extraction procedures for evaluation of micronutrient availability. The present work was carried out to study the influence of liming on the availability and redistribution of zinc (Zn) and copper (Cu) among soil fractions. Additionally, the effect of liming was evaluated on the recovery of these micronutrients by different chemical extractants (Mehlich‐1, Mehlich‐3, and diethylenetriaminepentaacetate (DTPA), which were correlated with Zn and Cu concentrations in corn (Zea mays L.) plants and soil fractions (exchangeable, organic matter, amorphous iron oxides, and crystalline iron oxides). The results showed that Zn added to soil samples that did not receive lime was retained mainly in the exchangeable and organic matter fractions. The liming resulted in distribution of Zn into iron oxides and as a result decreased the plant accumulation of Zn. Mehlich‐3 was the most efficient extractant to predict the plant accumulation of Zn in the acid soils, whereas DTPA was the most efficient in the limed soils. The oxide crystalline fraction was the major fraction responsible for retaining Cu in the soils. However, Cu added to soil was distributed mainly into organic matter. Mehlich‐3 was the most suitable extractant for predicting the bioavailability of Cu in limed or unlimed soils.  相似文献   

2.
Abstract

A pot experiment was carried out in the greenhouse with two loamy sand Dystric Cambisols derived from schist to investigate the effect of liming and phosphorus (P) application on plant growth and P availability and its assessment by four soil test methods: 0.01M calcium chloride (CaCl2), cation anion exchange membrane (CAEM), Egnér‐Riehm, and Olsen procedures. Soils were first incubated for two weeks with lime at four levels, depending on their content of exchangeable aluminum (Al). Phosphorus was added at two rates (75 and 150 mg P kg‐1) and the incubation proceeded for an additional two‐week period. Sudangrass (Sorghum sudanenses cv. Tama) was then planted and harvested four weeks later. During incubation and plant growth, soils were maintained at 70% of field moisture capacity. Although pH value and soil extractable P in original soils were similar, the results showed a significant difference on the effect of liming and P application. Acidity was the major limitation for DM yield in the soil with the highest amount of exchangeable Al, while P availability was the main constraint in the other soil. Liming above pH (0.01M CaCl2) 5.3–5.5 did not increase DM yield in either soil and showed a negative effect on one soil (9.7 to 6.9 and 10.2 to 7.8 g pot‐1). Phosphorus content and uptake by sudangrass increased with liming, revealing a positive effect of lime on the availability of P to plants. Added P showed a lower efficiency in the soil with highest amounts of Al compounds. Soil tests performed after the execution of the pot experiment showed variable tendencies to predict P availability, according to the nature of the procedures and soils. Soluble‐P in 0.01M CaCl2 increased with the rise of soil pH. Extractable CAEM‐P and Egnér‐Riehm‐P also increased with liming, but reflected the soil depletion caused by plant uptake. Extractable Olsen‐P presented the most inconclusive results, suggesting the limitation of this method for acid soils which have been limed.  相似文献   

3.
Soil liming may increase phosphorus (P) availability, but this increase may also be achieved with generous P applications. However, it is not well known which practice has longer-term effects. Thus, in a pot experiment, an acidic soil (pH 4.57), limed to pH 6.5, was added with P and sown with Lolium perenne L. We conducted three cuttings (on Days 40, 80, and 120) in order to evaluate P dynamics in each of the treatments. As expected, biomass increased significantly with liming. We also found that plant P concentration increased in the liming treatment, but not in the P-added treatment, although the difference was reduced on Day 120. This shows that in severely acidic soils, liming should be preferred over P addition, although the beneficial effects may not last for a very long time, since in this experiment, they only lasted for 4 months. Similar conclusions were drawn from soil P extraction results.  相似文献   

