Application Of Dolomitic Lime Research Articles

Dolomitic lime and silicate in no‐till: Nutritional status, soil fertility, and soybean agronomic performance

AbstractLimestone is the most widely used agricultural input for soil acidity correction and calcium (Ca) and magnesium (Mg) fertilization. However, other materials have the potential to fulfill these purposes, such as steel slags, also known as silicates. Silicates have higher solubility than limestone, serving as agents for increase pH in no‐till, in addition to being a source of Ca, Mg, and silicon (Si). This study aimed to compare the effects of surface application of dolomitic lime and calcium magnesium silicate on soil chemical properties, soybean [Glycine max (L.) Merr.] nutritional status, and grain yield under no‐till. The experiment was installed in the northwest Paraná State, Brazil, on a Rhodic Eutrustox. Lime and silicate rates were applied by broadcasting before the sowing of soybean. Silicate treatment increases soil Ca2+, pH, and base saturation up to a depth of 0.10 m. By contrast, liming effects on soil chemistry were restricted to the 0.05 m top layer after 24 months of application. The acidity correction and Ca2+ supply to greater soil depths and the increased leaf Si as a beneficial element provided by silicate treatment contributed to increasing soybean yield in the 2018/2019 and 2019/2020 seasons. Lime application, regardless of the rate, did not improve soybean yield. Waste from the steel industry can be used as acidity correctives and source of Si, Ca, and Mg, improving the agronomic performance of soybean.

RENDIMIENTO DE BANANO DÁTIL EN SISTEMA DE CALLEJONES DE Inga spp., A DIFERENTES DOSIS DE FERTILIZANTES DE POTASIO Y FOSFORO

<p><strong>Background: </strong>the agronomic yield of crops of importance for rural households in the humid tropics, such as banana, cultivated in association with leguminous trees, such as Inga spp., must be studied because of the little available information on that association, especially with regards to yield response to the application of P and K under agroforestry systems, and the interaction between organic (leguminous residues) and inorganic sources of nutrients. <strong>Objective: </strong>the objective of this study was to evaluate the yield of lady finger banana alley cropped with <em>Inga</em> spp., under several levels of natural fertilizers such as K<sub>2</sub>SO<sub>4</sub> + Mg, and phosphoric rock (RF). <strong>Methodology: </strong>Yield response of lady finger banana (<em>Musa acuminata </em>Colla) under an alley cropping system with guama (<em>Inga</em> spp.). Prior to the establishment of the crop, dolomitic lime (Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>CaF<sub>2</sub>) at a rate of 2 ton ha<sup>-1</sup> was applied. In addition, phosphoric rock (RF) was added to the crop at diverse levels (0, 20, 40, 80 kg ha<sup>-1</sup>), and potassium sulphate and magnesium (K<sub>2</sub>SO<sub>4</sub> + Mg) at three levels (0, 45, 90 kg ha<sup>-1</sup>) with five replicates in a total of 35 alleys for treatments. <em>Inga</em> spp. trees provided with nitrogen (N). Two crop cycles were evaluated, cycle 1 (2015) and cycle 2 (2017). <strong>Results: </strong>the highest average weight per bunch were obtained with 80 FP and 0 RF in the first cycle, and with 90 K and 45 K in the second cycle, which were significantly higher than other levels. The highest yield on yearly basis was 45 K among the treatments during the first cycle, and the highest yields during the second cycle were obtained with 45 y 90 K<sub>2</sub>SO<sub>4</sub> + Mg. <strong>Implications:</strong> There are no prior studies for lady finger banana crop associated with <em>Inga </em>spp. trees under alley cropping, this reflects that the study is an original contribution to nutrient-response studies under agroforestry system with Inga. <strong>Conclusion:</strong> the highest yields were obtained with 90 and 45 kg ha<sup>-1</sup> of potassium sulphate and magnesium. The application of dolomitic lime promoted P and K availability for the crop, and better use of applied K<sub>2</sub>SO<sub>4</sub> + Mg and of RF in the treatments.</p>

The short-term effects of surface-applied dolomitic lime and gypsum on soil chemical properties and yields of sugarcane ratoon crops in KwaZulu-Natal, South Africa

