Organic Amendments for Soil Reclamation: A Review

The principle that presents human activities and forms the basis of sustainable soil management must not negatively impact future generations. The soil can be degraded by human activity, natural events like erosion and other factors. Degraded or disturbed soil sometimes lacks organic matter when compared with neighbouring undisturbed areas. Organic amendments that are produced in huge quantity worldwide and have the potential to be widely used for soil reclamation include animal manure, biosolids, waste from fruit pulp, kitchen trash, paper mills, wood scraps, crop residues, etc. This review article explores the mechanisms through which organic addition alters physical, chemical and biological properties of the soil and defines significance of organic amendments in the soil reclamation, with a focus on amendment types and application rates for soil amelioration and biomass production. A large-scale use of organic amendments can speed up the initial reclamation process and produce self-sustaining net production. Though easily decomposable organic additions may have immediate but transient impacts, stable and less decomposable molecules may cause effects that last longer. Organic additions consisting of waste products from the forestry, urban and agricultural sectors are used to achieve land reclamation to attain mutual benefits.

The impact of cow dung augmentation on soil restoration and bio-accumulation of metals (Lead and Cadmium) in Pheretima posthuma (Annelida: Clitellata) / O impacto do aumento de esterco de vaca na restauração do solo e bioacumulação de metais (chumbo e cádmio) em Pheretima posthuma (Annelida: Clitellata)

Abstract To investigate the role of cow dung in soil reclamation and bio assimilation along with bio accumulation of heavy metals in earthworm (P. posthuma) (N=900) earthworms were used and treatment groups of CD-soil mixture of different proportion of cow dung were designed. Nonlethal doses of lead acetate and cadmium chloride were added in treatment groups. Mature P. posthuma were released in each experimental pot maintaining the favorable conditions. The pH, carbon, nitrogen, phosphorus, exchangeable cations, and heavy metal level of each mixture was evaluated. The results indicated that bio-assimilation of Pb and Cd by P. posthuma were significantly (P ˂ 0.01) higher in different soil-CD treatments compared to control. Highest bio-assimilation of both metals was observed in T1 of both groups (Pb = 563.8 mg/kg and Cd = 42.95 mg/kg). The contents of both metals were significantly (P ˂ 0.05) lowered in casting. The nutrient concentration in the final castings of all soil-CD treatments were also equally transformed from less or insoluble to more soluble and available for plants, except for carbon level which increased with CD proportion. It is concluded that cow dung as organic matter has a positive effect on soil reclamation and bio-assimilation of metals by P. posthuma.

RESUMO Para investigar o papel do esterco de vaca na recuperação do solo e bioassimilação, juntamente com a bioacumulação de metais pesados ​​em minhocas (P. posthuma) (N = 900), minhocas foram usadas e grupos de tratamento de mistura CD-solo de diferentes proporções de esterco de vaca foram projetados. Doses não letais de acetato de chumbo e cloreto de cádmio foram adicionadas aos grupos de tratamento. P. posthuma maduros foram liberados em cada vaso experimental, mantendo as condições favoráveis. Foram avaliados o pH, carbono, nitrogênio, fósforo, cátions trocáveis ​​e nível de metais pesados ​​de cada mistura. Os resultados indicaram que a bioassimilação de Pb e Cd por P. posthuma foi significativamente (P ˂ 0,01) maior em diferentes tratamentos de solo-CD em relação ao controle. A maior bioassimilação de ambos os metais foi observada em T1 de ambos os grupos (Pb = 563,8 mg / kg e Cd = 42,95 mg / kg). O conteúdo de ambos os metais foi significativamente (P ˂ 0,05) reduzido na fundição. A concentração de nutrientes nas fundições finais de todos os tratamentos de solo-CD também foi igualmente transformada de menos ou insolúvel para mais solúvel e disponível para as plantas, exceto o nível de carbono que aumenta com a proporção de CD. Conclui-se que o esterco de vaca como matéria orgânica tem um efeito positivo na recuperação do solo e na bioassimilação de metais por P. posthuma.

