Search

A colheita mecanizada da cana-de-acucar foi implantada devido a questoes economicas, operacionais e ambientais. Desta forma o material remanescente das operacoes de colheita mecanizada pode causar problemas como a incidencia de pragas de dificil controle e incendios acidentais e criminosos. A utilizacao do residuo disponivel no campo, atraves do recolhimento e enfardamento desse material, proporciona novas fontes de energia para a industria. Esse trabalho teve como objetivo avaliar o desempenho operacional e economico de duas enfardadoras de palhico de cana-de-acucar em condicoes distintas de velocidade e quantidades de palhico Aleirada para enfardamento, em uma usina canavieira no municipio de Sao Miguel dos Campos – AL. As maquinas foram avaliadas em tres volumes diferentes de recolhimento do palhico, regulando-se o aleirador para o recolhimento de cada volume de palhico. Foi avaliado, o tempo de producao entre cada fardo, a quantidade de fardos produzidos por hora por cada maquina, distâncias entre fardos, capacidade operacional, custo horario e operacional de trabalho. Os resultados obtidos mostram que o T1 proporcionou menor tempo na producao entre fardos. A menor distância entre fardos foi no T1 com media de 61 metros, entre cada fardo produzido A Maquina 2 produziu maior quantidade de fardos por hora. A Maquina 2 apresentou maior rendimento operacional (49,7% e 51,8%) no volume de 50% e 70% respectivamente. A enfardadora 2 apresentou menor custo operacional de R$ 28,39 ha -1 quando recolhido 70% do volume total do palhico. Quanto mais se recolhe palhico, menor sera o custo por fardo. PALAVRAS-CHAVE : Enfardamento, Residuo Vegetal, Biomassa COMPARISON OF TWO BALERS PRODUCTION OF SUGAR CANE STRAWBALES PRISMATIC SQUARE. ABSTRACT: The mechanized harvesting of sugar cane was implemented due to economic, operational, and environmental issues. Thus, the remaining material of mechanized harvesting operations can cause problems such as the incidence of difficult to control pests and accidental and criminal fire. The use of the residue available in the field, through collection and baling of this material provides new energy sources for industry. This study aimed to evaluate the operational and economic performance of two balers for sugar cane straw under conditions of speed and amounts of straw accumulated for baling, at a sugar cane company located in Sao Miguel dos Campos - AL. The machines were evaluated in three different volumes of straw gathering, regulating the straw collecting volume. The production time between each burden, the quantity of bales produced per hour for each machine, the distances between bales operating capacity and operating cost per hour of labor were assessed. The results showed that the T1 took less time in production between bales. The shortest distance between bales was reach by the T1 with an average of 61 meters between each bale produced Machine 2 produced the greatest amount of bales per hour. The machine 2 presented higher operating efficiencies, 49.7% and 51.8%, collecting 50% and 70% volume of straw, respectively. The baler 2 showed lower cost (R$ 28.39 ha -1 ) collecteing 70% of the total volume of straw. The more straw volume was collected, the lower was the cost per bale. KEYWORDS: Baling, Plant residue, Biomass.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:44:00Z No. of bitstreams: 1 S1806-66902012000400016.pdf: 68745 bytes, checksum: 020e528b57965b0e764cc0ccdc0232df (MD5) Made available in DSpace on 2013-08-22T18:44:00Z (GMT). No. of bitstreams: 1 S1806-66902012000400016.pdf: 68745 bytes, checksum: 020e528b57965b0e764cc0ccdc0232df (MD5) Previous issue date: 2012-12-01 Made available in DSpace on 2013-09-30T19:31:58Z (GMT). No. of bitstreams: 2 S1806-66902012000400016.pdf: 68745 bytes, checksum: 020e528b57965b0e764cc0ccdc0232df (MD5) S1806-66902012000400016.pdf.txt: 38591 bytes, checksum: ccd4beeb26a94a4aca9882fac9e54523 (MD5) Previous issue date: 2012-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:19:48Z No. of bitstreams: 2 S1806-66902012000400016.pdf: 68745 bytes, checksum: 020e528b57965b0e764cc0ccdc0232df (MD5) S1806-66902012000400016.pdf.txt: 38591 bytes, checksum: ccd4beeb26a94a4aca9882fac9e54523 (MD5) Made available in DSpace on 2014-05-20T13:19:48Z (GMT). No. of bitstreams: 2 S1806-66902012000400016.pdf: 68745 bytes, checksum: 020e528b57965b0e764cc0ccdc0232df (MD5) S1806-66902012000400016.pdf.txt: 38591 bytes, checksum: ccd4beeb26a94a4aca9882fac9e54523 (MD5) Previous issue date: 2012-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) A eficiência da aplicação superficial de corretivos pode ser melhorada por meio de compostos orgânicos, quantificados através dos cátions hidrossolúveis, liberados por resíduos vegetais. Porém, não se sabe se os teores desses compostos podem ser modificados pela aplicação de calcário e silicato. Objetivou-se com este trabalho avaliar o efeito da aplicação superficial de calcário e silicato no teor de cátions solúveis e condutividade elétrica do extrato da parte aérea das culturas de soja, milheto, aveia branca, braquiária, milho, feijão e guandu. O experimento foi conduzido entre 2006 e 2008 em um Latossolo Vermelho distroférrico em Botucatu-SP, em sistema de semeadura direta consolidado. O delineamento experimental foi em blocos casualizados, com dezesseis repetições. Os tratamentos foram 3,8 t ha-1 de calcário dolomítico, 4,1 t.ha-1 de silicato de cálcio e magnésio e uma testemunha, sem aplicação de corretivos no solo. Foram determinados os teores de cátions hidrossolúveis e a condutividade elétrica da parte aérea das culturas. Variações nos teores e na somatória de cátions hidrossolúveis não foram detectadas pela condutividade elétrica dos extratos vegetais da parte aérea das culturas. A aplicação dos corretivos elevou os teores de Ca2+ e Mg2+ solúveis nos extratos dos resíduos de soja, aveia e milheto; para o milho, houve elevação nos teores de Mg2+; além de aumento nos teores de Mn2+ nos resíduos do primeiro ano de braquiária, não havendo, entretanto, influência nos teores nas culturas de feijão, guandu e braquiária no segundo ano. The efficiency of the surface application of correctives can be improved by means of organic compounds, quantified by water-soluble cations released by plant residue. However, it is unclear whether the levels of these compounds can be modified by the application of limestone and silicate. The aim of this study was to evaluate the effect of the surface application of limestone and silicate on the levels of soluble cations and the electrical conductivity of the extract from the shoots of soybean, millet, oats, brachiaria, maize, beans and pigeon pea. The experiment was carried out between 2006 and 2008 in dystrophic red latosol in Botucatu SP, under a system of consolidated direct seeding. The experimental design was of randomized blocks, with sixteen replications. The treatments were 3.8 t ha-1 of dolomitic limestone, 4.1t ha-1 of calcium silicate and magnesium, and a control with no application of correctives to the soil. The levels of water-soluble cations, and the electrical conductivity of the crop shoots were determined. Variations in the levels and sum of water-soluble cations were not detected through the electrical conductivity of the shoot extract. The application of correctives increased the levels of soluble Ca2+ and Mg2+ in extracts from the residue of soybean, oats, and millet; for maize, there was an increase in the concentrations of Mg2+; in addition to increased levels of Mn2+ in the first-year brachiaria residue, with no influence however, on the levels in bean, pigeon pea and brachiaria crops in the second year. Universidade Estadual Paulista Faculdade de Ciências Agronômicas Setor Agricultura Universidade Estadual Paulista Faculdade de Ciências Agronômicas Setor Agricultura