This study investigated the effects of surface-application of lime and gypsum on soil properties and yields of ratoon sugarcane crops. Treatments involved once-off surface application of dolomitic lime (L), gypsum (G) and dolomitic lime plus gypsum (LG) in factorial combination, with four replications. Soil chemical properties were measured on samples collected at intervals of 20 between depths of 0 and 80 cm in the first and fifth years after treatment application. Yield parameters were measured annually. In the first year, treatment effects were mainly restricted to a depth of 0–20 cm. The LG increased pH(CaCl2) from 3.9 to 4.5, and calcium from 123 to 350 mg L−1. Little treatment effect was observed on yield parameters in the first year. In the fifth year, L and LG generally showed similar impacts on soil properties. The L treatment led to markedly increased pH(CaCl2) and calcium and somewhat decreased magnesium levels in the topsoil. The sucrose and cane yields in LG were significantly higher than in other treatments, which all had similar results. It was, therefore, concluded that LG may be a viable option for the correction of soil acidity through surface application in the sugarcane ratoon crops grown in the sandy soils of KwaZulu-Natal.

Gypsum and potassium application to acid soils for maize (Zea mays L.) production in La Frailesca, Chiapas, Mexico

Introduction. Maize (Zea mays L.) production in La Frailesca region, Mexico, is limited by sandy soils, low in potassium (K), and with acidic arable layers and subsoils. There is information on the management of lime but not on amendments that could be used for subsoil acidity — such as gypsum — nor on the interactions between amendments for soil acidity and K fertilization. Objective. To evaluate the effects of K and gypsum on maize and on previously limed soils. Materials and methods. The evaluations were conducted in farmers’ fields in La Frailesca region, Chiapas (Mexico) in 2016 and 2017. Four gypsum rates (0, 1.25, 2.5 and 5 t ha-1) and four K rates (0, 60, 90, and 120 kg ha-1 as K2O) were factorially combined in a randomized block design, with three replicates. In both years, before the beginning of the experiments, dolomitic lime was applied to the experimental area following standard practices. Responses of crop yield, soil exchangeable K, Ca, Mg, and Al, and soil pH were obtained. Results. Maize yields increased with gypsum (stabilizing at 1.25-3.0 t ha-1), and K (stabilizing at 70-120 kg ha-1 of K2O) applications. In soils, K application increased exchangeable K content, while gypsum increased exchangeable Ca content and pH, and decreased exchangeable Al content. Liming increased pHCa and exchangeable Ca and Mg contents, and lowered the exchangeable Al content in the top 7.5 cm of soil. Conclusion. Soils with exchangeable K (≤0.3 cmolc kg-1) were responsive to K fertilization. The positive effects on yields from gypsum were probably linked to a greater Ca supply in the top 7.5 cm. These results are encouraging about the benefits of the combined application of dolomitic lime, gypsum, and K, but longer evaluations are needed to properly determine the effects of gypsum on subsoil acidity.

Liming still positively influences sugar maple nutrition, vigor and growth, 20 years after a single application

Despite the decrease in acid deposition observed over the last decades, the health of sugar maple (SM; Acer saccharum Marshall), a species known as sensitive to base cation availability, is still a concern in many areas of northeastern North America. Twenty years after a single application of dolomitic lime, a widely available soil amendment, the effect of liming was evaluated on SM nutrition, vigor and growth in a declining stand affected by acid deposition. Lime doses of 0–50 t·ha−1 were applied over a 5 m radius around each selected tree. This experiment is unique in that it monitors the effects of doses that are economically feasible (“lower doses”; 0, 0.5, 1, 2 and 5 t·ha−1) and of higher ones (10, 20, 50 t·ha−1). We found that lime still had a positive effect on all variables studied after 20 years. In addition, SM nutrition, stem growth and crown vigor improved as lime dose increased. On average, foliar Ca and Mg concentrations increased by 35% and 46% for trees that received the 2 and 5 t·ha−1 doses, respectively, and by as much as 70% and 95% for those that received the 50 t·ha−1 dose. Crown dieback decreased from 44% for the control trees to less than 5% for those that received lime doses ≥5 t·ha−1. Basal area increment increased by 93% and 144% for trees that received lower and higher doses, respectively, compared to non-limed trees. Results indicate that a lime dose of approximately 5 t·ha−1, which is both potentially economic and operationally feasible, can have a beneficial effect on SM nutrition, vigor and growth for at least 20 years on such acidic and base-poor soils. Preserving SM tree health in this changing world is important to ensure its sustainability in maple forests.

