The aim of this study was to assess the effect of composting process of cow manure and rice straw with application of cow urine and to evaluate the quality of composting products. There were two treatment piles, in which one pile was applied with cow urine every week and another pile without urine application. Each pile was set up by one tone cow manure and 500kg rice straw. The piles were half-covered by plastic foil to protect from rain and turned one a week. The composting duration lasted 8 weeks. The parameters such as temperature, pH, DM, density and nitrogen were monitored and observed during the 8-week period. The results showed that there was a significant difference in temperature, compost quality and duration between two piles with and without cow urine application. The application of cow urine increased significant nitrogen and phosphorous content and shortened the composting process. This study recommends that cow urine should be applied for composting process of cow manure and rice straw in order to increase the quality of compost. The final product was in the range of matured compost level and can be used directly for agriculture crop. / Mục tiêu của nghiên cứu nhằm đánh giá ảnh hưởng đến chất lượng phân compost của việc bổ sung nước tiểu vào trong quá trình ủ phân từ nguyên liệu phân bò và rơm rạ. Thí nghiệm được thực hiện trên hai đống ủ phân, một đống ủ được bổ sung nước tiểu bò hàng tuần và một đống ủ không bổ sung nước tiểu bò như là một nghiệm thức đối chứng. Mỗi đống ủ được trộn 1 tấn phân bò và 500kg rơm. Đống ủ phân được đậy kín một nửa phía trên nhằm ngăn cản ảnh hưởng của mưa và được đảo trộn một lần mỗi tuần. Quá trình thí nghiệm được tiến hành trong 8 tuần. Các chỉ tiêu như nhiệt độ, pH, DM, mật độ và chất dinh dưỡng Nitơ và Phốt Pho được quan trắc trong thời gian ủ. Kết quả cho thấy có sự khác biệt đáng kể giữa hai đống phân ủ đối với các chỉ tiêu như nhiệt độ, chất lượng phân compost và thời gian ủ. Đống ủ phân có bổ sung nước tiểu có hàm lượng Nitơ và Phốt pho cao hơn và thời gian ủ ngắn hơn. Kết quả nghiên cứu khuyến cáo nên bổ sung nước tiểu bò cho quá trình ủ phân compost nhằm tăng hàm lượng chất dinh dưỡng cho sản phẩm phân compost. Sản phẩm sau quá trình ủ đạt mức độ phân hữu cơ và có thể sử dụng cho cây trồng.

O uso de determinadas fontes nitrogenadas, doses e formas de nitrogênio (N) pode aumentar a eficiência de uso de N (EUN) em soqueiras de cana-de-açúcar (Saccharum spp.), mantendo, em longo prazo, elevados índices de produtividade, lucro e proteção ao ambiente. Experimentos de campo e de casa-de-vegetação foram desenvolvidos com os seguintes objetivos: (i) avaliar o efeito do manejo do N-fertilizante e dos ciclos de soqueira da cultura na produtividade, parâmetros tecnológicos, acúmulo de biomassa, acúmulo e balanço de nutrientes e nas alterações dos atributos químicos do solo; (ii) avaliar a produção de biomassa seca, metabolismo e nutrição de plantas de cana-de-açúcar cultivadas em solução nutritiva, com suprimento exclusivo ou misto de nitrato (NO3-) e amônio (NH4+) como fontes de N; (iii) avaliar a EUN do 15N-nitrato (15NH4NO3), 15N-amônio (NH415NO3) e 15N-amida [(15NH2)2CO] aplicados na quarta soqueira de cana-de-açúcar em condições de campo; e avaliar a EUN do 15N-amônio e 15N-nitrato aplicados em mudas de cana-de-açúcar cultivadas em solução nutritiva. No campo, o N-fertilizante foi repetido nas mesmas parcelas experimentais (parcelas estáticas), em anos subsequentes (quatro ou cinco soqueiras) e o manejo de N-fertilizante, que incluiu fontes e doses de N, não influenciou na produtividade de colmos e de açúcar no local 1 (Latossolo Vermelho Amarelo distrófico - LVAd). Entretanto, no local 2 (também LVAd), o NA100 e o NAC100 [nitrato de amônio (NA) e nitrato de amônio e cálcio (NAC), ambos na dose de 100 kg ha-1 de N] foram os manejos mais vantajosos para a obtenção das maiores produtividades de colmo e de açúcar em soqueiras quando comparado aos demais tratamentos. No geral, nos dois locais, o NAC150 (150 kg ha-1 de N) proporcionou os maiores acúmulos de biomassa, N e K nas plantas. Além disso, enquanto o controle (sem adição de N) apresentou