@masterthesis{Richter, type = {Bachelor Thesis}, author = {Richter, Sebastiaan}, title = {The influence of lime, iron sulphate-lime mixtures, and iron compounds on bioavailable phosphorous}, school = {Hochschule Rhein-Waal}, abstract = {Available nutrients for higher plants in the soil are crucial in agriculture and can be repressed by farming practices. The objective of this thesis was to determine if the application of a lime-FeSO4 mixture reduces the available phosphorus for higher plants further than conventional liming. For this, soils from the Lower Rhine region in Germany with different soil properties were collected, treated with different applications, and incubated over a predefined time. Aerobic and anaerobic conditions were created by raising the soils' water content to 50\% and 100\% of their maximum water holding capacity. Bioavailable phosphorus was extracted from the incubated samples with the Calcium-acetate-lactate (CAL) method, and analysed in the Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Statistical analysis was conducted with the open-source program "R for statistical computing". Results showed that not the treatment but rather the type of soil had a significant effect on the phosphorus availability. At some extent the WHC significantly influenced the phosphorus availability. In general, lime-FeSO4 mixtures showed a tendency to have higher phosphorus availability than conventional liming. Effects of long-term field application cannot be determined because the experiment was conducted under laboratory conditions for a limited time. For farming, further field experiments and monitoring of fields where the lime-FeSO4 mixtures are regularly applied can exclude negative long-term effects and determine sufficient the effect of lime-FeSO4 mixtures on bioavailable phosphorus.}, language = {en} } @masterthesis{Hoeft, type = {Bachelor Thesis}, author = {H{\"o}ft, Mattis}, title = {Influence of humic acids on nutrient use efficiency of three phosphorus sources in a sandy soil}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:1383-opus4-2978}, school = {Hochschule Rhein-Waal}, pages = {74}, abstract = {A pot trial was conducted under greenhouse conditions to assess the effect of humic acid (HA) application in combination with rock phosphate (RP) on the plant phosphorus (P) nutrient use efficiency (NUE), in comparison to the performance of struvite (ST) and triple superphosphate (TSP) amended plants. A sandy soil, exhibiting a low P content, was used in combination with a lignite derived, liquid humic acid product, with a HA content of 4.8 \%. Nine groups of perennial ryegrass (Lolium perenne L.) were set up as experimental plants, in replications of six, each containing 4.5 kg air dry soil with a P supply of 27 mg P kg-1 soil, causing P deficiency during the experiment. HA was applied at rates of 1, 30 and 100 mg kg-1 soil, directly to the soil as coated RP or as foliar application. Aboveground biomass was harvested biweekly, five times in total. Amendment performance was evaluated by analysing plant biomass, soil pH, plant phosphorus-, carbon-, nitrogen-, iron-, zinc-, manganese- and boron contents. The label doses of 1 mg kg-1 soil as well as 100-fold increases in HA concentration didn't result in a significant difference in plant shoot or root growth and P NUE compared to untreated plants. Positive trends were displayed at higher foliar application rates. Plant tissue micronutrient concentrations of HA treated samples were generally lower and partly significantly lower than the control. The detected effects were accredited to the hormone-like influence of HA on plants' metabolism and the ability to alter soil conditions. The lack of calcium in ST amended samples resulted in better plant P availability, significantly higher P uptake and better shoot biomass development. Trends show that ST could be applied in combination with HA to further increase plants P NUE in the future.}, language = {en} } @masterthesis{Nidola, type = {Bachelor Thesis}, author = {Nidola, Marta}, title = {Frass upcycling: study on the properties of frass and its use as fertilizer and soil amendment in agriculture}, school = {Hochschule Rhein-Waal}, abstract = {Frass, as by-product of the emerging insect market, has been used as fertiliser worldwide. However, the impacts on soil microbial community structure and activity have been not yet well characterized. The aim of this study was to assess the effects that frass from black soldier fly reared on 3 different diets may cause when applied fresh and dried (70°C) on a sandy loam soil, in 2 application rates (0.2 and 2\% w/w). For that, frass was chemically characterized before a 28-days incubation, at the end of which samples were