Chemical and physical-hydric characterisation of a red latosol after five years of management during the summer between-crop season

Agricultural production systems that include the production of mulch for no-tillage farming and structural improvement of the soil can be considered key measures for agricultural activity in the Cerrado region without causing environmental degradation. In this respect, our work aimed to evaluate the chemical and physical-hydric properties of a dystrophic Red Latosol (Oxisol) in the municipality of Rio Verde, Goias, Brazil, under different soil management systems in the between-crop season of soybean cultivation five years after first planting. The following conditions were evaluated: Brachiaria brizantha cv. Marandu as a cover crop during the between-crop season; Second crop of maize intercropped with Brachiaria ruziziensis; Second crop of grain alone in a no-tillage system; Fallow soil after the soybean harvest; and Forest (natural vegetation) located in an adjacent area. Soil samples up to a depth of 40 cm were taken and used in the assessment of chemical properties and soil structure diagnostics. The results demonstrated that the conversion of native vegetation areas into agricultural fields altered the chemical and physical-hydric properties of the soil at all the depths evaluated, especially up to 10 cm, due to the activity of root systems in the soil structure. Cultivation of B. brizantha as a cover crop during the summer between-crop season increased soil water availability, which is important for agricultural activities in the region under study.

Aggregate stability by the "high energy moisture characteristic" method in an oxisol under differentiated management

Studies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, and 28 Mg ha-1 of agricultural gypsum rates distributed on the soil surface of the coffee rows, between which Brachiaria was grown and periodically cut, and compared with a treatment without Brachiaria between coffee rows and no gypsum application. To determine the aggregation state using the HEMC method, soil aggregates were placed in a Büchner funnel (500 mL) and wetted using a peristaltic pump with a volumetric syringe. The wetting was applied increasingly at two pre-set speeds: slow (2 mm h-1) and fast (100 mm h-1). Once saturated, the aggregates were exposed to a gradually increasing tension by the displacement of a water column (varying from 0 to 30 cm) to obtain the moisture retention curve [M = f (Ψ) ], underlying the calculation of the stability parameters: modal suction, volume of drainable pores (VDP), stability index (slow and fast), VDP ratio, and stability ratio. The HEMC method conferred sensitivity in quantifying the aggregate stability parameters, and independent of whether gypsum was used, the soil managed with Brachiaria between the coffee rows, with regular cuts discharged in the crop row direction, exhibited a decreased susceptibility to disaggregation.

Changes in the Structure of a Nigerian Soil under Different Land Management Practices

Quantification of soil physical quality (SPQ) and pore size distribution (PSD) can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system), and contrast the effects of these practices on the structure of PSD using soil water retention data. Soil water retention curves obtained from a pressure chamber were fitted to van Genuchten’s equation, setting m (= 1-1/n). Although values for soil bulk density were high, soils under the continuous arable cropping system had good SPQ, and maintained the capacity to support root development. However, soils under the natural bush fallow system had a worse structure than the continuous arable system, with restrictions in available water capacity. These two management systems had different PSDs. Results showed the inferiority of the natural bush fallow system with no traffic restriction (which is the common practice) in relation to the continuous arable cropping system in regard to physical quality and structure.