With this research it was objectified to evaluate the abundance and equity of the macro and mesofaunal of the alone front to the type of agricultural handling in areas of plantation of coffee under three types of handling: conventional system-CONV, agroecological-AGRO, agroforestry-SAF evaluated in two collection periods. For the evaluation of macro and soil mesofaunal hypogaeic were collected soil blocks of 20 x 20x 10 cm, being collected, first, the whole plant residue on the soil surface. Soil and litter were placed in Berlese funnels for seven days, and the pitfalls remained in the field for 72 hours. Measured to the abundance, richness, diversity of soil animals and functional groups. Finally, one concludes that the times of collection influence the abundance of wild life and diversity of groups; the collected groups of the faunal collected are present in all management systems with coffee, the exception of the parasitoids group; in traps pitfall total wealth groups is higher in relation to soil-litter compartments, the family Formicidae and microphage are the dominant in agroecosystems evaluated. &nbsp, Com esta pesquisa, objetivou-se avaliar a abundância e a equidade da macro e mesofauna da frente isolada para o tipo de manejo agrícola em áreas de plantio de café sob três tipos de manuseio: sistema convencional-CONV, agroecológico-AGRO, agroflorestal. SAF avaliado em dois períodos de coleta. Para a avaliação do macro e do solo hipogaeico mesofaunal foram coletados blocos de solo de 20 x 20x 10 cm, sendo coletados, primeiramente, todo o resíduo vegetal na superfície do solo. O solo e o lixo foram colocados nos funis berleses por sete dias, e as armadilhas permaneceram no campo por 72 horas. Medido quanto à abundância, riqueza, diversidade de animais no solo e grupos funcionais. Finalmente, conclui-se que os tempos de coleta influenciam a abundância de vida silvestre e a diversidade de grupos; os grupos coletados da fauna coletada estão presentes em todos os sistemas de manejo com café, com exceção do grupo parasitóide; nas armadilhas armadilhas, os grupos de riqueza total são maiores em relação aos compartimentos do solo, a família Formicidae e os micrófagos são dominantes nos agroecossistemas avaliados.

This paper is based on data compiled in the course of developing, for InterAmerican Development Bank (IDB), a WTE Guidebook for managers and policymakers in the Latin America and Caribbean region. As part of this work, a list was compiled of nearly all plants in the world that thermally treat nearly 200 million tons of municipal solid wastes (MSW) and produce electricity and heat. An estimated 200 WTE facilities were built, during the first decade of the 21st century, mostly in Europe and Asia. The great majority of these plants use the grate combustion of as-received MSW and produce electricity. The dominance of the grate combustion technology is apparently due to simplicity of operation, high plant availability (>90%), and facility for training personnel at existing plants. Novel gasification processes have been implemented mostly in Japan but a compilation of all Japanese WTE facilities showed that 84% of Japan’s MSW is treated in grate combustion plants. Several small-scale WTE plants ( Since the beginning of history, humans have generated solid wastes and disposed them in makeshift waste dumps or set them on fire. After the industrial revolution, near the end of the 18th century, the amount of goods used and then discarded by people increased so much that it was necessary for cities to provide landfills and incinerators for disposing wastes. The management of urban, or municipal, solid wastes (MSW) became problematic since the middle of the 20th century when the consumption of goods, and the corresponding generation of MSW, increased by an order of magnitude. In response, the most advanced countries developed various means and technologies for dealing with solid wastes. These range from reducing wastes by designing products and packaging, to gasification technologies. Lists of several European plants are presented that co-combust medical wastes (average of 1.8% of the total feedstock) and wastewater plant residue (average of 2% of the feedstock).

The recycling of plant residues can be an important source of available sulphate in soils. This study investigates the effects of soil sulphate availability on residue decomposition and the relationships between plant residue quality and S and C mineralizationA soil incubation experiment examined rapeseed straw mineralization after adding sulphate at rates of 20 and 50 mg S-SO4 kg(-1) soil in a loamy soil. Soils amended with wheat straw, tall fescue, mustard or beech leaf residues were incubated. Net C and S mineralization were measured continuously during a 175-day incubation at 20 A degrees C and gross S mineralization and immobilization were quantified using S-35 soil labeling.The addition of sulphate did not change C mineralization, indicating that soil S supply was high enough to supply microbial needs during decomposition. The chemical quality of the residue significantly modified the rate of decomposition and the gross and net S mineralization, with a high release of sulphate from mustard and fescue residues but little net change in soil sulphate with the other residues.The chemical composition and C/S ratio of plant residues are important criteria for predicting both the dynamics and the amount of sulphate available during residue decomposition.

Fifteen day old B6C3F1 male mice were exposed by intraperitoneal (IP) injection to a Maximally Tolerated Dose of Manufactured Gas Plant (MGP) residue (1:32 dilution in DMSO or 1:8 in corn oil), 375 μg total of benzo[a]pyrene in DMSO or corn oil (CO) or DMSO and CO vehicle alone. On days 2, 4 and 7 post-treatment mice were injected IP with bromodeoxyuridine (BRdU) at a concentration of 50 μg/g of weight 1 hour prior to euthanasia. Immunoperoxidase staining for BRdU was performed and mitotic index (MI) determined for target tissues: bronchial mucosa, forestomach and liver. In MGP-exposed mice, MI in bronchial mucosa was increased 842% with DMSO vehicle and 555% in CO vehicle at day 2, MI was increased in forestomach mucosa by 40% at day 4 and MI was increased in liver by 50% at day 7 compared to controls. Therefore, complex mixtures such as MGP residue are capable of inducing transient cell proliferation. (Supported by EPRI RP2963-04)

The MetaPath knowledge base was developed for the purpose of archiving, sharing and analyzing experimental data on metabolism, metabolic pathways and crucial supporting metadata. The MetaPath system grew out of the need to compile and organize the results of metabolism studies into a systematic database to facilitate data comparisons and evaluations. Specialized MetaPath data evaluation tools facilitate the review of pesticide metabolism data submitted for regulatory risk assessments as well as exchange of results of complex analyses used in regulation and research. Customized screen editors called Composers were developed to automate data entry into MetaPath while also streamlining the production of agency specific study summaries such as the Data Evaluation Records (DER) used by the US EPA Office of Pesticide Programs. Efforts are underway through an Organization for Economic Co-operation and Development (OECD) work group to extend the use of DER Composers as harmonized templates for rat metabolism, livestock residue, plant residue and environmental degradation studies.

Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and (lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when 25 % of the residues were decomposed. From 15 to 30 days, the decomposition rate decreased on both farms. On the farm in Pedra Dourada (PD), the decomposition constant k increased in the order C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. On the farm in Araponga (ARA), there was no difference in the decomposition rate among leguminous plants. The N release rates varied from 0.0036 to 0.0096 d-1. Around 32 % of the total N content in the plant material was released in the first 15 days. In ARA, the N concentration in the S. aterrimum residues was always significantly higher than in the other residues. At the end of 360 days, the N released was 78 % in ARA and 89 % in PD of the initial content. Phosphorus was the most rapidly released nutrient (k values from 0.0165 to 0.0394 d-1). Residue decomposition and nutrient release did not correlate with initial residue chemistry and biochemistry, but differences in climatic conditions between the two study sites modified the decomposition rate constants. Leguminosas utilizadas como adubos verdes são consideradas uma fonte importante de nutrientes para a cultura do cafeeiro, especialmente em solos com baixa disponibilidade de nutrientes. Experimentos de campo foram realizados com o objetivo de avaliar as taxas de decomposição e liberação de nutrientes de leguminosas empregadas como adubos verdes em cafezais sob sistemas agroflorestais na Zona da Mata de Minas Gerais. Os teores iniciais de N e P nos materiais vegetais variaram de 25,7 a 37,0 e de 2,4 a 3,0 g kg-1, respectivamente. As relações lignina/N, lignina/polifenol e (lignina+polifenol)/N apresentaram baixos valores para todas as espécies estudadas. As maiores perdas de matéria seca ocorreram nos primeiros 15 dias de avaliação, quando 25 % do material foi decomposto. Entre 15 e 30 dias de avaliação, houve redução da taxa de decomposição em ambas as propriedades. Na propriedade de Pedra Dourada (PD), a constante de decomposição k aumentou na sequência C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. Já em Araponga (ARA), não houve diferença nas taxas de decomposição das leguminosas estudadas. As taxas de liberação de N variaram entre 0,0036 e 0,0096 d-1. Cerca de 32 % do total de N no material vegetal foi liberado nos primeiros 15 dias. Até os 360 dias, foram liberados pelos adubos verdes, em média, 77,5 % do N em Araponga e 88,5 % em Pedra Dourada. O P apresentou a maior velocidade de liberação, variando de 0,0165 a 0,0394 d-1. As taxas de decomposição e liberação de nutrientes não se correlacionaram com as composições química e bioquímica iniciais, porém as diferenças climáticas entre as duas áreas modificaram as constantes de decomposição dos resíduos das leguminosas.

In forest systems, leaf litter is usually the main source of nutrients for the vegetation and microorganisms. Leaf litter composition may vary according to the biomass and quality of the materials produced by different species. Tree roots affect the development and activity of microflora. The aim of this study was to evaluate the influence of two implanted tree species, with different composition of plant residues, on the soil characteristics. The soil is classified as an Andisol and is located in the Trevelín Forest Station, Chubut, Argentina, Lat. 43° S, Long 71°31' West. The samples were extracted from the surface soil of two forest plots with a dominant species each: Radiata Pine (Pinus radiata D. Don.) and European Oak (Quercus robur). The following analytical determinations were carried out on soil samples: organic carbon, microbial respiration, deshydrogenase activity, microbial count (bacterial communities, amilolytic, actinomyces and fungi) as well as the functional diversity of associated microbial communities. The Shannon-Weaver index (H) was calculated. The soil under Oak trees showed the highest values of microbial respiration, organic carbon and amilolytic and bacterial community counts. No significant differences were found in deshydrogenase activity, actinomyces and fungi counts between species. The principal component analysis showed significant variations in the physiology of microbial communities associated with these two tree species. The microorganism H diversity index was significantly greater for Pine. Plants residues of broadleaf species such as Oak have lower contents of recalcitrant substances than conifer species, and this fact, associated with the higher development of total and amylolytic bacteria, could result in an increase in the decomposition of plant residues in the soil and in higher organic carbon and microbial respiration values.

Field experiments were carried out under the irrigated semi-arid conditions of Central Saudi Arabia to examine the response of yield and quality of hyacinth bean to Rhizobium inoculation and N-fertilization complemented with or without phosphorus, and to determine the relationship between the chemical composition of some constituents of the bean and their mineralizable N capacity in soil. The results obtained indicated that possible yield and quality advantages may accrue to bean from inoculation and N-fertilizer plus P. Statistical analysis revealed that organic C and total N of the plant material were not significantly correlated with the cumulative amount of N-mineralized when the plant residue was incorporated into the soil. The relationship between the C : N ratio of the plant material and the percentage of N-mineralized showed a linear response (r = 0·93*** foliage fraction; r = 0·90*** foliage + stem fraction). This result supports the view that the C : N ratio is a poor index for the mineralization susceptibility.

Co-polarized and cross-polarized radar characteristics were measured from different types of plant residue cover on the soil surface, resulting from various tillage treatments. A first-order model was developed that relates the radar backscatter coefficient to percent residue cover. Application of the model to the data indicates that percent residue cover can be estimated from radar backscatter if the type of crop is known. In addition, the optimal polarization combination needs to be chosen for maximizing the sensitivity. These results demonstrate the potential for remote measurement of crop residue using airborne radar sensors. An advantage of this technique is that it can function well independent of sunlight conditions.

