Reference
Lina Suzette B., Okazaki M, Kimura DS, Yonebayachi K, Igura M, Quevedo MA, and Loreto AB. 2009. Nitrogen uptake by sago palm (Metroxylon sagu Rottb.) in the early growth stages. Soil Science and Plant Nutrition 55: 114-123.
soil and its relation to environment, agriculture, global warming, and human health
Dear Sir or Madam,
Political debate on higher education is currently focused on enhancing the internationalisation of
The award recognises outstanding talent, above average initiative and a creative approach to research and grants exceptional research conditions: The award amount totalling up to 1.65 million EUR provides award winners with valuable risk capital, enabling them to put innovative research ideas into practice. They may spend five years working on research projects at an institute of their own choice, untroubled by administrative constraints. Furthermore, building up their own working groups allows the award winners to lay important foundations for a promising research career at a very early stage. The programme is funded by the Federal Ministry of Education and Research.
Scientists and scholars of all disciplines from abroad with outstanding qualifications, who have completed their doctorates within the last six years, are eligible to apply. The programme is also open to German academics working abroad. Applications must be submitted by 15 October 2009.
We should be very grateful if you would help us to search for international research talents. For example by disseminating the announcement at your institution or asking researchers you know to draw the attention of junior researchers who might be potential candidates to the award. Details of the application procedure for the Sofja Kovalevskaja Award can be found on our website at http://www.humboldt-foundation.de/SKP_en
Please do not hesitate to contact Dr. Oliver Lange (0228-833-274, oliver.lange@avh.de) or Monika Appmann (0228-833-186, monika.appmann@avh.de) if you have any further questions regarding the Sofja Kovalevskaja award.
With many thanks for your support and kind regards,
Dr. Georg Schütte
Secretary General
Alexander von Humboldt Foundation
The keynote address on “Rice Science for Food Self-sufficiency” was given by Atty. Ronilo A. Beronio, Executive Director of PhilRice. He discussed the rice self-sufficiency program to be achieved by 2013 and challenged soil scientists to educate farmers on how to make soil productive, to lead and preach the science of managing available farm and soil resources, and to effectively explain the synergistic effects of various fertilizers on plant growth.
The technical session was divided into three categories: junior, senior-competing, and senior-non-competing. For the junior category, three PSSST scholarship grantees presented their undergraduate thesis and competed for the best paper. At the same time, ten papers /presentations competed for the senior category while five others presented for the non-competing (senior) category. Moreover, 19 posters were presented and judged for the best poster award.
Best Paper- Effects of Varying Soil Moisture Levels on the Growth and Development of Lakatan (Musa acuminate Colla.) (Kathy Tafere)
Senior Category
Best Paper – Studying the Effects of Drought on Rice Production in Nueva Ecija Using Remote Sensing Technology (Judith Carla P. dela Torre)
Best Poster – Can we use commercially available fertilizers for Soil NPK test? (Julie D. Elijay, Constancio A. Asis, Jr., and Jesiree Elena Ann P. dela Torre)
It is generally known that continuous cultivation causes a decline in soil organic carbon and nutrient contents. This has been shown by many years of research on upland soils starting with the classic study by Nye and
But a recent paper by Benbi and Brar (2009) published in the international journal Agronomy for Sustainable Development does not support this widely held view. In fact, they showed that intensive cultivation increased soil organic carbon by 38 % after 25 years. These researchers evaluated the impact of intensive cultivation of an irrigated and optimally fertilized rice-wheat system in
Results of the study also revealed that the rice-wheat cropping in alkaline soils creates a favourable pH environment by lowering soil pH towards neutrality. During the 25-year period, the soil pH declined from 8.8. to 7.7 which resulted in the improvement in nutrient availability. Continuous application of phosphoric fertilizer led to build-up of soil P and the magnitude of accumulation was proportional to the amount of fertilizer applied.
References
Asio V.B., R Jahn, K. Stahr, and J. Margraf. 1998. In: Soils of
Nye P.H. and D.J.
