Soil phosphorus

Plants acquire phosphorus from soil solution as phosphate anion. It is the least mobile element in plant and soil contrary to other macronutrients. It precipitates in soil as orthophosphate or is absorbed by Fe and Al oxides through legend exchange. Phosphorus solubilizing bacteria play role in phosphorus nutrition by enhancing its availability to plants through release from inorganic and organic soil P pools by solubilization and mineralization. Principal mechanism in soil for mineral phosphate solubilization is lowering of soil pH by microbial production of organic acids and mineralization of organic P by acid Phosphatase. Use of phosphorus solubilizing bacteria as inoculants increases P uptake. These bacteria also increase prospects of using phosphatic rocks in crop production. Greater efficiency of P solubilizing bacteria has been shown through co-inoculation with other beneficial bacteria and mycorrhiza. This article incorporates the recent developments on microbial P solubilization into classical knowledge on the subject.

The Applied Anthropology Laboratories (AAL) of Ball State University conducted an archaeological reconnaissance and reinvestigation project for archaeological materials in Dearborn County, Indiana, for a FY2013 Historic Preservation Fund Grant (Grant 13FFY03). We specifically focused on Late Prehistoric period (cf. Fort Ancient) settlement and community organization patterns. We targeted previously identified Late Woodland and Late Prehistoric archaeological sites for pedestrian survey, soil phosphate, and geophysical investigations. Second, AAL attempted to identify new archaeological sites through pedestrian survey of agricultural fields in the county. Approximately 345.67 acres (139.89 ha) of agricultural land were subject to pedestrian survey, encountering 50 archaeological sites and 12,363 artifacts. Sites 12D45, 12D396, and 12D480 were subjected to soils (chemical and geophysical) analyses revealing new details of settlement organization. Diagnostics from pedestrian surveys indicate activity during the Middle Archaic, Middle Woodland, Late Woodland, and Late Prehistoric periods. We also examined landowner collections from investigated sites which demonstrate occupation spanning the Early Archaic through Late Prehistoric periods. Overall, the average site density recorded is one site per 7.18 acres (0.14 sites/acre). The average artifact density is one
artifact per 0.03 acres (34.42 artifacts/acre). As a result of the surveys conducted, nine sites were recommended as potentially eligible for the Indiana Register of Historic Sites and Structures (IRHSS) and the National Register of Historic Places (NRHP).

За умов антропогенного підвищення вмісту рухомих форм Фосфору у біосфері обов’язковим є контроль за біогеохімічними потоками цього елемента, а також пошук шляхів їхньої оптимізації з метою уникнення забруднення, в першу чергу, природних вод.

The Applied Anthropology Laboratories (AAL) of Ball State University conducted an archaeological reconnaissance and reinvestigation project for archaeological materials in Dearborn County, Indiana, for an FY2013 Historic Preservation Fund Grant (Grant 13FFY03). The focus of this Historic Preservation Fund Grant project was three-fold. First, this research targeted Dearborn County, Indiana, specifically focusing on Late Prehistoric period (cf. Fort Ancient) settlement and community organization patterns. AAL targeted previously identified Late Woodland and Late Prehistoric archaeological sites for pedestrian survey, soil phosphate, and geophysical investigations. Second, AAL attempted to identify new archaeological sites through pedestrian survey of agricultural fields in the county. Third, AAL attempted to reinvestigate five archaeological sites (12D200 and 12D272 in Township and 12D202, 12D203, and 12D205 in Township) for the purpose of data correction and enhancement.
Approximately 345.67 acres (139.89 ha) of agricultural land underwent pedestrian survey, encountering 50 archaeological sites (5 reinvestigated sites, and 45 newly defined sites) and 12,363 artifacts. Sites 12D45, 12D396, and 12D480 were subjected to soils (chemical and geophysical) analysis (24.5 acres, 9.91 ha) revealing new details of community organization. The project recovered 12,297 prehistoric artifacts and 66 historic artifacts from the ten survey areas that underwent pedestrian survey. Multiple cultural periods are represented in the artifact assemblage recovered from pedestrian surveys, including diagnostics of the Middle Archaic, Middle Woodland, Late Woodland, and Late Prehistoric. Multiple cultural periods are represented in landowner collections obtained for this project as well. These include the Early Archaic, Middle Archaic, Late Archaic, Terminal Archaic, Early Woodland, Middle Woodland, Late Woodland, and Late Prehistoric. Artifact assemblages from pedestrian survey and landowner collections both contain historic artifacts. Overall, the average site density recorded for the project is one archaeological site per 7.18 acres (0.14 sites/acre). Excluding SA2, this overall site density becomes one archaeological site per 8.60 acres. Density for survey areas within the Uplands is one archaeological site per 31.54 acres. Density for survey areas within the lowlands is one archaeological site per 1.84 acres. The average artifact density for this project is one artifact per 0.03 acres (34.42 artifacts/acre). When excluding SA2, this average artifact density is one artifact per 1.33 acres (0.75 artifacts/acre).
Of all the sites from this project, a total of nine are recommended as potentially eligible for Indiana Register of Historic Sites and Structures (IRHSS) and the National Register of Historic Places (NRHP)