analysed from the chemical and biological point of view. It was found that thermal treatments and diets didn't vary significantly in microbiota stimulation, even though a chemical analysis would suggest the potential for enriched-frass from pig effluent and wheat bran to encourage microorganisms differently from beer \& coffee diet. Furthermore, fresh frass contrarily to what expected didn't contribute with living microorganisms to enhance microbial activity and growth. However, a difference was reported for the application rates, with the 2\% leading to more mineralisation than control. A trend for 2\% dried frass from B\&C was found, indicating the establishment of an efficient community of fungi slowly mineralizing recalcitrant and exhausted frass. Results indicate that more studies testing application rates ranging between 2 and 2.5\% have to be conducted. In fact, there is evidence that BSFF between the mentioned application rates could enhance a fast microbial growth leading to a substantial mineralisation of frass, thus availability of nutrients in the short and long term.}, language = {en} } @misc{EzeobiChris, type = {Master Thesis}, author = {Ezeobi-Chris, Chimaobi}, title = {Quantification of carbon rhizodeposition of different biomes and arable crops from above- and below-ground biomass}, school = {Hochschule Rhein-Waal}, abstract = {As more global warming data become increasingly available, climate change has become one of today's greatest environmental threats. Terrestrial ecosystem plays an essential part in the uptake of "greenhouse gases (GHGs) such as Nitrous oxide (N2O), Methane (CH4) and Carbon dioxide (CO2)" through photosynthetic sequestration of atmospheric CO2 released from fossil fuel emission, cement manufacturing and deforestation. Rhizodeposits is the released carbon from the root rhizosphere containing a large amount of carbon, essential nutrients and organic compounds. This process is known as rhizodeposition and is often quantified as carbon derived from rhizodeposition (CdfR). This thesis aims to review selected existing literature on above and below-ground biomass carbon (AGB-C and BGB-C) inputs which were used to quantify the carbon sequestration of rhizodeposits in the below-ground biomass (BGB) of different terrestrial ecosystem biomes in the world and to know where the carbon sequestration is lacking the most. Measurement of rhizodeposition in the soil is mostly carried out in the laboratory involving the use of tracing root-derived C by isotopic and non-isotopic techniques, but in this thesis, about 60 papers from different sources were reviewed, and data on above- and below-ground biomass carbon were collected to quantify the C rhizodeposition in the terrestrial ecosystem biomes. The carbon content of the dry weight biomass was estimated by multiplying the above-ground biomass (AGB) and below-ground biomass (BGB) by 0.45. The C-rhizodeposition from the BGB-C was calculated by multiplying the BGB-C by 0.5. Quantification of global C stored in the biomes, including arable crops, was quantified by multiplying the world land area of different biomes with average AGB-C and BGB-C. The estimated values of the mean, median and range of AGB-C, BGB-C and C-rhizodeposition of different biomes (tropical forest, boreal forest, temperate forest, temperate grassland, tropical grassland) and arable crops were reported in this paper. The global C-storage of above- and below-ground of different biomes and arable crops were also quantified. The values were 210, 116, 93, 7.4, 47.2 in Gt C for the tropical forest, boreal forest, temperate forest, temperate grassland, tropical grassland, and 2.4 Gt C for below-ground arable crops only. Even though the comparison between these ecosystems might be an issue because different methods were used in evaluating the above- and below-ground vegetations plant, which in turn can influence the final quantity of C allocated in above- and below-ground biomass, the findings from this thesis for the biomes show that tropical forest has the highest C stored below ground while arable crops have the least.