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The continuous release of persistent iron-cyanide (Fe-CN) complexes from various industrial sources poses a high hazard to the environment and indicates the necessity to analyze a considerable amount of samples. Conventional flow injection analysis (FIA) is a time and cost consuming method for cyanide (CN) determination. Thus, a rapid and economic alternative needs to be developed to quantify the Fe-CN complexes. 52 soil samples were collected at a former Manufactured Gas Plant (MGP) site in order to determine the feasibility of diffuse reflectance infrared Fourier spectroscopy (DRIFTS). Soil analysis revealed CN concentrations in a range from 8 to 14.809 mg kg⁻¹, where 97% was in the solid form (Fe₄[Fe(CN)₆]₃), which is characterized by a single symmetrical CN band in the range 2092-2084 cm-1. The partial least squares (PLS) calibration-validation model revealed IR response to CNtot which exceeds 2306 mg kg⁻¹(limit of detection, LOD). Leave-one-out cross-validation (LOO-CV) was performed on soil samples, which contained low CNtot (<900 mg kg⁻¹). This improved the sensitivity of the model by reducing the LOD to 154 mg kg⁻¹. Finally, the LOO-CV conducted on the samples with CNtot > 900 mg kg⁻¹ resulted in LOD equal to 3751 mg kg⁻¹. It was found that FTIR spectroscopy provides the information concerning different CN species in the soil samples. Additionally, it is suitable for quantifying Fe-CN species in matrixes with CNtot > 154 mg kg⁻¹. Thus, FTIR spectroscopy, in combination with the statistical approach applied here seems to be a feasible and quick method for screening of contaminated sites.
Beginning in 2020 the research of the MultiFruit cluster seeks to optimize food production and the provision of ecosystem services in multifunctional landscapes. Joining agricultural production with the provision of ecosystem services and the preservation of biological diversity, the outcomes of this project aim to provide comprehensive findings to farmers, and the agricultural community as a whole, that are also applicable in the face of climate change. Active apple orchards located in greater Brandenburg, Germany of both organic and conventional management practices have been selected as the sites of research. The present state of organic apple orchards in Germany can best be described as organic “conventionalization”; high yielding orchards with little to no plant diversity, with the major differences being the substitution of synthetic fertilizers, pesticides, herbicides, and fungicides with organic alternatives certified by the Federal Office of Consumer Protection and Food Safety (Bundesamt für Verbraucherschutz und Lebensmittelsicherheit). The project implements an interdisciplinary approach, with researchers of ecology, economics, soil and microbial sciences. The ecological subproject is investigating how local management measures and the surrounding landscapes affect natural pest control by beneficial insects. The soil group are investigating the toxicological and soil health impacts of conventional and organic practices through analysis of both plant and soil material collected from the orchards. Microbial studies seek to provide information on the microorganisms that promote the growth, health, and performance of fruit trees. The economic studies aim to assess the costs and benefits of management measures and resulting pest control services for fruit growers and society as a whole. The overall expected outcome of this cluster is to maximize ecosystem services provided by the orchards while optimizing yield and maintaining soil and orchard health. Here we show the preliminary results of the 2021 field campaign related to the soil group. The processed plant and soil material was analyzed at our laboratory and total elemental concentration of all constituents was determined using Microwave assisted MP-AES for select metals and cations (Zn, Cu, Fe, Al, Mg, Ca, K). These results, in conjunction with measured soil properties (pH, EC, Scheibler carbonate measurement, Total N, Total C) aid in the effort to determine the effects of the various management practices on the soil health and the mobility and translocation of metals and cations within the plant tissues.
Agriculture is a massive production with intensive practices, like large variety of agro-chemicals, heavy machinery etc., that support food security. However, recently more and more attention is given to food safety in relation to human, environment and soil health. An alternative strategy is organic agriculture that avoids the use of synthetic chemicals and maintain the sustainable food production. But organic farming cannot completely support the worlds foods demand, so adaptation is needed to reach a sustainable productivity while protecting the environment.
