Liming Strategies Research Articles

Lime microdosing: A new liming strategy for increased productivity in acid soils

AbstractDespite the effectiveness of the fertilizer microdosing technique, lime microdosing (LMD) to alleviate the negative impacts of soil acidity has not been comprehensively assessed. In a 3‐year study at four sites across three countries (one in the United States, two in Ghana, and one in Burkina Faso), we evaluated the effectiveness of the microdosing technique for lime application to alleviate the adverse effects of soil acidity in cropping systems, using corn (Zea mays L.) as the study crop. LMD was evaluated at four lime application rates, including 5%, 10%, 25%, and 50% of the calculated lime‐requirement rate (LR), which was compared to the traditional lime broadcasting strategy using 75% and 100% LR. Averaged across all experimental sites for the duration of the study, LMD with 25% LR resulted in similar grain yield, and nitrogen, phosphorus, and potassium recovery efficiency as those of the traditional lime broadcast techniques with 100% LR, but significantly greater than those of the lime broadcast techniques with 75% LR. Postharvest rhizosphere aluminum saturation percentage of the LMD with 25% LR was similar to that of the traditional lime broadcast techniques with 100% LR. However, LMD with lime application rates lower than 25% LR was not agronomically effective. The combined results suggest that LMD could be an efficient liming technique, and that with this technique, as little lime material as 25% LR could be used to mitigate the negative impacts of Al toxicity associated with soil acidity. Nevertheless, economic analyses are required to determine the profitability of utilizing the LMD technique to mitigate the negative impacts of soil acidity on crop production relative to the traditional lime‐broadcast approach.

Liming guidelines for soils under wheat cropping in the eastern Free State, South Africa

Soil acidity hampers the sustainability of wheat production in the eastern Free State, South Africa. Specific guidelines for liming are needed by farmers and advisors to ameliorate this condition. In this study, soils from four representative wheat producing farms were used for incubation and field studies to generate data for the development of liming guidelines. The clay content of the soils ranged between 8 and 33%, with pH (KCl) values below 4.5 and percentage acid saturation (%AS) above 8. These parameters are regarded as thresholds for wheat cultivation. Liming of the topsoil (0–200 mm) at different rates increased pH (KCl) linearly and decreased %AS exponentially. Either the resulting pH (KCl) or %AS values can be used in the development of liming guidelines. Using these values, an equation was established that is suitable for the estimation of lime requirement of soil: y 8.320× 1 + 0.0459× 2 − 1.0370, R 2 = 0.86 where y is the lime requirement (tonnes ha−1), x 1 = ΔpH (KCl) and x 2 = clay content (%). This equation was also used to compile a look-up table from which the soils’ lime requirement can be derived. Farmers and advisors can improve liming strategies for wheat production by applying this information.

Site characteristics determine the duration of structure liming effects on clay soil

Adding carbonated or non-carbonated lime to clay soils can lead to changes in aggregate stability. In Sweden, ‘structure liming’ with a mixed product (normally 80–85% calcium carbonate and 15–20% calcium hydroxide) is subsidised through environmental schemes to increase aggregate stability, thereby mitigating losses of particulate phosphorus (PP). This study assessed the effects of structure liming on aggregate stability in eight clay soils in southern Sweden, using turbidity as a proxy for aggregate stability. Turbidity in leachate from simulated rain events performed on aggregates (2–5 mm) in the laboratory was measured one and six years after application of four treatments 0, 4, 8 and 16 t ha-1 of a mixed structure liming product. The effect on turbidity was analysed for all application rates, but also as the contrast between the unlimed control and the mean of the limed treatments, to identify the general effect. A significant effect of structure liming on turbidity was found after one year. The effect decreased over time, but was still detectable after six years. However, there was a significant interaction between trial and treatment, indicating different reactions on different soils and suggesting that not all clay soils are suitable for structure liming if the desired objective is to lower the risk of PP losses. Clay content, initial pH and mineralogy may explain the different responses to structure liming. These findings show a need for a site-specific structure liming strategy. As a tentative recommendation, soils with a minimum clay content of approximately 25–30% and pH <7 should be preferred for structure liming.

