Rapid soil analytical techniques for international agricultural research and development

Soil analysis is used to assess natural resources and inform management to improve long-term farming profitability. Conventional techniques typically use different methods, equipment, reagents and skills to measure each soil property of interest. The consequence is that a conventional soil laboratory is expensive to set up, maintain and run. These issues result in many countries (and organisations) having to do without a well-functioning conventional soil laboratory. Developments in spectroscopic and potentiometric methods of soil analysis means that these countries need not go without reliable soil analysis

京都府下丹後地方のカンキツ園土壌の化学的性質と葉成分の時期的変化について(農芸化学部門)

京都府下丹後地方のカンキツ園において開園時期を異にする園を供試し, 土壌の化学的性質および葉成分について時期的変化を調べた。その結果, 土壌の反応は新しい園(高石)が古い園(石浦)にくらべると酸性が強い傾向を示したが, マンガンについては両園とも水溶性および置換性マンガンが少なかった。葉成分については石浦でマンガン欠乏, 高石でマンガンおよび亜鉛欠乏の可能性が推定された。また, 結果枝は無結枝にくらべるとカルシウムマンガンおよび亜鉛を多く含み, 窒素および加里は逆に少ない傾向を示した。Studies were carried out on the seasonal change of chemical properties of soils and inorganic compositions of leaves at the two citrus groves (variety UNSHU)-old ones (the age of tree : 60 years) and young ones (the age of tree : 10 years)-in northern part of Kyoto Prefecture and the following results overe obtained : The soil of young grove (TAKAISHI) showed more acidic properties than the soil of old grove (ISHIURA). A small amount of water soluble and exchang-able manganese were found on the both soils. The seasonal change of inorganic compositions of leaves showed no distinct differences between the two kinds of groves. However, from the compositions of leaves, a manganese defficiency found at the old grove, and also manganese and zink defficiency at the young groves were expected. Calcium, manganese and zink contents in the leaves were higher in the bearing shoots than in the non bearing shoots, Nitrogen and potassium contents showed a reverse relation to these three elements

Environmental impact assessments of the Three Gorges Project in China: issues and interventions

The paper takes China's authoritative Environmental Impact Statement for the Yangzi (Yangtze) Three Gorges Project (TGP) in 1992 as a benchmark against which to evaluate emerging major environmental outcomes since the initial impoundment of the Three Gorges reservoir in 2003. The paper particularly examines five crucial environmental aspects and associated causal factors. The five domains include human resettlement and the carrying capacity of local environments (especially land), water quality, reservoir sedimentation and downstream riverbed erosion, soil erosion, and seismic activity and geological hazards. Lessons from the environmental impact assessments of the TGP are: (1) hydro project planning needs to take place at a broader scale, and a strategic environmental assessment at a broader scale is necessary in advance of individual environmental impact assessments; (2) national policy and planning adjustments need to react quickly to the impact changes of large projects; (3) long-term environmental monitoring systems and joint operations with other large projects in the upstream areas of a river basin should be established, and the cross-impacts of climate change on projects and possible impacts of projects on regional or local climate considered. © 2013 Elsevier B.V.Xibao Xu, Yan Tan, Guishan Yan

Rate of Belowground Carbon Allocation Differs with Successional Habit of Two Afromontane Trees

Background: Anthropogenic disturbance of old-growth tropical forests increases the abundance of early successional tree species at the cost of late successional ones. Quantifying differences in terms of carbon allocation and the proportion of recently fixed carbon in soil CO2 efflux is crucial for addressing the carbon footprint of creeping degradation. Methodology: We compared the carbon allocation pattern of the late successional gymnosperm Podocarpus falcatus (Thunb.) Mirb. and the early successional (gap filling) angiosperm Croton macrostachyus Hochst. es Del. in an Ethiopian Afromontane forest by whole tree 13CO2 pulse labeling. Over a one-year period we monitored the temporal resolution of the label in the foliage, the phloem sap, the arbuscular mycorrhiza, and in soil-derived CO2. Further, we quantified the overall losses of assimilated 13C with soil CO2 efflux. Principal Findings: 13C in leaves of C. macrostachyus declined more rapidly with a larger size of a fast pool (64% vs. 50% of the assimilated carbon), having a shorter mean residence time (14 h vs. 55 h) as in leaves of P. falcatus. Phloem sap velocity was about 4 times higher for C. macrostachyus. Likewise, the label appeared earlier in the arbuscular mycorrhiza of C. macrostachyus and in the soil CO2 efflux as in case of P. falcatus (24 h vs. 72 h). Within one year soil CO2 efflux amounted to a loss of 32% of assimilated carbon for the gap filling tree and to 15% for the late successional one. Conclusions: Our results showed clear differences in carbon allocation patterns between tree species, although we caution that this experiment was unreplicated. A shift in tree species composition of tropical montane forests (e.g., by degradation) accelerates carbon allocation belowground and increases respiratory carbon losses by the autotrophic community. If ongoing disturbance keeps early successional species in dominance, the larger allocation to fast cycling compartments may deplete soil organic carbon in the long run.© Shibistova et a