Microbial use of organic substrates and maize growth, especially in saline and alkaline soils of Pakistani Punjab

This thesis consists of 4 main parts: (1) impact of growing maize on the decomposition of incorporated fresh alfalfa residues, (2) relationships between soil biological and other soil properties in saline and alkaline arable soils from the Pakistani Punjab, (3) decomposition of compost and plant residues in Pakistani soils along a gradient in salinity, and (4) interactions of compost and triple superphosphate on the growth of maize in a saline Pakistani soil. These 4 chapters are framed by a General Introduction and a Conclusions section. (1) In the first study, the effects of growing maize plants on the microbial decomposition of freshly chopped alfalfa residues was investigated in a 90-day pot experiment using a sandy arable soil. Assuming that the addition of alfalfa residues did not affect the decomposition of native soil organic matter, only 27% of the alfalfa residues were found as CO2. This suggests that a considerable part of alfalfa-C remained undecomposed in the soil. However, only 6% of the alfalfa residues could be recovered as plant remains in treatment with solely alfalfa residues. Based on d13C values, it was calculated that plant remains in treatment maize + alfalfa residues contained 14.7% alfalfa residues and 85.3% maize root remains. This means 60% more alfalfa-C was recovered in this treatment. (2) In the second study, the interactions between soil physical, soil chemical and soil biological properties were analysed in 30 Pakistani soils from alkaline and saline arable sites differing strongly in salinisation and in soil pH. The soil biological properties were differentiated into indices for microbial activity, microbial biomass, and community structure with the aim of assessing their potential as soil fertility indices. (3) In the third study, 3 organic amendments (compost, maize straw and pea straw) were added to 5 Pakistani soils from a gradient in salinity. Although salinity has depressive effects on microbial biomass C, biomass N, biomass P, and ergosterol, the clear gradient according to the soil salt concentration was not reflected by the soil microbial properties. The addition of the 3 organic amendments always increased the contents of the microbial indices analysed. The amendment-induced increase was especially strong for microbial biomass P and reflected the total P content of the added substrates. (4) The fourth study was greenhouse pot experiment with different combinations of compost and triple superphosphate amendments to investigate the interactions between plant growth, microbial biomass formation and compost decomposition in a strongly saline Pakistani arable soil in comparison to a non-saline German arable soil. The Pakistani soil had a 2 times lower content of ergosterol, a 4 times lower contents of microbial biomass C, biomass N and biomass P, but nearly a 20 times lower content of NaHCO3 extractable P. The addition of 1% compost always had positive effects on the microbial properties and also on the content of NaHCO3 extractable P. The addition of superphosphate induced a strong and similar absolute increase in microbial biomass P in both soils.

Salinity-induced changes in the microbial use of sugarcane filter cake added to soil