as menores produções de biomassa e acúmulos de nutrientes (com exceção ao P), o balanço de nutrientes do solo nesse tratamento foi relativamente neutro após anos de cultivo da cana-de-açúcar. Em condições controladas, plantas de cana-de-açúcar supridas exclusivamente com amônio apresentaram menor produção de biomassa, acúmulo de nutrientes e área foliar do que os outros tratamentos (supridos com combinações de NO3-/NH4+ e somente com nitrato), indicando que o uso exclusivo dessa forma de N não foi eficiente para sustentar o crescimento vegetal. A maior EUN foi obtida com o fornecimento exclusivo de nitrato, que também proporcionou maior produção de biomassa seca, área foliar, acúmulo de macronutrientes, atividade fotossintética e crescimento do sistema radicular. A utilização de 15N indicou que, no campo, não houve diferença na EUN pelas plantas devido à utilização do 15N-nitrato e 15N-amônio. Em contraste, a EUN do 15N-amônio foi maior que a do 15N-nitrato durante o 1º, 4º e 7º dia após a aplicação do fertilizante (DAAF), em condições controladas. Contudo, o uso do 15N-nitrato teve maior EUN nas raízes e planta inteira que o 15N-amônio no 15º DAAF. Isso indica que a cana-de-açúcar pode aproveitar eficientemente as duas formas minerais de N, embora o aproveitamento do amônio seja mais rápido. / The use of different fertilizers and rates of nitrogen (N) can increase the N use efficiency (NUE) in sugarcane ratoon (Saccharum spp.), sustaining high yield levels, profitability and environmental protection in long-term. Thus, field and greenhouse studies were performed with the following objectives: (i) evaluate the effect of fertilizer-N management and ratoon crop cycles on sugarcane yield, technological parameters, biomass accumulation, nutrient content, temporal variation in soil chemical properties and soil nutrient balance; (ii) evaluate the biomass production, metabolism and nutrient acquisition of sugarcane plants cropped in nutrient solution, with solely or combined supply of ammonium and nitrate as N sources; (iii) evaluate the NUE of 15N-ammonium (15NH4NO3), 15N-nitrate (NH415NO3), and 15N-amide [(15NH2)2CO] applied to sugarcane under field conditions and the NUE of 15N-ammonium and 15N-nitrate applied to seedlings sugarcane under nutrient solutions. In the field, N fertilizers were replicated in the same experimental plots (static plots) in subsequent years (four or five ratoons) and the management of N-fertilizer, which included fertilizers and N rates, resulted in lack of influence on cane and sucrose yield at Site 1 (Typic Hapludox). However, at Site 2 (also Typic Hapludox), the N treatments AN100 and CAN100 [ammonium nitrate (AN) and calcium ammonium nitrate (CAN), both at a rate of 100 kg N ha-1] provided the highest cane and sugar yield as compared to the remaining treatments. Overall, at both sites, CAN150 (150 kg N ha-1) resulted in the highest biomass accumulation and N and K content by sugarcane. In addition, while the control (no N added) had the lowest biomass accumulation and nutrient content (except for P), the soil nutrient balance in this treatment was relatively neutral, after years of sugarcane cultivation. Under controlled conditions, NH4+-fed plants presented lower biomass accumulation, nutrient content and leaf area than the other treatments (different NO3-/NH4+ ratios and NO3--fed plants), indicating that this N form, when applied solely, was not effective for the proper plant growth. The highest NUE was obtained with NO3--fed plants, which also had the highest production of dry biomass, leaf area, nutrient accumulation, photosynthetic activity, and growth of the root system. The use of 15N-nitrate and 15N-ammonium indicated that there was no difference in NUE by plants in the field. In contrast, the NUE of 15N-ammonium was greater than 15N-nitrate during the 1st, 4th and 7th day after fertilizer application (DAFA), under controlled conditions. However, the use of 15N-nitrate had greater NUE in roots and whole plant than 15N-ammonium in the 15th DAFA. It can be concluded that sugarcane can use both N forms although the recovery of NH4+ was faster than NO3-.