Suppression Effects on Pineapple Soil-Borne Pathogens by Crotalaria juncea, Dolomitic Lime and Plastic Mulch Cover on MD-2 Hybrid Cultivar

The development and implementation of sustainable and environmentally friendly agricultural practices are indispensable as alternatives to pesticide use and to keep populations of soil-borne plant pathogens at levels that do not affect crop productivity. The present research evaluates the incidence of soil-borne phytopathogens on the pineapple variety MD-2, which was subjected to different treatments: Incorporation of <i>Crotalaria juncea</i> into the soil (organic amendment), application of dolomitic lime to soil (inorganic amendment), and the use of plastic mulch covering the soil. During the crop cycle (15 months), the following variables were evaluated: plant height (cm), fruit weight (kg·plant⁻¹ ), crop yield (ton·ha⁻¹ ), the bud root disease incidence caused by <i>Phytophthora nicotianae</i>, number of soil phytoparasitic nematodes and colony-forming-units (CFUs) of soil fungi and oomycetes. The results indicate that <i>Crotalaria juncea</i> treatment reduced the pathogen population (nematode and oomycetes) at levels that did not affect crop development, so that yield increased (18–20%). The incorporation of <i>C. juncea</i> into the soil as an organic amendment favors the populations of fungi disease suppressors (<i>Trichoderma-Aspergillus</i>). The phytoparasitic nematodes (<i>Meloidogyne</i> sp., <i>Pratylenchus</i> sp., and <i>Mesocriconema</i> sp.) and oomycetes (<i>Phytophthora</i> spp., and <i>Pythium</i> spp.) showed a reduction of their population levels by effects of organic amendment (<i>C. juncea</i>). The plastic mulch was also effective, probably due to the maintenance of optimal condition to crop growth and weed control. However, the dolomitic lime application had the poorest effect under the conditions of the study area on the variables analyzed. The described observations are characteristics of a system-based approach for the potential management of soil-borne pathogens of pineapple MD-2 in Veracruz, México.

Evaluation of the Effect of Dolomitic Lime Application on Pastures—Case Study in the Montado Mediterranean Ecosystem

The Montado ecosystem, predominant in the Mediterranean region, consists of poor soils, a sparse cover of cork and holm with an understory of natural biodiverse pastures, grazed by animals in extensive regime. The recommended procedure for increasing productivity of these pastures is based on the application of phosphate fertilizer. One of the main productivity-limiting factors is, however, associated with soil acidity. The objective of this work was to evaluate the simultaneous effect of the holm oak canopy and the application of dolomitic lime on the productivity and quality of a permanent biodiverse pasture, grazed by sheep, in an acid soil (pH = 5.4 ± 0.3). Pasture was monitored at the end of autumn 2018 and winter and spring 2019. The results show that amendment of soil acidity is a slow and gradual process that improves soil Mg/Mn ratio and has a positive impact on pasture productivity and quality. Pasture crude protein availability (CP, kg·ha−1), which is based on both pasture dry matter yield (kg·ha−1) and quality (CP, %), proved to be a very practical indicator of the contributions of tree canopy and soil acidity correction to the holistic management of the Montado ecosystem.

