<p>The main project Dry preservation of source-separated organic household wastes involves a new technique for treatment of biowaste through drying. Investigations are going on to determine how the dried biowaste best can be used to close the natural circular flow of nutrients. The objective of this degree project is to determine if the dried biowaste can be used as a soil conditioner. By restoring the nutrients in the material to the ground, the natural circular flow is closed. A declaration of contents, including the nutrient levels, C/N ratio, pH and the electrical conductivity of the dried biowaste, was constructed and a germination test was done to make sure that the material did not inhibit sprouting. Further on a method was developed to study the decomposition process, and in particular the nitrogen mineralization of the dried biowaste. This method was then used practically.</p><p>The results of this degree project indicate that the decomposition capacity of the dried biowaste is very good. The germination test showed that the material in a diluted form (up to 50 % dried biowaste) did not inhibit sprouting. The examination of the nitrogen mineralization showed a fast liberalisation of nutrients available to plants, with only a shorter period of nitrogen immobilization. Together these results imply that the dried material could function well as a soil conditioner.</p> / <p>Projektet Torrkonservering av matavfall från hushåll innefattar en helt ny teknik för behandling av bioavfall genom torkning. Undersökningar pågår angående hur det torkade bioavfallet bäst kan användas för att sluta det naturliga kretsloppet. Examensarbetets huvudsyfte var, som ett led i dessa undersökningar, att utreda om det torkade bioavfallet kan användas som ett jordförbättringsmedel. Genom att tillföra bioavfallet till jord så återförs näringen i materialet till marken och kretsloppet sluts. En varudeklaration, med materialets näringshalter, C/N-kvot, pH och elektrisk konduktivitet, togs fram och ett groningstest utfördes för att kontrollera att bioavfallet inte var groningshämmande. Vidare utvecklades en metod för att studera det torkade bioavfallets nedbrytningsegenskaper i form av dess kvävemineralisering. Denna metod användes därefter praktiskt.</p><p>Resultatet av detta examensarbete tyder på att torkat bioavfall har mycket goda nedbrytningsegenskaper. Groningsförsöket visade att materialet i utspädd form (upp till 50 % torkat bioavfall) inte är groningshämmande, och mineraliseringsförsöket visade på en snabb frigörelse av växttillgängligt kväve, och en immobiliseringsperiod på ett par veckor. Tillsammans indikerar dessa resultat att det torkade materialet kan fungera väl som ett jordförbättringsmedel.</p>

The main project Dry preservation of source-separated organic household wastes involves a new technique for treatment of biowaste through drying. Investigations are going on to determine how the dried biowaste best can be used to close the natural circular flow of nutrients. The objective of this degree project is to determine if the dried biowaste can be used as a soil conditioner. By restoring the nutrients in the material to the ground, the natural circular flow is closed. A declaration of contents, including the nutrient levels, C/N ratio, pH and the electrical conductivity of the dried biowaste, was constructed and a germination test was done to make sure that the material did not inhibit sprouting. Further on a method was developed to study the decomposition process, and in particular the nitrogen mineralization of the dried biowaste. This method was then used practically. The results of this degree project indicate that the decomposition capacity of the dried biowaste is very good. The germination test showed that the material in a diluted form (up to 50 % dried biowaste) did not inhibit sprouting. The examination of the nitrogen mineralization showed a fast liberalisation of nutrients available to plants, with only a shorter period of nitrogen immobilization. Together these results imply that the dried material could function well as a soil conditioner. / Projektet Torrkonservering av matavfall från hushåll innefattar en helt ny teknik för behandling av bioavfall genom torkning. Undersökningar pågår angående hur det torkade bioavfallet bäst kan användas för att sluta det naturliga kretsloppet. Examensarbetets huvudsyfte var, som ett led i dessa undersökningar, att utreda om det torkade bioavfallet kan användas som ett jordförbättringsmedel. Genom att tillföra bioavfallet till jord så återförs näringen i materialet till marken och kretsloppet sluts. En varudeklaration, med materialets näringshalter, C/N-kvot, pH och elektrisk konduktivitet, togs fram och ett groningstest utfördes för att kontrollera att bioavfallet inte var groningshämmande. Vidare utvecklades en metod för att studera det torkade bioavfallets nedbrytningsegenskaper i form av dess kvävemineralisering. Denna metod användes därefter praktiskt. Resultatet av detta examensarbete tyder på att torkat bioavfall har mycket goda nedbrytningsegenskaper. Groningsförsöket visade att materialet i utspädd form (upp till 50 % torkat bioavfall) inte är groningshämmande, och mineraliseringsförsöket visade på en snabb frigörelse av växttillgängligt kväve, och en immobiliseringsperiod på ett par veckor. Tillsammans indikerar dessa resultat att det torkade materialet kan fungera väl som ett jordförbättringsmedel.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2000. / Härtill 4 uppsatser.

