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Archive for the 'Plant nutrition' Category

Incubation experiment, nutrient use efficiency and total N recovery in ryegrass and white clover systems

Nutrient fluxes in soil plant systems, by BrynerS, HattF, WeberV Introduction Nitrogen is often the most limiting nutrient in organic cropping systems where no synthetic mineral N fertilizers are applied and where total N inputs are usually lower than in conventional systems (Oberson et al. 2007). There are several possibilities to improve N supply in [...]

June 30th, 2008
Topic: Crop Science, Plant nutrition Tags: None

Benefits of Azolla in lowland rice (Oryza sativa) cropping systems concerning N losses and fertilization

F. Hatt, V. Weber (2008) Azolla, a free-floating aquatic fern having symbiotic association with the N2 fixing cyanobacterial symbiont Anabaena Azollae can fix 30-60 kg N/ha in 30 days. It is either incorporated as green manure at the beginning of the cropping season or grown as a dual crop along with rice, in the standing [...]

June 14th, 2008
Topic: Crop Science, Plant nutrition, Sustainable production under environmental stresses Tags: None

“The availability of calcium dihydrogen phosphate fertilization for lolium, soybean and lupine.”

Written report for the course “Radio-isotopes in plant nutrition” in 2007/08 by DürrN and WeberV 1    Abstract Plants fertilized with different P-sources can have different ability to grow. It depends on the availiability of P from the fertilizer. In a pot experiment we compared the growth of ray grass, soybean and white lupine fertilized with [...]

February 3rd, 2008
Topic: Crop Science, Plant nutrition Tags: None

Arbuscular mycorrhiza fungi

Lab Report, Rhizosphere Ecology (weberv) Background Arbuscular mycorrhiza (AM) fungi are obligate symbionts that colonize the roots of over 80% of plants in all terrestrial environments. AM use C from plants and improve their growth through: Improve of nutrients supply such as P. Increase of the resistance to disease by physical protection and reduce of [...]

December 24th, 2007
Topic: Crop Science, Plant nutrition Tags: None

Direct and indirect bacterial number assessment in the soil

Lap report, Rhizosphere Ecology, WeberV, 24.12.2007 1 Practical Session No 2 1.1 Bacterial number assessment through cultivation To the soil NaCl solution was added. Then different dilutions from 10-1 to 10-10 of soil suspension were prepared. 200 µl of each suspension was spread on an agar plate. 1.2 DNA extraction from soil DNA extraction was followed after the [...]

December 24th, 2007
Topic: Crop Science, Plant nutrition Tags: None

Root architecture and organic acids

Lap report, Rhizosphere Ecology, WeberV, 24.12.2007 1 Practical Session No 1 1.1 Root architecture The roots of maize, flax and lupin were cut from the shoot and spread on a scanning plate. The roots were separated to achieve minimum root crossing points. Then water with 40°C was added to ensure that no water bobbles develop. Then the [...]

December 24th, 2007
Topic: Crop Science, Plant nutrition Tags: None

Gas chromatography of fatty acids extracted from soil

The gas chromatographie of lipids was practiced in “rhizosphere ecology”. The results were presented by WeberV and BrynerS. Membranes of organisms are composed of lipids. These lipids are only produced in a living organismis, so the lipid concentration is a index for the activity of organisms. Different organisms have a www.coinstar-money.com different lipid composition. Lipid [...]

November 10th, 2007
Topic: Crop Science, Plant nutrition Tags: None

K-Fraktionen im Boden

Kategorie: Düngemittel und Nährsstoffdynamik, von WeberV (2006) Vorkommen Die Kalium-Gehalte im Boden betragen meist 0,2-3,3%. Umgerechnet befinden sich somit 150.000 bis 300.000 kg K2O je Hektar und einen Meter Tiefe. Die K+-Konzentration in der Bodenlösung liegt im Bereich von 2-20mg/l. Kalium liegt im Boden als K+ und KSO-4 vor. Nichtaustauschbares  K+ liegt in Mineralkalium vor. Z. [...]

May 28th, 2006
Topic: Crop Science, Plant nutrition Tags: None

Möglichkeiten zur Reduktion der Nitratauswaschung durch Fruchtfolgegestaltung und Zwischenfruchtbau

Kategorie „Ackerbausysteme“ WeberV (2005) Warum wird Stickstoff gedüngt Stickstoff (N) ist ein Pflanzennährstoff, der in Form von Nitrat von den Pflanzen aufgenommen wird. N ist wesentlicher Bestandteil von Proteinen, Enzymen und anderen Pflanzeninhaltsstoffen. Aufgrunddessen fördert eine N-Düngung das vegetative Wachstum und damit den Ertrag. Ungefähr 16-20 kg N je kg Korn werden von der Pflanze gespeichert [...]

November 20th, 2005
Topic: Crop Science, Plant nutrition Tags: None