}, language = {en} } @masterthesis{Voegerl, type = {Bachelor Thesis}, author = {V{\"o}gerl, Jakob}, title = {Assessing the effect of N-fertilisation on biomass development and plant interactions in the ancient Milpa compared to pure stands and its potential to reduce fertiliser inputs in traditional small-scale farming}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:1383-opus4-6214}, school = {Hochschule Rhein-Waal}, pages = {55}, abstract = {Over the past years, nitrogen (N) fertilisation has been identified as an issue that has a major negative impact on the environment. Therefore, sustainable agricultural practices aim to reduce external fertiliser inputs and focus more on naturally available resources and sustainable cropping practices. One example of that is the ancient milpa polyculture which is practised by traditional small-scale farmers in Central America. It consists of climbing bean (Phaseolus vulgaris var. vulgaris), maize (Zea mays), and squash (Cucurbita moschata) that are said to represent a holistic symbiosis in which beans assume the task to accumulate additional nitrogen via N2-fixation and subsequently transfer it to its companions. The potential of intercropping, and thus nitrogen transfer to level out and reduce nitrogen fertiliser inputs compared to monocultures has not been assessed yet and little is known about the resulting practical implementation for small-scale farmers. Therefore, a pot trial with monoculture treatments (100 kg N/ha) of each crop and milpa treatments with varying levels of nitrogen fertilisation (0, 25, 50, 75, and 100 kg N/ha) was established. The intercropped beans were labelled with the 15N isotope using the cotton wick method to track nitrogen transfer in the system. Further, the Land Equivalent Ratio (LER) was used to determine the productivity of the system. Results showed that all polyculture treatments performed similarly or significantly better than the pure stands in terms of total dry matter content per pot. Milpas provided with 100 and 25\% of the recommended nitrogen rate were most productive and achieved a total LER of 1.25 and 1.30, respectively. Also, the non-fertilised milpa was still as productive as the respective plants grown in a monoculture. Due to external reasons, the importance of nitrogen transfer and the related microorganisms could not be evaluated. However, growing a milpa instead of monocultures enables farmers to greatly reduce N fertiliser inputs and provides higher yields in the growing season, while other intercropping benefits are also present. It further has the potential to maintain yields and enhance natural nutrient cycling even if no fertiliser is applied.}, language = {en} } @masterthesis{Stublla, type = {Bachelor Thesis}, author = {Stublla, Arlind}, title = {Nitrogen fixation of Lathyrus odoratus (sweet pea), Vicia sativa (common vetch) and Phaseolus vulgaris (common beans)}, school = {Hochschule Rhein-Waal}, pages = {45}, abstract = {Current agricultural practices depend heavily on inorganic and organic fertilizer use. These fertilizers not only can cost a lot of money, but also impose major environmental and health risks for the farmers that apply it. A solution to this problem, is the use of legume`s BNF (biological nitrogen fixation) to ecologically and inexpensively increase the amount of nitrogen (N) in the soil and the crops grown by the farmers. The aim of this study is to investigate this ability in three plants: Lathyrus odoratus (sweet peas), Vicia sativa (common vetch) and Phaseolus vulgaris (common beans) with a greater focus on Lathyrus ssp. The plants were grown in the Rhine-Waal University`s greenhouse, where two treatments were applied: one treatment with no additional N added to the soil and the other treatment with 20 kg/ha N. The soil was a mixture of agricultural soil and quartz sand. To detect the BNF (\%NDFA and mg NDFA), the 15N isotope dilution method was used. This method requires the application of 15N enriched fertilizer on both nitrogen fixer crop and a control crop (Secale cereale). As such for each plant species five pots with 4 plants (later thinned out to 3) and one pot for the control crop per treatment were planted. The plants were supported with sticks and ropes to properly allow them to grow. Phaseolus vulgaris was harvested with flowers and beans present, while Lathyrus odoratus and Vicia sativa showed no signs of flowers buds. All plant species had a good amount of \%NDFA (nitrogen derived from atmosphere) with Phaseolus vulgaris achieving the highest amount of 71.31\% for the 0N treatment and Lathyrus odoratus, 35.01\% for the 20N treatment. The most amount of mg N derived from atmosphere (mg NDFA) was collected from Phaseolus vulgaris (33.464 and 27.858 mg NDFA for 0N and 20N treatment respectively). When investigated for correlation between several factors affecting BNF, length and nodule size had a positive significant relationship with BNF with a Spearman`s rho value of 0.69 and 0.39 respectively for the 0N treatment. Although Lathyrus odoratus had the lowest performance from all plant species, it has been suggested that this may be due the plant being in the initial stages of growth. Lathyrus odoratus will require field experiments to properly quantify the amount of BNF (kg/ha) and to assess the adaptability of the crop in field environments}, language = {en} }