While organic fertilization is now widely known to improve the general soil quality, more data from field experiments are still needed to support this notion. Cwalina-Ambroziak and Bowszys (2009) carried out a 3-year field experiment to determine the influence of organic fertilization on the community of soil fungi as compared to no fertilization and NPK fertilization only. Findings of the study revealed a significantly higher total number of fungal colony-forming units in soil applied with organic fertilizer than in soil without fertilizer application and the one applied with NPK mineral fertilizers. Moreover, pathogen population was highest in soil without fertilization and lowest in the soil added with organic fertilizer.
The study demonstrated that organic fertilization has a positive influence on the structure of soil fungi communities. This was particularly more observable in the qualitative changes in fungi composition than in the changes in fungi numbers. Results of the study support the findings of other researchers that organic fertilization stimulates the growth of soil microorganisms and that it protects the plants against pathogens of the genus Pythium and Phytophthora.
According to Terekhova (2007) fungal communities represent one of the most important functional and structural components of biological systems. Fungi affect the properties of the soil via the regulation of pedogenic processes; the composition of soil organic matter; the soil structure status; the soil acidity; the soil temperature characteristics; and certainly via the regulation of the functioning of soil microbiota.
References
Cwalina-Ambroziak B. and T. Bowszys. 2009. Changes in fungi communities in organically fertilized soil. Plant Soil Environ 55: 25-32.
Terekhova V.A. 2007. The importance of mycological studies for soil quality control. Eurasian Soil Science 40: 583-587.
Exotic tree species are introduced species from other regions. They are widespread in tropical and subtropical countries since they are popular as reforestation species even in harsh environments (Nyland, 1996) due to their ability to adapt easily to variable site conditions (Weidelt, 1976). Many are considered economically viable because of their fast growth characteristic. Farmers value exotic species more than the native ones because of forestry extension recommendations and desirable cultural attributes (Cromwell and Bradie, 1996). In the
Native tree species are species which originated from the region where they are growing. Among the more commonly known Philippine native tree species are Bagtikan (Parashorea plicata Brandis), Hagakhak (Dipterocarpus validus Blume) and Narra (Pterocarpus indicus Willd.). The first two species belong to Dipterocarpaceae family, the latter to the Fabaceae.
Presently, there is widespread notion that the use of exotic tree species for reforestation causes negative ecological effects such as soil degradation (Sawyer, 1993). Lindsay and French (2005) cited early studies showing that there are strong positive feedbacks between plant species composition and soil properties such that introduction of a new species can change nutrient cycling and soil properties. It is also believed that native tree species have positive effects on the site. However, very little data exist to support these claims.
We evaluated the effects of incorporation and subsequent decomposition of leaves of exotic tree species (Gmelina arborea, Sweitenia macrophylla and Tectona grandis) and native tree species (Pterocarpus indicus, Dipterocarpus validus and Parashorea plicata) on the quality of forest soil. Forty-two pots filled with an acidic and clayey forest soil and added with fresh leaves of the different tree species were set-up in an open area in
Our main findings were:
1. Decomposition of the leaves of exotic tree species generally did not change soil pH except that of S. macrophylla which increased soil pH after 5 months. In contrast, the leaves of the native species tended to decrease soil pH particularly in the first two months of decomposition.
2. There was no considerable difference between the effects of the leaves of exotic and those of native tree species on the organic matter and total nitrogen contents of the soil.
3. Available phosphorus content of the soil was significantly increased by the decomposition of leaves of both exotic and native species.
4. The leaves of exotic tree species decompose faster than those of the native species. This finding agrees with that of a separate litter decomposition study by litterbag method conducted at the same site by
Batistel CC and VB Asio. 2009. Effects of leaf decomposition of selected exotic and native tree species on forest soil quality. Annals of Tropical Research (in press)
References
Cromwell E and A Bradie. 1996. Germplasm for Multipurpose Trees: Access and Utility in Small-farm Communities. ODI
Gartner TB and ZG Cardon. 2004. Decomposition dynamics in mixed species leaf litter. Oikos 104: 230-246.