Nutritional Behavior of Heliconia Grown Under Different Levels of Lime

Production and commercialization of tropical flowers and plants has grown in recent years, mainly due to the increasing value of these products in temperate climate countries, such as heliconia, one of the most cultivated tropical ornamental plants in Brazil. This study was developed to determine the effect of lime applications on the nutrients in heliconia plants (Heliconia psittacorum L. &amp;times; Heliconia sparthocircinata Arist. [cv. Golden Torch]) cultivated in yellow latosol in a greenhouse. The macronutrient levels in the leaves, pseudostem and roots of the heliconia plants were determined after cultivating the plants in containers with a medium texture, yellow latosol, collected from the 0 to 20 cm layer and submitted to doses of 0, 0.9, 2.6, 4.2 and 5.9 t of lime ha-1. Nitrogen and phosphorous performed better in the absence of the correction and in the 0.9 t ha-1 dose for the vegetative parts of the heliconia plants. The application of dolomitic lime promoted greater absorption of potassium, calcium and magnesium, and sulfur performed better for the doses 2.6 and 5.9 t of lime ha-1, for the pseudostem and roots, respectively.

The importance of harvest residue and fertiliser on productivity of Pinus patula across various sites in their first, second and third rotations, at Usutu Swaziland

BackgroundConcern is growing about the future of forestry productivity due to intensive nutrient removal, as a result of different harvesting operations. This study aimed to determine the effects on forest productivity when using different slash-retention scenarios with the recommended amounts of mineral fertiliser in Usutu forest. Usutu is a plantation forest that grows mostly softwood where the predominant species is Pinus patula Schiede ex Schltdl. & Cham.MethodsThe first trial series (F) comprised of one trial located in each of five forest blocks. It was established in 1971 and compared the effects of various site preparation scenarios (slash removal, slash retention and cultivation) on the early growth of Pinus patula for adjacent first (F1R) and second rotation (F2R) sites (i.e. grassveld and clearfelled first-rotation sites). The second (S) trial series was re-established in April 1991 on exactly the same position as the first trial series, and involved second (S2R) and third rotation (S3R) sites. Three main treatments, standard pitting through harvest residue (control); manual pitting after removal of harvest residue and forest floor (cleared); and manual pitting and broadcast application of dolomitic lime (2 t ha− 1) over the slash (lime), were undertaken in factorial combination with the application of phosphate and potassium fertiliser. The data reported here are for tree volume productivity across the five sites of the first trial series up to age 10 years and three of the five sites of the second trial series up to age 9 years.ResultsSlash removal decreased volume productivity by 9 and 13% in the F1R and F2R at 10 years of age and further by 21 and 33% in S2R and S3R, respectively at 9 years of age. However, fertiliser application increased volume productivity by 14 and 15% in the F1R and F2R at 10 years age and further by 18 and 10% in the S2R and S3R, respectively at 9 years of age.ConclusionsIn order to sustain or increase productivity, it is recommended that harvest residue slash should be conserved and fertiliser containing phosphate and potassium be applied at planting at Usutu.

Resposta de Brachiaria brizantha cv. Xaraés a níveis de calagem

The response of Brachiaria brizantha var. Xaraés to the application of dolomitic lime (0; 800; 1,600; 2,400 and 3,200 kg/ha; PRNT = 100%), broadcasted and incorporated into the soil 2 months before planting, was evaluated under greenhouse with natural conditions of light and temperature. The soil was a Yellow Latosol, with clayey texture (pH = 5.5; Al = 1.5 cmolC/dm3; Ca + Mg = 1.7 cmolC/dm3; P = 2.0 mg/kg; and K = 59 mg/kg). A randomized block design was used with three replications. At establishment, a uniform application was made of 40 mg/dm3 of nitrogen (urea), 22 mg/dm3 of P2O5 (triple superphosphate), and 40 mg/dm3 of K2O (potassium chloride). The application of lime increased dry matter (DM) production significantly as well as the nitrogen, phosphorus, calcium, and magnesium concentrations in the plant. Maximum DM yield and phosphorus, calcium, and magnesium contents were obtained with the application of 3,087; 2,300; 3,123 and 3,111 kg lime/ha, respectively. Critical internal levels of calcium and magnesium related to 80% maximum DM production were estimated in 4.17 and 3.35 g/kg, respectively.

