Wie wirken "effektive Mikroorganismen" auf EM-Bokashi in der Bananenproduktion (Musa ssp.)?

In Costa Rica, ‘effective microorganisms’ (EM) are used to produce organic fertiliser in the form of Bokashi. This study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production in comparison to different non-EM control variants (Bokashi produced with: W= water, M= molasses as an EM additive, EMst= sterilized EM). Furthermore, the effects of the above mentioned Bokashi variants on the growth of young banana plants and their effects on the secondary root growth of adult banana plants were evaluated. In comparison to non-EM controls, no increasing effects of EM on the N-mineralization of banana material were observed. All nutrient concentrations were similar for all treatments as well as the weight loss of approximately 77.9 %. The ergosterol concentration was significantly highest in EM Bokashi (77 µg g-1 dry soil), whereas it was lowest in EMst (29 µg g-1 dry soil). Application of all Bokashi variants significantly increased shoot growth of young banana plants under greenhouse conditions compared to a control grown in unamended soil. EM Bokashi and Bokashi produced with molasses significantly decreased the number of root nematodes under greenhouse conditions if compared to the control (nematodes per 100 g: C = 254; W = 143; EMst = 143; M = 67; EM = 38). Furthermore, EM Bokashi increased secondary root growth of adult banana plants in the field (186.7 g) compared to non-composted fresh banana leaves (134.6 g) and a control without mulch application (147 g)

Estimation of spatial variability in pearl millet growth with non-destructive methods

Growth variability in pearl millet (Pennisetum glaucum) over short distances is a severe constraint on the interpretation of agricultural experiments in the West African Sahel. The purpose of this study, therefore, was to compare different non-destructive methods to estimate, spatially, millet growth and final yields. Aerial photography, georeferenced radiometric measurements and a chlorophyll meter were tested during three rainy seasons (1996-98) in a nitrogen rate × density × genotype experiment in western Niger. For the radiometric measurements, normalized difference vegetation indices (NDVI) obtained and calibrated for individual millet hills spaced 1.5 m apart were aggregated for the entire experiment with 6000 samples per hectare. A simple calibration procedure was used to correct for variation in soil background reflectance and incident light. For NDVI measurements of individual planting hills, the correlation between plant total dry matter (TDM), leaf weight, leaf area and NDVI was high (r2=0.89-0.91) and regression parameters were genotype-specific. Aggregated georeferenced NDVI measurements at the plot level correlated with grain and TDM at harvest (r2=0.40-0.87). The analysis of true-colour and infrared aerial photographs permitted the monitoring of millet growth and the quantitative evaluation of treatment responses throughout the growing season. The infrared images were the most efficient in the detection of vegetation followed by the normalized green band of true-colour images. The red band was the least effective because of the influence of soil albedo and image vignetting. Although chlorophyll meter measurements reflected relative differences in plant nitrogen status between treatments, their interpretation required destructive sampling and proved unsuitable to predict millet yields. The results demonstrate the potential of georeferenced radiometric data and aerial photographs to improve soil sampling strategies, sequential plant growth monitoring and the statistical design and analysis of experiments. By providing intermediate data sets, the tested tools can also help in the upscaling of ground truth to satellite data in yield prediction studies

Aerial photography to determine fertiliser effects on pearl millet and Guiera senegalensis growth

Variability in plant growth is high on most sandy soils of the West African Sahel, often requiring extensive destructive sampling for the reliable estimation of treatment effects. A non-destructive method using aerial photographs and topographic measurements integrated in a Geographic Information System (GIS) was evaluated to determine the effects of organic and inorganic soil amendments on the growth of millet [Pennisetum glaucum (L.) R. Br.] and Guiera senegalensis J.F. Grmel. Based on aerial photographs, quantitative methods were developed to estimate the dry matter of millet plants and Guiera coppices present in the field each year prior to millet sowing. Integrating digital images of both plant species, measurements of the field's topography and a map of the experimental layout in a GIS allowed successful monitoring of the growth of both species as influenced by phosphorus application and the shrub-crop interaction. Regressions between the dry matter of Guiera coppices and the canopy area were good (r = 0.76 to 0.93) and permitted the calculation of the individual coppice dry matter for the entire field with fewer than 40 destructive measurements. The information on coppices' positions extracted from the aerial photographs and the topographic grid used as covariates explained a significant proportion of the millet growth variability. The use of these covariates also improved the precision of the analysis of variance of millet dry matter data by reducing the residual sum of squares by as much as 33% in the first experimental year. The study demonstrates the potential of non-destructive measurements integrated in a GIS to improve the collection and interpretation of data from field experiment

Changes in bulk and surface properties of two biochar types during 12 months of field ageing in two West-African soils