International audience; The dynamics of indigenous bacterial and fungal soil communities were followed throughout the decomposition of wheat straw residue. More precisely, such dynamics were investigated in the different soil zones under the influence of decomposing wheat straw residue (i.e. residues, soil adjacent to residue = detritusphere, and bulk soil). The genetic structures of bacterial and fungal communities were compared throughout the decomposition process long by applying B- and F-ARISA (for bacterial and fungal-automated ribosomal intergenic spacer analysis) to DNA extracts from these different zones. Residue decomposition induced significant changes in bacterial and fungal community dynamics with a magnitude of changes between the different soil zones ordered as followed: residue > detritusphere > bulk soil, confirming the spatial structuration of the sphere of residue influence to the 4–6 mm soil zone in contact with residue. Furthermore, significant differences in the structure of bacterial and fungal communities were apparent between the early (14 and 28 days) and late (from 56 to 168 days) stages of decomposition. These could be related to ecological attributes such as the succession of r- (copiotrophs) and K- (oligotrophs) strategists. Microbial diversity at the early (28 days) and late (168 days) stages of degradation was further analysed by a molecular inventory of 16S and 18S rDNA in DNA extracts from the residue zone. This confirmed the succession of different populations during residue decomposition. Fluorescent Pseudomonas spp. and Neurospora sp. were dominant in the early stage with subsequent stimulation of Actinobacteria and Deltaproteobacteria taxa, as well as Basidiomycota fungal taxa and Madurella spp. According to the ecological attributes of these populations, microbial succession on fresh organic residue incorporated in soil would be dominated by copiotrophs and r-strategists in the early stages, with oligotrophs (K-strategists) increasing in relative abundance as substrate quantity and/or quality declines over time.

The large amounts of by-products and wastes from the processing of fruit and vegetables, characterised by reusable substances of high value, are investigated as potential new raw materials. The principal aim of the upgrading concept is described in terms of the reintegration of residual matter into the chain of food production and the strategy, based on the synchronisation of waste and product streams for realising an industrial implementation of plant residue recycling, is outlined. Selected examples are presented using the perspectives of the triangle ‘pre-, prime and adaptation processing’ to underline the need for sustainability

A substrate-induced respiration (SIR) method is described to measure the contributions of fungi and bacteria to total glucose-induced microbial respiration on plant residues of differing composition. Relationships between fungal, bacterial and total SIR and biomass were used to develop regression equations for predicting microbial biomass C from measures of SIR. Total SIR rates (100–2000 μg CO2-C g−1 h−1) and biomass-specific SIR rates (64–72 ng CO2-C h−1 μg−1 biomass C) from plant residues were considerably greater than those calculated from the literature for soils. Results of longer term decomposition studies indicate that the C:N ratios of plant residues through time account for the greatest amount of the variation in total SIR. Annual decomposition rate constants (k) for plant residues were positively correlated (r2=0.99) to overall mean estimates of total SIR. The plant residue SIR method has advantages over conventional direct count methods because it distinguishes a physiologically active component of the microbial biomass. Furthermore, it allows separation of fungal and bacterial components that may aid in understanding microbial controls on plant residue decomposition.

Plant residue and soil depth effects on metribuzin degradation were investigated. Dundee silt loam soil collected at depth increments of 0–10 cm (SUR) and 10–35 cm (SUB) was treated with labeled [5−14 C]metribuzin. Samples were assayed at several time points up to 140 days after treatment. Soybean residue was added to half of the SUR samples (RES), with remaining SUR unamended (NORES). None of the SUB samples were amended with soybean residue. Metribuzin mineralization to 14CO2 proceeded more slowly in RES and SUB than in NORES and SUR, respectively. Extractable components in SUR samples included polar metabolites, plus deaminated metribuzin (DA) in the RES, and parent metribuzin in the NORES. Deaminated diketometribuzin (DADK) and metribuzin comprised major 14C components extracted from SUB, while in SUR, faster degradation of metabolites resulted in metrizubin as the primary identifiable compound. Unextractable 14C increased until day 35 for both RES and NORES, after which it remained constant for NORES. but declined for RES. A corresponding rise in RES polar 14C suggested that as soybean residue decomposed, 14C bound in the residue was released as extractable polar material. Soil with soybean residue accumulation may alter metabolite degradation patterns, but does not impede initial metribuzin degradation. Depth differences in metribuzin degradation were attributed to reductions in microbial activity with increasing soil depth.

The contact between soil and plant residues has a major effect on the fate of carbon in soil. In this study, we used published data on soil and plant residue incubations. Results showed that larger residues decomposed more slowly because it provides less surface area in contact with the soil. We tested two models with these data. The first was a simple C–N compartmental model with no spatial dimension, in which the contact factor is a multiplicative function of the decomposition constant. The second was an individual-based model that explicitly describes the 3D distribution of organic matter, microbial biomass and inorganic N and their spatial interactions. In this model, we hypothesized that each soil aggregate was a microbial habitat. Both models gave simulated results close to the data. The second, without fitting, reproduced similar results to the empirical macroscopic parameter of the first and indicated that the slower decomposition rate of larger residues was partly because less inorganic nitrogen was available to microorganisms.

The effects of phosphogypsum and plant residue mulches on soil crusting and infiltration were studied on a Rhodic Paleustalf in Northern Natal, South Africa. Under field conditions infiltration rates were considerably higher than those obtained with a laboratory type rainfall simulator. Both ameliorants were effective in countering crust formation. Their effect continued over a growing season (4–5 months). Scanning electronmicrographs showed that under moist conditions microbial hyphae and residues were prominent in the surface crust. Extractable soil P built up to high levels in the phosphogypsum treated plots.

Conservation tillage mitigates soil loss in cropland because plant residues help protect the soil, but effects on pesticide movement in surface runoff are not as straightforward. Effects of soil disturbance on surface runoff loss of chlorimuron and alachlor were evaluated utilizing runoff trays. Soil in the trays was either disturbed (tilled) and kept bare or was not tilled, and existing decomposed plant residue was left on the surface. Rainfall (25 mm, 20 min) was simulated 1 d after alachlor (2.8 kg ha−1) or chlorimuron (54 g ha−1) application, and runoff was collected. Runoff fractions were analyzed for herbicide and sediment. Total alachlor loss from bare plots was greater than that in no-tillage plots (4.5% vs. 2.3%, respectively). More than one-third of total alachlor lost from bare plots occurred in the first l of runoff, while no-tillage plots had less runoff volume with a more even distribution of alachlor concentration in the runoff during the rainfall simulation and subsequent runoff period. In contrast, more chlorimuron was lost from no-tillage plots than bare plots (12% vs. 1.5%) even though total runoff volume was lower in the no-tillage plots (10.6 mm vs. 13.6 mm). This was attributed to dense coverage with partially decomposed plant residue in no-tillage plots (1652 kg ha−1) that intercepted chlorimuron. It was likely that chlorimuron, a polar compound, was more easily washed off surface plant residues and transported in runoff.