Nitrogen is usually the element present in higher concentration in pig slurry and the one that causes the major problems related to environmental pollution, since it is subjected of several transformations after soil slurry application. This work was carried out in order to evaluate the soil nitrogen biotransformation during the wheat straw and pig slurry decomposition. The experiment was conduced under controlled conditions, in the Soil and Environmental Microbiology Laboratory, Soil Department, UFSM - RS. The pig slurry, with the ammoniacal fraction enriched of 15N, and the wheat straw were applied to a Hapludalf soil. The experimental was set as a completely randomized design with three repetitions. The treatments were the following: T1 - Soil; T2 - Soil + straw in surface; T3 - Soil + incorporated straw; T4 - Soil + pig slurry in surface; T5 - Soil + incorporated pig slurry; T6 - Soil + incorporated pig slurry + straw in surface; T7 - Soil + incorporated pig slurry + incorporated straw; T8 - Soil + straw in surface + pig slurry in surface. Soil humidity was adjusted for 100% of the field capacity. The experimental units were conditioned in an incubator for 95 days to a temperature of 25ºC. The mineral N, organic N and 15N organic concentrations was determined in each soil experimental unit. The soil nitrogen nitrification rates of the slurry ammoniacal nitrogen and the mineralization/immobilization were estimated. The main conclusions were: a) the ammoniacal N of pig slurry is quickly nitrified with or without the incorporation of slurry into the soil; b) the mineralization of the organic nitrogen of pig slurry occur in the first days after the slurry application in the soil; c) the wheat straw incorporation favor the N immobilization compared to its maintenance in soil surface; d) the N application through of pig slurry together with wheat straw stimulate the microbial N immobilization; e) the mineral N position in the soil affects the amount of immobilized N, with the highest values observed when N is in the active decomposition zone of the straw. / O nitrogênio é, normalmente, o elemento presente em maior concentração nos dejetos de suínos e também aquele que provoca os maiores problemas de poluição ambiental, em função das inúmeras transformações a que está sujeito após a aplicação dos dejetos ao solo. Este trabalho foi realizado a fim de avaliar as biotransformações do nitrogênio no solo durante a decomposição de palha de trigo e dejetos líquidos de suínos. Para isso, foi conduzido um experimento em condições controladas, no Laboratório de Microbiologia do Solo e do Ambiente do Departamento de Solos, na UFSM - RS. Num Argissolo Vermelho distrófico arênico foram adicionados dejetos líquidos de suínos, com a fração amoniacal enriquecida com15N, e palha de trigo. O delineamento experimental foi o inteiramente casualizado com três repetições. Os tratamentos avaliados foram os seguintes: T1 - Solo; T2 - Solo + palha em superfície; T3 - Solo + palha incorporada; T4 - Solo + dejetos em superfície; T5 - Solo + dejetos incorporados; T6 - Solo + dejetos incorporados + palha em superfície; T7 - Solo + dejetos incorporados + palha incorporada; T8 - Solo + palha em superfície + dejetos em superfície. A umidade do solo foi ajustada para 100% da capacidade de campo. As unidades experimentais foram acondicionadas em uma incubadora por 95 dias a uma temperatura de 25ºC. No solo de cada unidade experimental foram avaliados os teores de N mineral, N orgânico e 15N orgânico. Com base nestas avaliações, foram realizadas estimativas das taxas de nitrificação do N amoniacal dos dejetos e da mineralização e imobilização do N no solo. Os resultados obtidos permitiram concluir que: a) o N amoniacal dos dejetos líquidos de suínos é rapidamente nitrificado com ou sem a incorporação dos mesmos ao solo; b) a mineralização da fração nitrogenada orgânica dos dejetos ocorre nos primeiros dias após a sua aplicação ao solo; c) a incorporação da palha de trigo favorece a imobilização de N, comparado a sua manutenção na superfície do solo; d) a aplicação de N, através dos dejetos, juntamente com a palha de trigo, estimula a imobilização microbiana de N; e) a localização do N mineral afeta a quantidade de N imobilizada, com os maiores valores sendo observados quando o N permanece na zona de decomposição ativa da palha.