4.
Summary We studied the effects of limining on growth and nutrient concentrations of Brachiaria decumbens inoculated with five vesicular-arbuscular mycorrhizal (VAM) fungal assemblages which orginated from soils with different acidity. Liming increased plant growth when applied at rates up to 3 g kg-1 soil and depressed growth at higher rates. Mycorrhizal plants grew better than non-mycorrhizal ones in unlimed soil and also liming rates of 4.5 and 6.0 g kg-1 soil. The growth amelioration effects of VAM in highly acid or over-limed soils were related to nutrient uptake. VAM fungi isolated from an acidic soil exhibited a high symbiotic effectiveness and were better adapted to unlimed soil than those that originated from non-acidic soils. VAM root colonization, 90 days after planting, was little affected by liming. Fungal spore production and species compositions were highly affected by liming. A mixture of Glomus diaphanum and Glomus occultum predominated in unlimed soils inoculated with VAM assemblages isolated from non-acidic soils. In these fungal assemblages, an increased liming rate favored Glomus etunicatum over the other VAM fungi. Gigaspora margarita sporulated abundantly when introduced into unlimed soils, but rarely in limed soils. VAM appear to be crucial for the establishment of brachiaria pastures in the nutrient-deficient acidic soils of Central Brazil. It is suggested that liming may cause striking shifts in VAM populations which may, in turn, have a long-term impact on agricultural productivity in the tropics.  相似文献   

5.
Abstract

The effects of liming (7 500 kg CaCO3/ha) and rate of urea application (0,50,100, and 200 kg N/ha) and its placement at the surface or at 5 cm depth on grain yield and nutrient uptake by corn grown on an acidic tropical soil (Fluventic Eutropept) were studied. Liming significantly increased grain yield, N uptake, and P and K uptake although Ca and Mg uptake, generally, were unaffected. Sub‐surface application of urea increased N uptake only. Yield response to applied N was observed up to 50 kg N/ha when limed but at all rates in the absence of liming. It therefore, reduced the fertilizer N requirement for optimum grain yield. Liming the acidic soil also reduced exchangeable Al but increased nitrification rate and available P in the soil profile (at least up to 0.6 m depth).  相似文献   

6.
Lime is a common amendment to overcome soil acidity in agricultural production systems. However, plant root effects on lime and soil carbon (C) dynamics in acidic soils under varied temperature remain largely unknown. We monitored root effects of soybean on the fate of lime applied to an acidic soil at 20 and 30°C in growth chambers. Soil respired CO2 was continuously trapped in columns without and with plants until the final stage of vegetative growth. Lime‐derived CO2 was separated from total respired CO2 based on δ13C measurements in CO2. Leaching was induced at early and late vegetative growth stages, and the leachates were analysed for dissolved organic (DOC) and inorganic C (DIC) concentrations. Soil respiration significantly increased with lime addition at both temperatures (p < 0.001). The presence of soybean doubled the recovery of lime‐derived CO2‐C at 20°C at the early growth stage; however, by the end of the experiment, the contribution of lime‐derived CO2‐C to soil respiration was negligible in all treatments, indicating that the contribution of lime to soil respiration was shortlived. In contrast, DIC and DOC concentrations in leachates remained elevated with liming and were greater in the presence of soybean. We observed no main temperature effects and no interactive effects of temperature and soybean presence on lime‐derived CO2‐C, DIC and DOC. These results highlight the role of plant‐modulated processes in CO2 release and C leaching from lime in acidic soils, whereas an increase in temperature may be less important. Temperature and plant roots alter the rate of key processes controlling C dynamics in a limed acidic soil. Lime‐derived CO2‐C, DIC and DOC increased more in the presence of plants than with increased temperature. Root effects are more important than temperature for inorganic and organic carbon dynamics in limed acidic soils.  相似文献   

7.