RECOVERY OF AN OXISOL DEGRADED BY THE CONSTRUCTION OF A HYDROELECTRIC POWER PLANT

ABSTRACT The removal of thick layers of soil under native scrubland (Cerrado) on the right bank of the Paraná River in Selvíria (State of Mato Grosso do Sul, Brazil) for construction of the Ilha Solteira Hydroelectric Power Plant caused environmental damage, affecting the revegetation process of the stripped soil. Over the years, various kinds of land use and management systems have been tried, and the aim of this study was to assess the effects of these attempts to restore the structural quality of the soil. The experiment was conducted considering five treatments and thirty replications. The following treatments were applied: stripped soil without anthropic intervention and total absence of plant cover; stripped soil treated with sewage sludge and planted to eucalyptus and grass a year ago; stripped soil developing natural secondary vegetation (capoeira) since 1969; pastureland since 1978, replacing the native vegetation; and soil under native vegetation (Cerrado). In the 0.00-0.20 m layer, the soil was chemically characterized for each experimental treatment. A 30-point sampling grid was used to assess soil porosity and bulk density, and to assess aggregate stability in terms of mean weight diameter (MWD) and geometric mean diameter (GMD). Aggregate stability was also determined using simulated rainfall. The results show that using sewage sludge incorporated with a rotary hoe improved the chemical fertility of the soil and produced more uniform soil pore size distribution. Leaving the land to develop secondary vegetation or turning it over to pastureland produced an intermediate level of structural soil quality, and these two treatments produced similar results. Stripped soil without anthropic intervention was of the lowest quality, with the lowest values for cation exchange capacity (CEC) and macroporosity, as well as the highest values of soil bulk density and percentage of aggregates with diameter size <0.50 mm, corroborated by its lower organic matter content. However, the percentage of larger aggregates was higher in the native vegetation treatment, which boosted MWD and GMD values. Therefore, assessment of some land use and management systems show that even decades after their implementation to mitigate the degenerative effects resulting from the installation of the Hydroelectric Plant, more efficient approaches are still required to recover the structural quality of the soil.

Carbon in Humic Fractions of Organic Matter in Soil Treated with Organic Composts under Mango Cultivation

ABSTRACT Soil organic matter (SOM) plays a key role in maintaining the productivity of tropical soils, providing energy and substrate for the biological activity and modifying the physical and chemical characteristics that ensure the maintenance of soil quality and the sustainability of ecosystems. This study assessed the medium-term effect (six years) of the application of five organic composts, produced by combining different agro-industrial residues, on accumulation and chemical characteristics of soil organic matter. Treatments were applied in a long-term experiment of organic management of mango (OMM) initiated in 2005 with a randomized block design with four replications. Two external areas, one with conventional mango cultivation (CMM) and the other a fragment of regenerating Caatinga vegetation (RCF), were used as reference areas. Soil samples were collected in the three management systems from the 0.00-0.05, 0.05-0.10, and 0.10-0.20 m layers, and the total organic carbon content and chemical fractions of organic matter were evaluated by determining the C contents of humin and humic and fulvic acids. Organic compost application significantly increased the contents of total C and C in humic substances in the experimental plots, mainly in the surface layer. However, compost 3 (50 % coconut bagasse, 40 % goat manure, 10 % castor bean residues) significantly increased the level of the non-humic fraction, probably due to the higher contents of recalcitrant material in the initial composition. The highest increases from application of the composts were in the humin, followed by the fulvic fraction. Compost application increased the proportion of higher molecular weight components, indicating higher stability of the organic matter.

Phosphorus Forms in Ultisol Submitted to Burning and Trituration of Vegetation in Eastern Amazon

ABSTRACT The use of fire to prepare agricultural areas is a technique still used by small farmers in eastern Amazon. This type of management changes the dynamics of soil nutrients, especially phosphorus, which constitutes the most limiting nutrient for crop production in tropical soils. This study was carried out to evaluate changes in phosphorus forms in an Argissolo Amarelo Distrófico (Ultisol) submitted to burning and trituration of secondary forest in eastern Amazon. The evaluated systems were: slash-and-burn of vegetation; slash-and-mulch of vegetation; and secondary vegetation. The labile, moderately labile, moderately recalcitrant, available and total phosphorus fractions were assessed at the soil depths of 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. The results showed a predominance of soluble P in acid (moderately labile P) over other forms in all management systems. The management systems influence the content and distribution of the forms of P, where the slash-and-mulch system presented the prevalence of the labile fraction, and the slash-and-burn system contained less labile forms. The slash-and-mulch system favored the accumulation of labile P and total organic P.