O uso de determinadas fontes nitrogenadas, doses e formas de nitrogênio (N) pode aumentar a eficiência de uso de N (EUN) em soqueiras de cana-de-açúcar (Saccharum spp.), mantendo, em longo prazo, elevados índices de produtividade, lucro e proteção ao ambiente. Experimentos de campo e de casa-de-vegetação foram desenvolvidos com os seguintes objetivos: (i) avaliar o efeito do manejo do N-fertilizante e dos ciclos de soqueira da cultura na produtividade, parâmetros tecnológicos, acúmulo de biomassa, acúmulo e balanço de nutrientes e nas alterações dos atributos químicos do solo; (ii) avaliar a produção de biomassa seca, metabolismo e nutrição de plantas de cana-de-açúcar cultivadas em solução nutritiva, com suprimento exclusivo ou misto de nitrato (NO3-) e amônio (NH4+) como fontes de N; (iii) avaliar a EUN do 15N-nitrato (15NH4NO3), 15N-amônio (NH415NO3) e 15N-amida [(15NH2)2CO] aplicados na quarta soqueira de cana-de-açúcar em condições de campo; e avaliar a EUN do 15N-amônio e 15N-nitrato aplicados em mudas de cana-de-açúcar cultivadas em solução nutritiva. No campo, o N-fertilizante foi repetido nas mesmas parcelas experimentais (parcelas estáticas), em anos subsequentes (quatro ou cinco soqueiras) e o manejo de N-fertilizante, que incluiu fontes e doses de N, não influenciou na produtividade de colmos e de açúcar no local 1 (Latossolo Vermelho Amarelo distrófico - LVAd). Entretanto, no local 2 (também LVAd), o NA100 e o NAC100 [nitrato de amônio (NA) e nitrato de amônio e cálcio (NAC), ambos na dose de 100 kg ha-1 de N] foram os manejos mais vantajosos para a obtenção das maiores produtividades de colmo e de açúcar em soqueiras quando comparado aos demais tratamentos. No geral, nos dois locais, o NAC150 (150 kg ha-1 de N) proporcionou os maiores acúmulos de biomassa, N e K nas plantas. Além disso, enquanto o controle (sem adição de N) apresentou as menores produções de biomassa e acúmulos de nutrientes (com exceção ao P), o balanço de nutrientes do solo nesse tratamento foi relativamente neutro após anos de cultivo da cana-de-açúcar. Em condições controladas, plantas de cana-de-açúcar supridas exclusivamente com amônio apresentaram menor produção de biomassa, acúmulo de nutrientes e área foliar do que os outros tratamentos (supridos com combinações de NO3-/NH4+ e somente com nitrato), indicando que o uso exclusivo dessa forma de N não foi eficiente para sustentar o crescimento vegetal. A maior EUN foi obtida com o fornecimento exclusivo de nitrato, que também proporcionou maior produção de biomassa seca, área foliar, acúmulo de macronutrientes, atividade fotossintética e crescimento do sistema radicular. A utilização de 15N indicou que, no campo, não houve diferença na EUN pelas plantas devido à utilização do 15N-nitrato e 15N-amônio. Em contraste, a EUN do 15N-amônio foi maior que a do 15N-nitrato durante o 1º, 4º e 7º dia após a aplicação do fertilizante (DAAF), em condições controladas. Contudo, o uso do 15N-nitrato teve maior EUN nas raízes e planta inteira que o 15N-amônio no 15º DAAF. Isso indica que a cana-de-açúcar pode aproveitar eficientemente as duas formas minerais de N, embora o aproveitamento do amônio seja mais rápido. / The use of different fertilizers and rates of nitrogen (N) can increase the N use efficiency (NUE) in sugarcane ratoon (Saccharum spp.), sustaining high yield levels, profitability and environmental protection in long-term. Thus, field and greenhouse studies were performed with the following objectives: (i) evaluate the effect of fertilizer-N management and ratoon crop cycles on sugarcane yield, technological parameters, biomass accumulation, nutrient content, temporal variation in soil chemical properties and soil nutrient balance; (ii) evaluate the biomass production, metabolism and nutrient acquisition of sugarcane plants cropped in nutrient solution, with solely or combined supply of ammonium and nitrate as N sources; (iii) evaluate the NUE