Calculation of spatially explicit amounts and intervals of agricultural lime applications at county-level in China

Liming is a long-established and widely used agricultural practice to ameliorate soil acidity and improve crop production. Sustainable liming strategies for regional applications require information on both lime requirements and liming intervals given land use and soil dependent acidification rates. We developed a method to optimize lime requirements and liming intervals at regional level. Lime requirements were based on soil pH buffering capacity and liming intervals were estimated by ongoing soil acidity production, derived from major cations and anions balances in cropland systems. About 66% of croplands in Qiyang required liming to raise soil pH to 6.5, with a total lime requirement of 2.4 × 105 t CaCO3, with an average rate of 2.4 t ha−1 for paddy soils and 2.6 t ha−1 for upland soils. The remaining 34% were mainly calcareous soils. Nutrient management practices and crop rotations, affecting N transformation and crop removal, were the main drivers controlling the spatial variation in total acid production in non-calcareous soils, on average contributing 73% and 25%, respectively. Under current soil acidification rates, 33% of Qiyang's croplands would need liming within 30 years after raising the soil pH to 6.5. Averaged liming interval was 20 years, and 6.8 t ha−1 would be required to maintain soil pH ranges between 5.5 and 6.5. Areas with high soil acidification risk were mostly located in the southeast of Qiyang.

Adjusting P-K Fertilization and Liming Strategies to Enhance Yield of Cherry Tomato Plants Grown on an Oxisol

ABSTRACT Although cherry-tomato is becoming more popular in the last years, there are no specific recommendations for P and K fertilization or liming strategies for this specific variety. Our aim was to assess rates of P and K and liming strategies in order to improve the yield of cherry-tomato grown on an Oxisol with a limited P-availability. Two pot experiments were developed. In the first-one, a two-factor factorial design was developed with 4 P (first-factor) and 4 K rates (second-factor), being these rates the 0%, 50%, 100%, and 200% of the recommended fertilization for tomato in South-Brazil. In the second experiment, the soil pH (4.3) was adjusted to 5.5, 6.0, and 6.5 with limestone. Soil P-availability, plant growth, diameter, number of fruits and cherry tomato yields were increased with the P addition, while a non-significant effect was observed after adding K. The highest yield was produced with 50% of the suggested amount of P for tomato in comparison with the non-fertilized plants (yield increase of 674%), while higher P rates (100% and 200%) produced a lower yield increase. The significant effect of soil liming was observed on increase of the flower bunches number when the soil pH was amended to 6.5. Cherry-tomato requirements seem to be different from the recommended for other varieties. Our results indicate that higher yields were achieved with a lower amount of chemical inputs than the recommended for tomato in general, stressing the importance of P for tomato cherry production over the other factors assessed here.

Optimal lime rates for soil acidity mitigation: impacts of crop choice and nitrogen fertiliser in Western Australia

Many agricultural soils are naturally acidic, and agricultural production can acidify soil through processes such as nitrogen (N) fixation by legumes and application of N fertiliser. This means that decisions about mitigation of soil acidity (e.g. through application of lime), crop rotation and N fertiliser application are interdependent. This paper presents a dynamic model to determine jointly the optimal lime application strategies and N application rates in a rainfed cropping system in Western Australia. The model accounts for two crop rotations (with and without a legume break crop), for the acid tolerance of different crop types, and for differences in the acidifying effect of different N fertilisers. Results show that liming is a profitable strategy to treat acidic soils in the study region, but that there are interactions between N and acidity management. Choice of fertiliser affects optimal lime rates substantially, with the use of a more acidifying ammonium-based fertiliser leading to higher lime rates. The optimal liming strategy is also sensitive to inclusion of a legume crop in the rotation, because its fixed N can be less acidifying than fertiliser, and it allows a reduction in fertiliser rates. Higher rainfall zones have greater N leaching, which contributes to a higher optimal rate of lime. We find that injection of lime into the subsoil increases profit. Optimal lime rates in the absence of subsoil incorporation are higher than usual current practice, although the economic gains from increasing rates are small.