Effect of soil management on the white grub population and damage in soybean

To evaluate the effect of soil management systems on population of white grubs, (Phyllophaga cuyabana Moser), and on its damage in soybean, experiments were set up under no-tillage and conventional tillage (one disk plow, and a leveling disk harrow) areas. Primary tillage equipment, used in other soil management systems, such as moldboard plow, disk plow, chisel plow and heavy duty disk harrow were also tested. Fluctuation of P. cuyabana population and the extent of its damage to soybean was similar under no-tillage and conventional tillage systems. Results comparing a range of primary tillage equipment showed that it affected soil insect populations differently, depending on the time during the season in which tillage was executed. Larval mortality could mostly be attributed to their exposure to adverse factors, soon after tillage, than to changes in soil conditions. Reduction of white grub population was more evident in plots managed by heavier equipment, such as the moldboard plow. Soil tillage could be one component within the soil pest management system in soybean, however, its use can not be generalized.

Systems Genetics of Metabolism: The Use of the BXD Murine Reference Panel for Multiscalar Integration of Traits.

Metabolic homeostasis is achieved by complex molecular and cellular networks that differ significantly among individuals and are difficult to model with genetically engineered lines of mice optimized to study single gene function. Here, we systematically acquired metabolic phenotypes by using the EUMODIC EMPReSS protocols across a large panel of isogenic but diverse strains of mice (BXD type) to study the genetic control of metabolism. We generated and analyzed 140 classical phenotypes and deposited these in an open-access web service for systems genetics (www.genenetwork.org). Heritability, influence of sex, and genetic modifiers of traits were examined singly and jointly by using quantitative-trait locus (QTL) and expression QTL-mapping methods. Traits and networks were linked to loci encompassing both known variants and novel candidate genes, including alkaline phosphatase (ALPL), here linked to hypophosphatasia. The assembled and curated phenotypes provide key resources and exemplars that can be used to dissect complex metabolic traits and disorders.

Growth, yield, water and effluent quality in ponds with different management during tambaqui juvenile production

The objective of this work was to evaluate the effect of pond management on fish feed, growth, yield, survival, and water and effluent quality, during tambaqui (Colossoma macropomum) juvenile production. Fish were distributed in nine 600 m² earthen ponds, at a density of 8 fish per m²; the rearing period was 60 days. Three different pond management were applied: limed and fertilized (LimFer), limed (Lim), and natural (Nat). Fish were fed with a commercial ration containing 34% crude protein three times daily. There were no significant differences in fish growth or yield. Three main items found in tambaqui stomach were insect, zooplankton and ration, without a significant difference among treatments in proportion. Alkalinity, hardness, and CO2 were greater in LimFer and Lim ponds. Chlorophyll a, transparency, ammonia, nitrite, temperature, and dissolved oxygen of pond water were not significantly different among treatments. Biochemical oxygen demand, total phosphorus, orthophosphate, ammonia, and nitrite were significantly greater in effluents from LimFer ponds. Pond fertilization should be avoided, because growth and yield were similar among the three pond management systems tested; besides, it produces a more impacting effluent.

Soil macrofauna under integrated crop-livestock systems in a Brazilian Cerrado Ferralsol

The objective of this work was to assess the effects of integrated crop-livestock systems, associated with two tillage and two fertilization regimes, on the abundance and diversity of the soil macrofauna. Four different management systems were studied: continuous pasture (mixed grass); continuous crop; two crop-livestock rotations (crop/pasture and pasture/crop); and native Cerrado as a control. Macrofauna was sampled using a modified Tropical Soil Biology and Fertility method, and all individuals were counted and identified at the morphospecies level for each plot. A total of 194 morphospecies were found, distributed among 30 groups, and the most representative in decreasing order of density were: Isoptera, Coleoptera larvae, Formicidae, Oligochaeta, Coleoptera adult, Diplopoda, Hemiptera, Diptera larvae, Arachnida, Chilopoda, Lepidoptera, Gasteropoda, Blattodea and Orthoptera. Soil management systems and tillage regimes affected the structure of soil macrofauna, and integrated crop-livestock systems, associated with no-tillage, especially with grass/legume species associations, had more favorable conditions for the development of "soil engineers" compared with continuous pasture or arable crops. Soil macrofauna density and diversity, assessed at morphospecies level, are effective data to measure the impact of land use in Cerrado soils.