Lindsay EA and K French. 2005. Litterfall and nitrogen cycling following invasion by Chrysanthemoides monilifera ssp. Rotundata in coastal
Nyland R 1996. Silviculture (Concepts and Application). McGraw-Hill Co. Inc.
Sawyer J 1993. Plantations in the Tropics: Environmental Concerns. IUCN/UNEP/WWWF, Gland, Switzerland.
Weidelt H A 1976. Manual of Reforestation and Erosion Control for the
The Philippine Society of Soil Science and Technology (PSSST), the country’s national professional organization of soil scientists and soil practitioners, is holding its 12th Annual Meeting and Scientific Conference on 20-23 May 2009 at Eden Nature Park and Resort, a beautiful man-made resort on the slopes (about 800 m asl) of Mount Talomo, Toril, Davao City.
One person deserves a special mention: Dr. Neo Manguiat. It's largely because of his guidance and support that PSSST has been very successful as a professional organization.
The current PSSST officers are: Dr. D.M. Mendoza, President; Ms. C.G. Mangao, Vice-President; Dr. V.M. Padilla, Secretary; Ms. C.D. Bacatio, Tresurer; Dr. P.P. Juico, Auditor; Dr. C.A. Asis, Jr., PRO; Ms. R.N. Atienza, Business Manager; Ms. E.F. Javier, Dr. C.P. Laurea, Dr. E.P. Paningbatan, Jr., Dr. P.B. Sanchez, Mr. M.M. Marquez, Board Members; and Dr. C.P. Mamaril and Dr. I.J. Manguiat, Advisers. Ms. B.C. Magno, Ms. A.C. Marca, and Ms. A.T. Guy, Liaison Officers.
Asio VB, CC Cabunos, ZS Chen. 2006. Soil Science 171: 648-661.
Chang CP, Z Wang, J McBride, CH Lieu. 2005. J. Climate 18: 287-301.
Hall R. 2002. J. Asian Earth Sci. 20: 353-431.
Heemsbergen DA, MP Berg, M Loreau, JR Van Hal, JH Faber, HA Verhoef. 2004. Science 306: 1019-1020.
Nakashizuka T. J. 2004. J. For. Res. 9: 293-298.
Navarrete, IA, VB Asio, R Jahn, K Tsutsuki. 2007. Australian J. Soil Research 45: 153-163.
Verstappen H.Th. 1997. J. Quaternary Sci. 12: 413-418.
It is now recognized that plants take up N from the soil in three forms: nitrate, ammonium, and amino acids (dissolved organic N). Although scientific evidence on plant uptake of amino acids has existed in the last few decades, it is only recently that the contribution of amino acids to plant nutrition has been recognized (see Warren 2009 and literatures cited). So the traditional view that organic N has to be mineralized first into nitrate and ammonium in order to be available to the plant is not anymore valid.
Warren CR. 2009. Does nitrogen concentration affect relative uptake rates of nitrate, ammonium, and glycine? J. Plant Nutr. Soil Sci. 172: 224-229.
Scientists predict that tropical regions will receive the most dramatic increase in nitrogen (N) deposition over the next decades. This is due to increased fertilizer use, legume cultivation, fossil fuel consumption and biomass burning. There is thus a need for a better understanding of N cycling in tropical forest ecosystems. In a recent study by Arnold et al. (2009) across an Andosol (young volcanic ash soil) toposequence in Ecuador (Equitorial South America), it was revealed that gross rates of N transformations, microbial N turnover time, and δ15 N signatures in soil and leaf litter decreased with increasing elevation, indicating a decreasing N availability across the toposequence. Accompanying the above-mentioned trend was a decreasing degree of soil development with increasing elevation as indicated by declining clay content, total C, total N, effective cation exchange capacity and increasing base saturation. The study also revealed that soil N-cycling rates and δ15 N signatures were highly correlated with mean annual temperature but not with mean annual rainfall. Microbial immobilization was the largest fate of produced NH4+ whereas nitrification activity was only 5-11% of gross NH4+ produced. A fast reaction of NO3- to organic N which suggests abiotic NO3- immobilization, was also observed.
