Soil quality management (Phase III)

Sub-project: Gaseous and leachate losses of C and N from fertilized and irrigated soils of a subtropical coastal oasis. >>> GRAKO1397
DFG-Graduiertenkolleg
2013-2015, Gunadish Khanal.

Regulation of soil organic matter and nutrient turnover in organic agriculture (Phase II).

Gaseous and leachate losses of C and N from fertilized and irrigated soils of a subtropical coastal oasis
Deutsche Forschungsgemeinschaft (DFG) -  Research Training Group 1397
2009-2012

Sub-project F1: Melanie Willich

Sub-project F2: Mariko Ingold

Regulation of soil organic matter and nutrient turnover in organic agriculture (Phase I)

Sub-project F1:  Gaseous and leaching nutrient losses in irrigation farming of fertilised sandy soils in Oman - Effects of manure quality and cropping system
Deutsche Forschungsgemeinschaft (DFG) - Research Training Group 1397
"Regulation of soil organic matter and nutrient turnover in organic agriculture"
2007-2010, Konrad Siegfried

Organic and conventional irrigation farming on the eastern coast of the arid Arabian Peninsula leads to high gaseous and leaching losses of nutrients and carbon from cultivated soils. In order to analyze such losses, the emissions _NH3, _N2O,_CO2 and CH4_were measured on an experimental field near to the town of Sohar in the Sultanate of Oman. This was done using an INNOVA photo-acoustic infrared multi-gas monitor (INNOVA 1312-5, LumaSense Technologies A/S, Ballerup, Denmark) in a closed chamber system. Cumulative leaching losses of nitrogen (TN, _NO3-N, _NH4-N), phosphorous (P), potassium (K) and dissolved organic carbon (DOC) were measured by suction plates and mixed-bed ion-exchange resin cartridges (_NO3-N, _NH4-N, _PO4-P). Seepage was estimated with the software Hydrus 1d using crop-specific evapotranspiration and hydraulic soil parameters.

The experiment on an irrigated sandy soil with four replications comprised of two types of buffalo manure, characterized by a C/N ratio of 23 with high fiber content (high-high, HH), a C/N ratio of 15 with low fiber content (low-low, LL) and a control treatment with equivalent levels of mineral nitrogen (N), phosphorous (P) and potassium (K). These three fertility treatments were combined with a crop rotation comprised of radish (Raphanus sativus) transplanted on all plots followed by cauliflower (Brassica oleracea var. botrytis) and carrot (Daucus carota ssp. sativus).

Sub-project F2: Gaseous and leaching C and N losses from fertilized and irrigated croplands of subtropical mountain oases
Deutsche Forschungsgemeinschaft (DFG) - Research Training Group 1397
2007-2010, Mohammed Al-Rawahi