Improving Searching and Browsing Capabilities of Learning Object Repositories

Learning object repositories are a basic piece of virtual learning environments used for content management. Nevertheless, learning objects have special characteristics that make traditional solutions for content management ine ective. In particular, browsing and searching for learning objects cannot be based on the typical authoritative meta-data used for describing content, such as author, title or publicationdate, among others. We propose to build a social layer on top of a learning object repository, providing nal users with additional services fordescribing, rating and curating learning objects from a teaching perspective. All these interactions among users, services and resources can be captured and further analyzed, so both browsing and searching can be personalized according to user pro le and the educational context, helping users to nd the most valuable resources for their learning process. In this paper we propose to use reputation schemes and collaborative filtering techniques for improving the user interface of a DSpace based learning object repository.

Ympäristötietämyksen hallintasovelluksen kehittäminen

Uudistunut ympäristölainsäädäntö vaatii energiantuotantolaitoksilta yhä enemmän järjestelmällistä ympäristötiedon hallintaa. LCP- ja jätteenpolttoasetuksen velvoitteet ovat asettaneet uusia vaatimuksia päästöjen valvontaan ja siihen käytettävien mittausjärjestelmien laadunvarmennukseen sekä päästötietojen raportointiin. Uudistukset ovat lisänneet huomattavasti laitoksilla ympäristötiedon käsittelyyn kuluvaa aikaa. Laitosten toimintaehdot määritellään ympäristöviranomaisen myöntämässä ympäristöluvassa, joka on tärkein yksittäinen laitoksen toimintaa ohjaava tekijä. Tämän lisäksi monet toimijat haluavat parantaa ympäristöasioiden tasoaan vapaaehtoisilla ympäristöjärjestelmillä. Tässä diplomityössä kuvataan energiantuotantolaitosten ympäristöasioiden tallentamiseen ja hallintaan kehitetty selainpohjainen Metso Automationin DNAecoDiary'sovellus. Työ on rajattu koskemaan Suomessa toimivia LCP- ja/tai jätteenpolttoasetuksen alaisia laitoksia. Sovelluksen avulla voidaan varmistaa energiantuotantolaitosten poikkeamien, häiriöilmoitusten, päästömittalaitteisiin liittyvien tapahtumien ja muun ympäristöasioiden valvontaan liittyvän informaation tehokas hallinta. Sovellukseen tallennetaan ympäristötapahtumiin liittyvät perustiedot sekä etenkin käyttäjien tapahtumiin liittyvä kokemustietämys. Valvontakirjaukseen voidaan liittää tapahtuman perustietojen lisäksi myös tiedostoja ja kuvia. Sovellusta ja sillä kerättyä tietoa voidaan hyödyntää laitoksella käsilläolevien ongelmien ratkaisuun, ympäristötapahtumien todentamiseen sekä ympäristöraporttien laadintaan. Kehitystyön tueksi järjestettiin asiakastarvekartoitus, jonka perusteella ideoitiin sovelluksen ominaisuuksia. Tässä työssä on esitetty ympäristötiedon hallinan perusteet, selvitetty DNAecoDiaryn toimintaperiaatteet ja annettu esimerkkejä sen hyödyntämisestä. Sovelluksen lopullinen sisältö määritellään kunkin asiakkaan ympäristöluvan ja oma-valvonnan tarpeiden mukaisesti. Sovellus toimii itsenäisesti tai osana laajempaa Metso Automationin päästöjenhallinta- ja raportointisovelluskokonaisuutta.