The mineral nutrition of native plant species is still poorly understood. This is particularly true for the various tree species in rain forest ecosystems. In order to evaluate the mineral nutrient status of the dominant tree species and its relation to environmental factors such as elevation, slope, landscape position, and soil nutrient status, Z.S. Chen and co-workers (Wu et al., 2007) collected leaf, stem, and wood samples for nutrient analysis from a total of 636 trees belonging to 20 dominant species from 27 contiguous 20m x 20m quadrants along an altitudinal transect in a subtropical rain forest in southern Taiwan. They also collected composite soil samples from the 0-5 and 5-15 cm depths in each quadrant for chemical analysis.
Their results revealed that leaf concentration was better correlated with the environmental factors than stem and wood nutrient concentrations. This means that leaf analysis is more appropriate than stem and wood analyses to evaluate the nutrient status of native tree species. They also found wide concentration ranges for most mineral nutrients except P and Cu and most tree species were clustered at the lower end of the concentration ranges indicating they have low nutrient status. Among the macronutrients, P had the lowest and narrowest foliar concentration (0.25-2.8 g kg-1) confirming the results of other studies from other tropical areas that P is the most limiting nutrient in tropical ecosystems. For the micronutrients, the lowest concentration was shown by Cu (3.88-17 mg kg-1). A few tree species were found to accumulate (called “accumulator species”) nutrients like N, P, K, Ca, Mg, Cu and Zn indicating high absorption capacity for these nutrients. Foliar mineral nutrient concentration of the trees was generally correlated with the environmental factors such as elevation, topographic position, slope, vegetative type and soil nutrient status.
Wu CC, Tsui CC, Hseih CF, Asio VB and Chen ZS. 2007. Mineral nutrient status of tree species in relation to environmental factors in the subtropical
Lake Danao (also called Imelda Lake in former times) is a natural lake with an area of 1.9 km2 in the form of guitar located at 700 m above sea level (ASL) in the central highlands of Leyte, Philippines (see photo). Surrounded by mountains with young loamy volcanic soils (Andisols), the lake provides water for home consumption and industrial uses, and opportunities for livelihood of people living nearby. It is a national reserve and popular tourist attraction due to its beautiful scenery and generally cooler climate than the lowlands of
Until now there is lack of published data on the capacity of Philippine soils to filter pollutants as well as on the environmental impacts of the application of chemical and organic fertilizers to soils bordering surface water bodies like lakes and rivers.
In view of the above a laboratory study was conducted to find out if Lake Danao soil allowed leaching of nitrate and phosphate after addition of chemical fertilizers and manure. The leaching experimental set-up was designed and constructed using PVC cylinders containing the Lake Danao soil and amended with various amounts of poultry manure and chemical fertilizers like urea and solophos. The treatments were based on the application rate employed by the farmers around the lake. Results revealed that high amount of nitrate was leached from the soil amended with urea but only small amount in soil added with poultry manure. Findings also showed low amount of phosphate that was leached from the soil amended with either poultry manure or chemical fertilizer. Although field verification of the results maybe necessary, the study implies that the practice of using urea by the farmers can lead to eutrophication of the nearby lake. The use of poultry manure as fertilizer will minimize the said environmental effects.
Source:
Magahud JC and VB Asio. 2009. Nitrate and phosphate leaching from Lake Danao Andisol treated with manure and chemical fertilizer. Paper presented during the National Scientific Conference of the Philippine Society of Soil Science and Technology (PSSST), 20-23 May 2009,
Garcia P.P., E.A. Saz, V.B. Asio, T.A. Patindol and Z.M. de la Rosa. 2005. Multisectoral watershed planning in
Logan, T.J. 2000. Soils and environmental quality. In: Handbook of Soil Science (M.E. Sumner, ed.). CRC Press,
Scheffer F. and P. Schachtschabel. 1992. Lehrbuch der Bodenkunde. (13th ed.). Ferdinand Enke Verlag, Stuttgart, 491pp.