Soil nitrogen (N) pool consists of inorganic and organic fractions. Inorganic and a part of labile organic N is a primary nutrient source for plants and microbes. Different nitrogen fractions play various roles in soil ecosystems and can be strongly influenced by the site management. Soil nitrogen transformations are directly relatable to plant health, thus strongly influence healthy functioning of soil ecosystem. Knowledge about the soil nitrogen pools is necessary to assess the proper and sustainable fertilization approaches under various management practices. To evaluate various N fractions, fresh soil samples were sampled (20 cm depth, row and near tree) at 8 conventional and 8 organic apple farms (Germany: states of Brandenburg, Saxsony and Saxony-Anhalt), with various age, locations and management practices. Soil samples were analyzed using CNS, Kjeldhal digestion, spectrophotometer and chloroform fumigation. The aim of this study is to compare the total and labile (particulate organic, microbial biomass and water extractable organic) N fractions in soil samples considering various site management approaches, topography and climate.
Contaminated sites create a significant risk to human health, by poisoning drinking water, soil, air and as a consequence
food. Continuous release of persistent iron-cyanide (Fe-CN) complexes from various industrial sources poses a high hazard to the environment and indicates the necessity to analyze considerable amount of samples. At the present time quantitative determination of Fe-CN concentration in soil usually requires a time consuming two step process: digestion of the sample (e.g., micro distillation system) and its analytical detection performed, e.g., by automated spectrophotometrical flow injection analysis (FIA). In order to determine the feasibility of diffuse reflectance
infrared Fourier spectroscopy (DRIFTS) to quantify the Fe-CN complexes in soil matrix, 42 soil samples were collected (8 to 12.520 mg kg-1CN) indicating single symmetrical CN band in the range 2092 - 2084 cm-1. Partial least squares (PLS) calibration-validation model revealed IR response to CNtot exceeding 1268 mg kg-1 (limit of detection, LOD). Subsequently, leave-one-out cross-validation (LOO-CV) was performed on soil samples containing low CNtot (<900 mg kg-1), which improved the sensitivity of the model by reducing the LOD to 154 mg kg-1. Finally, the LOO-CV conducted on the samples with CNtot >900 mg kg-1 resulted in LOD equal to 3494 mg kg-1. Our results indicate that spectroscopic data in combination with PLS statistics can efficiently be used to predict Fe-CN concentrations in soil. We conclude that the protocol applied in this study can strongly reduce the time and costs essential for the spatial and vertical screening of the site affected by complexed Fe-CN.
Vital, fertile soil is a limited resource and must be considered equal to air and water in its status as a protected good. In Europe, there are around 2.5 million potentially contaminated due to natural and anthropogenic activities. One third of these areas have been identified and 15% of them have already been remediated. An efficient approach for remediation is phytoremediation, a cost-effective and ecosystem-friendly method compared to conventional methods.
We showed that hyperaccumulator plants, which have a high tolerance to the accumulation of potentially toxic elements (PTE), are suitable for phytoremediation methods. Imaging spectroscopy allowed us to monitor and optimize the process of accumulation. Our study was conducted in two steps: First we analysed the potential of multivariate procedures using Partial Least Squares Regression (PLSR) and Random Forest Regression (RFR) to predict highly contaminated areas with an inhomogeneous distribution of PTE concentrations from image data. Therefore, we used contaminated soil samples analysed for heavy metal contents as training data. The fully-trained models assisted to monitor PTE contaminated areas during phytoremediation. In a second step, we investigated hyperaccumulator plants and their spectral fingerprints during PTE uptake to detect the highest possible amount of PTE the plant can tolerate.
Soil samples were measured after different preparation steps (“oven-dried”, “sieved”, “ground”, “Loss on Ignition (LOI)”) with a HySpex VNIR-1600 and HySpex SWIR 320m-e hyperspectral sensor under laboratory conditions. The spectral range of both sensors covers 450 nm to 2500 nm with a spectral sampling interval of 3.7 nm for the VNIR sensor and 6.25 nm for the SWIR sensor.
The resulting spectral library was used for the PLSR and RFR analysis. Considering the optimal coefficient of determination (R2), PLSR showed an improving performance and accuracy with increasing preparation steps: R2_Cr: 0.52–0.78; R2_Cu: 0.36–0.73; R2_Ni: 0.19–0.42 and R2_Zn: 0.41–0.74. In comparison, RFR showed a weaker estimation performance, even when using higher sample preparation levels (R2_Cr:0.36–0.62; R2_Cu: 0.17–0.72; R2_Ni: 0.20–0.35 and R2_Zn: 0.26–0.67). The results indicate that PLSR provides a more robust estimation than the user-friendly RFR method. Additionally, the PTE estimation performance in strong heterogeneous soil samples can be improved by pre-treatment of soil samples in the laboratory.