Effect of gypsum rates and lime with different reactivity on soil acidity and crop grain yields in a subtropical Oxisol under no-tillage

The low solubility of lime (CaCO3) and the absence of soil disturbance in fields under no-tillage (NT) may diminish the effectiveness of surface liming to reduce exchangeable Al3+ (toxic to plants) and increase the base saturation in deep soil layers. However, the effects of subsurface soil acidity can be attenuated by applying agricultural gypsum (CaSO4⋅2H2O), which is more soluble than lime, and thus, can leached bases (exchangeable Ca2+, Mg2+ and K+) and S-SO42− to deeper soil layers as well as decrease Al3+ toxicity to plants. Therefore, gypsum can be applied individually or in combination with lime. Herein, we conducted a field experiment aiming to evaluate short- (1 year) and long-term (11 years) effects of surface liming and gypsum application on the chemical properties of the 0.00–0.10, 0.10–0.20, 0.20–0.40 and 0.40–0.60 m soil layers and also on crop yield of 22 crop seasons (i.e., 10 soybean, 3 maize, 4 white oat, 3 wheat and 2 barley crops). The study was performed in a clayey Typic Hapludox of moderate acidity managed under NT for more than 25 years in Guarapuava, Paraná State, southern Brazil. Three soil surface-applied lime strategies were tested in order to raise base saturation to 70%, namely: (a) 4.62 Mg ha–1 rate of lime of low effective calcium carbonate equivalent (ECCE = 75%); (b) 3.47 Mg ha–1 rate of lime with a high ECCE value (101%); and (c) the same rate of high-ECCE lime split in three applications (i.e., 1/3 at the start of experiment; 1/3 after 1 year and 1/3 after 2 years). A control treatment without liming was also conducted. The liming strategies were combined with four rates of agricultural gypsum (i.e., 0, 3, 6 and 9 Mg ha–1) applied at the start of the experiment. Our findings did not reveal synergistic effect of lime and gypsum on soil chemical properties nor on crop yield. Gypsum resulted in very slight gains in grain yield (4% on average) and limited to just 25% of cereal (corn and winter cereals) crop seasons. On the other hand, liming increased soybean yields by 14% in 40% of crop seasons. Gypsum was more efficient than lime in raising exchangeable Ca2+ levels up to −0.60 m in the short term; however, lime promoted greater reduction of soil acidity and had a more marked residual effect on exchangeable Ca2+ contents than gypsum. The liming strategies did no promote substantial differences in crop yield, but low-ECCE lime sustained better soil chemical condition to plant growth for a longer period. Surface liming efficiently reduced subsurface acidity in a moderately acidic Oxisol managed under NT even in the short-term, promoting increments on soybean crop yields. In this case, the application of gypsum rates did not bring additional benefits to soil or plant yield.

Response of ‘Red Delicious’ apple trees to different liming strategies after drip fertigation with ammonium nitrate

Response of ‘Red Delicious’ apple trees to different liming strategies after drip fertigation with ammonium nitrate

Liming in the conversion from degraded pastureland to a no-till cropping system in Southern Brazil

A significant area in Brazil is covered with degraded pasturelands, which could be more appropriately used under no-till system. These soils are highly acid and physically fragile, and then there is a need to identify a better liming strategy that will improve the establishment of no-till systems. We hypothesized that the surface application of lime would be more efficient to alleviate soil acidity on degraded pastureland soils. A 4-year field trial examined the effect of a lime application (4.8Mgha−1) that had either been incorporated (0–20cm) or surface-applied to an acid sandy loam Oxisol, originally under degraded pasture in Southern Brazil. Control treatments (no-lime) were applied with and without soil disturbance. A black oat (Avena strigosa Schreb) – soybean (Glycine max L. Merrill) cropping sequence was used for 4 years after no-till establishment. Soil chemical attributes, plant nutrient uptake, black oat dry biomass production and soybean grain yield were assessed. Soil acidity amelioration was achieved either by incorporating the lime or applying it onto the soil surface. Lime incorporation resulted in a faster neutralization reaction, whereas surface-applied lime provided longer lasting soil profile benefits. At 0–5cm layer, both tillage treatments, especially with lime application, provided lower soil organic carbon levels than no-till treatments, with or without lime application, until the second year. These differences in soil organic carbon levels were not observed at the end of evaluation, after 4 years, probably because the residual tillage effect disappeared. Over time, the soil organic carbon levels at 5–10cm layer were slightly increased or maintained close to the initial level, regardless of treatment. Overall, the plants responded to lime application, with an increase by 35% on soybean yield, regardless of the application method. Surface liming provided better economic returns than incorporated liming. Lime incorporation is not recommended in degraded lands due to the risks of SOC losses with soil disturbance and rapid pH increase. Despite of high soil acidity before no-till cultivation, the surface application of lime was the best alternative for alleviating soil acidity when establishing a no-till system on degraded pastureland.