Five laboratory incubation experiments were carried out to assess the salinity-induced changes in the microbial use of sugarcane filter cake added to soil. The first laboratory experiment was carried out to prove the hypothesis that the lower content of fungal biomass in a saline soil reduces the decomposition of a complex organic substrate in comparison to a non-saline soil under acidic conditions. Three different rates (0.5, 1.0, and 2.0%) of sugarcane filter cake were added to both soils and incubated for 63 days at 30°C. In the saline control soil without amendment, cumulative CO2 production was 70% greater than in the corresponding non-saline control soil, but the formation of inorganic N did not differ between these two soils. However, nitrification was inhibited in the saline soil. The increase in cumulative CO2 production by adding filter cake was similar in both soils, corresponding to 29% of the filter cake C at all three addition rates. Also the increases in microbial biomass C and biomass N were linearly related to the amount of filter cake added, but this increase was slightly higher for both properties in the saline soil. In contrast to microbial biomass, the absolute increase in ergosterol content in the saline soil was on average only half that in the non-saline soil and it showed also strong temporal changes during the incubation: A strong initial increase after adding the filter cake was followed by a rapid decline. The addition of filter cake led to immobilisation of inorganic N in both soils. This immobilisation was not expected, because the total C-to-total N ratio of the filter cake was below 13 and the organic C-to-organic N ratio in the 0.5 M K2SO4 extract of this material was even lower at 9.2. The immobilisation was considerably higher in the saline soil than in the non-saline soil. The N immobilisation capacity of sugarcane filter cake should be considered when this material is applied to arable sites at high rations. The second incubation experiment was carried out to examine the N immobilizing effect of sugarcane filter cake (C/N ratio of 12.4) and to investigate whether mixing it with compost (C/N ratio of 10.5) has any synergistic effects on C and N mineralization after incorporation into the soil. Approximately 19% of the compost C added and 37% of the filter cake C were evolved as CO2, assuming that the amendments had no effects on the decomposition of soil organic C. However, only 28% of the added filter cake was lost according to the total C and d13C values. Filter cake and compost contained initially significant concentrations of inorganic N, which was nearly completely immobilized between day 7 and 14 of the incubation in most cases. After day 14, N re-mineralization occurred at an average rate of 0.73 µg N g-1 soil d-1 in most amendment treatments, paralleling the N mineralization rate of the non-amended control without significant difference. No significant net N mineralization from the amendment N occurred in any of the amendment treatments in comparison to the control. The addition of compost and filter cake resulted in a linear increase in microbial biomass C with increasing amounts of C added. This increase was not affected by differences in substrate quality, especially the three times larger content of K2SO4 extractable organic C in the sugarcane filter cake. In most amendment treatments, microbial biomass C and biomass N increased until the end of the incubation. No synergistic effects could be observed in the mixture treatments of compost and sugarcane filter cake. The third 42-day incubation experiment was conducted to answer the questions whether the decomposition of sugarcane filter cake also result in immobilization of nitrogen in a saline alkaline soil and whether the mixing of sugarcane filter cake with glucose (adjusted to a C/N ratio of 12.5 with (NH4)2SO4) change its decomposition. The relative percentage CO2 evolved increased from 35% of the added C in the pure 0.5% filter cake treatment to 41% in the 0.5% filter cake +0.25% glucose treatment to 48% in the 0.5% filter cake +0.5% glucose treatment. The three different amendment treatments led to immediate increases in microbial biomass C and biomass N within 6 h that persisted only in the pure filter cake treatment until the end of the incubation. The fungal cell-membrane component ergosterol showed initially an over-proportionate increase in relation to microbial biomass C that fully disappeared at the end of the incubation. The cellulase activity showed a 5-fold increase after filter cake addition, which was not further increased by the additional glucose amendment. The cellulase activity showed an exponential decline to values around 4% of the initial value in all treatments. The amount of inorganic N immobilized from day 0 to day 14 increased with increasing amount of C added in comparison to the control treatment. Since day 14, the immobilized N was re-mineralized at rates between 1.31 and 1.51 µg N g-1 soil d-1 in the amendment treatments and was thus more than doubled in comparison with the control treatment. This means that the re-mineralization rate is independent from the actual size of the microbial residues pool and also independent from the size of the soil microbial biomass. Other unknown soil properties seem to form a soil-specific gate for the release of inorganic N. The fourth incubation experiment was carried out with the objective of assessing the effects of salt additions containing different anions (Cl-, SO42-, HCO3-) on the microbial use of sugarcane filter cake and dhancha leaves amended to inoculated sterile quartz sand. In the subsequent fifth experiment, the objective was to assess the effects of inoculum and temperature on the decomposition of sugar cane filter cake. In the fourth experiment, sugarcane filter cake led to significantly lower respiration rates, lower contents of extractable C and N, and lower contents of microbial biomass C and N than dhancha leaves, but to a higher respiratory quotient RQ and to a higher content of the fungal biomarker ergosterol. The RQ was significantly increased after salt addition, when comparing the average of all salinity treatments with the control. Differences in anion composition had no clear effects on the RQ values. In experiment 2, the rise in temperature from 20 to 40°C increased the CO2 production rate by a factor of 1.6, the O2 consumption rate by a factor of 1.9 and the ergosterol content by 60%. In contrast, the contents of microbial biomass N decreased by 60% and the RQ by 13%. The effects of the inoculation with a saline soil were in most cases negative and did not indicate a better adaptation of these organisms to salinity. The general effects of anion composition on microbial biomass and activity indices were small and inconsistent. Only the fraction of 0.5 M K2SO4 extractable C and N in non-fumigated soil was consistently increased in the 1.2 M NaHCO3 treatment of both experiments. In contrast to the small salinity effects, the quality of the substrate has overwhelming effects on microbial biomass and activity indices, especially on the fungal part of the microbial community.