of 15N-ammonium (15NH4NO3), 15N-nitrate (NH415NO3), and 15N-amide [(15NH2)2CO] applied to sugarcane under field conditions and the NUE of 15N-ammonium and 15N-nitrate applied to seedlings sugarcane under nutrient solutions. In the field, N fertilizers were replicated in the same experimental plots (static plots) in subsequent years (four or five ratoons) and the management of N-fertilizer, which included fertilizers and N rates, resulted in lack of influence on cane and sucrose yield at Site 1 (Typic Hapludox). However, at Site 2 (also Typic Hapludox), the N treatments AN100 and CAN100 [ammonium nitrate (AN) and calcium ammonium nitrate (CAN), both at a rate of 100 kg N ha-1] provided the highest cane and sugar yield as compared to the remaining treatments. Overall, at both sites, CAN150 (150 kg N ha-1) resulted in the highest biomass accumulation and N and K content by sugarcane. In addition, while the control (no N added) had the lowest biomass accumulation and nutrient content (except for P), the soil nutrient balance in this treatment was relatively neutral, after years of sugarcane cultivation. Under controlled conditions, NH4+-fed plants presented lower biomass accumulation, nutrient content and leaf area than the other treatments (different NO3-/NH4+ ratios and NO3--fed plants), indicating that this N form, when applied solely, was not effective for the proper plant growth. The highest NUE was obtained with NO3--fed plants, which also had the highest production of dry biomass, leaf area, nutrient accumulation, photosynthetic activity, and growth of the root system. The use of 15N-nitrate and 15N-ammonium indicated that there was no difference in NUE by plants in the field. In contrast, the NUE of 15N-ammonium was greater than 15N-nitrate during the 1st, 4th and 7th day after fertilizer application (DAFA), under controlled conditions. However, the use of 15N-nitrate had greater NUE in roots and whole plant than 15N-ammonium in the 15th DAFA. It can be concluded that sugarcane can use both N forms although the recovery of NH4+ was faster than NO3-.

In den meisten Ländern Mitteleuropas gilt weniger als ein Prozent des verbleibenden Laubwaldes als ungestört und temperierte Wälder sind Herausforderungen wie Arteninvasion, Klimawandel und steigender Stickstoff(N)-Deposition ausgesetzt. In der Vergangenheit wurde gezeigt, dass hohe N-Einträge N-Limitierungen verringern, Phosphor(P)aufnahme behindern und P-Mängel in der Buche auslösen können. Die Artendiversität von Bäumen kann die Bestandsproduktivität durch die Prozesse Komplementarität und Facilitation (Wachstumserleichterung) erhöhen, wenn diese einen wachstumslimitierenden Nährstoff betreffen. Ein Schlüsselprozess im Nährstoffkreislauf ist der Weg von Nährstoffen durch die mikrobielle Biomasse während der Dekomposition. Es wurde gezeigt, dass die mikrobielle Biomasse um N bspw. mit Buchen und um P mit tropischen Moorpflanzen konkurriert. Die Buche ist eine sehr konkurrenzfähige Baumart in temperierten Waldökosystemen aber kann von der Eiche in trockenen Bereichen übertrumpft werden, während Hainbuche und Linde eine geringere Rolle spielen. Eichen erfahren jedoch in der jüngsten Vergangenheit in europäischen Wäldern einen Rückgang, der womöglich auf hohe N-Einträge zurückzuführen ist. Für diese Arbeit untersuchten wir die Nährstoff-, Konkurrenz- und strukturelle Dynamik eines unbewirtschafteten, sehr naturnahen Laubwaldes in Mitteldeutschland, der aus Buche (Fagus sylvatica), Eiche (Quercus petraea und Quercus robur), Hainbuche (Carpinus betulus) und Linde (Tilia cordata und Tilia platyphyllus) aufgebaut ist. Unsere Ziele waren (1) zu erforschen, ob Komplementarität und/oder Facilitation die Produktivität in diesem Waldökosystem erhöht, (2) festzustellen, ob es Konkurrenz um die Nährstoffe N, P und K zwischen Bäumen und mikrobieller Biomasse gibt und, (3) die Nachbarschaftsdynamik der genannten Baumarten zu untersuchen und