Revegetation and Soil Management Effects on Chemical Properties of a Saprolite Resulting from Deep Soil Removal

During the building of a hydroelectrical power plant at Ilha Solteira in the Parana River (Brazil), materials of a highly weathered soil Oxisol were extracted from a depth between 5 and 8 m for engineering works. This resulted in an abandoned depression area. The topsoil was not salvaged and the open pit was not backfilled, and as result vegetation hardly or not at all recovered. On the residual saprolite materials, an experimental field was established to assess different soil rehabilitation treatments. Field experiments were initiated in 1992. After soil tillage, two different crops and three different liming strategies were compared, giving six combinations. In addition, two uncropped control treatments, tilled and no-tilled, were established so that a total of eight treatments were assessed. The experimental design consisted of four randomized experimental blocks, which included a total of 32 plots with a plot area of 100 m2. This experiment was used to study the effectiveness of the soil-reclamation treatments after a 9-year period. Soil samples were taken at three different depths (0–10, 10–20, and 20–40 cm), and they were analyzed routinely for pH, organic-matter content, and cation exchange capacity (CEC). Revegetation of the abandoned saprolite material increased soil organic-matter content and cation exchange capacity (CEC), and to some extent small differences between treatments were evidenced. Exchangeable calcium (Ca) and magnesium (Mg) recovered faster than organic-matter content. A significant linear relationship was found between organic-matter content and CEC, suggesting continued addition of organic material will further approach the value of these parameters to those levels corresponding to natural soils under “Cerrado” vegetation.

Soil Acidity Indices in East Lithuania

In Lithuania, decades of regular soil liming ceased in 1990. At present, ∼18.7% of Lithuanian agricultural land is acidic and ∼1 million ha are at risk of chemical degradation by acidification. Intrasite observations of long-term experiments (monitored for >30 years) provide valuable datasets that allow evaluation of current soil conditions and enable landscape-scale acidification modelling. Acidic soil properties, soil acidity indices, and their response to liming practices are important issues that must be addressed to maintain the ecological functions of these acidifying agricultural landscapes. An experiment was conducted that involved four liming strategies based on two direct and two indirect lime requirement (LR) determination methods. These strategies are common practices, both generally and in the Baltic States. Results indicate the effect of soil liming on soil acidity indices significantly (P < 0.05) differ between the chosen LR determination method and soil acidity gradations.

Acidification Remediation Alternatives: Exploring the Temporal Dimension with Cost Benefit Analysis

Acidification of soils and surface waters caused by acid deposition is still a major problem in southern Scandinavia, despite clear signs of recovery. Besides emission control, liming of lakes, streams, and wetlands is currently used to ameliorate acidification in Sweden. An alternative strategy is forest soil liming to restore the acidified upland soils from which much acidified runoff originates. This cost-benefit analysis compared these liming strategies with a special emphasis on the time perspective for expected benefits. Benefits transfer was used to estimate use values for sport ffishing and nonuse values in terms of existence values. The results show that large-scale forest soil liming is not socioeconomically profitable, while lake liming is, if it is done efficiently-in other words, if only acidified surface waters are treated. The beguiling logic of "solving" an environmental problem at its source (soils), rather than continuing to treat the symptoms (surface waters), is thus misleading.

Sorghum growth, root responses, and soil‐solution aluminum and manganese on pH‐stratified sandy soil§