Management approaches in organic potato and tomato production

The presented thesis considered three different system approach topics to ensure yield and plant health in organically grown potatoes and tomatoes. The first topic describes interactions between late blight (Phytophthora infestans) incidence and soil nitrogen supply on yield in organic potato farming focussing in detail on the yield loss relationship of late blight based on results of several field trials. The interactive effects of soil N-supply, climatic conditions and late blight on the yield were studied in the presence and absence of copper fungicides from 2002-2004 for the potato cultivar Nicola. Under conditions of central Germany the use of copper significantly reduced late blight in almost all cases (15-30 %). However, the reductions in disease through copper application did not result in statistically significant yield increases (+0 – +10 %). Subsequently, only 30 % of the variation in yield could be attributed to disease reductions. A multiple regression model (R²Max), however, including disease reduction, growth duration and temperature sum from planting until 60 % disease severity was reached and soil mineral N contents 10 days after emergence could explain 75 % of the observed variations in yield. The second topic describes the effect of some selected organic fertilisers and biostimulant products on nitrogen-mineralization and efficiency, yield and diseases in organic potato and tomato trials. The organic fertilisers Biofeed Basis (BFB, plant derived, AgroBioProducts, Wageningen, Netherlands) and BioIlsa 12,5 Export (physically hydrolysed leather shavings, hair and skin of animals; ILSA, Arizignano, Italy) and two biostimulant products BioFeed Quality (BFQ, multi-compound seaweed extract, AgroBioProducts) and AUSMA (aqueous pine and spruce needle extract, A/S BIOLAT, Latvia), were tested. Both fertilisers supplied considerable amounts of nitrogen during the main uptake phases of the crops and reached yields as high or higher as compared to the control with horn meal fertilisation. The N-efficiency of the tested fertilisers in potatoes ranged from 90 to 159 kg yield*kg-1 N – input. Most effective with tomatoes were the combined treatments of fertiliser BFB and the biostimulants AUSMA and BFQ. Both biostimulants significantly increased the share of healthy fruit and/or the number of fruits. BFQ significantly increased potato yields (+6 %) in one out of two years and reduced R. solani-infestation in the potatoes. This suggests that the biostimulants had effects on plant metabolism and resistance properties. However, no effects of biostimulants on potato late blight could be observed in the fields. The third topic focused on the effect of suppressive composts and seed tuber health on the saprophytic pathogen Rhizoctonia solani in organic potato systems. In the present study 5t ha-1 DM of a yard and bio-waste (60/40) compost produced in a 5 month composting process and a 15 month old 100 % yard waste compost were used to assess the effects on potato infection with R. solani when applying composts within the limits allowed. Across the differences in initial seed tuber infestation and 12 cultivars 5t DM ha-1 of high quality composts, applied in the seed tuber area, reduced the infestation of harvested potatoes with black scurf, tuber malformations and dry core tubers by 20 to 84 %, 20 to 49 % and 38 to 54 %, respectively, while marketable yields were increased by 5 to 25 % due to lower rates of wastes after sorting (marketable yield is gross yield minus malformed tubers, tubers with dry core, tubers with black scurf > 15% infested skin). The rate of initial black scurf infection of the seed tubers also affected tuber number, health and quality significantly. Compared to healthy seed tubers initial black scurf sclerotia infestation of 2-5 and >10 % of tuber surface led in untreated plots to a decrease in marketable yields by 14-19 and 44-66 %, a increase of black scurf severity by 8-40 and 34-86 % and also increased the amount of malformed and dry core tubers by 32-57 and 109-214 %.

