4 research outputs found
The importance of semi-arid natural mountain pastures for feed intake and recycling of nutrients by traditionally managed goats on the Arabian Peninsula
No full textGoat husbandry in Oman's Hajar Mountains supplies income and manure to farmers. An earlier analysis concluded that it uses purchased feeds inefficiently, but did not value the contribution of mountain pastures to goat nutrition and cropland fertilization. Therefore intake of pasture vegetation, cultivated forages and purchased feeds was determined in goats from three villages in spring and autumn 2005. Faecal excretion was quantified using TiO2 and diet digestibility was calculated from faecal nitrogen (N). Organic matter (OM) intake varied from 71 to 107 g kg(-0.75) d(-1). Pasture vegetation supplied 45-71% of OM intake, and at least 28%, 33% and 42% of phosphorus (P), metabolizable energy (ME) and N intake. While ME intake just covered maintenance and locomotion requirements, N and P intake exceeded the animals' requirements. Therefore faecal concentrations (g kg(-1) OM) of 26-36 g N and 4-8 g P were high, making goat dung a key element of sustainability for the local cropping systems. Since mountain pastures supply nutrients to goats and cropland, their long-term productivity is crucial. Feeding cultivated forages seemingly reduces intake on pasture, but a comprehensive evaluation of nutritional and economic implications of this strategy and possible alternatives is needed. (C) 2011 Elsevier Ltd. All rights reserved.Deutsche Forschungsgemeinschaft [BU1308
Accuracy and precision of photoacoustic spectroscopy not guaranteed
No full textBecause of their accuracy and precision for measuring gas concentrations, gas chromatographs (GC) are standard analytical instruments used in investigations of nitrous oxide (N2 O) and carbon dioxide (CO2 ) exchange between the soil and the atmosphere. Iqbal et al. (2012) indicate that photoacoustic spectroscopy (PAS) performs similar to GCs for this purpose. We welcome this addition to the literature, given the increasing number of studies using PAS (e.g., Predotova et al. 2009; Leytem et al. 2011) and the few comparative analyses available (Ambus & Robertson 1998; Yamulki & Jarvis 1999). However, poor performance of PAS in some assessments (Akdeniz et al., 2009) and data from our own tests (reported below) raise questions about whether Iqbal et al.'s (2012) results are generally applicable to PAS instruments or unique to the experimental conditions and calibration of their instruments
Heavy metal signatures in urban and peri-urban agricultural soils across the Mumbai Metropolitan Region, India
No full textThe authors are grateful for the cooperation of the UPA gardeners in the Mumbai Metropolitan Region and for funding of this study by the German Academic Exchange Service (DAAD) through the International Centre of Development and Decent Work (ICDD) at University of Kassel, Germany. We thank Fiat Panis Foundation (Ulm, Germany) for providing a scholarship and research funding to the first author. For technical analysis and support thanks go to the Department of Earth Sciences, IITB and the staff at the Sophisticated Analytical Instrument Facility (SAIF, IITB) and the Centre for Technology Alternatives for Rural Areas (CTARA, IITB) in Mumbai, India. The lab assistance of Mrs. Eva Wiegard and Claudia Thieme at Kassel University is gratefully acknowledged. The authors are also thankful for the comments and support from Prof. Dr. Andreas Buerkert, Dr. Martina Predotova, Dr. Alexandra zum Felde, Dr. Christoph Steiner, and Dr. Salini Sasidharan