Purpose  

Acidic soils exhibit high trace element availability compared to neutral pH soils, and thus, when trace metals are added (e.g. due to sewage sludge application), measures should be taken to reduce their mobility. In this experiment, we tested two such methods, liming and zeolite addition. The aim was to measure the availability, in ryegrass (Lolium perenne L.), of heavy metals (Cu and Zn) added to soil with sewage sludge in both acidic and limed soil.  相似文献   

8.
We evaluated the effect of polyacrylate polymers as immobilizing agents to aid phytostabilization of two mine soils. One soil had a very low pH (3.7) and a large Pb content, while the other was less acidic but had a greater content of Cu and Zn. Growth of perennial ryegrass ( Lolium perenne L. cv. Victorian) was stimulated in polymer-amended soils. After ryegrass had been growing for 35 days, the amounts of water-extractable Cu, Zn and Pb (one soil only) present in the polymer-amended soils were smaller than those from soil without polymer. The number of culturable heterotrophic bacteria and the activities of dehydrogenase and β-glucosidase increased following polymer application. In contrast, the urease activity was impaired by polymer application, presumably because of the presence of ammonium as a counter ion. In another experiment, the acidic soil was limed to pH 6.5 before growth of perennial ryegrass took place. Liming the soil greatly enhanced plant growth, but by the third cut, differences between treatments became apparent, with plants from polymer-amended limed soil accumulating a greater biomass compared with limed soil without polymer. After ryegrass had been growing for 119 days (five cuts), the amount of water-extractable Pb and the urease activity in the polymer-amended soil were smaller than those from limed soil without polymer. The numbers of culturable heterotrophic bacteria and the activities of dehydrogenase, β-glucosidase and acid phosphatase increased following polymer application. The results are consistent with phytostabilization being achieved by the application of polyacrylate polymers, improving soil chemical and biological properties. In very acidic soils, the use of both a liming material and polymer together appears to give a considerable advantage.  相似文献   

9.
Abstract

Loss of soil‐water saturation may impair growth of rainfed lowland rice by restricting nutrient uptake, including the uptake of added phosphorus (P). For acidic soils, reappearance of soluble aluminum (Al) following loss of soil‐water saturation may also restrict P uptake. The aim of this study was to determine whether liming, flooding, and P additions could ameliorate the effects of loss of soil‐water saturation on P uptake and growth of rice. In the first pot experiment, two acid lowland soils from Cambodia [Kandic Plinthaqult (black clay soil) and Plinthustalf (sandy soil)] were treated with P (45 mg P kg?1 soil) either before or after flooding for 4 weeks to investigate the effect of flooding on effectiveness of P fertilizer for rice growth. After 4 weeks, soils were air dried and crushed and then wet to field capacity and upland rice was grown in them for an additional 6 weeks. Addition of P fertilizer before rather than after flooding depressed the growth of the subsequently planted upland rice. During flooding, there was an increase in both acetate‐extractable Fe and the phosphate sorption capacity of soils, and a close relationship between them (r2=0.96–0.98). When P was added before flooding, Olsen and Bray 1‐extractable P, shoot dry matter, and shoot P concentrations were depressed, indicating that flooding decreased availability of fertilizer P. A second pot experiment was conducted with three levels of lime as CaCO3 [to establish pH (CaCl2) in the oxidized soils at 4, 5, and 6] and four levels of P (0, 13, 26, and 52 mg P kg?1 soil) added to the same two acid lowland rice soils under flooded and nonflooded conditions. Under continuously flooded conditions, pH increased to over 5.6 regardless of lime treatment, and there was no response of rice dry matter to liming after 6 weeks' growth, but the addition of P increased rice dry matter substantially in both soils. In nonflooded soils, when P was not applied, shoot dry matter was depressed by up to one‐half of that in plants grown under continuously flooded conditions. Under the nonflooded conditions, rice dry matter and leaf P increased with the addition of P, but less so than in flooded soils. Leaf P concentrations and shoot dry matter responded strongly to the addition of lime. The increase in shoot dry matter of rice with lime and P application in nonflooded soil was associated with a significant decline in soluble Al in the soil and an increase in plant P uptake. The current experiments show that the loss of soil‐water saturation may be associated with the inhibition of P absorption by excess soluble Al. By contrast, flooding decreased exchangeable Al to levels below the threshold for toxicity in rice. In addition, the decreased P availability with loss of soil‐water saturation may have been associated with a greater phosphate sorption capacity of the soils during flooding and after reoxidation due to occlusion of P within ferric oxyhydroxides formed.  相似文献   