Effect of planting methods and cyanobacterial inoculants on yield, water productivity and economics of rice cultivation

The impact of two crop planting methods and of the application of cyanobacterial inoculants on plant growth, yield, water productivity and economics of rice cultivation was evaluated with the help of a split plot designed experiment during the rainy season of 2011 in New Delhi, India. Conventional transplanting and system of rice intensification (SRI) were tested as two different planting methods and seven treatments that considered cyanobacterial inoculants and compost were applied with three repetitions each. Results revealed no significant differences in plant performance and crop yield between both planting methods. However, the application of biofilm based BGA bio-fertiliser + 2/3 N had an overall positive impact on both, plant performance (plant height, number of tillers) and crop yield (number and weight of panicles) as well as on grain and straw yield. Higher net return and a higher benefit-cost ratio were observed in rice fields under SRI planting method, whereas the application of BGA + PGPR + 2/3 N resulted in highest values. Total water productivity and irrigation water productivity was significantly higher under SRI practices (5.95 and 3.67 kg ha^(-1) mm^(-1)) compared to practices of conventional transplanting (3.36 and 2.44), meaning that using SRI method, water saving of about 34 % could be achieved and significantly less water was required to produce one kg of rice. This study could show that a combination of plant growth promoting rhizobacteria (PGPR) in conjunction with BGA and 2/3 dose of mineral N fertiliser can support crop growth performance, crop yields and reduces overall production cost, wherefore this practices should be used in the integrated nutrient management of rice fields in India.

Gestió de les dejeccions ramaderes d'una explotació avícola mitjançant compostatge

Estudi de la la problemàtica de la gestió de les dejeccions ramaderes presentada per una empresa dedicada a la integració avícola

Desarrollo de un huerto casi ecológico y un pequeño jardín botánico en el IES Benjamín Jarnés.

Seleccionado en la convocatoria: Ayudas a la innovación e investigación educativa en centros docentes de niveles no universitarios, Gobierno de Aragón 2009-10

Perfils. Josep Tero, alumne i amic de M. Àngels Anglada

La primera vegada que Josep Tero va sentir el nom de M. Àngels Anglada va ser quan M. Rosa Gratacós, pianista i cantautora, el va convidar a cantar les cançons que ell mateix havia compost. Gratacós parlava d'Anglada i dels seus poemes amb tanta definició de perfils i amb tant d'èmfasi sobra la seva tendència clàssica que, tot i no haver-la vist mai, el jove cantautor se la va imaginar com en realitat la va trobar al matí que la va conèixer. Tero ha estat a Girona per presentar el seu darrer disc, en què ha musicat poemes de M. Àngels Anglada

No está solo el Guiniguada.

El proyecto trata sobre la necesidad actual de preservar recursos naturales tan básicos como las tierras de cultivo y los bosques. Se desarrollan dos temas prácticos y monográficos, taller de papel y taller de compost, bajo una misma actividad: reciclaje de los residuos orgánicos y sus aplicaciones prácticas. Se parte del conocimiento del medio cercano, natural y social, a través de visitas, monografías y estudio de ecosistemas concretos. Se proponen una serie de objetivos para el alumnado y otra serie de ellos para el profesorado, fundamentalmente de perfeccionamiento a traves de cursos. La metodología, fundamentalmente activa y globalizadora, incluye actividades como correpondencia escolar, salidas y conocimiento del entorno más cercano, reciclaje de papel, etc. Los objetivos propuestos se llevaron a cabo con éxito por lo que se valora positivamente. Se propone prolongar el proyecto para el curso siguiente profundizando en el tema y elaborando material propio.

No está solo el Guiniguada.