The provision of farmers with proper and balanced fertilizer recommendations is becoming increasingly important, for reasons of crop productivity, food security, and sustainability.
Phosphorus (P) response trials with wheat were conducted on Nitisols at 14 sites in the central Ethiopian highlands during the 2010 and 2011 cropping seasons. The treatments, comprising six levels of P fertilizer (0, 10, 20, 30, 40, and 50 kg P ha−1), were arranged in a randomized complete block design with three replicates. Based on a yield difference between the control and the P treatments, 90% of sites responded to P fertilizer. Application of P fertilizer increased wheat grain yield, up to 30% more than the control. Extractable soil P concentrations (Bray 2, 0–15 cm deep) 3 weeks after planting significantly responded to P fertilizer rate. The critical P concentration (for 90% relative yield) was 13.5 mg kg−1. Most sites tested had Bray 2 P values <10 mg kg−1. In the absence of a soil test, a recommendation of 40 kg P ha−1, resulting in the best response overall, could be made for the first year of application.We also recommend that
to prevent a potential loss of wheat yield, a maintenance application of at least 5–12 kg P ha−1 be applied every year, irrespective of the calculated recommended rate, in order to
replace P exported from the field in produce. Further field trials are required to determine interactions between P response and the effects of climate, soil properties, and other management practices.

Keywords Critical P concentration, Nitisol, phosphorus, relative yield, wheat

The applicability of soil chemical analysis to the interpretation of ancient human activity areas in the Maya region was studied for potential implications in anthropogenically modified soils. We studied chemical signatures associated with a horizontally excavated site in Piedras Negras, Guatemala. The focus of this study is on soil phosphate and trace metals as indicators of ancient activity. We compared total phosphate with Mehlich extractable phosphate to see which method was superior. We also compared total (nitric-perchloric) digestion with the DTPA extraction procedure of heavy metal determination to resolve which method most accurately indicates ancient activity areas. We used principal component analysis to compare the metals and give probable locations of ancient activities. Statistical analysis of chemical patterns indicated possible areas of food preparation and craft production as well as sweeping patterns. We found that elevated phosphate, barium and manganese levels indicate areas of organic refuse disposal. Mercury and lead concentrations indicate areas of craft production. These observations are compared with the artifact data. We were also able to determine areas associated with similar activities using chemical analysis. The comparison of the total and extractable element analysis demonstrated that both methods yield important information regarding activity areas. However, because of the resolution obtained, convenience, economy, and safety, we suggest the extractable DTPA and Mehlich methods.