Effects of two types of Ca fertilizer on sugar maple nutrition, vigor and growth after 7 years

Sugar maple (Acer saccharum Marsh., hereafter SM) dieback has been of concern in many stands of northeastern North America for decades. In acidic, base-poor forest soils, this phenomenon has often been attributed to calcium (Ca) deficiency. Corrective measures such as dolomitic lime addition (CaMg(CO3)2) have been tested to restore SM vitality in these ecosystems. However, few studies have evaluated the effect of Ca addition alone on SM. Furthermore, liming experiments have showed that the Mg content of lime could induce a nutritional antagonism which hinders potassium (K) uptake. This may have limited the response of SM to dolomitic lime application. To address these issues, two calcium fertilizers with negligible Mg content (CaCO3 and CaSO4·2H2O) were applied at rates of 1, 2 and 4tCaha−1 on SM trees. After 7years, foliar Ca nutrient concentrations of treated trees increased in both Ca treatments, reaching published concentration ranges for healthy SM trees. These increases were greater than those observed after a similar period in two nearby experiments in which CaMg(CO3)2 and CaCO3 were used at comparable or lower doses. Also, no nutrient antagonism was detected in the present study. Tree crown vigor and basal area growth were improved by the Ca treatments, but the magnitude of the growth response for trees treated with the CaCO3 fertilizer was far less than in the other nearby experiment where CaCO3 was also used. This strongly suggests that Mg nutrition is not a limiting factor in this ecosystem. The comparatively lower growth response of trees to Ca treatments in this study is unclear, but better growth conditions at the studied site, compared to the two other nearby experiments, may have played a role in this phenomenon. Long-term monitoring of these experiments seems warranted to clarify these issues.

Interacting effects of wildfire severity and liming on nutrient cycling in a southern Appalachian wilderness area

Aims Wilderness and other natural areas are threatened by large-scale disturbances (e.g., wildfire), air pollution, climate change, exotic diseases or pests, and a combination of these stress factors (i.e., stress complexes). Linville Gorge Wilderness (LGW) is one example of a high elevation wilderness in the southern Appalachian region that has been subject to stress complexes including chronic acidic deposition and several wildfires, varying in intensity and extent. Soils in LGW are inherently acidic with low base cation concentrations and decades of acidic deposition have contributed to low pH, based saturation, and Ca:Al ratio. We hypothesized that wildfires that occurred in LGW followed by liming burned areas would accelerate the restoration of acidic, nutrient depleted soils. Because soils at LGW had extremely low concentrations of exchangeable Ca 2+ and Mg 2+ dolomitic lime was applied to further boost these cations. We evaluated the effectiveness of dolomitic lime application in restoring exchangeable Ca 2+ and Mg 2+ and subsequently increasing pH and Ca:Al ratio of soils and making Ca and Mg available to recovering vegetation. Methods Five treatment areas were established: severely burned twice (2000 & 2007) with dolomitic lime application (2xSBL); moderately burned twice with lime application (2xMBL); severely burned twice, unlimed (2xSB); moderately burned once (2000), unlimed (1xMB); and a reference area (REF; unburned, unlimed). In 2008 and 2009, we measured overstory, understory, and ground-layer vegetation; forest floor mass and nutrients; and soil and soil solution chemistry within each treatment area. Results All wildfire burned sites experienced substantial overstory mortality. However, understory biomass doubled between sample years on the most recently burned sites due to the rapid regrowth of ericaceous shrubs and prolific sprouting of deciduous trees. Burning followed by lime application (2xSBL and 2xMBL) significantly increased shallow soil solution NO3-N, but we found no soil solution NO3-N response to burning alone (2xSB and 1xMB). Surface soil base saturation and exchangeable Ca 2+ were significantly affected by liming; Ca 2+ concentrations were greater on 2xMBL and 2xSBL than 2xSB, 1xMB and REF.