10.
Acidic soils typically suffer from high phosphorus (P) retention, a problem that can be dealt with using greater P fertilization, soil liming, or both. The aim of this work was to examine which of these practices bears the more beneficial result for Lolium perenne L. growth. In a pot experiment, five acidic soils were treated as follows: L0P0 (unamended control), L1P0 (liming only), L0P1 (P addition only), and L1P1 (both liming and P addition). We found that P amendment alone was sufficient to increase plant P levels when the initial soil P concentrations were low. Liming without P addition increased plant P satisfactorily only in the high-P soil. We conclude that P addition alone is a better practice than liming alone for improved plant growth conditions in acidic, low-P soils, unless there is relatively high P content in soil, in which case liming alone may be sufficient to increase P availability.  相似文献   

11.
Abstract

A laboratory incubation experiment was conducted to study the influence of organic matter and lime application on the recovery of added boron (B) by four different extractants (hot‐CaCl2, mannitol‐CaCl2, tartaric acid, and ammonium acetate) in two B‐deficient acid alluvial soils. Soils were brought to four relatively constant pHs and three organic matter levels before application of B. Recovery percentages of 23.9 to 60.9 of added B by the four extractants indicate a soil fixation of B. This is more so in fine‐than in coarse‐textured soils. Both liming (from pH 4.8 to 6.8) below neutrality and organic matter application increased such recovery of added B in all the extractable forms, the effect being more pronounced in fine‐than in coarse‐textured soils. A positive interaction between liming and organic matter particularly at the latter's higher level was observed. Complexation of added B and coating of the surfaces of Fe‐and Al‐oxides by soluble organic compounds are suggested as the possible reasons for such increased recovery of added B in soils.  相似文献   

12.
Abstract

Pressurized hot water and DTPA‐Sorbitol are two relatively new, proposed alternative soil boron (B) extraction methods for which no data on yield or plant nutrient uptake have been reported for validation. Both methods initially have shown significant correlation with the hot water extraction method in untreated soils as well as soils incubated with various levels of B. The objective of the research was to extract samples of B‐treated soils by using all three extraction methods and correlate the B values obtained to yield, B tissue concentration, and total B removal of alfalfa (Medicago sativa). Greenhouse and field experiments on alkaline and limed acid soils naturally low in hot water‐extractable B were conducted to test alfalfa response to B fertilizer. In the greenhouse, highly significant relationships exist between plant uptake and extractable B with all three methods at varying levels of applied B, but no alfalfa yield response was observed. All three methods result in accurate predictions of plant B tissue concentrations and total B removal. The field experiment exhibited a significant positive relationship between total alfalfa yield and extractable B using hot water and pressurized hot water extractions. Extractable B using DTPA‐Sorbitol was not related to total alfalfa yield in the field experiment. This work, coupled with the earlier incubation studies, supports the pressurized hot water extraction method as an improvement over hot water in diverse soil types. The lack of relationship in the acid soil supports DTPA‐Sorbitol as an improvement over hot water in alkaline soils.  相似文献   

13.
A field study was conducted to determine the plant uptake of metals in soils amended with 500 Mg ha?1 of municopal sewage sludge applied 16 yr previously. Results showed that metals were available for plan uptake after 16 yr, but that liming greatly reduced the plant availability of most metals. The application of sludge also resulted in high rates nitrification and subsequent lowering of the soil pH before the uptake study was started. The sludge-amended soil (a mesic Dystric Xerochrept) was adjusted with lime one month prior to planting from an unlimed pH of 4.6 to pH 5.8, 6.5 and 6.9. Food crops grown were: (i) bush bean (Phaseolus vulgaris L. cv. Seafarer), (ii) cabbage (Brassica oleracea L. v. capitata L. cv. Copenhagen market), (iii) maize (Zea mays L. cv. FR37), (iv) lettuce (Lactuca sativa L. cv. Parris Island, (v) (Solanum tuberosum L. cv. (vi) tomato (Lycopersicum esculentum L. cv. Burpee VF). With the exception of maize, yields were significantly reduced in the unlimed sludge-amended soil. However, liming increased yields above the growth level of the unlimed untreated soil for cabbage, maize, lettuce, potato tuber and tomato fruit. Soluble and exchangeable of Cd. Ni and Zn were also reduced after liming the sludge-amended soil. In both limed and unlimed soils, the majority of the soil Cu was found in insoluble and unavailable soil fractions. To evaluate trace metal uptake, the edible portion of each crop was analyzed for Cd, Cu, ni and Zn. Liming redoced uptake of Cd, Ni and Zn in most crops, but generally did not change Cu, This study shows the benefit of pH adjustment in reducing relative solubility and plant uptake of metals as well as increasing crop yield in acid soils.  相似文献   