Sharpley AN, T Daniel, T Sims, J. Lemunyon, R Stevens, R Parry. 2003. Agricultural phosphorus and eutrophication. 2nd ed. USDA-ADS, ARS-149, 44pp.
Toor G.S., L.M. Condron, H.J. Di, K.C. Cameron and B.J. Cade-Menun. 2003. Characterization of organic phosphorus in leachate from a grassland soil. Soil Biol. Biochem.5: 1317-1323.
World Health Organization. 1993. Guidelines for Drinking Water Quality, Volume 1. Recommendations. Second Edition. WHO Geneva. 110 pp.
Soil fertility in terrestrial ecosystems has received increased attention from ecologists since it is now widely recognized that nutrient availability drives ecosystem functioning and processes (Wardle and Zackrisson, 2005). N and P are believed to be the most limiting nutrients in many terrestrial ecosystems particularly forests. Availability of N and P vary considerably during soil development as P is lost through leaching and fixation while N accumulates through biological N fixation (Walker and Syers, 1976; Crews et al., 1995). Thus, young soils have the tendency to be N limited while old soils are P limited. Ecosystem studies have confirmed this relationship of N and P indicated by the N:P ratio. It has been found that the leaf N:P ratio can detect nutrient limitation for wetland terrestrial ecosystem. An N:P ratio >16 indicates P limitation which is in clear agreement with the Redfield ratio (Redfield, 1958) for marine ecosystems. An N:P ratio <14 indicates N limitation and between 14 and 16 means either N or P is limiting (Koerselman and Meuleman (1996). It has also been reported that P limitation relative to N is widespread in terrestrial ecosystems (Elser et al., 2000a and 2000b) and that it is the cause of biomass decline in forest ecosystems in strongly weathered soils (Wardle et al., 2004a). Kitayama (2005) argued, however, that despite P limitation, tropical rain forests in
Elemental stoichiometry or the ratio of key elements such as carbon (C), nitrogen (N), and phosphorus (P) in organisms is useful in analyzing how the organisms influence or is being influenced by the ecosystem in which they are found (Elser and Dobberfuhl, 1996). While the elemental stoichiometry (Redfield ratio) of 106 C: 16 N: 1P is well-established for marine ecosystems it is just starting to be applied to terrestrial ecosystems. Thus, Elser and Urabe (1999) suggested that scientists working in other ecosystems (e.g. forest) might profitably apply stoichiometric approaches to food web dynamics and nutrient cycling. This is particularly valid for terrestrial systems since autotroph biomass N:P in terrestrial and freshwater systems has been found to be closely similar (Elser et al., 2000b)
References
Crews T.E et al. 1995. Changes in soil phosphorus fractions and ecosystem dynamics across a long chronosequence in
The global distribution of soils is a function of climate and thus is related to latitude. Consequently, soil processes are known to vary with latitude. But a recent study by Jones et al. (2009) which used soils collected from 40 latitudinal points from the Arctic through to Antarctica, showed that this is not the case for key soil processes like the turnover of amino acids (amino acids represent a key pool of carbon and nitrogen in soil and their availability to plants and microorganisms is considered a major driver in regulating ecosystem functioning). They found that “soil solution amino acid concentrations were relatively similar between sites and not strongly related to latitude. In addition, when constraints of temperature and moisture were removed, they demonstrated that soils worldwide possess a similar innate capacity to rapidly mineralize amino acids. Similarly, they showed that the internal partitioning of amino acid-C into catabolic and anabolic processes is conservative in microbial communities and independent of global position. This supports the view that the conversion of high molecular weight (MW) organic matter to low MW compounds is the rate limiting step in organic matter breakdown in most ecosystems.”