Phosphorus is the second important key element after nitrogen as a mineral nutrient in terms of quantitative plant requirement. Although abundant in soils, in both organic and inorganic forms, its availability is restricted as it occurs mostly in insoluble forms. The P content in average soil is about 0.05% (w/w) but only 0.1% of the total P is available to plant because of poor solubility and its fixation in soil (Illmer and Schinner, Soil Biol Biochem 27:257-263, 1995). An adequate supply of phosphorus during early phases of plant development is important for laying down the primordia of plant reproductive parts. It plays significant role in increasing root ramification and strength thereby imparting vitality and disease resistance capacity to plant. It also helps in seed formation and in early maturation of crops like cereals and legumes. Poor availability or deficiency of phosphorus (P) markedly reduces plant size and growth. Phosphorus accounts about 0.2 -0.8% of the plant dry weight. To satisfy crop nutritional requirements, P is usually added to soil as chemical P fertilizer, however synthesis of chemical P fertilizer is highly energy intensive processes, and has long term impacts on the environment in terms of eutrophication, soil fertilility depletion, carbon footprint. Moreover, plants can use only a small amount of this P since 75-90% of added P is precipitated by metal-cation complexes, and rapidly becomes fixed in soils. Such environmental concerns have led to the search for sustainable way of P nutrition of crops. In this regards phosphate-solubilizing microorganisms (PSM) have been seen as best eco-friendly means for P nutrition of crop. Although, several bacterial (pseudomonads and bacilli) and fungal strains (Aspergilli and Penicillium) have been identified as PSM their performance under in situ conditions is not reliable and therefore needs to be improved by using either genetically modified strains or co-inoculation techniques. This review focuses on the diversity of PSM, mechanism of P solubilization, role of various phosphatases, impact of various factors on P solubilization, the present and future scenario of their use and potential for application of this knowledge in managing a sustainable environmental system.

The choice of friction material can have a direct influence on the wear life of the brake block or wheel, which is typically much more expensive to replace. The classical cast iron brake block is gradually replaced by organic composite or sintered composite brake blocks. Nowadays, attention is devoted to solving problems connected with using modern brake materials and their impact on thermal and mechanical loading of railway wheels. In this paper, the investigated subjects are the gray cast iron brake shoes, with lamellar graphite and with high content of phosphorus (0.8–1.1%), according to requirements for the brake shoes

THIS IS JUST THE DESCRIPTION OF THE PROJECT I AM CURRENTLY WORKING ON!
Phosphorus (P) constitutes an essential but non-renewable resource, limiting plant growth in many environments. Organic P constitutes a major pool in the soil, but little is known about its forms and dynamics. In order to reduce unnecessary inputs and associated environmental pollution, alternative management strategies have to be developed 3,4, as cover crops and reduced tillage, a promising bundle of techniques with additional benefits for the agroecosystem 5. The present work aims to study the influence of these techniques on the soil microbial community, the associated P dynamics and the subsequent effects on the P nutrition status of the crops.
One of the keystones is the assessment of inositol, a P storage compound accounting for the majority of soil organic P, which is characterized by Turner et al. 3 as the greatest gap in our understanding of the global P cycle. The development of a method for the quantification of the activity of phytase, the unique enzymes capable of the degradation of inositol would be a major step forward.
The samples will proceed from the project “Konservierender Ackerbau” (HfWU), along with laboratory, pot and field experiments of other sites. The soil microbial community abundance, diversity and activity under different cover crop management options will be assessed, with an emphasis on the components involved in the P cycle.
The results of this thesis will support our understanding of the underlying mechanisms of the P cycle, supporting farmers to manage the limited P resources more efficiently using advanced sustainable farming techniques.

Les études d'adsorption et de désorption ont montré dans le cas
des rendzines riches en calcaire actif (RDZ1, RDZ2 et RDZ4), que
l'adsorption des ions phosphates ne se fait qu'aux faibles doses
apportées. Aux fortes doses, les ions phosphates précipitent. La RDZ3 et
le pélosol par contre, se comportent différemment. La réversibilité de
l'adsorption des ions phosphates confirme ce que nous avons observé
sur les courbes d'adsorption et ce mécanisme ne se produit qu'aux
faibles doses apportées et surtout dans les RDZ1, RDZ2 et RDZ4.Au
contraire dans le cas du pélosol la désorption est une fonction croissante
du P adsorbé.

Geoscience approaches are being applied for prospection and intra-site analysis with increasing frequency
in a variety of contexts around the world. There currently are a variety of archaeochemical procedures
in use, each of which suffers from inherent limitations Colorimetric measurement is limited in the
number of elements measured simultaneously. Inductively Coupled Plasma techniques are expensive
and restricted to a narrow range of institutions. Yet the recent availability of Portable X-ray Fluorescence
(pXRF) offers a more flexible (wide spectrum of elements) and relatively inexpensive piece of
equipment that is potentially more widely applicable to archaeological issues. However, pXRF is most
often used for whole-sample, dry chemistry which introduces a potentially geological confounding factor.
In contrast, weak acid extraction preferences weakly adsorbed, and more likely anthropogenic, ions.
We perform a comparative analysis of colorimetric measurement of phosphate, ICP-OES measurement
of multiple elements, and both wet and dry pXRF of soil samples from a variety of glacial till plain contexts
to assess the ability of pXRF to comparably measure the chemical imprint of human activity in till
plain soils.

