mortiz085

Sago palm ( Metroxylon sagu Rottb.) is widely found in the tropical lowland forest and freshwater swamps across Southeast Asia and New Guinea. Sago, the starch extracted from the pith of sago palm stems, is a staple food for the lowland peoples of Papua New Guinea and the Moluccas (http://en.wikipedia.org/wiki/Sago). In recent years, the plant has received increased scientific interest as new uses for sago starch like in the manufacture of alcohol, citric acid, bio-ethanol and biodegradable plastics are being explored. One important research issue is on how to increase sago production since, like most wild plants, the mineral nutrition of sago palm is still poorly understood. Little scientific information is also available about its response to fertilizer application. In a new study published in the international journal Soil Science and Plant Nutrition, Lina and co-workers (Lina et al. 2009) found that N uptake of sago palm increased significantly but inconsistently with increasing N...

The Alexander von Humboldt Foundation based in Bonn , Germany , announces that it now accepts application for the prestigious Sofja Kovalevskaja Award for Top Level Junior Scientists and Scholars . Below is the official announcement from Dr. Georg Schütte , Secretary General of the Foundation: Dear Sir or Madam, Political debate on higher education is currently focused on enhancing the internationalisation of Germany as a research location. Endeavours are underway to improve the showcasing of German research and to create offers designed to promote collaboration between German and foreign researchers. The Alexander von Humboldt Foundation is delighted to be able to contribute to this by announcing once again the Sofja Kovalevskaja Award for Top Level Junior Scientists and Scholars . This attractively endowed research award is an outstanding career opportunity for junior research talents of all disciplines from abroad to establish their own junior research groups at German resea...

Contributed by Judith Carla P. dela Torre (PhilRice) The 12 th Annual Meeting and Scientific Conference of the Philippine Society of Soil Science and Technology, Inc. (PSSST) was held at Eden Nature Park, Toril, Davao City last May 21-22, 2009. About 140 members from the different international and local institutions, agencies, and state colleges and universities participated in the said event. With this year’s theme titled “Enhancing Soil Productivity and Environmental Quality”, scientists, researchers, extension workers, and students presented their paper and posters to help in finding solutions to issues like soil erosion, decreasing soil fertility and climate change; and to achieve better soil productivity for our country’s sustainable food production program. 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 challe...

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 Greenland (1960). Our studies in the volcanic mountain of Leyte , Philippines , have also confirmed this (e.g. Asio et al., 1998; Navarrete and Tsutsuki, 2008). 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 Punjab , India , and found that intensive cultivation enhanced carbon sequestration due to improved crop productivity, greater belowground C transport to the soil and reduced organic matter decomposition during the wetl...

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...

Decomposition of organic materials on the forest floor is a vital link between the various components of the forest ecosystem. Through this process, mineral nutrients bound to the biomass are released into the soil and then subject to uptake by plants, fixation by soil components, and losses through leaching and erosion. Decomposition can have considerable influence on the biological and chemical properties of the forest soil depending on the kind of organic material, soil properties, climate, and the availability of decomposers (e.g. Gartner and Cardon, 2004). 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 t...

The Philippine Society of Soil Science and Technology (PSSST), the country’s national professional organization of soil scientists and soil practitioners, is holding its 12 th 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. The conference which aims to meet the challenges in enhancing soil productivity and environmental quality, reflects the state of the art of soil research, development, extension and policy support in the Philippines . It provides an excellent forum for the exchange of research findings and scientific ideas among established and young soil scientists and soil practitioners working at the various universities, colleges, research centers, and government agencies. I wish to congratulate the officers led by Dr. Danny Mendoza and the members of the society for organizing this very important activity. I hope most members will b...

The soils in the tropical islands of SE Asia may be distinct from those in other tropical areas like Africa and the Americas because of the unique environmental factors that influenced their formation (Asio et al., 2006; Navarrete et al., 2007). Geologically, much of SE Asia was the result of recent tectonic event and many areas emerged from the sea recently (Hall, 2002). Consequently, it is much younger than Africa and Central and South America . In terms of climate, SE Asia is also different from the other regions. During the drier period of the Quaternary, the effects of climatic changes in landform development were unique because large areas were under the regime of the monsoonal system (Verstappen 1997). Chang et al. (2005) reported that the present climate that prevails in SE Asia is also unique since it is located in the transitional region between the boreal summer Asian monsoon and the boreal winter Asian monsoon. In terms of the soil-forming factor organisms (flora and fa...