The impact of cow dung augmentation on soil restoration and bio-accumulation of metals (Lead and Cadmium) in Pheretima posthuma (Annelida: Clitellata) / O impacto do aumento de esterco de vaca na restauração do solo e bioacumulação de metais (chumbo e cádmio) em Pheretima posthuma (Annelida: Clitellata)

To investigate the role of cow dung in soil reclamation and bio assimilation along with bio accumulation of heavy metals in earthworm (P. posthuma) (N=900) earthworms were used and treatment groups of CD-soil mixture of different proportion of cow dung were designed. Nonlethal doses of lead acetate and cadmium chloride were added in treatment groups. Mature P. posthuma were released in each experimental pot maintaining the favorable conditions. The pH, carbon, nitrogen, phosphorus, exchangeable cations, and heavy metal level of each mixture was evaluated. The results indicated that bio-assimilation of Pb and Cd by P. posthuma were significantly (P ˂ 0.01) higher in different soil-CD treatments compared to control. Highest bio-assimilation of both metals was observed in T¹ of both groups (Pb = 563.8 mg/kg and Cd = 42.95 mg/kg). The contents of both metals were significantly (P ˂ 0.05) lowered in casting. The nutrient concentration in the final castings of all soil-CD treatments were also equally transformed from less or insoluble to more soluble and available for plants, except for carbon level which increased with CD proportion. It is concluded that cow dung as organic matter has a positive effect on soil reclamation and bio-assimilation of metals by P. posthuma.

Para investigar o papel do esterco de vaca na recuperação do solo e bioassimilação, juntamente com a bioacumulação de metais pesados em minhocas (P. posthuma) (N = 900), minhocas foram usadas e grupos de tratamento de mistura CD-solo de diferentes proporções de esterco de vaca foram projetados. Doses não letais de acetato de chumbo e cloreto de cádmio foram adicionadas aos grupos de tratamento. P. posthuma maduros foram liberados em cada vaso experimental, mantendo as condições favoráveis. Foram avaliados o pH, carbono, nitrogênio, fósforo, cátions trocáveis e nível de metais pesados de cada mistura. Os resultados indicaram que a bioassimilação de Pb e Cd por P. posthuma foi significativamente (P ˂ 0,01) maior em diferentes tratamentos de solo-CD em relação ao controle. A maior bioassimilação de ambos os metais foi observada em T1 de ambos os grupos (Pb = 563,8 mg / kg e Cd = 42,95 mg / kg). O conteúdo de ambos os metais foi significativamente (P ˂ 0,05) reduzido na fundição. A concentração de nutrientes nas fundições finais de todos os tratamentos de solo-CD também foi igualmente transformada de menos ou insolúvel para mais solúvel e disponível para as plantas, exceto o nível de carbono que aumenta com a proporção de CD. Conclui-se que o esterco de vaca como matéria orgânica tem um efeito positivo na recuperação do solo e na bioassimilação de metais por P. posthuma.

The impact of cow dung augmentation on soil restoration and bio-accumulation of metals (Lead and Cadmium) in Pheretima posthuma (Annelida: Clitellata)

Abstract To investigate the role of cow dung in soil reclamation and bio assimilation along with bio accumulation of heavy metals in earthworm (P. posthuma) (N=900) earthworms were used and treatment groups of CD-soil mixture of different proportion of cow dung were designed. Nonlethal doses of lead acetate and cadmium chloride were added in treatment groups. Mature P. posthuma were released in each experimental pot maintaining the favorable conditions. The pH, carbon, nitrogen, phosphorus, exchangeable cations, and heavy metal level of each mixture was evaluated. The results indicated that bio-assimilation of Pb and Cd by P. posthuma were significantly (P 0.01) higher in different soil-CD treatments compared to control. Highest bio-assimilation of both metals was observed in T1 of both groups (Pb = 563.8 mg/kg and Cd = 42.95 mg/kg). The contents of both metals were significantly (P 0.05) lowered in casting. The nutrient concentration in the final castings of all soil-CD treatments were also equally transformed from less or insoluble to more soluble and available for plants, except for carbon level which increased with CD proportion. It is concluded that cow dung as organic matter has a positive effect on soil reclamation and bio-assimilation of metals by P. posthuma.