Proyecto de educación desarrollado por seis profesores en el CP 'Adela Santana'. Los objetivos fueron: establecer diálogos en los lugares de estudio cercanos a los centros, fomentar la actitud de recoger y no desperdiciar recursos naturales, aprender nuevas formas de reciclaje del papel, investigar y desarrollar la creatividad en la reutilización de los residuos, iniciar la recogida de plástico, cristal, pilas y papel y, elaborar materiales didácticos. El plan de trabajo desarrollado por el grupo se ajustó a las siguientes pautas: información, búsqueda de contenedores y recogida de pilas, información y elaboración de compost para los jardines, puesta en marcha de la campaña de recogida de papel e, información y comienzo de los jardines ornamentales escolares. Los resultados de la experiencia fueron positivos pues a lo largo del curso se consiguieron llevar al aula con gran éxito toda clase de actividades que incluyeron: obtención de compost para adornar los jardines escolares, adquisición de las técnicas de creación de semilleros y germinaciones óptimas, extensión de las técnicas de reciclar papel a mano, creación de un jardín de plantas autóctonas del piso basal en el Colegio Público San Lorenzo, creación de jardines ornamentales en todos los centros implicados, recogida de 60 kilogramos de pilas, recogida de 2.919 kilogramos de papel para su reciclaje y, presentación de una comunicación en las Jornadas Zonales de Innovación Educativas.

Construcción y utilización didáctica del jardín botánico.

El desarrollo del proyecto se llevó a cabo en el IES José del Campo en Ampuero. El colectivo de profesores está implicado en el proyecto ya que todos los cursos participarán del jardín, pero concretamente son cinco profesores lo encargados directamente. Los objetivos son: 1. Implicar a los alumnos que participen en el proyecto en tareas que les induzcan a desarrollar una actitud de respeto hacia las instalaciones del centro. 2. Desarrollar en los alumnos hábitos manuales (manejo de azadas, rastrillos, preparación de compost, aprendizaje de técnicas de riego, poda, etc). 3. Fomentar en los alumnos una actitud flexible y de cooperación en el trabajo en equipo, asumiendo responsabilidades en el desarrollo de las tareas. 4. Potenciar en los alumnos una valoración por un medio ambiente no alterado por el hombre. 5. Conseguir que los alumnos sean prudentes en la utilización de los recursos. 6. Desarrollar una actitud de respeto y cuidado por los vegetales. 7. Que los alumnos aprendan a reconocer y valorar la importancia del suelo, del agua, etc. 8. Que aprendan a valorar críticamente el efecto de los productos químicos. 8. Sensibilidad por el orden y limpieza del lugar de trabajo. 9. Sensibilización hacia el peligro de extinción que sufren muchas plantas. 10. Desarrollar hábitos de recuperación, reutilización y reciclaje de materiales desechables. Se elaboraron 5 unidades didácticas para el desarrollo del proyecto: 1. Estudio morfológico de los principales tipos de hojas. 2. Estudio morfológico de las flores. 3. Estudio e identificación de las principales especies arbustivas y arbóreas autóctonas en función de sus características foliares. 4. Estudio de los frutos. 5. Estudio de las plagas y de los principales trastornos fisiológicos de los especímenes del jardín. Los materiales utilizados han sido semillas, azadas, rastrillos, plantas, regaderas.

Estudio del manejo de residuos sólidos en el Relleno Sanitario Doña Juana con el fin de delinear un borrador de propuesta para el manejo integral de residuos sólidos en la ciudad de Bogotá D.C

Con el presente trabajo se busca realizar una propuesta de solución al sistema de manejo de los residuos sólidos urbanos en el relleno sanitario de Doña Juana en la ciudad de Bogotá, porque los desechos producidos por el consumo humano al no ser tratados de la forma correcta, afectan negativamente a la ciudad, rompen el cirulo vital del desarrollo y desequilibran el medio ambiente. Se realiza un diagnostico histórico al manejo de los residuos sólidos en la ciudad de Bogotá, para poder entender la forma en que el sistema funciona, teniendo en cuenta, sus errores y aciertos, posteriormente por medio Programa 21 de Naciones Unidas, se lleva a cabo el análisis de la información obtenida en el diagnóstico, para que de esta forma, se pueda realizar una propuesta a los problemas identificados en el relleno sanitario de Doña Juana, partiendo de los aspectos económicos, ambientales y sociales.