The study investigated the changes in properties of rice husk and corn cob biochars applied in urban agricultural field soils in Tamale (northern Ghana) and Ouagadougou (Burkina Faso), respectively. The biochars were both pyrolyzed at 500 °C with a batch reactor. Fine polyethylene mesh (litter bags) filled with 10 g of each type of biochar were buried at 20 cm depth in urban fields trials with a 3 x 2 factorial layout replicated 4 times. Factor 1 involved soil management practices at 3 levels: (1) farmers’ practice (FP), (2) 20 t biochar ha-1 and (3) control (no biochar). The second factor was time (duration) at two levels (6 and 12 months). Aged and fresh biochars were analyzed for volatile matter (VM), ash and fixed carbon (FC) contents, pH, effective cation exchange capacity (ECEC), and total surface acidity (Sa) and basicity (Sb). Dissolved organic carbon contents were determined sequentially by cold (cDOC) and hot water extractions (hDOC), respectively and aromaticities of cold water DOC (cSUVA) and hot water DOC (hSUVA) were determined. There was no significant interaction effect of soil management practices and time on measured ageing biochar properties. Time significantly affected most biochar ageing properties except Sa and Sb in rice husk biochar and ECEC in corn cob biochars at 6 months of exposure. In both biochars, Ash content, Fixed carbon (FC), cDOC, hDOC, cSUVA and hSUVA increased whilst pH and volatile matter contents decreased significantly. The hDOC was 2-3 times higher than cDOC contents for both biochars. Aromaticity of DOC contents of aged rice husk biochar exposed to soil management practices and time in the experimental site in Tamale showed persistence with time compared to corn cob biochar exposed in Ouagadougou experimental site. The results imply that rainfall, soil organic matter contents with interplay of soil minerals are key drivers to ageing and sequestration of these biochars and that these forces act at different scales but driven by time

Destructive and non-destructive measurements of residual crop residue and phosphorus effects on growth and composition of herbaceous fallow species in the Sahel

Little is known about the residual effects of crop residue (CR) and phosphorus (P) application on the fallow vegetation following repeated cultivation of pearl millet [Pennisetum glaucum (L.) R. Br.] in the Sahel. The objective of this study, therefore, was (i) to measure residual effects of CR, mulched at annual rates of 0, 500, 1000 and 2000 kg CR h

Agronomische Effekte von Biokohle in einem nährstoffarmen sandigen Boden nach Nutzung in der Bewässerungswasseraufbereitung

Urbane Landwirtschat in Entwicklungsländer leistet einen wesentlichen Beitrag zur Ernährungssicherheit und –diversität. Oftmals wird zur Bewässerung ungeklärtes Abwasser benutzt. Diese Praxis stellt eine Gesundheitsgefährdung von Bauern und Konsumenten dar. Kohlenstoffbasierte Materialen wie z.B. Aktivkohle werden oftmals zur Wasseraufbereitung genutzt. Biokohle, das feste Produkt der Pyrolyse von Biomasse, kann gesundheitsgefährdende Substanzen und Keime durch Filtration zurückgehalten und Untersuchungen zeigten eine Akkumulation von Nährstoffen in den Filterbetten. In dieser Studie wurde die Hypothese getestet, dass Nährstoffeigenschaften von Biokohle durch Einsatz in der Wasserfiltration verändert werden und dadurch veränderte Effekte auf das Pflanzenwachstum bei Bodeneinarbeitung zeigen. Dazu wurde ein Filter mit einem Biokohlefilterbett konstruiert und über drei Monate mit Abwasser beschickt. Nach der Filtration wurden Gesamtgehalte von Nährstoffen, Kohlenstoff, pH-Wert, elektrische Leitfähigkeit und Oberflächengröße der Filterkohle ermittelt und mit frischer Biokohle verglichen. In einem sechswöchigen Topfexperiment wurde die Biomasseproduktion von Sommerweizen in einem sandigen Boden aus Niger getestet. Außerdem wurde die Nährstoffaufnahme der Pflanzen, pflanzenverfügbares Phosphor (BrayI) und min. Stickstoff im Boden am Ende des Experiments bestimmt. Als Varianten wurden 20 t/ha Biokohle, Filterkohle und eine Kontrolle ohne Zusätze genutzt. Alle Varianten wurden mit und ohne Düngung in jeweils fünf Wiederholungen durchgeführt. Die Daten zeigen mit Ausnahme von Stickstoff eine Verringerung der Nährstoffgehalte der Biokohle nach der Filtration, besonders von P. Die Biomasseproduktion war am höchsten in der Variante mit Biokohle (+72%) im Vergleich zur Kontrolle. Die Filterkohle-Variante produzierte etwas weniger Biomasse, lag jedoch mit +37% über dem Niveau der Kontrolle. Die Pflanzenaufnahme von P wurde durch Einsatz der Biokohle erhöht, die Aufnahme von Stickstoff aber verringert. Die Böden mit Biokohle und Filterkohle zeigten eine wesentlich höheren Anteil an verfügbarem Phosphor (+106% und +52%) im Vergleich zur Kontrolle, jedoch eine Verringerung von mineralischem N am Ende des Experiments. Es ist anzunehmen, dass die erhöhte Biomasseproduktion durch Biokohle vor allem durch einen P Düngeeffekt bestimmt wird. Obwohl die Nährstoffgehalte der Filterkohle durch die Filtration herabgesetzt wurden, wirkt sie positiv auf das Pflanzenwachstum