No description available.

Pine tree substrate (PTS) produced from freshly harvested loblolly pine (Pinus taeda L.) trees has potential for replacing or reducing the use of aged pine bark (PB) and peat moss as container substrates for horticulture crop production. The objective of this work was to determine the factors influencing nutrient availability in PTS compared to PB or peat substrates. Chapter two reports data on the response of japanese holly and azalea to fertilizer rate when grown in PTS and PB. This study demonstrated that an additional 2.4 kg·m-3 of Osmocote Plus (15N-3.9P-10K) controlled release fertilizer is required for both species when grown in PTS compared to PB. Data are reported in chapter three on the effects of fertilizer rate, substrate particle size, and peat amendment on growth and floral quality, and on post-production time-to-wilting of poinsettias. Data from this work show that PTS requires an additional 100 mg·L-1 N to grow poinsettias comparable to plants grown in peat unless the particle size of PTS was decreased or 25% peat was added, in which case no additional fertilizer was needed. Results also indicated that PTS shrinkage was similar to that of peat, and that post-production time-to-wilting in PTS plants was similar as plants grown in peat. Data in chapter four compares nitrogen (N) immobilization rates, substrate carbon dioxide (CO₂) efflux levels, and nutrient leaching in peat, PB, and PTS over time. Data from these studies indicated that more N immobilization occurs in PTS than in PB or peat and that the substrate CO₂ efflux levels (estimate of microbial activity) corresponds to N immobilization in all substrates. Nutrient availability, changes in physical and chemical properties, substrate shrinkage, and microbial activity in PTS compared to PB during long-term nursery production are reported in chapter five. Results showed that substrate nutrient levels remain lower in PTS and that pH levels of PTS decrease considerably over two growing seasons compared to PB. Results also indicate that PTS does decompose over time in containers, but substrate shrinkage of PTS is similar to that of PL and PB during crop production. / Ph. D.