Prediction of soil shear strength in agricultural and natural environments of the Brazilian Cerrado

The objective of this work was to develop uni- and multivariate models to predict maximum soil shear strength (τmax) under different normal stresses (σn), water contents (U), and soil managements. The study was carried out in a Rhodic Haplustox under Cerrado (control area) and under no-tillage and conventional tillage systems. Undisturbed soil samples were taken in the 0.00-0.05 m layer and subjected to increasing U and σn, in shear strength tests. The uni- and multivariate models - respectively τmax=10(a+bU) and τmax=10(a+bU+cσn) - were significant in all three soil management systems evaluated and they satisfactorily explain the relationship between U, σn, and τmax. The soil under Cerrado has the highest shear strength (τ) estimated with the univariate model, regardless of the soil water content, whereas the soil under conventional tillage shows the highest values with the multivariate model, which were associated to the lowest water contents at the soil consistency limits in this management system.

Verkko-oppimateriaalien uudelleenkäytettävyys ja siirrettävyys oppimisalustalta toiselle

Työssä tarkastellaan oppimisalustoilla käytettäviä testikysymyksiä ja oppisisältöjä uudelleen-käytettävyyden ja siirrettävyyden näkökulmasta. Tavoitteena on selvittää, minkälaisia välineitä määrämuotoisten sisältöjen tuottamista varten on olemassa, ja miten niillä luodut materiaalit ovat siirrettävissä työvälineestä toiseen ja oppimisalustoille. Tutkittavana ovat sisällön paketointiin tarkoitetutSCORM- ja IMS Content Packaging -spesifikaatiot sekä kysymysten esittämiseen tarkoitettu IMS Question and Test Interoperability -spesifikaatio. Pääpaino työssäon selvittää, miten oppisisällöt ovat siirrettävissä WebCT- ja Moodle-alustojenvälillä. Tähän liittyen on luotu ohjeistus, miten yksittäiset tiedostot, kysymykset ja Sisältökokonaisuus-työkalulla koostetut sisällöt siirretään WebCT:ltä Moodleen.

Toimintajärjestelmän rakentaminen laatu-, ympäristö- sekä työterveys- ja työturvallisuusstandardien vaatimusten mukaisesti

Diplomityön kohdeyritys on Lassila & Tikanoja Oyj:n (L&T) Vantaan jätehuolto -yksikkö.Yrityksen yhtenäiset toimintatavat ovat edellytyksenä toiminnan tehostamiselle,jatkuvalle kehittämiselle ja hallitulle laajentumiselle. Yrityksen toimintajärjestelmä (johtamisjärjestelmä) muodostuu laadun (ISO 9001), ympäristön (ISO 14001) sekä työterveyden ja työturvallisuuden (OHSAS 18001) hallintajärjestelmistä. Integroitu toimintajärjestelmä muodostaa yritykselle tehokkaan ja kokonaisvaltaisen kehittämisen työvälineen.Diplomityön tavoitteena on luoda teoreettinen perusta L&T:n Vantaan jätehuolto -yksikön sertifiointi -projektille. Diplomityön teoriasisältö muodostuu seuraavien asiakokonaisuuksien käsittelystä: kohdeyrityksen liiketoiminta-alan tunnuspiirteet, standardien sisältövaatimukset, toimintajärjestelmä yrityksen johtamisvälineenä sekä suorituskyvyn mittaaminen ja analysointi. Diplomityö kokoaa selkeät esitiedolliset lähtökohdat yksikön sertifiointi -projektille.Diplomityön muodostama teoreettinen perusta saavuttaa varsin onnistuneesti sille asetetut tavoitteet. Diplomityön määrittelemien lähtökohtien pohjalta rakentui yksikön varsinainen toimintajärjestelmä. Diplomityö tulee toimimaanhyvänä tukimateriaalina työn kohdeyritykselle jatkossakin; työstä on helppo tarkastaa ja kerrata toimintajärjestelmään liittyviä asiakokonaisuuksia.