Publisher Summary This chapter discusses the dynamics of soil organic matter and nutrient cycling. Knowledge of the turnover rates of plant and animal residues, microbial bodies, and soil organic matter (SOM) is a prerequisite for understanding the availability and cycling of nutrients such as carbon, nitrogen, sulfur, and phosphorus. Understanding the dynamics of nutrient, plant residue, or SOM transformations in the field requires meaningful mathematical expressions for the biological, chemical, and physical processes involved. Models can be used to gain an understanding of the processes and controls involved in nutrient cycles, to generate data on the size of various pools and the rates at which nutrients are transformed, and to make predictions when experiments are inappropriate. While conceptual models may be sufficient for the first task, only quantitative models can achieve the latter tasks. Quantitative models of SOM and nutrient dynamics are attempts to describe soil biological processes rather than strictly mathematical expressions and statistical procedures used to find best-fitting curves. This chapter presents the Rothamsted, Van Veen and Paul, and Century models as examples with the focus on how they are constructed. It discusses in detail about reaction kinetics, modeling the dynamics of decomposition and nutrient transformations, and establishing pool sizes and kinetic constants.

In this Chapter we present a general discussion of the dynamics of soil nutrient cycles with special attentions to the interaction with hydrological processes in semi-arid systems, and with emphasis on modeling issues. We will present an analytical approach developed by the authors and co-workers to model the propagation of hydrologic fluctuation through the various components of the soil biogeochemical cycles of arid and semiarid ecosystems. We do not attempt to provide here a complete review of the subject (see Chapters 12-14, and 18 for related discussion on soil nutrient cycles in drylands) but rather focus on interaction between hydrological and ecological processes and outline some open problems and future directions for research.

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. Cover crop residues mobilize cations and benefit the action of lime applied on the soil surface owing to the release of low molecular weight organic acids from the soluble fraction of residues. However, these effects in no-till system are yet to be confirmed in field studies. A five-year trial was carried out on a no-till dystrophic Rhodic Hapludox in Ponta Grossa, State of Paraná, Brazil, with the aim of evaluating changes in chemical soil attributes, as well as the corn and soybean response to surface application of dolomitic lime (0, 2.5, 5.0 and 7.5 t ha-1), with and without black oat cover. Lime rates were applied onto the main plots in November 2000 and the treatments on the subplots consisted of the presence or absence of black oat in 2001 and 2002, preceding corn and soybean crops. Surface-applied lime did not influence the dry matter yield of black oat, which was approximately 4 t ha-1 in both 2001 and 2002 years. Liming did not affect the H+ ions neutralizing capacity (482 mmol c dm-3), the sum of soluble cations (29.5 mmol c L-1) or electric conductivity (1,230 µS cm-1) of the black oat extract either. Liming applied on the soil surface decreased exchangeable Al3+ and increased pH, exchangeable Ca2+ and exchangeable Mg2+ down to a 10 cm depth. Black oat residue on the soil surface under no-till did not benefit the mobility of surface-applied lime to alleviate subsoil acidity. Surface application of lime did not affect corn mineral nutrition or corn and soybean yields, but decreased Zn and Mn concentrations in soybean leaves. Cover black oat residue raised the P, Ca, and Mg concentrations in the corn and N and P in the soybean leaves and caused a decrease of Mn concentration in the soybean leaves. The black oat cover on the soil surface increased corn yield, but did not affect soybean yield, grown under no-till after corn.

International audience; A field experiment was conducted to determine the effect of water management techniques for maintaining rice production and reducing methane emission in a Crowley silt loam paddy soil receiving high rice straw additions. A 2 × 5 factorial experiment was arranged in a split-plot design with two water management practices; alternately flooded and drained and continuously flooded, and five rates of rice straw incorporation as subplot treatments (0, 3, 6, 12 and 24 t ha-1), with four replications. Rice yield was significantly greater in the alternately flooded and drained treatment as compared with the continuously flooded treatment. High rice straw application (12 and 24 t ha-1) reduced rice yield in both water management treatments. Methane emission increased with increase in the rice straw application rate. However, emissions were lower in the alternately flooded and drained treatment plots. The results demonstrate that draining a field for a short period of time during the growing season can enhance rice growth and rice yield while reducing methane emission.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:46:50Z No. of bitstreams: 1 S0100-204X2005000200009.pdf: 788221 bytes, checksum: df8913e4b09ac985627128f70e67ffd9 (MD5) Made available in DSpace on 2013-08-22T18:46:50Z (GMT). No. of bitstreams: 1 S0100-204X2005000200009.pdf: 788221 bytes, checksum: df8913e4b09ac985627128f70e67ffd9 (MD5) Previous issue date: 2005-02-01 Made available in DSpace on 2013-09-30T19:36:20Z (GMT). No. of bitstreams: 2 S0100-204X2005000200009.pdf: 788221 bytes, checksum: df8913e4b09ac985627128f70e67ffd9 (MD5) S0100-204X2005000200009.pdf.txt: 24218 bytes, checksum: e25358903694082236982fc046767817 (MD5) Previous issue date: 2005-02-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:30:04Z No. of bitstreams: 2 S0100-204X2005000200009.pdf: 788221 bytes, checksum: df8913e4b09ac985627128f70e67ffd9 (MD5) S0100-204X2005000200009.pdf.txt: 24218 bytes, checksum: e25358903694082236982fc046767817 (MD5) Made available in DSpace on 2014-05-20T13:30:04Z (GMT). No. of bitstreams: 2 S0100-204X2005000200009.pdf: 788221 bytes, checksum: df8913e4b09ac985627128f70e67ffd9 (MD5) S0100-204X2005000200009.pdf.txt: 24218 bytes, checksum: e25358903694082236982fc046767817 (MD5) Previous issue date: 2005-02-01 A palhada das plantas de cobertura, mantida sobre o solo no plantio direto, representa uma reserva de nutrientes para cultivos subseqüentes. O objetivo deste trabalho foi avaliar a decomposição e a liberação de macronutrientes de resíduos de nabo forrageiro. O experimento foi realizado no campo, durante o ano de 1998, no Município de Marechal Cândido Rondon, PR. O nabo forrageiro foi dessecado e manejado com rolo-faca 30 dias após a emergência. Avaliaram-se a persistência de palhada e a liberação de nutrientes dos resíduos aos 0, 13, 35 e 53 dias após o manejo. O delineamento experimental foi de blocos casualizados, com quatro repetições. O nabo forrageiro produziu, até o estádio de pré-florescimento, elevada quantidade de massa seca da parte aérea em cultivo de inverno (2.938 kg ha-1), acumulando 57,2, 15,3, 85,7, 37,4, 12,5 e 14,0 kg ha-1, respectivamente, de N, P, K, Ca, Mg e S. O manejo do nabo forrageiro no estádio de pré-florescimento apresenta rápida degradação da palhada, acarretando liberação de quantidades significativas de macronutrientes. Os nutrientes disponibilizados em maior quantidade e velocidade para a cultura subseqüente, são o K e o N. A maior velocidade de liberação de macronutrientes pelo nabo forrageiro ocorre no período compreendido entre 10 e 20 dias após o manejo da fitomassa. Straw of covering plants kept on soil surface in no-tillage system is an important source of nutrients for subsequent tillage. The objective of this work was to evaluate decomposition and macronutrients release from forage turnip residues. The experiment was set under field conditions during 1998 in Marechal Cândido Rondon, PR, Brazil. Forage turnip plants were desiccated and lodged 30 days after emergence. Straw persistence and nutrient release were evaluated at 0, 13, 35 and 53 days after management. The experimental design was a randomized block with four replications. Until pre-flowering stage, the forage turnip showed a great dry matter yield (2,938 kg ha-1) during winter growing and 57.2, 15.3, 85.7, 37.4, 12.5 and 14.0 kg ha-1 of N, P, K, Ca, Mg and S were respectively accumulated. Forage turnip management at pre-flowering stage cause a quick straw degradation and macronutrients release. Potassium and nitrogen were released in the highest amounts and in the shortest time to the subsequent tillage. Quickest liberation of nutrients occurred between 10 to 20 days after plant management. Universidade Estadual Paulista Fac. de Ciências Agronômicas Universidade Estadual do Oeste do Paraná (UNIOESTE) Centro de Ciências Agrárias Universidade Federal Rural da Amazônia (UFRA) Unesp Fac. de Engenharia Universidade Estadual Paulista Fac. de Ciências Agronômicas Unesp Fac. de Engenharia