RESUMO Para investigar o papel do esterco de vaca na recuperação do solo e bioassimilação, juntamente com a bioacumulação de metais pesados em minhocas (P. posthuma) (N = 900), minhocas foram usadas e grupos de tratamento de mistura CD-solo de diferentes proporções de esterco de vaca foram projetados. Doses não letais de acetato de chumbo e cloreto de cádmio foram adicionadas aos grupos de tratamento. P. posthuma maduros foram liberados em cada vaso experimental, mantendo as condições favoráveis. Foram avaliados o pH, carbono, nitrogênio, fósforo, cátions trocáveis e nível de metais pesados de cada mistura. Os resultados indicaram que a bioassimilação de Pb e Cd por P. posthuma foi significativamente (P 0,01) maior em diferentes tratamentos de solo-CD em relação ao controle. A maior bioassimilação de ambos os metais foi observada em T1 de ambos os grupos (Pb = 563,8 mg / kg e Cd = 42,95 mg / kg). O conteúdo de ambos os metais foi significativamente (P 0,05) reduzido na fundição. A concentração de nutrientes nas fundições finais de todos os tratamentos de solo-CD também foi igualmente transformada de menos ou insolúvel para mais solúvel e disponível para as plantas, exceto o nível de carbono que aumenta com a proporção de CD. Conclui-se que o esterco de vaca como matéria orgânica tem um efeito positivo na recuperação do solo e na bioassimilação de metais por P. posthuma.

A Survey Report on Ikki-Ryo : A Moxibustion Clinic Affiliated with the Uchihara Training Camp (1938-1945) for the Japanese Youth Volunteer Brigade for Reclamation of Manchuria and Mongolia / 日本東洋医学雑誌

Ikki-Ryo was a moxibustion clinic established as part of a national project facility that belonged to the Uchihara Training Camp (1938-1945) for the Japanese Youth Volunteer Brigade for Reclamation of Manchuria and Mongolia. Since such a case is extremely rare in the modern medical history of Japan, this article summarizes the information on Ikki-Ryo obtained through documents collection and analysis, interviews, and fieldwork investigation. Ikki-Ryo was proposed by acupuncturists Bunshi Shirota and Kyohei Tanaka, and was established under the directorship of Kanji Kato. It played a role in the clinical practice and training of moxibustion techniques. The data suggests that Ikki-Ryo provided advantageous clinical effects in the promotion of good health and in the treatment of some diseases (e.g. enuresis, suspected tuberculosis) for the trainees, while it is indicated that this clinic had a certain geographical, organizational, and emotional distance from other medical or healthcare departments at the camp. Although the role of moxibustion has changed throughout history, the concept and activities of Ikki-Ryo are still thought-provoking from the perspective of the diversity, versatility, complementarity, and sustainability of healthcare tools.

Analysis on theory and mode of wastes reclamation in process of industrialization of Chinese materia medica resources / 中草药

With the rapid development of Chinese materia medica (CMM) industry, ecological problems brought by CMM wastes in the process of industrialization of traditional Chinese medicine have become increasingly serious. This article analyzes the pattern of CMM wastes resource utilization deeply based on the externality theory of economics, theory of circular economy and value innovation. It comes up with trinity comprehensive utilization mode, which is the combination of extensive low utilization mode, conversion efficiency utilization mode, and high value-added utilization mode. Finally it puts forward specific measures in the process of industrialization of CMM waste resources development technology and resources management value-added.

Estrutura de um solo construído cultivado com diferentes espécies de poáceas / Structure of a constructed soil cultivated with different species of poaceae

Na mineração de carvão a céu aberto, a superfície é completamente suprimida de vegetação e as camadas de solo e rochas que recobrem os bancos de carvão são removidas, causando drásticas alterações no perfil do solo original. Este trabalho teve como objetivo avaliar a influência de diferentes espécies de poáceas na recuperação da estrutura de um solo construído, como parte da estratégia de recuperação de áreas degradadas por mineração de carvão. Os tratamentos avaliados foram: T1 - Hemarthria altissima, T2 - Paspalum notatum, T3 - Cynodon dactilon, T4 - Urochloa brizantha. Como testemunha, utilizou-se o solo construído sem cobertura vegetal, denominada T5. Foram coletadas amostras de solo não preservadas e preservadas nas camadas de 0,00-0,10m e 0,10-0,20m, para as determinações da porcentagem de macroagregados e microagregados, diâmetro médio ponderado, carbono orgânico, densidade e macroporosidade do solo construído. Os resultados obtidos foram analisados aos 05, 41 e 78 meses após o estabelecimento do experimento. Aos 78 meses de condução do experimento, observa-se ação positiva das quatro espécies vegetais na recuperação da agregação do solo construído, com destaque para a Urochloa brizantha que proporcionou a menor densidade do solo e um dos maiores valores de macroporosidade. As poáceas proporcionaram uma melhoria na estruturação do solo construído, principalmente a partir dos 41 meses de condução do experimento, quando houve um incremento nos valores de DMP, principalmente na camada de 0,00-0,10m. Os teores de carbono orgânico foram incrementados ao longo do tempo, entretanto, isso não se refletiu em aumento do DMP aos 78 meses.