Abstract Climate change and its warming effects on vegetation and soils are a widely recognized phenomenon. In addition to warming, the understorey vegetation in northern environments has been subjected to several environmental changes, such as increasing nitrogen (N) and other disturbances. This thesis examines the effects of N-fertilization and disturbances on the vegetation biomass and abundance, plant community composition and plant, soil and microbial N and C pools. Seedling establishment of the most common dwarf shrubs (deciduous Vaccinium myrtillus, evergreens V. vitis-idaea and Empetrum nigrum ssp. hermaphroditum) was investigated after artificial disturbance treatments (vegetation and soil removal). These studies were conducted in the boreal and subarctic ecosystems and in the forest-tundra ecotone in northern Finland. N-fertilization and disturbances enhanced the amount of graminoids in plant communities, and the recovery ability of graminoids was enhanced after N-fertilization, which homogenized the vegetation and resulted in a new stable state in the plant community. The recovery ability of evergreen dwarf shrubs was low after disturbances. Disturbances created habitats for seed germination, but the seedling establishment of dwarf shrubs studied was still limited by seed availability. N-fertilization had no effect on microbial biomass. Instead, microbial biomass decreased with disturbance treatment in the boreal forest. However, the concentration of N increased in above-ground vegetation, both after N-fertilization and disturbance without any indication of N immobilization, suggesting that plant species captured the available N effectively for their recovery. The study shows that the likely outcome of N enrichment, when combined with disturbances, is the enhanced growth of graminoids. The seedling establishment does not compensate for the reduction of the vegetative recovery of evergreen dwarf shrubs, which makes evergreen dwarf shrubs sensitive to environmental changes. As the understorey is more resilient to perturbations in the boreal forest than in the subarctic ecosystem, these results emphasize the sensitivity of the vegetation to simultaneous environmental changes in the northernmost ecosystems. Moreover, microbial properties are more resilient to environmental changes than is above-ground vegetation. / Tiivistelmä Ilmaston muutos ja siitä aiheutuvan lämpenemisen vaikutus kasvillisuuteen ja maaperään on laajasti tunnustettu ilmiö. Lämpenemisen lisäksi pohjoisten alueiden aluskasvillisuuteen kohdistuu useita muutospaineita, kuten lisääntynyt typpipitoisuuden nousu ja kasvillisuutta muokkaavat häiriöt. Tässä tutkimuksessa mitattiin lisääntyneen typpipitoisuuden ja häiriöiden vaikutus kasvillisuuden biomassaan ja runsauteen sekä yhteisörakenteeseen, sekä kasvilajeihin, maaperään ja mikrobibiomassaan sitoutuneen typen ja hiilen määrään. Lisäksi tutkittiin yleisimpien varpukasvien (lehtensä pudottava mustikka, ikivihreät puolukka ja variksenmarja) siemenellistä lisääntymistä kokeellisen häiriön (kasvillisuuden tai maaperän poisto) jälkeen. Tutkimukset tehtiin boreaalisessa ja subarctisessa ekosysteemeissä sekä metsänrajaympäristössä Pohjois-Suomessa. Typpilannoitus ja häiriöt lisäsivät heinien määrää kasviyhteisöissä. Lisäksi typpilannoitus edisti heinien kasvullista palautumiskykyä häiriön jälkeen, joka johti kasvillisuuden homogenisoitumiseen ja kasviyhteisön uuteen tasapainotilaan. Häiriöt heikensivät ikivihreiden varpujen kasvullista palautumista häiriön jälkeen. Häiriö loi sopivia elinympäristöjä siementen itämiselle, mutta tutkittujen lajien siementen määrä rajoitti siemenellistä lisääntymistä. Typpilannoitus ei vaikuttanut mikrobibiomassaan, mutta häiriö vähensi mikrobibiomassaa boreaalisessa ekosysteemissä. Kuitenkin kasvien typen pitoisuudet lisääntyivät sekä lannoituksen että häiriön jälkeen ilman viitteitä typen sitoutumisesta mikrobibiomassaan. Tämä viittaa siihen, että kasvit käyttävät maaperän typen tehokkaasti häiriön jälkeiseen palautumiseen. Väitöskirjan mukaan typen lisääntyminen häiriöiden yhteydessä edistää heinien esiintymistä. Koska ikivihreiden varpujen siemenellinen lisääntyminen ei kompensoi häiriöstä kasvulliselle palautumiselle aiheutuvaa haittaa, ovat ikivihreät varvut erityisen herkkiä häiriöille. Aluskasvillisuus on vastustuskykyisempi ympäristön muutoksille boreaalisessa kuin subarktisessa ekosysteemissä, mikä korostaa pohjoisimpien alueiden herkkyyttä yhtäaikaisille ympäristön muutoksille. Maaperän olosuhteet ovat kasvillisuutta kestävämpiä ympäristön muutoksille.