Ancient anthrosols known as Amazonian dark earths or terra preta are part of the human built landscape and often represent valuable landscape capital for modern Amazonian populations in the form of fertile agricultural soils. The fertility, resilience, and large stocks of carbon in terra preta have inspired research on their possible role in soil fertility management and also serve as an example for a growing biochar industry it is claimed will sequester carbon for climate change mitigation. Although there is considerable scientific and public interest in terra preta, there is still much debate and little concrete knowledge of the specific processes and contexts of its formation. Research indicates that the formation of terra preta occurred mainly in midden deposits, themselves patterned around habitation areas, public areas, and routes of movement. Data from topographic mapping, soil analyses, and excavations in three regions of Amazonia demonstrate a widespread pattern of anthrosol formation in ring-shaped mounds surrounding flat terraces that extend across large areas of prehistoric settlements. It is hypothesized that there is a widespread type or types of occupation where the terraces were domestic areas (houses or yards) surrounded by refuse disposal areas in middens which built up into mounds over time, forming large deposits of terra preta and creating what could be called a ‘middenscape.’ Initial results support the hypotheses, showing the interrelationship of residential and public areas, anthrosols, routes of movement, and natural resources. The patterning of anthrosols in ancient settlements indicates the use of space and can therefore serve as a basis for comparison of community spatial organization between sites and regions.

The nitrogen (N) cycle is an important part of earth's biogeochemical cycles and N is a critical element for all life. Whereas the response to N-and more rarely phosphorus, P-fertilization of some microbial groups involved in soil N cycling has been studied, a comprehensive view of how the major microbial groups involved in soil N dynamics respond to combined N and P fertilization is lacking, which restricts our understanding of ecosystem responses to fertilization. Here we investigated the effects of different N, P and NP fertilizer levels (4 N levels without P; 4 P levels without N; and 4 P levels with constant N addition) on the abundances of 9 microbial groups involved in N dynamics. Real time PCR was used to target free N 2 fixers, nitrifiers (bacterial and archaea ammonia oxidizers, AOB and AOA, respectively; and the nitrite oxidizers Nitrobacter and Nitrospira), nitrate reducers, nirK-and nirS-nitrite reducers, and nitrous oxide reducers. Soil physical-chemical characteristics and potential nitrification, PNR, were also measured. N fertilization increased the abundances of AOB and Nitrobacter but did not affect the abundances of the other groups. P fertilization decreased the abundances of N 2 fixers, nitrate reducers and AOA, and increased the abundances of Nitrobacter and nitrous oxide reducers. NP fertilization decreased the abundances of AOA and nirK-nitrite reducers. Using a correlation network analysis, we demonstrate the strong coupling generally observed in these grasslands between N 2 fixers, AOA, Nitrospira, narG-nitrate reducers and nirK-denitrifiers (most of them responding to N/P availability, and being known to be favored by low oxygen availability); and between AOB and Nitrobacter (known to be favored by high oxygen and high N levels) that controlled changes in PNR. The observed (de)coupling between the responses of the different microbial groups may have major consequences for N cycling and N losses from fertilized Tibetan alpine meadows.

Ce travail est une étude de caractérisation de la biodisponibilité du
phosphore de cinq sols calcimorphes après apport ou non de phosphate
diammonique et de paille de riz a été caractérisée par des cinétiques de
dilution isotopique. Les résultats montrent que les apports de P diminuent le
pouvoir fixateur (augmentation de R1/R0) et augmentent leur biodisponibilité par
les plantes. Les apports de paille augmentent aussi le rapport R1 /R0 dans la
RDZ1, RDZ3 et le pélosol (donc une diminution du pouvoir fixateur), et
diminuent, par contre, la valeur de M1 et E(t) dans la RDZ2, RDZ4 et le pélosol.
Mots-clés : Biodisponibilité du phosphore, Sols, Phosphate diammonique, Paille de riz, Cinétiques de dilution isotopique