14.
Abstract

Open pollinated ‘York Imperial’ apple (Malus domestica Borkh.) seeds were germinated and grown for a period of 7 months in: (1) sand with complete nutrient solutions added; (2) limed and unlimed soil, (3) limed and unlimed soil amended with two different sewage sludges at rates of 25, 50 or 100 dry kg ha‐1. A third composted, lime stabilized sludge was added either sieved or non‐sieved (to remove wood chips) at the same rates. The sludge materials used were: (1) a high metal, composted sludge from Baltimore, MD (BALT); (2) a high Cd sewage sludge (CITY) and (3) a low metal, composted sewage sludge from Washington, D.C. (DC).

Germination was unaffected by treatments. After 7 months, the best growth was obtained from the sand plus nutrient solution media. Two of the three sludge materials increased seedling growth over that of the soil, either limed or unlimed. The BALT compost treated soils produced the lowest growth, particularly when unlimed. Elevated tissue metal levels indicated that Mn, Zn, Cu and Ni were the probable causes of reduced growth noted from the BALT compost treatment. The use of soil with or without low metal sludges as media for early apple seedling growth when compared to standard sand culture is not recommended.  相似文献   

15.
Abstract

Negative yield responses are common when highly leached soils are limed to neutrality. A number of explanations have been proposed, but very few have been experimentally verified or are entirely acceptable. In this paper the problem is re‐examined and a new possible causal mechanism is proposed.

Data assembled from the literature are used to demonstrate that a consistently observed reduction in Mg uptake by plants when soils are limed to neutrality is often accompanied by a generally ignored reduction in exchangeable soil Mg. Using data for soils of North American and African origin, it is demonstrated that when the soils were limed with pure Ca sources, the level of exchangeable soil Mg was reduced between 36 and 93%. Furthermore, after treatment with a Mg containing liming material, initial increases in the level of exchangeable Mg were followed by similarly large decreases when the soil pH approaches neutrality.

The applicability of known Mg fixation mechanisms is briefly discussed and the suggestion is made that Mg fixation may offer an acceptable explanation for some of the yield depressions observed on liming to neutrality. Research is currently in progress to gather sufficient data to answer the many questions raised.  相似文献   

16.
Abstract

Results of field trials with sunflowers grown on an Ultisol over three seasons indicated that applications of lime and gypsum had little effect on the boron concentration in plant tissues. Only when 30 kg borax/ha/annum had been applied did soil amelioration slightly but significantly decrease the B concentration in 1‐month‐old sunflower seedlings. Liming for three seasons significantly decreased the B concentration in the topmost mature leaf at flowering only when 30 kg borax/ha/annum had been applied and the pH (N KCl) was 4.4 and above. A pot experiment with the same soil was designed to test whether high pH levels affected B uptake. The reduction of toxic aluminum markedly increased top and root growth but higher rates of line had no further benefit. Liming significantly decreased the B concentration in seedling tope but the total B content of the tops was increased by liming. It appeared that liming to pH (N KCl) 7.0 did not adversely affect the uptake and translocation of B by sunflower roots, and that the decreased B concentration in seedling tops resulted from a dilution effect due to the benefit from liming.  相似文献   

17.
Abstract

The relative effectiveness of two African rock phosphate (Morocco rock, MR and Togo rock, TR) was compared with the more reactive North Carolina rock phosphate (NCR) and with Triple superphosphate (TSP) in greenhouse using two strongly acidic Ultisols from southern Nigeria with and without application of lime.