Second, we cultivated Brassica juncea in a greenhouse and applied the plants with different controlled zinc, nickel and copper concentration levels (low, medium, high). Measurements with a HySpex VNIR-SWIR hyperspectral sensor (408-2500 nm) and a point spectrometer PSR+ from Spectral Evolution (350-2500 nm) were conducted in-situ and in the laboratory. A principal component analysis (PCA) was performed on reflectance spectra to identify and visualize spectral changes with increasing PTE uptake. In addition, different indices were calculated, such as Leaf Area Index (LAI) and Red-Edge Inflection Point (REIP). First results revealed changes at the chlorophyll feature between 500-600 nm and at the REIP position with increasing PTE concentration. Further spectral features and indices will be investigated to check hyperspectral responses of PTE concentration. With reflectance imaging we are already able to detect differences of the PTE accumulation within the hyperaccumulator plants.
Progressing degradation of agricultural soil demands a change to more sustainable cropping systems accounting for crops that can sustain the soil health. Hemp is known for the improvement of soil physical, chemical and biological properties. The objective of the research is to analyze the hemp plant capability to grow under nutrient poor soil conditions and dense canopy and to assess hemp’s ability to uptake plant nutrients applied with/by soil amendments produced from biowaste. Additionally, the research aims to analyze how the hemp nutrition affects its morphogenesis, thus the fiber content.
In the greenhouse set up, Cannabis Sativa L. was grown in sandy substrate, with limited water supply that corresponded to the common drought periods in Brandenburg (Germany) and with addition of soil amendments in form of pellets from organic waste (OW) digestives. The treatments included: 5 control pots, 10 pots with pellets (19 kg soil / 230 g pellets according to the allowed application of 13 t/ha) and 10 pots with 19 kg soil / 3 kg pellets. When needed, a universal liquid fertilizer was applied which contained water soluble minerals like N, P2O5 and K2O. After 92 days, the plants were harvested, dried and weighted. The root structure was examined visually. The stems were decorticated using BMS-FLAKSY® (Rossmanith GmbH) to analyze the fiber content. The Elementar vario MAX cube analyzer device was used to analyse C and N contents.
The results showed that hemp could still flourish in water and nutrient limited environment. A deeper and denser rooting was observed in the treatments with pellets. It was observed that fine roots were encircled and attached to the pellets to access the nutrients stored there. The highest C:N ratio in soil and in leaves was found in treatments that contained the most pellets. The option to apply pellets produced from OW in larger quantities instead of a fertilizer application had a striking effect on hemp growth and biomass accumulation hence, increased dry matter amount and fiber yield.
Extended dry periods and increasing soil degradation compel the conventional agriculture to shift towards the sustainable practices. Hemp (Cannabis Sativa L.) accounts for crops that require low agricultural inputs and has a high potential to improve soil health hence fertility. The rapid hemp growth, high biomass production and remarkably expanded rooting zone have the vast potential in carbon (C) sequestration and nitrogen (N) fixation. Hemp fibers in the European Union (EU) are commonly used for pulp and paper industry and isolation materials. The study aims to (i) analyze hemp feasibility to grow and contribute to C sequestration under the water scarce conditions in initially nutrient-poor arable sandy soil with high and low canopy densities, and (ii) assess the use of hemp residues like shives and leaves as soil amendments for oat and corn crops in order to increase soil water holding capacity and serve as a long-term nutrient supply. Hemp, oat and corn crops were grown in a greenhouse experiment under LED illumination and wind ventilation for 17 h per day until the harvest. Hemp fibers were obtained through decortication. The biomass of all crops, hemp roots separated into fine and main, soil prior and after the experiment, and soil amendments were investigated for the total C and N content with an ELEMENTAR Vario Max Cube. Also, the elemental analysis for Ca, Mg, K, Zn, Cu, Fe, Al, Na was performed using HNO3 and MP-AES analyses. Total dry root mass for oat and corn crops was measured. Additionally, the soil pH and electrical conductivity (EC) were determined. The results showed that water scarcity had hindered hemp height and biomass production. While under the water limited conditions, the low hemp canopy density had showed slightly advanced growth in comparison to the high canopy density. Furthermore, the results of oat and corn experiment indicated difference between the treatments, where the soil amendment from hemp leaves compared to hemp shives showed enhanced growth in both plant and root biomass