Soil and sugar maple response 15 years after dolomitic lime application

Dolomitic lime (CaMg(CO3)2) was applied in 1994 at rates of 0–50Mgha−1 to sugar maples (SMs) (Acer saccharum Marsh.) in a base-poor and declining northern hardwood stand subjected to a high level of acid deposition in Quebec. The soil chemistry and the SM nutrition, growth, crown vigor, and regeneration status were evaluated 15years after treatment. The soil chemical properties still responded strongly to lime after 15years. Similarly, the foliar Ca and Mg concentrations were still higher for treated trees relative to the control trees. After 15years, the mean crown dieback of trees decreased quadratically with the lime rate, from 39% for the control trees to a value of 1–3% for the lime rates of 5Mgha−1 and higher. Additionally, the stem basal area increment for the limed trees was nearly double that of the unlimed trees in 2009. The lime application was also beneficial to the SM regeneration. The overall SM seedling density increased with the lime rate, being nearly twice as much in the 50Mgha−1 (32 seedlings m−2) compared with the controls (16 seedlings m−2). The proportion of the SM seedlings to all of the other species increased quadratically from 22% in controls to more than 55% in the 5–50Mgha−1 treatments. In contrast, the proportion of competitive species decreased quadratically with the lime rate, including American beech (Fagus grandifolia Ehrh.) for which the proportion in the treated plots (24%) was nearly half the proportion observed in the controls (46%). However, increase in stem density of regeneration and canopy closure in response to lime application limit the development of the regeneration which did not benefit in terms of diameter and height. These results show that a single lime addition has long-term beneficial effects on the soil chemistry and the SM nutrition, vigor, growth, and regeneration in base-poor and declining northern hardwood stands. Moreover, the results confirm that liming is an essential tool to restore the SM representation and health in acidic and base-poor soils.

Effects of two Ca fertilizer types on sugar maple vitality

Over the last decades, continuous signs of sugar maple ( Acer saccharum Marsh.) dieback in stands of northeastern North America have promoted the experimentation of corrective measures to restore sugar maple vitality. To verify the hypothesis that K–Mg antagonism may have limited the full response of sugar maple to dolomitic lime application in a previous experiment (CaMg(CO3)2, 12% Mg), two Ca fertilizers (CaCO3 and CaSO4·2H2O), having negligible Mg content, were applied at rates of 1, 2, and 4 t Ca·ha–1 on sugar maple trees adjacent to the limed area. After 3 years, most of the foliar nutrient concentrations of treated trees were improved, particularly Ca, for both Ca fertilizers, in line with published ranges for healthy sugar maple trees, except for Mg. Moreover, no persistent nutrient antagonism was observed. The crown dieback rate of treated sugar maple was ≤5.8% after 3 years, while it reached 12% for the controls. Also, relative basal area growth showed that both Ca sources can improve growth rate. Growth response following Ca treatments was, however, lower than for the former lime experiment after the same period of time. In this context, our results suggest that Mg nutrition could be more important for sugar maple in this ecosystem than initially thought.

Soil properties and maple–beech regeneration a decade after liming in a northern hardwood stand

Soil properties, regeneration, sugar maple (SM, Acer saccharum Marsh.) crown dieback, and light interception were evaluated following dolomitic lime application (CaMg(CO 3) 2; 0, 2, 5, 10 and 20 t ha −1) in a base-poor and declining northern hardwood stand of Quebec (Canada). Ten years after liming, soil pH, cation exchange capacity and base saturation increased with the lime rate. Meanwhile, concentrations of exchangeable K, Na, and acidity (0–20 cm) decreased. Concentrations and content of total carbon, organic matter, and total N decreased in the top sampled soil layer, mainly for the highest lime rate. Mean crown dieback of SM ranked from 0 to 3.4% among lime treatments, while it ranked 18.4% for the unlimed controls. Light interception by the canopy responded with an opposite pattern to crown dieback, with higher interception in lime treatments and lower in control. Proportion and diameter of SM regeneration stems increased with lime rate while proportion of American beech (AB, Fagus grandifolia Ehrh.) regeneration stems decreased in the understory. Height and stem diameter of the three taller regeneration stems (mainly AB) in each plot were inversely correlated with lime rate. Overall, the results suggest that the increase in soil fertility following liming had a beneficial effect on SM regeneration within 10 years, even if light availability was lower under treated SM than under control, and had an overall negative impact on AB regeneration.