ReferenceJones DL, K Kielland, FL Sinclair, R A Dahlgren, KK Newsham, JF Farrar, DV Murphy. 2009. Soil organic nitrogen mineralization across a global latitudinal gradient. Global Biogeochem. Cycles, 23, GB1016, doi:10.1029/2008GB003250
Nitrate pollution of groundwater systems is a serious problem in many countries. Application of nitrogen-containing fertilizers to irrigated crops is widely known as the major cause of nitrate pollution in groundwater systems. Nitrate is assumed to move downward through the vadose zone (unsaturated zone) and then move horizontally in the groundwater. But a recent study revealed that this may not be the case. Abit et al. (2008) evaluated the fate of nitrate in the capillary fringe (i.e. the subsurface layer at the boundary between the vadose zone and the zone of saturation) and shallow groundwater for a sandy soil with shallow water table. They found that nitrate entered the capillary fringe from the unsaturated zone then moved horizontally in the capillary fringe until it was partially carried into the groundwater by the fluctuating water table following rain events.
The influence of the physical environment on the outcome of battle is well-known but not the effects of warfare upon the environment particularly the soil. In view of this Hupy and Schaetzl (2008) studied the WWI battlefield of
Landscape is a three dimensional section of the Earth’s surface with specific pattern of topography, rocks, soil, water and flora and fauna. E. Schlichting (1923-1988) proposed that soils in different positions in the landscape (or catena) exchange materials through transport processes which could be compared to the transfer processes between horizons in a soil profile (Schlichting, 1964). Landscape pedology is an emerging science focusing on soil as part of the landscape particularly on the variability of soil properties at the landscape scale (1-10km) (Sommer, 2006).
Ecosystem is a natural system consisting of a biosystem (community of organisms) interacting with the geosystem (its physical environment). The geosystem includes soil, water, relief, and climate. Soil is a major component of geosystem in that it provides nutrients, water and living space to the organisms in the ecosystem. Two emerging fields of science are ecopedology and geoecology. The former focuses on the ecological role of soil while the latter on the geosystem (soil, rock, water) component of ecosystems.
The two major types of ecosystems are the terrestrial ecosystem (or ecosystem on land) and aquatic ecosystems. In the humid tropics, a common landscape consists of the following terrestrial ecosystem types: forest, agricultural (agro-ecosystem), wetland, urban and mangrove. All the terrestrial ecosystem types are linked by the soil. The transfer of water, nutrients and soil material occurs largely in the soil. The soil also determines to a great extent the biological system that develops in each terrestrial ecosystem type. Further, degradation of the soil in the terrestrial ecosystem also affects the health of the aquatic ecosystem nearby. For instance, in many places in the
References
Schlichting, E. 1964. Einführung in die Bodenkunde. Verlag Paul Parey, Hamburg, 93pp.
Sommer M. 2006. Influence of soil pattern on matter transport in and from terrestrial biogeosystems- a new concept for landscape pedology. Geoderma 133: 107-123.
Soil is not dirt. It is a vital life-support system for human survival. Below are the major functions of soil:
a) Production function. Soil acts primarily as a medium for the growth of natural vegetation and cultivated plants. It assures the supply of food, fodder, renewable energy and raw materials. This is also referred to as the forestry and agricultural function of the soil.
Victor B. Asio is a professor of soil science & geo-ecology at Visayas State University (VSU), Philippines. A recipient of the world renowned & highly competitive Humboldt Research Fellowship, he has published papers in international journals & has co-authored the Guidelines for Soil Description (2006, 4th ed) published by FAO of the United Nations in English, Spanish, Polish, Russian & Turkish. He studied at VSU, Univ Philippines Los Banos, Justus Liebig University Giessen, & University of Hohenheim, Stuttgart. He did postdoctoral studies at the Univ Halle-Wittenberg & the National Taiwan University. He was a Research Fellow at the International Rice Research Institute (IRRI) & Vice-Chair of Soil Geography Commission, International Union of Soil Sciences (IUSS). He is an elected member of Sigma Xi The Scientific Research Honor Society.