AbstractA stratified subsurface layer of acidic soil can develop in minimally disturbed soil such as no‐till receiving injection of N fertilizer (e.g., anhydrous ammonia). The objective of this study was to evaluate the effectiveness of subsurface band treatments in alleviating soluble Al3+ and Mn2+ toxicities on sorghum growth. Soil columns 40 cm in length were packed with soil (Valentine fine sand mixed mesic Typic Ustipsamment and Thurman loamy sand mixed Mesic Udorhentic Haplustoll) with treatments applied at the 10–18 cm depth to mimic soil pH stratification. The treatments at this depth were: (1) entire layer at soil pH of 3.7; (2) band of soil 6 cm wide at pH of 5.8 with the rest of the soil at pH 3.7; (3) band of soil 6 cm wide at pH of 6.3 with the rest of the soil at pH 3.7; and (4) entire layer at soil pH of 5.8. The soil above and below the 10–18 cm depth was at pH 5.8. Sorghum (Sorghum bicolor L. Moench) was grown in the soil columns under a controlled environment for 6 weeks. High concentration of Al in soil solution was found in soil at soil pH 3.7 which was overcome by either banding to pH 5.8, 6.3, or having the soil layer at pH 5.8. Treatment with pH of 5.8 throughout the soil 10–18 cm depth produced significantly greater top growth, although all other pH or liming strategies performed better than the soil pH 3.7 treatment. The banded treatments at pH 5.8 and 6.3 allowed roots to grow below the 10–18 cm layer of soil, but root growth was still significantly less than in the soil where the entire soil treatment layer was at pH 5.8. The increase in biomass yield with soil pH of 5.8 in the entire treatment layer was higher compared to band treatment at pH 5.8; however, the lime requirement would be 3.4 times more with liming the entire layer compared to banding a portion of the soil to pH 5.8 and would thus be translated into a higher liming cost.

Optimal control of lake pH for mercury bioaccumulation control

Mercury is recognized internationally as an important pollutant since mercury and its compounds are persistent, bioaccumulative and toxic, and pose human and ecosystem risks. A critical aspect of mercury cycling is its bioaccumulation, mainly as methylmercury, along the aquatic food web resulting in high risk of human exposure through contaminated fish consumption. Since lake acidity (pH) and mercury methylation are correlated, control of lake pH through lake liming is a possible option to mitigate mercury bioaccumulation. This work proposes to use optimal control theory to derive time-dependent lake liming strategies for a tighter control of lake pH. Since the behavior of the freshwater ecosystems such as lakes is often associated with considerable uncertainties, a robust and realistic analysis should incorporate such uncertainties. This work models the time-dependent uncertain variations in the basic lake pH value and derives the liming profiles in the presence of such seasonal pH fluctuations. Established techniques from real options theory are employed for modeling the uncertainty as a stochastic process, and stochastic optimal control is used for deriving liming profiles. The approach is critically evaluated through applications to various case study lakes. Considering the substantial costs associated with liming operations, the work formulates a multi-objective problem highlighting the tradeoff between accurate pH control and liming cost. The results of the control problem solution are also compared with heuristics based liming. The results, while highlighting the success of using time-dependent liming, put forth certain interesting aspects that might be helpful to a decision maker. The analysis is expected to make liming operation more reliable, thereby presenting one more tool to manage the harmful effects of mercury pollution.

Episodic acidification in northern Sweden: a regional assessment of the anthropogenic component

Spring flood is the period in boreal ecosystems that is most sensitive to acid deposition since as much as half of the year's precipitation melts and enters streams or the soil in the space of a few weeks. The ‘Episode Project‘ in northern Sweden found a consistent relationship between the SO 4 2− concentration of snow and the anthropogenic component of acid neutralization capacity (ANC) decline during spring flood. This correlation creates the possibility for a regional prediction of the severity of anthropogenic episodic acidification during spring flood episodes using SO 4 2− deposition data together with chemical data from 1240 lakes selected to be representative of northern Sweden. The regional assessment found that in 1998, ca 6% of the region was seriously affected by anthropogenic acidification during spring flood. The results from this study have important implications for both the national liming strategy and international negotiations to further reduce emissions of air pollutants in Europe.

A Review of Liming Options for Afforested Catchments in Ireland

Afforested catchments with acid bedrock are particularly susceptible to surface-water acidification. Liming has been used throughout Europe and North America as a means of mitigating the adverse effects of increased acidity of surface waters. One of the principal aims of liming is to increase alkalinity and pH to ensure suitable conditions for fish survival, in particular salmonids. This review examines the range of available liming methods in detail with specific emphasis on their potential use in afforested catchments in Ireland. The most promising method is the stream doser system because the dose rate can be varied automatically in response to changing stream conditions. Other methods worthy of further investigation include the spreading of lime on forest floors and the direct addition of limestone to stream beds. However, a better understanding of hydrological factors is required before a full assessment of terrestrial liming strategies can be made.