Aims An essential task of agricultural systems is to improve internal phosphorus (P) recycling. Cover crops and tillage reduction can increase sustainability, but it is not known whether stimulation of the soil microbial community can increase the availability of soil organic P pools. Methods In a field experiment in southwest Germany, the effects of a winter cover crop mixture (vs. bare fallow) and no-till (vs. non-inversion tillage) on microbial P-cycling were assessed with soybean as the main crop. Microbial biomass, phospholipid fatty acids (PLFAs), P cycling enzymes, and carbon-substrate use capacity were linked for the first time with the lability of organic P pools measured by enzyme addition assays (using phosphodiesterase, non-phytase-phosphomonoesterase and fungal phytase). Results Microbial phosphorus, phosphatase, and fatty acids increased under cover crops, indicating an enhanced potential for organic P cycling. Enzyme-stable organic P shifted towards enzyme-labile orga...

The Applied Archaeology Laboratories (AAL) of Ball State University conducted an archaeological reconnaissance project for archaeological materials in Hamilton County, Indiana, for an FY2012 Historic Preservation Fund Grant (Grant #18-12-41921-4). This Historic Preservation Fund grant project investigated the archaeological resources of Hamilton County, Indiana. This specific project focused on the White River and its associated tributaries, as well as the southern half of the county. Approximately 565 acres (228.55 ha) of agricultural land underwent pedestrian survey, uncovering 230 new archaeological sites and 1625 artifacts. Over 157 acres (63.54 ha) underwent soil phosphate survey, revealing multiple possible prehistoric agricultural fields or gardens. The project recovered 1154 prehistoric artifacts and 471 historic artifacts from 9 different parcels of land within Hamilton County. Multiple cultural periods are represented in the artifact assemblage, including diagnostics of the Early Archaic, Middle Archaic, Late Archaic, Middle Woodland, Late Woodland, and Historic periods. The average site density recorded for the project was one archaeological site per 2.46 acres (0.41 sites/acre). The average artifact density was one artifact per 0.34 acres (2.9 artifacts/acre).
A total of 13 sites are recommended as potentially eligible for Indiana Register of Historic Sites and Structures or the National Register of Historic Places

Application of Single Super Phosphate (SSP) fertilizer in soils with inadequate phosphorus (P) should elicit crop response. However, there is an indication of inconsistent response behaviour to SSP fertilizer in some Nigeria soils despite their low available P. This study identified major soil types in Southwestern Nigeria that are unresponsive to P fertilizer application under screenhouse condition and soil properties that are related to this unresponsive behaviour were determined. Soils from twenty locations in Southwestern Nigeria were selected to evaluate their response to four phosphorus fertilizer rates with a control replicated three times in a factorial arrangement laid out in randomized complete block design. Results indicated that most of the locations responded to initial P application except for Fashola 2 which produced significantly higher maize shoot yield in control soils. There were five other locations where no-response was observed. Multiple regression analysis showed that phosphorus sorption index was related to sand, organic matter and clay. Phosphorus accumulation in soil P reserves may explain the behaviour of the P-unresponsive soils irrespective of their available P levels.

Les résultats obtenus pour le phosphore minéral montrent que le
phosphore apporté dans les rendzines se retrouve lié au calcium sauf
dans le cas de la RDZ3, ou il se partage entre l'aluminium et le calcium.
Par contre dans le cas du pélosol, il se trouve lié au fer et à l'aluminium
Les différentes formes de P minéral dans les rendzines n'ont pas
été modifiées par les apports de paille alors que dans le cas du pélosol
nous avons remarqué un léger effet dépressif de ces apports sur les
formes P-Ca, P-Fe et P-Al et une nette augmentation du phosphore
d'inclusion.
Les résultats concernant le POT nous montrent que les différents
apports n'ont que faiblement modifié les teneurs initiales en POT des sols
étudiés.
Au contraire, l'apport conjugué de la paille et du phosphore semble
maintenir un niveau de POT semblable à celui des sols témoins