In surface coal mining the vegetation is completely suppressed and layers of soil and rocks that cover the coal seams are removed, causing drastic changes in the original soil profile. This study aimed to evaluate the influence of different species of grasses in the recovery of a constructed soil structure as part of the strategy of reclamation for coal mining. The treatments were: T1 - Hemarthria altissima, T2 - Paspalum notatum, T3 - Cynodon dactilon, T4 - Urochloa brizantha. As a control, a bare constructed soil was used, called T5. Disturbed and undisturbed soil samples were collected in 0.00-0.10m and 0.10-0.20m layers for the determination of the percentage of macroaggregates and microaggregates, mean weight diameter, organic carbon, bulk density and macroporosity. The results were evaluated at 05, 41 and 78 months after the establishment of the experiment. After 78 months of conducting the experiment, positive action of the four plant species in the reclamation of soil aggregation was observed, especially for Urochloa brizantha that showed the lowest bulk density and the highest values of macroporosity. The species provided a structural improvement in the constructed soil, mainly after 41 months of conducting the experiment when there was an increase in the values of MWD, mainly in the 0.00 to 0.1 m layer. The organic carbon contents were increased over time, however, did not result in increased of MWD at 78 months.

Assessment of Municipal Effluent Reclamation Process Based on the Information of Cost Analysis and Environmental Impacts.

Water shortage has now become a global issue. Reclamation of the effluent from municipal wastewater treatment plant is feasible for supplying the quick growth of water requirement. The objective of this study was to conduct both the cost analysis and environmental impact evaluation of two reclamation processes: sand filter – ultrafiltration - reverse osmosis (SF-UF-RO) and sand filter - electrodialysis reversal (SF-EDR). The results will serve as a reference for selecting the process in the scale-up construction works. Two processes were installed in a reclamation pilot plant in Futian Water Resource Recycling Center (Taichung City, Taiwan) and operated in parallel to evaluate their stability and product quality. The cost analysis was conducted to estimate the capital requirement of building large-scale plant for reclaiming the effluent. The cost of land construction, mechanical with electronic equipment and operation with maintenance were all considered in the analysis. On the other hand, the environmental assessment of these processes has been realized by Life Cycle Assessment (LCA). The software Sima Pro 7.3 was used as the LCA analysis tool. Four different evaluation methods, including Ecoindicator 99, Ecopoints 97, Impact 2002+ and CML 2 baseline 2000, were applied. The results show that the water quality of SF-EDR has similar potential in reclaiming the effluent from municipal water resource recycling center as SF-UF-RO. The cost of SFEDR is lower than that of SF-UF-RO. In the environmental analysis, the LCA demonstrates that SF-EDR may create more impacts on the environment due to more consumption on electricity and chemicals than SF-UF-RO. Using SF-UF-RO as the effluent reclamation process may be an option causing less impacts on climate change.

Study on application of biological iron sulfide composites in treating vanadium-extraction wastewater containing chromium (VI) and chromium reclamation.