Weathering is the physical, chemical, and biological alteration of minerals in rocks, sediments, and soils at or near the Earth’s surface. It is an important link in the global rock cycle and is also an essential process for the formation of soils and landforms. Chemical weathering of silicate minerals which compose over 90% of the Earth’s crust, removes CO 2 from the atmosphere so it helps regulate the Earth’s climate over long time scales. Basalts are among the more easily weathered crystalline rocks thus, weathering of these rocks acts as a major CO 2 sink. Chemical weathering of rocks likewise releases nutrient elements for use by the biota in the ecosystem and also produces clay minerals which are the central components of soils. We studied the weathering of basalt by evaluating the gain and loss of elements, stream water composition, weathering indices, and clay mineral formation in the soil derived from basalt under the humid tropical conditions (average annual rainfall of ...

The distribution of soils in the Philippines is largely controlled by parent material, relief, and vegetation. In general, Philippine soils are younger than the tropical soils in mainland Asia, Central and South America, and Africa. This is because most Philippine islands are geologically young since they were the result of, just like much of Southeast Asia, recent Cenozoic tectonic events and have emerged from the sea recently (Hall, 2002). Philippine soils maybe grouped based on geomorphology and for practical purposes, into: soils in lowland areas, soils in young and unstable uplands, and soils in old and stable uplands. Soils in lowland areas Lowland areas include all flatlands located near sea level. Most of these areas are underlain by recent alluvial sediments. Because of this and due to periodic deposition of sediments during flooding events, the soils in lowland areas are poorly developed. Arenosols (Entisols) . These are weakly developed sandy soils comm...

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. Different plant species vary in their preference for N forms. For instance, early successional plant species are known to have a higher capacity for nitrate uptake than late successional species. Uptake of N in the form of ammonium and amino acids is thus more important for the latter species. In a recent study to test the hypothesis that substrate concentration affects plant preference for N forms, Warren (2009) used the herb Ocimum basilicum and the evergreen tree Eucaly...

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 δ 15 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 δ 15 N signatu...

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...

Nitrogen and phosphorus are the most important nutrients that also function as environmental pollutants ( Logan , 2000). The natural levels of these nutrients in soils are not high enough to cause environmental pollution. But the heavy and long-term use of chemical and organic fertilizers can lead to leaching of nitrate (NO 3 - ) and phosphate (PO 4 3- ) from the soil and thereby result in the contamination of the groundwater as well as of nearby surface waters such as rivers and lakes (e.g. Scheffer and Schactschabel, 1992; Logan , 2000). High nitrate level in surface waters contributes to fish kills and makes the water unsafe for animal and human consumption. Increased phosphate concentration in surface waters leads to eutrophication since phytoplankton in these waters respond to increased P level since it is a major limiting nutrient in fresh water ecosystems (Logan, 2000; Toor et al., 2003). The resulting accelerated growth of water plants and general degradation of water quali...

One of the most influential books on soil science in the 20 th century was the Handbuch der Bodenlehre (Handbook of Soil Science), a 10-volume book edited by Professor Edwin Blanck of the University of Göttingen, Germany, and published by Verlag von Julius Springer, Berlin, from 1928-32 (see photo). The book presented the state of the art in soil science until the late 1920s. According to the prominent soil scientist Professor Dan Yaalon of Hebrew University , modern soil research took off at an accelerated rate as a result of the publication of this monumental book by Blanck (Yaalon and Berkowicz, 1997). The contents of the different volumes are as follows: Volume 1- The Natural Science Principles of the Origin of Soils; Volume 2- The Climatic Principles of the Formation and Weathering of Soils; Volume 3- The Distribution of Soil types on the Earth’s Surface, Regional and Zonal Soil Science; Volume 4- Non-climatic Soil Formation, the Soil Forms in Germany and Fossils Weathering; V...

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 indicates N limitation and bet...

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...

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. Reference Abit SM, Amoozegar A, Vepraskas MJ, Niewoehner CP. 2008. Fate of nitrate in the capillary fringe and shallow g...