Calagem superficial e cobertura de aveia preta antecedendo os cultivos de milho e soja em sistema plantio direto

Os resíduos de plantas de cobertura podem mobilizar cátions no solo e beneficiar a ação da calagem superficial, por meio da liberação de ácidos orgânicos de baixo peso molecular da fração solúvel dos resíduos. Entretanto, faltam estudos no campo que comprovem tais efeitos em sistema plantio direto. Para avaliar as alterações químicas do solo e a resposta do milho e da soja com a aplicação de doses de calcário dolomítico na superfície (0,0, 2,5, 5,0 e 7,5 t ha-1), na ausência e na presença de cobertura de aveia preta, foi realizado um experimento em um Latossolo Vermelho distrófico textura argilo-arenosa, há cinco anos no sistema plantio direto, em Ponta Grossa (PR). As doses de calcário foram aplicadas nas parcelas em novembro de 2000 e, nas subparcelas, foram realizados dois cultivos, sem e com aveia preta em 2001 e 2002, antecedendo as culturas de milho e soja. A massa de aveia preta produzida não foi influenciada pela aplicação de calcário, tendo-se obtido aproximadamente 4 t ha-1 de matéria seca de aveia, em 2001 e 2002. A calagem também não alterou a capacidade de neutralização do hidrogênio (482 mmol c kg-1), a soma de cátions solúveis (29,5 mmol c L-1) e a condutividade elétrica (1.230 µS cm-1) do extrato de aveia. O calcário aplicado na superfície aumentou o pH, Ca2+ e Mg2+ e reduziu o Al3+ do solo até à profundidade de 10 cm. O resíduo de aveia preta mantido na superfície do solo não ocasionou benefícios à ação da calagem superficial na correção da acidez de camadas do subsolo. A calagem superficial não modificou a nutrição do milho, reduziu as concentrações de Zn e Mn nas folhas de soja e não causou alterações no rendimento de milho e soja. A cobertura de aveia preta aumentou as concentrações de P, Ca e Mg, nas folhas de milho, de N e P, nas folhas de soja, e reduziu o Mn no tecido foliar de soja. A manutenção do resíduo de aveia preta sobre a superfície do solo aumentou o rendimento de milho, mas não influiu no rendimento de soja, cultivada após o milho, no sistema plantio direto.

Lime application in the establishment of a no-till system for grain crop production in Southern Brazil

Brazil has extensive pasturelands that could be used, in part, for grain production. A no-till system was established on pastureland to obtain a suitable method for liming upon conversion from pasture to a no-till cropping system. The study was conducted during the period from 1998 to 2003, in Paraná State (Brazil), on a clayey, kaolinitic, thermic Rhodic Hapludox. Soil chemical properties and grain production were evaluated after application of dolomitic lime. The experimental treatments were: control (no lime), split application of lime on the surface (three yearly applications of 1.5 t ha −1), surface lime (4.5 t ha −1), and incorporated lime (4.5 t ha −1). The lime rate was calculated to raise the base saturation in the topsoil (0–0.20 m) to 70%. The cropping sequence was: soybean ( Glycine max L. Merril), barley ( Hordeum distichum L.), soybean, wheat ( Triticum aestivum L.), soybean, corn ( Zea mays L.), and soybean. When surface-applied, liming neutralized acidity and increased exchangeable Ca 2+ + Mg 2+ to a depth of 0.10 m, and to a depth of 0.20 m, when incorporated. Split application of lime on the surface resulted in a slower neutralization reaction only in the first year after liming. Soil pH increased with liming and resulted in a decline of exchangeable Al 3+ and an increase in base saturation. At 0–0.05 m depth, lime incorporation resulted in lower levels of soil organic matter than surface application. It took 4–5 years after lime incorporation for soil organic matter to return to its baseline value. Liming increased grain yield in only one crop of soybean, and only when lime was surface-applied at the full rate. However, cumulative grain yield was higher with liming than in the control treatment (no lime), regardless of the application method. Surface application of lime, at either full or split rates, was the best alternative to neutralize soil acidity when establishing a no-till system on pastureland because, in addition to conserving soil structure, it provided a greater economic return.