In this study, the Cr(VI)-resistant properties and regeneration characteristics of biological iron sulfide composites were investigated, which consist of sulfate reducing bacteria (SRB) and its in situ synthesized nanosized iron sulfides. Then the application of the composites in treating vanadium-extraction wastewater containing high concentration Cr(VI) and reclaiming Cr were performed. It was found that SRB in composites still survived after being used to treat vanadium-extraction wastewater, which could reduce reaction products Fe3+ and sulphur into Fe2+ and S2- by using them as the electron acceptors and thus regenerating biological iron sulfide composites. The SRB also could be resistant to 600 mgl-1 Cr(VI) and reduce it gradually. Based on the Cr(VI)-resistant properties and regeneration characteristics of the composites, a reduction-regeneration recirculation process for treating vanadium-extraction wastewater and reclamation of Cr was developed. The results indicated that the contaminants in effluent reached the Chinese discharge standard of pollutants for vanadium industry (GB 26452-2011), i.e. the concentration of total Cr(TCr) was less than 0.912 mgl-1, Cr(VI) was less than 0.017 mgl-1 and V was less than 0.260 mgl-1. After 10 cycles of treatment, the Cr2O3 content in sludge reached 41.03%, and the ratio of Cr2O3/FeO was 7.35. The sludge reached the chemical and metallurgical (hydrometallurgy) grade of chromite ore and could be reclaimed.

Efecto de la conversión del manglar a potrero sobre la densidad y tallas de dos gasterópodos en el delta del río Turbo (golfo de Urabá, Caribe colombiano) / Effects mangrove conversion to pasture on density and shell size of two gastropods in the Turbo River Delta (Urabá Gulf, Caribbean coast of Colombia)

Mangrove deforestation is widespread in the Greater Caribbean but its impact on macrobenthos has not been evaluated to date. In order to assess the impact of mangrove conversion to pasture, densities and shell sizes of two dominant gastropods (Neritina virginea and Melampus coffeus) were compared among four mangrove types: 1) Rhizophora mangle-dominated fringing mangroves, 2) Avicennia germinans-dominated basin mangroves, 3) Mixed-species basin mangroves, and 4) A. germinansbasin mangroves converted to pastures, in the Turbo River Delta (Urabá Gulf, Colombia). Mangrove types were polygon-delimited with satellite images and color aerial photographs were taken in 2009. various (n<5) polygons per mangrove type were sampled in January, July and December 2009, and a total (n<20) 0.025m²-quadrats were randomly placed along each polygon. Forest structure variables, pore-water physico-chemical variables and sediment-grain metrics were measured in the four mangrove types. Mean density and size of both gastropod species were measured. The results showed that the mean density and size of both species were significantly greater in R. mangle-fringing mangroves. N. virginea density decreased gradually towards the A. germinans-basin mangroves seemly related to the diadromous life-history. This species nearly disappeared in the neighboring pastures because individuals were constrained to a few remaining flooded areas. In the pastures, M. coffeus individuals were clumped in the remaining A. germinans trees due to its climbing behavior as a pulmonate. We hypothesize that the decline of these two gastropods was related to physical microhabitat (e.g. trees, prop roots, and seedlings) degradation, and alteration of soil properties (e.g. temperature, pH, organic matter content). Finally, we also hypothesize that the local extinction of N. virginea due to clear-cutting may exert strong negative effects on the ecosystem function because it is a dominant omnivore.

El delta del río Turbo es una de las áreas del golfo de Urabá, Colombia donde la tala de manglar es más extensa y activa, por lo tanto, se evaluó el impacto de la conversión de manglar a potrero, comparando la densidad y talla promedio de dos gasterópodos (Neritina virginea y Melampus coffeus), variables dasonómicas, físico-químicas intersticiales y granulométricas del suelo entre varios parches de: 1) manglar de franja, 2) manglar de cuenca, 3) manglar de cuenca mixto y 4) manglar de cuenca convertido a potrero, en el delta del río Turbo de este golfo, entre enero y diciembre 2009. Las densidades y tallas de los gasterópodos fueron mayores en el manglar de franja. N. virginea fue muy abundante pero disminuyó hacia el manglar de cuenca (debido a sus hábitos diádromos), y desapareció casi completamente en los potreros, donde los individuos estuvieron agregados en las pocas áreas anegadas. En los potreros, los individuos de M. coffeus estuvieron agrupados en los árboles remanentes debido a su hábito arborícola y su condición de pulmonado. Se sugiere que la escasez de los gasterópodos está relacionada con la degradación del microhábitat físico, y la alteración de propiedades del suelo. Finalmente, también planteamos que la extinción local de N. virginea debida a la tala puede ejercer fuertes efectos negativos sobre la función ecosistémica debido a que es un omnívoro dominante.