Sawdust (SD) and ricehusk (RH)) used singly or mixed in varying proportions and enclosed in polyeth­ylene were used to study the storage life of mature green plantain fruits. There were two control treat­ments comprising fruits sealed in polyethylene without plant residue and fruits kept on laboratory shelf. Fruits were sealed in storage media for two weeks under ambient laboratory conditions and thereafter removed and lined on laboratory shelf to monitor ripening pattern. Culinary qualities of samples were evaluated 14 and 21 days after storage. Results showed that only fruits sealed in polyethylene without plant residue or polyethylene impregnated with 100% SD were still completely green after seven days of storage while fruits on the shelf were almost completely ripe. By the 14th day of storage fruits stored in polyethylene without plant residue or polyethylene impregnated with 100% SD were still at preclimac­teric phase (and only started ripening 17 days after storage) whereas fruits kept on the shelf or polyeth­ylene impregnated with 100% RH were at senescent phase. Fruitsin the former storage systems had the least weight loss after three weeks. Acceptability rating of boiled sample was strongly associated with taste. Fruits stored in polyethylene without plant residue or polyethylene impregnated with 100% SD had high acceptability rating when ripe. The study suggests that fruits could be harvested at full maturity to optimize yield and eating quality. And with a fairly long green life, the storage system could enhance availability and utilization potential of plantain fruits at household and small-scale retailing levels. Agro-Science Vol.2(2) 2001: 19-25

Water-soluble plant organic compounds have been proposed to be efficient in alleviating soil acidity. Laboratory methods were evaluated to estimate the efficiency of plant extracts to neutralize soil acidity. Plant samples were dried at 65ºC for 48 h and ground to pass 1 mm sieve. Plant extraction procedure was: transfer 3.0 g of plant sample to a becker, add 150 ml of deionized water, shake for 8 h at 175 rpm and filter. Three laboratory methods were evaluated: sigma (Ca+Mg+K) of the plant extracts; electrical conductivity of the plant extracts and titration of plant extracts with NaOH solution between pH 3 to 7. These methods were compared with the effect of the plant extracts on acid soil chemistry. All laboratory methods were related with soil reaction. Increasing sigma (Ca+Mg+K), electrical conductivity and the volume of NaOH solution spent to neutralize H+ ion of the plant extracts were correlated with the effect of plant extract on increasing soil pH and exchangeable Ca and decreasing exchangeable Al. It is proposed the electrical conductivity method for estimating the efficiency of plant extract to neutralize soil acidity because it is easily adapted for routine analysis and uses simple instrumentations and materials.Tem sido proposto que os compostos orgânicos de plantas solúveis em água são eficientes na amenização da acidez do solo. Foram avaliados métodos de laboratório para estimar a eficiência dos extratos de plantas na neutralização da acidez do solo. Os materiais de plantas foram secos a 65º C por 48 horas, moídos e passados em peneira de 1mm. Utilizou-se o seguinte procedimento para obtenção do extrato de plantas: transferir 3.0 g da amostra de planta para um becker, adicionar 150 ml de água deionizada, agitar por 8h a 175 rpm e filtrar. Avaliaram-se três métodos de laboratório: sigma (Ca + Mg + K) do extrato de planta, condutividade elétrica (CE) do extrato de planta e titulação do extrato de planta com solução de NaOH entre pH 3 a 7. Os métodos de laboratório foram comparados com o efeito dos extratos de plantas na reação do solo. Todos os métodos de laboratório foram correlacionados com a reação do solo: o aumento de sigma (Ca + Mg + K), Ce e o volume de NaOH gasto para neutralizar os íons H+ do extrato de plantas, foram correlacionados com o efeito nos aumentos de pH e Ca trocável e diminuição de Al trocável do solo. É proposto o método de CE para estimar a eficiência do extrato de plantas na neutralização da acidez do solo por ser facilmente adaptado para análise de rotina e por utilizar instrumentos e materiais simples.