UrbanFoodplus – African-German Partnership to enhance resource use efficiency in urban and peri-urban agriculture for improved food security in West African cities

Food security in West Africa not only depends on productivity increases in marginal rural areas, but also on enhanced use of intensively farmed agricultural “niche” lands such as the urban and peri-urban spaces. They are characterised by easy market access and input availability which allows self-reinforcing processes of agricultural intensification. However, too little is known about resource use efficiencies, matter flows and negative externalities in these systems. Starting from general assessments (status quo analyses), the African-German UrbanFoodPlus (UFP) network develops and tests site-specific, farmer-tailored innovations. These directly address the above mentioned knowledge gaps in the fourWest African cities of Ouagadougou (Burkina Faso), Tamale (Ghana), Bamako (Mali), and Bamenda (Cameroon). At all locations farmers attempt to cope with increasing land pressure by cultivating along electrical power lines, on public property, and on undeveloped private land

Localization and Functional Characterization of the Rat Oatp4c1 Transporter in an In Vitro Cell System and Rat Tissues

The organic anion transporting polypeptide 4c1 (Oatp4c1) was previously identified as a novel uptake transporter predominantly expressed at the basolateral membrane in the rat kidney proximal tubules. Its functional role was suggested to be a vectorial transport partner of an apically-expressed efflux transporter for the efficient translocation of physiological substrates into urine, some of which were suggested to be uremic toxins. However, our in vitro studies with MDCKII cells showed that upon transfection rat Oatp4c1 polarizes to the apical membrane. In this report, we validated the trafficking and function of Oatp4c1 in polarized cell systems as well as its subcellular localization in rat kidney. Using several complementary biochemical, molecular and proteomic methods as well as antibodies amenable to immunohistochemistry, immunofluorescence, and immunobloting we investigated the expression pattern of Oatp4c1 in polarized cell systems and in the rat kidney. Collectively, these data demonstrate that rat Oatp4c1 traffics to the apical cell surface of polarized epithelium and localizes primarily in the proximal straight tubules, the S3 fraction of the nephron. Drug uptake studies in Oatp4c1-overexpressing cells demonstrated that Oatp4c1-mediated estrone-3-sulfate (E3S) uptake was pH-dependent and ATP-independent. These data definitively demonstrate the subcellular localization and histological location of Oatp4c1 and provide additional functional evidence that reconciles expression-function reports found in the literature

Yield of Photoperiod-sensitive Sorghum Hybrids Based on Guinea-race Germplasm under Farmers’ Field Conditions in Mali

The first sorghum [Sorghum bicolor (L.) Moench] hybrids based on West African Guinea-race-derived parents were created to enhance farmer’s food security and income through increased yields. To assess their performance, eight hybrids, six experimental pure-line cultivars, one pure-line check (Lata), and a highly adapted landrace cultivar (Tieble) were evaluated in 27 farmer-managed and two on-station yield trials in Mali, West Africa, from 2009 to 2011. The hybrids were confirmed to have photoperiod sensitivity similar to the well-adapted Guinea landrace check cultivar. Genotypic differences for on-farm grain yield were highly significant and genotype × environment crossover interactions were limited. The yield superiorities of individual hybrids, relative to the landrace check, ranged from 17 to 37% over the 27 on-farm trials. The three top yielding hybrids showed 30% yield advantages across productivity levels, with absolute yield advantages averaging 380 kg ha−1 under lower (1.0–1.5 t ha−1) and 660 kg ha−1 under higher (2.0–3.5 t ha−1) productivity conditions. A mean male-parent (better parent) heterosis of 26% was observed for the four hybrids having Lata as a male parent. As the hybrids studied here were obtained with a low intensity of selection using a limited number of parents, even greater yield superiorities may be attained with development of distinct parental pools and scaled-up hybrid breeding