Descomposición de hojarasca y liberación de nutrientes en plantaciones de Acacia mangium (Mimosaceae) establecidas en suelos degradados de Colombia

Litter decomposition and nutrient release in Acacia mangium plantations established on degraded soils of Colombia. Several factors control the decomposition in terrestrial ecosystems such as humidity, temperature, quality of litter and microbial activity. We investigated the effects of rainfall and soil plowing prior to the establishment of Acacia mangium plantations, using the litterbag technique, during a six month period, in forests plantations in Bajo Cauca region, Colombia. The annual decomposition constants (k) of simple exponential model, oscillated between 1.24 and 1.80, meanwhile k1 y k2 decomposition constants of double exponential model were 0.88-1.81 and 0.58-7.01. At the end of the study, the mean residual dry matter (RDM) was 47% of the initial value for the three sites. We found a slow N, Ca and Mg release pattern from the A. mangium leaf litter, meanwhile, phosphorus (P) showed a dominant immobilization phase, suggesting its low availability in soils. Chemical leaf litter quality parameters (e.g. N and P concentrations, C/N, N/P ratios and phenols content) showed an important influence on decomposition rates. The results of this study indicated that rainfall plays an important role on the decomposition process, but not soil plowing. Rev. Biol. Trop. 59 (1): 113-128. Epub 2011 March 01.

La descomposición de hojarasca en los ecosistemas terrestres está regulada por varios factores, entre ellos, la humedad, temperatura, calidad de la hojarasca y la actividad de los microoganismos. Estudiamos el efecto de la precipitación y el tratamiento de subsolado del suelo previo establecimiento de plantaciones de Acacia mangium, usando la técnica de bolsas de descomposición durante seis meses en plantaciones del Bajo Cauca (Colombia). La constante de descomposición anual (k) del modelo simple exponencial, osciló entre 1.24 y 1.80. Las constantes k1 y k2 del modelo doble exponencial fluctuaron entre 0.88-1.81 y 0.58-7.01. Al final del experimento la materia seca residual promedio (MSR) fue del 47%. Las cantidades residuales de N, Ca y Mg en la hojarasca de A. mangium mostraron un patrón de liberación lento. La evolución del P en la MSR mostró un proceso dominante de inmovilización, dada su baja disponibilidad en el suelo. Algunos parámetros de calidad del sustrato (N, P, C/N, N/P y fenoles) fueron buenos predictores del proceso, así como la precipitación, situación contraria a la del tratamiento de subsolado.

Faunal diversity during rainy season in reclaimed sodic land of Uttar Pradesh, India.

Faunal diversity is an indicator of soil amelioration. Estimating the population size or density of an animal species in an area is fundamental to understand its status and demography, and to plan for its management and conservation. Considering this, faunal diversity in reclamed sodic land was monitored during rainy season 2000-01 at different locations of district viz., Aligarh, Etah, Fatehpur, Mainpuri and Raebareli in Uttar Pradesh. The Shannon-Weiner species diversity index (H) of different fauna complex of each location was compared with zero years (1995-1996) indexes (before reclamation). Insects diversity index, in reclaimed sodic soil, varied from 3.8178(Fatehpur: Bariyampur) to 4.623 (Fatehpur: Katoghan), which was 3.028 in zero year at Katoghan in Fatehpur. ‘H’ index of other-arthropods ranged widely from 0.9743 (Etah: Bawali) to 2.0674 (Mainpuri: Pundari). The species diversity index of molluscs registered as high as 1.8637 at Ladhauwa site in Aligarh, which exhibited identical with Saripur site of Raebareli. ‘H’index of mammal resulted with the highest (2.19) at Pundari in district Mainpuri.The avifauna and amphibian’s indices were recovered maximal at Saripur site of Raebareli and Bariyampur site of Fatehpur, respectively. Our result revealed that various fauna enriched with soil reclamation, which is good indicator of restoration of land, primarily due to soil- arthropods and earthworms and its eventual improvement along with succeeding rice-wheat cropping system widespread over there. It clearly shows that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of biodiversity.