Guia de compostatge. 'Guía de compostaje'.

Esta guía quiere ser una ayuda teórica y práctica para iniciarse en el compostaje, importante aportación individual en la gestión de residuos. Muestra como hacer compost en la ciudad con el mínimo espacio y equipamiento.

Sueño un planeta verde y azul.

Se presenta el proyecto 'Sueño un planeta verde y azul' de los alumnos de Infantil de dos colegios de Cantabria. El objetivo es preservar y proteger el entorno natural próximo. Se recoge información proporcionada por los alumnos y sus familias mediante datos y materiales gráficos para el proyecto; se elabora un mural del planeta con todos los elementos contaminantes; se celebran asambleas en las que se leen artículos de periódico, revistas y cuentos; se analizan fotografías; y se presentan los contenidos teóricos. Además, se realizan actividades de aula, como producciones escritas, lógica matemática, visualización de vídeos o narración de cuentos; y visitas externas con las que se confecciona un libro viajero; se confeccionan listados de residuos que se vierten en contenedores de diferentes colores, de tipos de pilas, de tipos de ruidos o de animales en peligro de extinción; se diferencian los residuos biodegradables de los que no lo son con la elaboración de un compost; se analiza la comunicación acústica y lumínica; y se elabora un nuevo mural del planeta Tierra en el que se representa el desarrollo sostenible y el ideal que se persigue poniendo en práctica las actitudes, las habilidades y las conductas cívicas adquiridas. Las claves del proyecto son reducir, reutilizar y reciclar.

El huerto escolar y su aprovechamiento interdisciplinar en el aula.

Esta experiencia, dirigida, sobre todo, a alumnos de ESO que cursen la asignatura de Botánica aplicada, gira en torno a la creación de un huerto escolar. Se divide en tres bloques: los vegetales y el Medio Ambiente; la aplicaciones de las plantas en alimentación, medicina, cosmética, etc.; y la importancia de las plantas en la historia de la Humanidad. El objetivo es potenciar la motivación, manipulación y expresión del alumnado, así como su actitud crítica en temas como la alimentación o el respeto a la naturaleza. Entre las actividades destacan sesiones de reciclado, obtención de compost, estudio de la contaminación, análisis ambiental del entorno del Instituto, preparación del huerto, elaboración de un climograma, y estudio de diferentes aplicaciones de las plantas. La evaluación se basa en cuadernos de campo y de laboratorio y en la participación en trabajos y debates.

El jardín botánico del cole, recurso didáctico.

El proyecto consiste en el diseño, gestión y construcción del jardín botánico del colegio, con el fin de actuar positivamente sobre el entorno. Los objetivos son conocer la naturaleza y respetarla, trabajar en equipo, y utilizar con eficacia y seguridad útiles y herramientas. La metodología potencia el trabajo en equipo y la adquisición de conocimientos y experiencias a través de la práctica y la observación. Se recupera una zona del patio escolar, en la que se plantan árboles y hiertas aromáticas. Para ello, se reparten las plantas en zonas, de manera que cada nivel trabaja cuatro plantas y al finalizar la educación primaria conocen 25 especies. Las actividades respetan las épocas del año y son de varios tipos: físicas, con la manipulación de herramientas; intelectuales, mediante la información sobre procesos y la elaboración de fichas para identificar las partes de las plantas; y artísticas, a través de la reproducción de las plantas. A a lo largo de la experiencia se evalúa la elaboración de las fichas, los trabajos de investigación y las realizaciones plásticas. Se elaboran materiales, como semilleros y compost elaborado a partir de desechos del jardín y del comedor, para autoabastecer de abono al jardín. Se incluye una memoria fotográfica de las actividades realizadas en el jardín, y modelos de fichas de actividades.