Without liming, the relative effectiveness of the four P sources is in the order of NCR>TSP>MR>TR; while with liming, the sequence becomes: TSP≥NCR>MR>TR.

Liming soils to pH near 5.5 depressed P uptake by plant from the rock P sources but increased P uptake from TSP.

Morocco and Togo rocks are poor sources of P for direct application under both limed and unlimed conditions.  相似文献   

18.
The main agrochemical treatment applied in agriculture to lower harmful soil acidity is liming. Long term studies showed that application of calcium carbonate fertilizer brought about higher leaching of dissolved organic matter (DOM) in pot, lysdmetric and field experiments. Outflows obtained from limed soils contained 44.8% more DOM in comparison with nonlimed soils. During four years of lysimetric experiments it was found that the amounts of DOM from limed soils were increased by 52.7%. In the field experiments the amounts leached from one hectare of limed and nonlimed soil ranged 25.6 kg and 19.2 kg per year, respectively. DOM leached from limed soils was characterized by higher (45.4%) contents of carboxylic groups and humic substances (19.7%). Dissolved organic substances particularly humus rich in functional groups, due their complexing properties bound plant nutrients leached from soils and modify geochemical mobility of metals and anions. Therefore, DOM can play a significant role in the migration of chemical substances in agriculture landscape.  相似文献   

19.
The effect of liming the A and B horizons of a number of acid soils on the subsequent adsorption of phosphate by soils retained moist or allowed to dry was investigated. Air-drying increased the phosphate adsorption capacity but the reason was not clear. When A horizons were maintained moist, incubation with lime for six weeks increased phosphate adsorption by four samples and had no effect on another. When A horizons were air-dried, the effect was considerably reduced or reversed. For B horizons, which had considerably greater phosphate adsorption capacities than A horizons, liming decreased phosphate adsorption irrespective of whether the soils remained moist or were dried. The relative decrease in adsorption was, however, greater when the soils were dried. In a more detailed study using one acid soil it was shown that incubation of the soil with lime for six weeks had no effect on phosphate adsorption by moist A and B horizons but after 36 weeks incubation liming decreased adsorption by the moist samples. If soils were dried then liming decreased phosphate adsorption after six or 36 weeks incubation. Such relative effects of liming on phosphate adsorption were confounded by the fact that air-drying greatly increased the phosphate adsorption capacity of the unlimed soil. The drying effect was at least partially reversible following rewetting of the soil. Results were interpreted in terms of the lime-induced increase in soil pH causing (i) the surface charge conferred on soil oxide surfaces to become more negative (thus decreasing phosphate adsorption) and (ii) the precipitation of exchangeable Al as hydroxy-Al polymers resulting in the formation of new, highly active, adsorbing surfaces (thus increasing phosphate adsorption). Phosphate adsorption by moist limed soils can, therefore, be increased, decreased or unaffected depending on the relative magnitudes of these two processes. It is suggested that after liming, and/or air-drying, crystallization of amorphous materials progressively decreases their surface area and adsorbing capacity. Thus, liming tends to decrease phosphate adsorption when the soils are dried.  相似文献   

20.
Abstract

In this study the influence of zeolite application and soil liming on cadmium (Cd) sorption by soils in Greece was investigated. The zeolite was natural and consisted mainly of clinoptilolite. The soil samples were strongly acid surface horizons of an Alfisol limed from a pH of 4.0 to 8.5, and a neutral Bt horizon. The result showed that liming and zeolite application substantially increased sorption of Cd in the soils. Cadmium sorption was described adequately by the Freundlich equation whereas the Langmuir model failed to describe Cd sorption in the soils. The Freundlich constant K increased in value by zeolite application as well as by soil liming. A strong relationship was observed between this parameter and soil pH. A high percentage of cadmium sorbed was released in the desorption procedure. The amount of Cd released was reduced by zeolite application as well as by soil liming. It is concluded that zeolite application as well as soil liming increased Cd sorption by the soils.  相似文献   

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