Land reclamation recovery with the sewage sludge use

In this work, investigations were carried out with five treatments [control, three doses of lime stabilized sludge (60, 120, 240 Mg ha-1 dry base) and soil corrective plus mineral fertilizer] to evaluate the immediate recuperation of a borrowed area. The application of stabilized alkaline sewage sludge acted as an acidity corrective, allowed the increase in the organic matter contents (21 to 43.5g dm-3) and available P (44 to 156 mg dm-3). Even with the use of the highest dose, no increase in the concentration of 32 analyzed metals was observed, due to the low concentration of metals in the sludge. The experiment showed that short term restoration of degraded area was possible by using high rates of sewage sludge without metal contamination.

Obras de infra-estrutura próximas aos grandes centros levam ao surgimento de áreas degradadas por decapamento que podem ser reintegradas a paisagem através dos processos de recuperação com o uso do lodo de esgoto. Estabeleceu-se um experimento com cinco tratamentos [testemunha, três doses de lodo alcalinizado (60, 120, 240Mgha-1 em base seca) e corretivo mais adubo mineral], para avaliar a recuperação imediata de uma área de empréstimo. A aplicação de lodo de esgoto alcalinizado atuou como corretivo da acidez, proporcionou aumento no teor de matéria orgânica (21 para 43,5g dm-3) e P disponível (4,4 para 156mg dm-3) e total, se mostrando superior ao mineral mais calagem. Mesmo com uso da maior dose, não foi observado acréscimos nos teores de 32 metais analisados, dado à baixa concentração de metais no lodo. Os resultados obtidos indicam que é possível o uso de doses elevadas de lodo de esgoto na recuperação de áreas degradadas.

Desenvolvimento do Pinus elliottii e do Eucalyptus tereticornis consorciado com plantas de cobertura, em solos degradados por arenização / Growth of Pinus elliottii and Eucalyptus tereticornis associated with cover plants, in degraded soils by arenization

Espécies florestais exóticas têm sido utilizadas para a recuperação de solos degradados, auxiliando no controle da erosão hídrica e eólica. No sudoeste do Rio Grande do Sul, foram testados o Pinus elliotii Engelm. e o Eucalyptus tereticornis Sm., com o objetivo de avaliar o crescimento destas espécies e testar sua capacidade na contenção do fenômeno da arenização. Os tratamentos consistiram do plantio das duas espécies sobre o solo degradado por arenização (SD), sobre o campo nativo (C), sobre o campo nativo associado a plantas de cobertura (C + PC) e sobre o solo degradado com plantas de cobertura (SD + PC). Como plantas de cobertura, foram testadas a aveia preta (Avena strigosa Schieb.) e um tremoço nativo do ecossistema dos campos sulinos, o Lupinus albescens H. et Arn.. Determinaram-se o percentual de sobrevivência inicial, a altura, o diâmetro à altura do colo (DAC) e o fator de produtividade (FP) das espécies florestais, aos 30 dias, seis meses e 12 meses após plantio. O experimento foi conduzido em delineamento inteiramente casualizado, e os resultados submetidos ao teste de Duncan, em um nível de 5 por cento de probabilidade de erro. Em relação à sobrevivência inicial, apenas o pínus apresentou diferenças estatísticas, com menor percentual no tratamento C+PC. Os resultados demonstraram que o eucalipto beneficiou-se do consórcio com plantas de cobertura, enquanto o pínus apresentou maior sensibilidade à competição interespecífica.

Exotic forest species have been used for soil reclamation, as well as helping in the control of water and wind erosion. In the southwest of Rio Grande do Sul state, Brazil, the Pinus elliotii Engelm. and the Eucalyptus tereticornis Sm., were tested with the objective of evaluating the growth of these species and testing its capacity for reducing the arenization process. The treatments consisted of planting the two species on the degraded soil by arenization (DS), on the native grassfield (C), on the native grassfield associated with cover crops (C + PC) and on the degraded soil associated with cover crops (DS + PC). As cover crops were tested the black oat (Avena strigosa Schieb.) and a Lupinus native from the southern grassfields ecosystem, the Lupinus albescens H. et Arn.. The plants survival rate, height, basal diameter and the productivity factor of the forest species were obtained in the thirty days, six months and twelve months after planting. The experiment was conduced in completely randomized design, and results submited to Duncan test, in level of 5 percent error probability. In relation to initial survival, only pine presented significative differences, with lesser percentual in the treatment C+PC. Results showed that Eucalyptus benefited from the consortium with cover crops, while pine presented greater sensibility to interespecific competition.