Water Quality Dependent Recovery from Aluminum Stress in Atlantic Salmon Smolt

In Norway, a variable pH target (pH 6.2–6.4 during most of the year, but 6.4 during the smoltification period) is used to reduce the cost of liming salmon rivers. Here we test the adequacy of this liming strategy. Atlantic salmon presmolts exposed to sublethal acidic water (pH 5.9, 210 hrs in water aged from 1 minute up to 2 hours after treatment (in a flow through system). More Al was eliminated from the gills when the fish were exposed to pH 6.3 than to pH 5.8 or 6.0, and when water was aged after pH increase. Recovery, defined as return of normal gill morphology, blood homeostasis and establishment of seawater tolerance was achieved within 210 hrs in channels treated with lime to pH 6.3, while a similar recovery was not obvious at lower pH values. Liming to pH 6.3 detoxified Al better than pH 6.1.

Incomplete mixing of limed water and acidic runoff restricts recruitment of lake spawning brown trout in Hovvatn, southern Norway

Repeated liming of Hovvatn during the 1981–1995 period assured successful reintroduction of lake spawning brown trout, Salmo trutta. Poor natural recruitment to the population was associated with low survival during early life stages (before hatching) as shown by the 0.5, 3.5, 0.9 and 1.0% of live embryos found in natural redds during the 1992–1995 period, respectively. The low survival was most likely caused by the combination of shallow spawning areas (<2.0 m) and acidic runoff (pH 4.0–4.8) which overlayed the limed part of the water body during the ice covered period. It is therefore concluded that this type of episodic acidification poses a major threat to lake spawning salmonids, and that it can retard or inhibit biotic recovery towards preacidified conditions expected as a result of liming. Addition of limestone gravel (8–32 mm) onto spawning grounds was an efficient alternative liming strategy as 33–36% live embryos were found in this substrate. Conversely, the trout actively avoided additions of shellsand, a behaviour most likely caused by the small particle size of shellsand (3–7 mm) relative to natural spawning gravel.

Magnesium in tropical and subtropical soils from north-eastern Australia. II. Response by glasshouse-grown maize to applied magnesium

A glasshouse trial, in which maize (Zea mays L. cv. Pioneer 3270) was grown in 35 north-eastern Australian soils of low magnesium (Mg) status, was undertaken to study the response to applied Mg. Of the soils studied, 20 were strongly acidic (pH1:5 soil : water &lt;5·4), and in these soils the response to Mg was studied in both the presence and absence of lime. Magnesium application significantly (P &lt; 0·05) increased dry matter yield in 10 soils, all of which were strongly acidic. However, significant Mg responses were recorded in 6 soils in the presence of lime, indicating that, in many situations, liming strategies may need to include consideration of Mg nutrition. Critical soil test values for 90% relative yield were 0·21 cmol(+)/kg of exchangeable Mg or 7% Mg saturation, whilst the critical (90% yield) plant tissue Mg concentration (whole shoots) was 0·15%.

FOLIAR POTASSIUM SPRAY TIMING EFFECTS ON SEASONAL LEAF POTASSIUM AND PRODUCTIVITY OF FRENCH PRUNE (PRUNUS DOMESTICA)

Soil applied potassium (K) may not alleviate K deficiency in fine textured California soils when high numbers of prunes per tree are produced leading to leaf necrosis and limb death. Because K demand is increased by fruit, K nitrate (KN) sprays appear to be a corrective option for growers in this situation. Our objectives were to determine best seasonal KN spray liming strategies to minimize K deficiency, quantify K uptake into leaves after spray and to evaluate spray effects on productivity. Results indicated that regardless of spray timing leaf K was increased by approximately 0.3% and three weeks later decreased 0.2%. Average leaf K in sprayed trees was 0.7% higher than untreated trees at harvest. Fruit fresh to dry weight ratios were lower (better) from summer sprayed trees than spring. Summer KN sprayed trees had yield efficiencies equal to those having soil applied K. Fruit size was similar regardless of K application method. Foliar KN sprays may be a viable K augmentation to soil application in heavy crop years on fine textured soils.