A qualidade do resíduo vegetal e a disponibilidade de nitrogênio (N) mineral são fatores que afetam a decomposição de resíduos vegetais. O presente trabalho teve por objetivo avaliar a produção de matéria seca, o acúmulo de nitrogênio de três plantas para cobertura de solo no inverno e a influência de diferentes épocas de aplicação da adubação nitrogenada na cultura do milho sobre a decomposição do resíduo vegetal mantido na superfície. O experimento foi desenvolvido na Universidade Federal de Santa Maria (RS), nos anos agrícolas de 1996/97 e 1997/98, em solo ARGISSOLO VERMELHO Distrófico arênico (Hapludalf), sendo que a avaliação da taxa de decomposição do resíduo superficial foi feita somente no ano agrícola de 1997/98. O delineamento experimental foi de blocos ao acaso com parcelas subdivididas e três repetições. Nas parcelas principais (25 x 5m), durante o inverno foram utilizadas três coberturas de solo: aveia preta (Avena strigosa Schieb), aveia+ervilhaca (Vicia sativa L.) e nabo forrageiro (Raphanus sativus). Nas subparcelas (5 x 5m), diferentes épocas de aplicação de N no milho: (i)00-00-00, (ii)00-30-90, (iii)30-30-60, (iv)60-30-30 e (v)90-30-00, que corresponde a quantidade de N em kg ha-1, aplicado em pré-semeadura (após a dessecação das plantas de cobertura), semeadura, e cobertura do milho (4 a 6 folhas desenroladas), respectivamente. Os resultados mostraram que o cultivo da ervilhaca juntamente com aveia preta não alterou a produção de matéria seca, mas determinou maior teor e acúmulo de nitrogênio na parte aérea das plantas na consorciação. As taxas de decomposição de resíduos de aveia preta, nabo forrageiro e aveia preta+ervilhaca não foram influenciadas pelas épocas de aplicação de nitrogênio para o milho cultivado em sucessão. The quality of plant residue and soil N availability, from mineral fertilizer, are some of the factors that affect residue decomposition. The objective of this study was to evaluate the dry matter production and its N accumulation in three winter cover crop and the effects of different corn sidedress N timing application on soil surface residue. The experiment was carried out at Federal University of Santa Maria experimental área in 1996/97 and 1997/98 crop season on a typic Hapludalf. The residue decomposition study was carried only in 1997/98 crop season. The experiment was laid out as random block design with split-plot. The main treatments were winter cover crops set up in 25 x 5m plots: a) black oat (Avena strigosa Schieb); b) Black oats+vetch (Vicia sativa L); and c) Raphanus sativus. The split-plot (5 x 5m) treatments were splitting and timing N sidedress for corn, which were composed by a sequence of N application, represented by: (1) 00-00-00, (2) 00-30-90, (3) 30-30-60, (4) 60-30-30, (5) 90-30-00, where the numbers, respectively, means N applied in kg ha -1 at: (a) corn pre-planted; (b) at corn seeding; and (c) corn sidedress at 4 to 6 leaves stage. The consortium, black oat+vetch, did not affected dry matter production but induced higher N content and accumulation of above ground biomass. The decomposition rate of winter cover crops was not affected by N sidedress timing for corn in succession of winter cover crops.

Publisher Summary Bioremediation of heavy metals is designed to concentrate metals in living organisms, including plant tissues, thus, minimizing the amount of solid or liquid hazardous wastes, which need to be treated and deposited at hazardous waste sites, with the ultimate goal of developing an economical method of reclaiming metals from plant residue. This will completely eliminate the need for costly off-site disposal. Bioremediation is certainly very old field, but it holds great potential. In order to realize this promise, it will be necessary to build a greater understanding of the many and varied processes that are involved. This will require a multidisciplinary approach, spanning fields as diverse as plant biology, agricultural engineering, agronomy, soil science, microbiology, and genetic engineering. However, excessive accumulation of these heavy metals can be toxic to most of the plants. The ability of certain plants to tolerate increased levels of toxic elements and their accumulation at high concentrations from various polluted environments can be exploited for the removal of toxic substances, including heavy metals from water. The use of plants for remediation of toxic substances is known as "Phytoremediation".

Environmental solid wastes increase more and more as a result of the industrial waste production day by day. Management of the solid wastes is the thrust area for researchers. In this study, the effects of asphalt plant residue (APR) on the properties of hot mix asphalt (HMA)s are investigated. APR was added into the asphalt concrete in 25, 50 and 100% by weight of the filler. In order to determine optimum bitumen content, Marshall Design procedure was applied. Optimum bitumen content (OBC) values were obtained less than control specimen (CS). APR specimens have shown little increase in Marshall stability and little decrease in flow except for APR-50 in comparison to the CS. All APR specimens have higher MQ than that of the control mixture. Although there are no meaningful differences between CS and APR specimens, APR can be used as a filler aggregate in asphalt mixtures. Use of APR will enable recycling of an environmental waste as well as providing some benefits in asphalt concrete performance. Thus, resources will be used more effectively all over the world as part of sustainability. Copyright © 2014 Inderscience Enterprises Ltd.

As alterações de manejo exercem significativas modificações na qualidade e na quantidade da matéria orgânica, na quantidade e nas formas de N no solo e no processo de mineralização de N. Neste trabalho, avaliaram-se a taxa de mineralização do N e a variação de N-NH4+ e N-NO3- durante a decomposição dos resíduos de duas cultivares de sorgo. Os tratamentos seguiram o esquema fatorial 2x3x2, em blocos ao acaso, com dois manejos de solo, três resíduos culturais, dois níveis de nitrogênio e três repetições. Tubos de percolação foram montados com a adição de 20 g dos solos amostrados, misturados com 20 g de areia. A cada conjunto de solo mais areia, adicionou-se 0,1 g do resíduo cultural das cultivares de sorgo, com ou sem 50 mg kg-1 de N, na forma de nitrato de amônio. Após um período de incubação de sete dias, semanalmente e por 49 dias, o nitrogênio foi extraído com 100 mL de CaCl2 0,01 mol L-1. No percolado, determinaram-se os teores de N-NH4+ e o N- NO3-. A mineralização apresentou dependência da cultivar e do N. Os resíduos de sorgo alteraram o tempo e a quantidade mineralizada de nitrogênio. A relação N-NH4+/ N-NO3- variou com o tempo de incubação e com a qualidade do resíduo. Houve aumento até aos quinze dias de incubação e decréscimos nos períodos seguintes. Na ausência de resíduo cultural o solo apresentou maior potencial de mineralização na forma de N-NO3. Management alterations induce significant modifications on organic matter quality and quantity, on N quantity and forms and on the mineralization process. The aim of this work was to study the influence of straw on the N mineralization rates of the N-NH4+ and N-NO3 forms during the decomposition of residues of two sorghum genotypes. The experimental design consisted of a 3x2x3 complete block outline, including two soil managements, three cultural residues and two nitrogen levels, with three replications. Percolation tubes were prepared with 20 g of soil mixed with 20 g of sand. Each tube with soil and sand received 0.1g residual straw from the two sorghum genotypes, with and without 50 mg N kg-1 in the form of ammonium nitrate. A control treatment was maintained without straw in the presence and absence of N. After an initial seven day incubation period, N was extracted weekly, over 49 days, using 100 mL of 0.01 mol L-1 CaCl2. The forms N-NH4+ and N-NO3- were determined spectroscoptically (UV/VIS) in the percolated extracts. N mineralization dependent on sorghum genotype and applied N. Sorghum straw influenced time and amount of N mineralized. The N-NH4+/ N-NO3- ratio showed variability during the incubation time as influenced by the incorporated residue. That ratio increased up to fifteen days of incubation time and decreased in subsequent periods. Without residues the mineralization potential was higher in the N-NO3 form.