herauszufinden, ob der Eichenrückgang mit hoher N-Deposition einhergeht. In Beständen einer Art sowie verschiedenen Mischbeständen aus je drei Arten ermittelten wir Biomasseproduktion und Nährstoffverfügbarkeit. Nährstoffnutzungseffizienzkurven (Nährstoffnutzungseffizienz = Biomasseproduktion pro verfügbare Nährstoffe) wurden genutzt um festzustellen, ob ein bestimmter Nährstoff das Baumwachstum limitiert. Die jährliche Netto-Nährstoffveränderung wurde in einer Laubbeutel-Studie als Differenz zwischen ursprünglichem und verbleibendem Nährstoffgehalt des sich zersetzenden Laubfalls nach einem Jahr kalkuliert. Die Nährstoffresorptionseffizienz berechneten wir über die Ermittlung der N-, P- und Kalium(K)-Konzentrationen in sonnenexponierten Blättern und im gefallenen Laub. Die Nachbarschaftsdynamik von Bäumen wurde über die Durchmesserverteilung, überirdische Holzbiomasse für jede Artenkombination sowie eine Polygon-Abschätzung von Wachstumsräumen erforscht. Zusätzlich wurde eine durchmesserbasierte nearest neighbor(nächster-Nachbar)-Analyse für Baumpaare durchgeführt. Ein Geographisches Informationssystem (GIS) wurde genutzt um Wachstumsraum-Polygone zu erstellen und nächste Nachbarn zu bestimmen. Auf Einzelbaum-Level, ermittelt durch einen Nachbarschaftsansatz, waren relative Wachstumsraten von Buchen im Einzelbestand geringer als in der Mischung mit Linde und Hainbuche während das Wachstum von Linde im Einzelbestand größer war als in Mischung mit Buche und Eiche. Die Nährstoffnutzungseffizienzkurve für Buche zeigte optimale P- und K-Nutzungseffizienz für die Art in Mischbeständen, während sie in Einzelbeständen  P- und K-limitiert war. Während die jährliche Netto-Nährstoffveränderung in sich zersetzendem Blattlaub die Verfügbarkeit von P und K im Boden beeinflusste, war dies für N nicht der Fall. Resorptionseffizienzen von N, P und K hingen negativ mit der jährlichen Netto-Nährstoffveränderung zusammen. In unserer Studie zur Nachbarschaftsdynamik von Bäumen fanden wir heraus, dass intraspezifische nearest neighbors gleiche Durchmesser aufwiesen und ihren Durchmesser gleichzeitig mit dem des Nachbarn vergrößerten. Im Gegensatz dazu waren die Durchmesser von interspezifischen nearest neighbors im Allgemeinen unterschiedlich und der Durchmesser des Nachbarn verringerte sich mit zunehmendem Durchmesser des Zielbaums. Eichen konnten ihren Wachstumsraum mit zunehmendem Durchmesser nicht vergrößern, aber dominierten ihre nearest neighbor über die Größe. Unsere Ergebnisse zeigten, dass im untersuchten Waldökosystem Nährstofflimitierungen artabhängig waren und dass die Nutzung von Nährstoffnutzungseffizienz und Nachbarschaftsansatz geeignete Mittel sind, den Einfluss einzelner Baumarten auf die Produktivität einer Art im Rein- und Mischbestand zu ermitteln – so wie die beobachtete Facilitation der Buche im Mischbestand. Diese Werkzeuge stellen eine wichtige Basis zur verbesserten Bewirtschaftung typischer temperierter Mischwälder dar. Wir schlussfolgerten weiterhin, dass Konkurrenz zwischen mikrobieller Biomasse und Bäumen für P und K hoch, aber für N weniger bedeutend war, was wahrscheinlich in hoher N-Deposition in diesem Waldökosystem begründet liegt, welche den internen N-Kreislauf entkoppelte. Die hohe N-Deposition trug wahrscheinlich auch zu geringer Verjüngung der Eiche bei, während ältere Eichen in unserem Untersuchungsgebiet im Wettbewerb um Licht erfolgreich waren. Die Bestandsstruktur war charakterisiert durch stärkere interspezifische verglichen mit intraspezifischer Konkurrenz. Daraus resultierend bildeten Reinbestände aus Buche, Eiche und Linde Klimaxbestände hoher Biomasse innerhalb eines sich verändernden, kleinskaligen Mosaiks verschiedener Artenzusammensetzungen. In Reaktion auf neue Bewirtschaftungsanforderungen des Globalen Wandels sind weiterführende Forschungen zu Nutzungseffizienz unterschiedlicher Ressourcen für Baumarten in verschiedenen Zusammensetzungen empfehlenswert.