Conservation management practices such as reduced tillage, fertilizer management, and buffer strips are well-established means by which to control erosion and nutrient losses from fields planted in annual row crops. However, agricultural systems which include perennial plant cover, such as the perennial forages found in grazing systems, may represent an alternative way to reduce these losses. In this study, management intensive rotational grazing (MIRG) was tested as a means by which to improve water quality on highly vulnerable row crop land, compared to more traditional conservation management schemes in the south branch of the Root River Watershed (a karst-influenced watershed in Southeastern Minnesota). The effects of both sets of alternative scenarios were evaluated with a watershed-based modeling approach using the Soil and Water Assessment Tool. Alternative conservation management practices included conservation tillage, cover crops, and filter strips. Conversion of row crop production to management-intensive rotational grazing of beef cattle was selected to occur on 2.6% of the total watershed area. Both the conservation management practices and land use changes were targeted to reduce contributions of sediment and phosphorus (P) loads from cropped upland areas. Watershed-wide implementation of all conservation management practices resulted in the greatest reductions in sediment (52%) and total P (28%) loads from upland crop areas, but had the largest land area requirements to achieve these results. Cover crops or filter strips on areas of high slope also showed large cumulative reductions across the watershed and also had the greatest reductions per-unit treated area of all conservation management practices. However, changing land use from row crop production to pasture for grazing was most effective at reducing total sediment and P loads on those acres changed, reducing sediment and P by greater than 85% on targeted areas. Simulation results indicate that utilizing alternative conservation management practices or MIRG, when targeted to areas of steeper slope (greater than 4%), could appreciably reduce sediment and P loads in this watershed, with limited reductions in row crop agriculture acreage.

The Applied Archaeology Laboratories (AAL) of Ball State University conducted an archaeological reconnaissance project for archaeological materials in Hamilton County, Indiana, for an FY2012 Historic Preservation Fund Grant (Grant #18-12-41921-4). This Historic Preservation Fund grant project investigated the archaeological resources of Hamilton County, Indiana. This specific project focused on the White River and its associated tributaries, as well as the southern half of the county. Approximately 565 acres (228.55 ha) of agricultural land underwent pedestrian survey, uncovering 230 new archaeological sites and 1625 artifacts. Over 157 acres (63.54 ha) underwent soil phosphate survey, revealing multiple possible prehistoric agricultural fields or gardens. The project recovered 1154 prehistoric artifacts and 471 historic artifacts from 9 different parcels of land within Hamilton County. Multiple cultural periods are represented in the artifact assemblage, including diagnostics of the Early Archaic, Middle Archaic, Late Archaic, Middle Woodland, Late Woodland, and Historic periods. The average site density recorded for the project was one archaeological site per 2.46 acres (0.41 sites/acre). The average artifact density was one artifact per 0.34 acres (2.9 artifacts/acre). A total of 13 sites are recommended as potentially eligible for Indiana Register of Historic Sites and Structures or the National Register of Historic Places.

Aims: An essential task of agricultural systems is to improve internal phosphorus (P) recycling. Cover crops and tillage reduction can increase sustainability, but it is not known whether stimulation of the soil microbial community can increase the availability of soil organic P pools.
Methods: In a field experiment in southwest Germany, the effects of a winter cover crop mixture (vs. bare fallow) and no-till (vs. non-inversion tillage) on microbial P-cycling were assessed with soybean as the main crop. Microbial biomass, phospholipid fatty acids (PLFAs), P cycling enzymes, and carbon-substrate use capacity were linked for the first time with the lability of organic P pools measured by enzyme addition assays (using phosphodi-esterase, non-phytase-phosphomonoesterase and fungal phytase).
Results: Microbial phosphorus, phosphatase, and fatty acids increased under cover crops, indicating an enhanced potential for organic P cycling. Enzyme-stable organic P shifted towards enzyme-labile organic P pools. Effects of no-till were weaker, and a synergy with cover crops was not evident.
Conclusions: In this experiment, cover crops were able to increase the microbially mediated internal P cycling in a non-P-limited, temperate agroecosystems.

A laboratory study was conducted to understand the effect of organic and inorganic amendment on phosphorus sorption characteristics of lowland rice soil. Soil samples (0-15 cm) were collected from a long-term integrated nutrient management experimental plots (three treatments- control, NPKS and NPKS + cow dung and ash) receiving different treatments over eight years. Collected soil samples were shaken with 0.01M CaCl2 solution containing P from 0 to 60 micro g/ml for 24 hours
at room temperature (28 degree C, soil to solution ratio 1:10). The phosphorus isotherm data for all the soils at equilibrium P concentration were found to fit well to Langmuir, Freundlich and Temkin equation (r2
=0.8851 to 0.9896). The application of inorganic fertilizer increased P buffering capacity and maximum adsorption capacity compared to control and organic amendment. Energy of P adsorption was the highest with control followed by organic amendment and inorganic amendment.