Reestablishment of Jeffrey Pine on an Acidic Sierra Nevada Surface Mine

A three-year study was initiated to evaluate the effectiveness of fertilization at outplanting with two controlled release nutrient amendments, High N 22-4-6 + Minors and Gromax 21-6-2 + Minors, and minisite application of dolomitic lime in enhancing the establishment and nutrition of bareroot Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seedlings on a strongly acidic Sierra Nevada surface mine site. Fertilization rates of 8 g and 16 g per seedling and a single liming rate of 32 g were examined. Controlled release fertilization produced a substantial seedling growth response, more so with the High N than the Gromax formulation and with the 16 g rather than the 8 g rate. In contrast, liming suppressed growth and induced excessive seedling mortality. Among numerous fertilization effects on nutrition over the course of the study, increases in foliar N, P, and K, reductions in several potentially phyto-toxic elements including Mn and Al, and elevation of Ca/Al, Mg/Al, K/Al, Mg/Mn, and K/Mn molar ratios were prominent and likely responsible in large part for the favorable responses to this treatment. Liming had relatively little influence on nutrition, and much of that was probably detrimental, as exemplified by the lower Mg/Al, Ca/Mn, Mg/Mn, Ca/Cu, and Mg/Cu ratios of seedlings with lime during the critical first season when the preponderance of the mortality occurred. Nevertheless, it is likely that, as applied here, this amendment impaired seedling water relations on a site already limited by moisture availability, and this was of primary importance in the overall unfavorable response. Viewed in total, this study readily demonstrated the benefits that controlled release fertilization can provide in the reforestation of surface mines and similar harsh sites in the Sierra Nevada, but also revealed that minisite lime application at the rate used here was counterproductive and therefore further experimentation is necessary before this practice is routinely employed.

Nutrient cycling in a Pinus patula plantation in the Mpumalanga Province, South Africa

The accumulation of litter on the forest floor was identified as a potential problem in managed plantations of Pinus patula (Schlechtd. et Cham.) in the Mpumalanga Province of South Africa in the late 1980s. Litter accumulation in pine plantations is regarded as a threat to site productivity as organic acids are released, moisture penetration is altered and nutrients are immobilised within the litter. This study examines the cycling of nutrients in a 42-year-old P. patula stand in which litter has accumulated. Samples of the vegetation, litter and soil components were collected and chemically analysed for total nitrogen (N), phosphorus (P) and the major cations potassium (K +), calcium (Ca 2+) and magnesium (Mg 2+). Complete nutrient budgets for N and P, and the cation pool sizes were determined. It was evident from these studies that large reserves of N (1442 kg ha −1) and P (103 kg ha −1) are stored in the litter layers, with levels of cations being low. The presence of large nutrient reserves within the litter and the predominance of fine feeder roots distributed within this layer indicated that a tightly closed plant–litter–plant nutrient cycle was in operation for the cycling of N and P. This may not be true for the major cations. Management of the litter should ensure retention of as many nutrients as possible in the system. This could be achieved through controlled burning to reduce nutrient loss through volatilisation; increasing forest floor temperatures by altering the planting density and application of dolomitic lime to replace cations and to alleviate the acidic conditions making the litter more favourable for decomposing organisms.

Effects of Lime and Wood Ash on Soil-solution Chemistry, Soil Chemistry and Nutritional Status of a Pine Stand in Northern Germany

Lime and wood ash may be useful to improve acidic forest soils. A field experiment was conducted in a pine stand on a sandy podzol at Fuhrberg, Germany, which involved an application of dolomitic lime (3 t ha-1) with three replications or wood ash (4.8 t ha-1) without replications on the forest floor. During the 2 yr study period, lime affected the soil solution composition only slightly. Ash had a marked effect on solution chemistry of the mineral soil at 10 cm and the pH values dropped temporarily from 3.7 to 3.1. Nineteen months after the treatments, exchangeable calcium in the organic layer and mineral soil increased by 222 (lime addition) or 411 kg ha-1 (ash addition) and exchangeable magnesium increased by 101 (lime addition) or 39 kg ha-1 (ash addition). After ash addition, no marked change in heavy metal content was found below 4 cm of the organic layer. In the ash treatment, the potassium concentration of the 1-yr-old pine needles increased from 5.6 to 5.9 g kg-1. This study suggests that ash from untreated wood may be recommended for amelioration of forest soils.