Growth of barley (Hordeum vulgare L.) roots in biopores with differing carbon and nitrogen contents

Large sized, vertical biopores can provide preferential pathways for root growth, hence facilitating the exploration of great soil depths by crop roots. This is of particular importance for organic production systems, where crops are more dependent on nutrient acquisition from the solid soil phase than under conditions of mainstream agriculture. The relevance of biopores for nutrient acquisition from the subsoil can possibly depend on their individual properties. The aim of this study was to test how different chemical pore wall properties affect the growth of barley (Hordeum vulgare L.) roots in large sized biopores. Bulk soil, pore wall material and roots from individual biopores were collected from three depth layers in 45-75 cm soil depth. C and N contents in the pore walls were up to 3 times higher than in the bulk soil. A large variation of C and N contents between the walls of individual biopores indicated that the quality of the pore wall is a function of pore colonization by earthworms over time. N-rich pores hosted more roots than N-poor pores. It is concluded that elevated C and N concentrations in pore walls can facilitate the exploration of the subsoil by crop roots

Bioporen: Ihre Bedeutung für das Wachstum der landwirtschaftlichen Kulturpflanzen

The subsoil (i.e. the soil beneath the ploughed soil layer) provides a large potential reservoir of nutrients for crops but the conditions for nutrient acquisition are generally adverse due tolow organic matter contents, low nutrient concentration in the soil solution, low microbial activity and high bulk density. However, the structural heterogeneity of the subsoil including biopores created by roots and earthworms requires a more detailed view on nutrient acquisition processes. First results from the DFG research unit ‘Crop Sequence and the Nutrient Acquisition from the Subsoil’ have shown that cultivation of perennial fodder crops with taproot systems can result in enhanced biopore density in the subsoil and increased root-length density of subsequent crops. Observations with endoscopes revealed that 80-90 % of roots growing in biopores established contact with the pore wall thus potentially accessing the nutrients stored therein

Charakterisierung des Wurzelwachstums in Bioporen mit in situ Endoskopie

More information on root growth in biopores is needed for quantifying nutrient acquisition from the subsoil. The article presents an approach for using in situ endoscopy in biopores that allowed to quantify root-soil contact and detect differences in root morphology and orientation between mallow (Malva sylvestris L.) and spring wheat (Triticum aestivum L.). While 85 % of all wheat roots entered the biopores laterally from the bulk soil, mallow roots in biopores grew predominantly (69 %) with vertical orientation and established contact to the pore wall predominantly via lateral roots. The current status and future perspectives of the method are discussed

Einfluss von Einstrahlungsintensität, Stickstoffangebot, Düngungsverfahren und Hornkieselapplikation auf den Nitrat-, Ascorbinsäure- und Glucosinolatgehalt bei Salatrauke (Eruca sativa)

Effects of nitrogen supply (high / low), fertilizer type (biodynamic / organic / mineral) and application of the biodynamic horn silica preparation on nitrate, ascorbic acid and glucosinolate contents of rocket (Eruca sativa L.) were studied under conditions of full sunlight (100% photosynthetically active radiation PAR) and shading (55% PAR). Nitrate contents increased in response to shading and under conditions of full sunlight also in response to high nitrogen supply and mineral fertilization. Ascorbic acid contents were significantly higher with low nitrogen supply, biodynamic and organic fertilization, horn silica application and under conditions of low nitrogen supply with full sunlight. Glucosinolate contents were significantly increased by low nitrogen supply, full sunlight (in combination with biodynamic fertilization) as well as biodynamic and organic fertilization (under conditions of full sunlight)

Wurzelwachstum und Nodulation von Luzerne: Einfluss von Bioporendichte im Unterboden und Nährstoffgehalt im Oberboden

Das Ziel dieser Studie war, die Auswirkungen großlumiger Bioporen und Bodennährstoffgehalte auf Nodulation von Luzerne Wurzeln zu quantifizieren. In einem Feldversuch auf einem tiefgründigem Lössboden wurde Luzerne (Medicago sativa L.) angebaut (i) auf nativem, nährstoffreichem Boden oder in Parzellen, auf denen der native Boden entfernt und mit Boden aus ungedüngten Parzellen eines Dauerfeldversuchs ersetzt wurde sowie (ii) nach Anbau bioporen-generierenden Wegwarte (Cichorium intybus L.) mit Pfahlwurzelsystem oder nach Rohrschwingel (Festuca arundinacea Schreb.) ohne Pfahlwurzeln. Wurzellängen-Dichte und Nodulation wurden mit der Profil-Wand-Methode und an Monolith Proben quantifiziert. Spross-Wachstum und Nährstoff-Aufnahme von Luzerne wurde durch nährstoffarmen Boden reduziert aber blieb unbeeinflusst von den Vorfrüchten. Hohe Nährstoffgehalte im Oberboden und hohe Bioporen-Dichte im Unterboden hatten tendenziell fördernde Wirkungen auf die Anzahl der Knöllchen, aber die Unterschiede waren nicht signifikant. Der Anteil der Knöllchen in großlumigen Bioporen im Unterboden betrug in der Regel zwischen 20 und 40 %. Da das Volumen der solcher Bioporen nur etwa 2 % des gesamten Bodens ausmacht, lässt sich schlussfolgern, dass Bioporen bevorzugte Orte der Nodulation und möglicherweise der N2-Fixierung sind