Plant cells are surrounded by a wall made up of molecules that are basically chains of sugars, so-called beta-glucans. At the 9th International Plant Molecular Biology Congress, researchers described progress in manipulating genes to increase the beta-glucan content of grains and other plant tissues. Those increases could translate into healthier foods by boosting fiber content. Manipulating beta-glucan content in plant cell walls can also increase our ability to fully utilize plant residue for many purposes such as biofuels.

Composting is Mother Nature’s original form of recycling. Simply, composting is the controlled biological decomposition and conversion of solid and liquid organic materials into a humus-like product. Managed composting, while somewhat limited in the U.S. since the green revolution, is a popular and successful animal waste and plant residue management option world-wide. It is more preferable to landfilling, incineration and roadside dumping. The benefits of the act of composting include a reduction in volume of compost inputs, destruction of pathogens, reduction in weed seeds, the degradation of many potentially harmful organic compounds, the binding-up of high-nitrogen materials such as manures, and the production of a useful soil amendment.

A soil incubation experiment was carried out in a complex experimental system to simulate the effect of environ- mental factors (temperature, soil moisture, lucerne shoot powder as plant residue with mineral N, and mineral P addition), and 3 trace elements (Mn, Zn, Cu) on the available N content (NH4 +-N and NO3 -N) of two soils. The applied DISITOBI model assures information about the experimental object characterized by a multidimensional response function.

The tumorigenic activity of manufactured gas plant residue (MGP) was evaluated in female A/J mice using a F0927 basal gel diet system. Adulterated diets containing MGP (0.10% or 0.25%) or benzo[a]pyrene (B[alpha]P; 16 or 98 ppm) were fed for 260 days. A negative control group was maintained on a nonadulterated basal gel diet. Mice dosed with a single ip injection of 1.79 mg of B[a]P in a tricaprylin vehicle and maintained on a NIH-07 pellet diet were positive controls. In addition, a nontreated group of mice and a group dosed with vehicle only were maintained on a NIH-07 pellet diet and used as negative controls. Animal body weight and consumption of MGP and B[a]P were monitored throughout the study. Ingestion of a 0.10 or 0.25% MGP adulterated diet resulted in 70 and 100% of the mice developing lung tumors with a multiplicity of 1.19 and 12.17 tumors/mouse, respectively. Mice maintained on a 0.10% MGP diet consumed 0.7 g of MGP containing 1.8 mg of B[a]P while those fed a 0.25% MGP diet ingested 1.5 g of MGP containing 4.2 mg of B[a]P. The incidence of lung tumors in mice fed only B[a]P was considerably lower than that observed for animals fed a MGP diet. A diet containing 98 ppm B[a]P produced a significant incidence of tumor-bearing mice with 52% developing lung tumors. The multiplicity observed in these animals, however, was not significant at 0.59 tumors/mouse. A diet containing 16 ppm B[a]P did not produce a significant tumorigenic response in lung. Animals fed a 16 or 98 ppm B[a]P diet consumed a total of 11 and 67 mg of B[a]P, respectively. A single ip dose of B[alpha]P (1.79 mg in 0.25 mL of tricaprylin) resulted in 100% lung tumorigenesis with a multiplicity of 15.79 tumors/mouse. In contrast to observed induction of lung tumors, no forestomach tumors were detected in any animal fed a 0.10 or 0.25% MGP adulterated diet. However, ingestion of a diet containing only 16 or 98 ppm of B[a]P resulted in 20 and 100% of the mice developing forestomach tumors, respectively. The multiplicity for forestomach tumors was 0.24 and 4.22 tumors/mouse, respectively. The incidence of forestomach carcinomas in tumor bearing mice was 8 and 52%, respectively. The ip administration of 1.79 mg of B[a]P resulted in an 83% forestomach tumor incidence having a multiplicity of 1.83 tumors/mouse. Forestomach carcinomas were induced in 34% of the mice exhibiting forestomach tumors. These data indicate that chronic ingestion of MGP- or B[a]P-adulterated diets produces significant differences in the tumorigenic response of female A/J mouse forestomach and lung tissues.

This article describes the effects of three seeding unit designs on plant residue clearance along the central line ofdirect corn (Zea Mays L.) seeding and the subsequent influence on crop emergence. The equipment assemblies testedwere three different combinations of the implements turbo coulter blade (TCB), double disc opener with a seed presswheel and covering/packing wheels (DDO), notched disc row cleaner with a track wheel or floating star cleaner (RC)as follows: (1) TCB+DDO, (2) RC+TCB+DDO and (3) TCB+RC+DDO. Under the field conditions tested, residueclearance before the cutting action of the turbo coulter blade (combination 2) gave rise to the best crop stand and cropuniformity. The seeding assembly that moves soil and clears away plant debris along the seeding furrow shows a directeffect on seed emergence. Se realizó un experimento de riego deficitario controlado (RDC) durante 1995 y 1996 en una parcela de "Clementina de Nules"/"Citrange" carrizo regada por goteo. El RDC se estudió a dos niveles (25% y 50% ET sub(lis)) en los tres periodos fenológicos principales, floración-cuajado, crecimiento rápido del fruto, crecimiento final y maduración. Asimismo, se estudió el riego deficitario permanente al 50% durante todo el año. Todos los tratamientos se compararon con un control, siempre bien regado. Se observó buena correlación entre la producción total de brotes, en las diferentes brotaciones, y la intensidad del estrés producida por los tratamientos. La correlación se debió más a los brotes florales que a los vegetativos. Resultados similares se observaron con la integral de estrés (...)

Fall burning produced an intense surface fire that reduced numbers of sclerotia in an alfalfa seed field by >95%. The fire killed sclerotia in the dense layer of surface plant residue and scorched and killed sclerotia in the surface soil (0-2 cm). Only 14% of the collected surface soil sclerotia were viable after the fall burn. During the next 6 mo, the detectable number of sclerotia in surface soil samples declined from 246/m 2 in May and viability of sclerotia declined from 12 to 0%, respectively. Winter burning reduced surface residue and numbers of sclerotia but had no detectable effect in reducing the viability and survival of surface soil sclerotia (.)