Land use change is an important ecological driver in the Philippines and other parts of the tropics. It is the major cause of the widespread occurrence of degraded lands in this humid tropical country. Navarrete and Tsutsuki (2008) investigated the effects of land use change in Mt. Pangasugan in Leyte. They found that conversion of forest into secondary land uses like mahogany plantation, rainforestation farm (a form of reforestation using native tree species in combination with fruit trees and some shade-loving crops), coffee plantation, and grassland decreased the soil carbon, nitrogen, and non-cellulosic neutral sugar (mainly arabinose and xylose) contents of the soil. Within land-use type, differences in the above-mentioned soil parameters could be attributed to differences in the vegetation cover, past land use, and the succeeding soil management after land use change. Their findings also revealed that the grassland and rainforestation farm (which was also a former grassland) had ...

Clay minerals are a major component of soils. They are an important source of negative charge which enable the soil to hold nutrients and pollutants. In recent years, the medicinal effect of clay minerals has gained increased interest among medical researchers. In a recent paper in the Journal of Antimicrobial Chemotherapy, Haydel et al. (2008) reported: "The capacity to properly address the worldwide incidence of infectious diseases lies in the ability to detect, prevent, and effectively treat these infections. Therefore, identifying and analyzing inhibitory agents are worthwhile endeavors in an era when few new classes of effective antimicrobials have been developed. The use of geological nanomaterials to heal skin infections has been evident since earliest recorded history, and specific clay minerals may prove valuable in the treatment of bacterial diseases." The researchers found that specific clay mineral products have antibacterial properties which have potential to tre...

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 Verdun , France (1916). The battlefield which encompasses an area of 29,000 km 2 , remains one of the most heavily shelled of all time. Their findings revealed that many craters penetrated the shallow limestone bedrock, and blasted out fragments of limestone found on nearby undisturbed soils had already been incorporated into the soil profile. Although the battle happened less than a century ago (88 years), weathering and pedogenesis have already occurred in the soils within the craters. A major pedogenic process noted by the researchers is the accumulation and decomposition of organic matter, which is intimately associated with (and aided by) earthworm bioturbation (soil mixing). The study shows that warfare can cause dramatic changes in the soil and landscape...

If you collect leaf litter from a Mahogany plantation and put it beaneath Gmelina trees or vice versa, the rate of litter decomposition will not be the same. According to a recent paper by Ayers et al. (2009), leaf litter decomposition is faster beneath the plant species from which the litter had been derived than beneath a different plant species. This is called home-field advantage. The authors observed that home-field advantage is widespread in forest ecosystems and hypothesized that this is due to the specialization of the soil organisms in decomposing litter derived from the plant above it. In other words, soil organisms living beneath the Mahogany trees are specialized in decomposing the leaf litter from this tree species. Reference: Ayers E et al. (2009). Home-field advantage accelerates leaf litter decomposition in forests. Soil Biology and Biochemistry 41: 606-610.

People living in areas with fertile soils are better nourished than those living in degraded soils due to the higher quantity and quality of food in the former than the latter. Likewise, people living in polluted environments are more exposed to the ill effects of pollutants. The paths of environmental contaminants leading to humans are the following ( Logan , 2000): a) Soil à crop à human b) Soil à livestock à human c) Soil à crop à livestock à human d) Soil à surface waters à fish à human e) Soil à groundwater à human f) Soil à air à human g) Soil à human The pathways a to e are indirect links between soil and human health and are relatively well-known. The pathways f and g are direct links and are little known and understood. Direct links between soils and human health is geophagy Humans ingest soil either involuntarily or deliberately. For the involuntary ingestion, every person ingests at least small quantities of soil. This is because any soil adhering to the skin 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 ecologic...

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. b) Ecological regulator . Soil acts as filter, buffer, and transformer of various substances in or that are added to the soil. As a filter, the soil cleans polluted waters that move through it. As a buffer, it resists sudden change in its chemical balance thereby protecting the plants and soil organisms living in it. As a transformer, the soil is able to transform substances through microbiological and biochemical processes. The latter function is vital to the cycling of elements, degradation of toxic substances, decomposition of organic matter and production of greenhouse gases. c) Habitat and liv...