Untersuchungen von Salatrauke (Eruca sativa) mit den drei Bildschaffenden Methoden Kupferchloridkristallisation, Steigbildmethode und Rundfilterchromatographie

Ten encoded rocket samples from 2009 were taken from a field trial on the comparison of nitrogen supply and different organic and conventional production systems at Hennef, Germany. The samples were examined with the image forming methods biocrystallization according to Pfeiffer, capillary dynamolysis according to Wala and circular chromatography according to Pfeiffer. The images of the encoded samples were a) characterised and b) assigned to experimental factors. The factors investigated were i) nitrogen supply, ii) fertilizer type, and iii) horn silica application. The ten samples were assigned 100% correctly to low and high N supply, to mineral fertilization and manure fertilization and to with or without horn silica application

Differenzierung und Identifizierung von Weizen aus ökologischen und konventionellen Anbausystemen durch die kombinierte Anwendung von drei Bildschaffenden Methoden

By combined application of the three picture forming methods biocrystallization ac-cording to Pfeiffer, capillary dynamolisis according to Wala and circular chromatogra-phy according to Pfeiffer encoded food samples from different production systems have been repeatedly differentiated and identified by Dr. Ursula Graf. In the present study we tested whether by using the combined three picture forming methods en-coded food samples from different production systems could also be differentiated and identified in a different laboratory by another trained person. Ten encoded wheat samples each from 2000 and 2005 harvests were taken from the long-term DOK- trial in Oberwil/Switzerland and examined with the pictomorphological methods. The wheat samples derived from the production systems ‘bio-dynamic’, ‘bio-organic’, ‘unfertil-ized’, ‘mineral fertilization’ and ‘conventional’ (mineral fertilization combined with ma-nure application) could be differentiated and identified, with partial differentiation and identification of the two production systems ‘bio-dynamic’ and ‘bio-organic’

Untersuchungen von Weizen (Triticum aestivum L.) mit den drei Bildschaffenden Methoden Kupferchloridkristallisation, Steigbildmethode und Rundfilterchromatographie

Ten encoded wheat samples from 2008 were taken from a field trial on the comparison of different organic and conventional production systems at Hennef, Germany. The samples were examined with the image forming methods biocrystallization, capillary dynamolysis and circular chromatography. The images of the encoded samples were a) characterised and b) assigned to experimental factors. The factors investigated were i) nitrogen supply, ii) fertilizer type, and iii) horn silica application. The ten samples were assigned 100% correctly to low and high N supply. Within the production methods, samples were assigned correctly to mineral fertilization and manure fertilization

Biopore characterization with in situ endoscopy: Influence of earthworms on carbon and nitrogen contents

Biopores have been shown to be enriched with plant available nutrients as compared to the surrounding bulk soil and therefore are considered hot spots for the nutrient acquisition especially in the otherwise nutrient-poor subsoil. However, depending on their individual biography, i.e. colonization by plant roots or earthworms, different nutrient status can be assumed. In this study, individual biopores were characterized with respect to signs of earthworm passage using in situ endoscopy, a non-destructive technique for display of pore wall characteristics. Subsequent sampling and analysis of biopore linings and blockages revealed that only biopores with visible earthworm coatings had significantly higher C and N contents as compared to the surrounding bulk soil. The results of this study highlight the special role of earthworms for enriching biopores with nutrients and underline the value of biopores for the nutrient acquisition from the subsoil

Untersuchungen von Traubensaft aus den Jahren 2007-2010 von unterschiedlichen Produktionssystemen mit drei Bildschaffenden Methoden

33 encoded grape samples from 2007-2010 were taken from a long-term field trial on the comparison of different organic and conventional production systems at Geisenheim, Germany. The samples were examined with the image forming methods biocrystallization, capillary dynamolysis and circular chromatography. The pictures of the encoded samples were i. differentiated and ii. characterised. The origin of 31 out of 33 encoded samples derived from ‘conventional’, ‘bio-organic’, ‘bio-dynamic‘ production was determined with highest accuracy