South Africa is one of the world's most biologically invaded countries and has spent billions of rands on efforts to eradicate alien invasive plants. Chemical and mechanical control methods have varied in success and the need for integrated management strategies has been realised. This requires a better understanding of all aspects of the invasion process. Some of the most invasive plant species rely on vertebrate dispersers which facilitate long-distance seed dispersal. Frugivory is based on a mutualism in which the frugivores gain a resource and the plants benefit from seed dispersal away from the parent plant. Seed germination itself may either be enhanced, reduced or not affected at all after gut passage. The first aim of this study was to determine if generalist avian frugivores and a fruit bat species (Epomophorus wahlbergi) enhance or decrease seed germination of invasive alien plants in South Africa, by either pulp removal or seed coat abrasion, or if they serve as dispersers only. The second aim was to determine if avian frugivores are able to meet their energetic demands by feeding on a specific alien fruit diet. Finally, we also quantified the nutritional content and morphological characteristics of fleshy fruits of various invasive alien and exotic plant species. Avian frugivores: Red-winged Starlings (Onychognathus morio), Speckled Mousebirds (Colius striatus), and Dark-capped Bulbuls (Pycnonotus tricolor), varied in their effects on the germination success of seeds of four invasive alien species, namely: Lantana camara, Solanum mauritianum, Cinnamomum camphora, and Psidium guajava. However, this was not associated with differences in seed retention times. Similar germination success was observed for avian ingested and de-pulped seeds. This was also observed for fruit bat spat and depulped seeds of Psidium guajava, Melia azedarach, Eriobotrya japonica, and Morus alba. Therefore seed coat abrasion was not important for the germination of these fleshy-fruited invasive alien plants. Pulp removal resulted in significantly earlier seed germination as well as higher seed germination percentages than in the case of whole fruit controls for some of these invasive species. Gut passage is thus important for long-distance dispersal, and in some cases, for enhanced germination of seeds. The invasive Solanum mauritianum and indigenous congener S. giganteum showed similar germination responses, with both ingested and depulped seeds germinating profusely. However, S. giganteum benefited from pulp removal as seeds from whole fruits had less germination. Avian frugivores varied significantly in most energetic parameters calculated when given diets of invasive alien fruit. Speckled Mousebirds and Dark-capped Bulbuls were able to maintain body mass and efficiently process fruits of all four alien invasive plants, while Red-winged Starlings were only able to do so on lipid-rich C. camphora and sugar-rich S. mauritianum. Furthermore, frugivores also adjusted their feeding behavior by eating more nutritionally poor fruit and less energetically rewarding fruit. Fruit bats consumed more fruit per gram body mass than avian frugivores did. They therefore process proportionately more seeds than avian dispersers and thus their role in invasive seed dispersal, which has previously been underestimated particularly in South Africa, is highlighted. Fruits of invasive plant species were similar in morphology, but greater in nutritional content, than fruits of indigenous species. These fruits also contained small, light seeds with approximately only 30% having more than 10 seeds per fruit. The ability of frugivores to efficiently process these fruits and the greater nutritional rewards offered by these provide new insights into why these invasive fruits are preferred by frugivores. In addition, invasive alien plants may have a competitive edge over indigenous species because of their larger reproductive outputs and not necessarily because of greater germination success. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.