In the Sub-Saharan Africa, soil-fertility depletion in smallholder farms is the fundamental biophysical root cause for declining per capita food production. In the soils of this region, Phosphorus deficiency is widely considered the main biophysical constraint to food production in large farmland areas. Therefore there is a need to adopt measures in order to build up soil P capital especially among smallholder farmers who are economically poor. It has been reported that use of inorganic fertilizers is a fast and immediate way to avail P mostly for plant uptake and boost crop yields. Meanwhile organic fertilizers either alone or combined with inorganic fertilizer have also shown its importance in rising up soil available P and other adjacent contribution to promote nutrient uptake and lastly increase crops yield. This review paper explores the different alternatives which may be adopted by the smallholder farmers in SSA in order to build up soil available P and increase the yields of their crop.

Available phosphorus levels and P sorption capacity were investigated in soils derived from coal mine spoils at As Pontes (Galicia, NW Spain), currently in the process of reclamation. Clays and shales, often in conjunction with pyrite and other sulphides, are the main constituents of the spoils; many are extremely acid as a result of oxidation of sulphides. Reclamation tasks consisted of topsoiling, chemical and organic fertilizing or various amendments. Two depths (O-15 and 15-30 cm) were sampled and analysed at each sampling site. In total, 140 samples were collected ranging in pH-H,O from 2.7 to 8.4. Olsen P values ranged between 1 and 54 mg. kg-'. The phosphorus sorption index (PSI), determined according to Bathe and Williams (1971), ranged between 2.4 and 55.1. Multiple correlation between PSI and several soil parameters was investigated using a stepwise linear regression method. Four soil parameters (oxalate-extractable Fe and Al, pH in KC1 and organic carbon) were shown to explain 79% of the variance in log PSI. The correlation equation found was: log PSI = 3.562 + 0.519 x log(A1 + Fe),-0.065 x pH-KC1 + 0.247 x log(org. C).

This paper describes analyses for understanding the general use of space on two Early Iron Age house sites on the site of Sønderris in South-West Jutland (South Scandinavia). The main method consists of the geoarchaeological techniques of soil P analysis by citric acid extraction, low frequency magnetic susceptibility analysis, and measurement of the soils organic content by loss-on-ignition. The results of these analyses are, moreover, interpreted alongside artefact distribution data, data on the dispersal of plant macrofossils, and an evaluation of the architectural details of the sites.

At both house sites, the geoarchaeological data shows patterning indicative of human activities. The main achievements are inference of outdoor areas which may have contained pyres or kilns, delineation of yard spaces with refuse deposition, and the characterisation of functional aspects of two small outbuildings. In general, the geoarchaeological results are consistent with the inferences attained from non-geoarchaeological sources. A notable exception is that few clear traces of stalling were identified in the geoarchaeological record, despite the presence of animal booth partition walls indicating the presence of byres in the longhouses. Possible reasons for this are discussed.

Overall, this study demonstrates the continued usefulness of long-established geoarchaeological methods for gaining insights about the nature, extent, and orientation of activities on prehistoric house sites. A key take-away from the study is that the potential of any individual method for reading activities (geoarchaeological or otherwise), increases when several techniques with overlapping, but not identical, scope for inferring activities are integrated. The resulting multiproxy analysis is, as a whole, more useful than the sum of its constituent parts.

How multiple, interacting components of complex soil communities assemble within forefields of receding glaciers is still largely unknown, especially at high-elevation sites (>5000 m a.s.l.) where plant succession is very slow. To examine succession of soil communities across different trophic levels, we investigated four major soil groups: bacteria, fungi, nematodes, and other non-fungal non-nematode microbial eukaryotes at the Puca Glacier in the Peruvian Andes spanning 9-, 24-, and 89-year-old deglaciated soils. This is the first study of microbial communities, other than bacteria, at a high-elevation chronosequence in the Andes Mountains. In addition, we characterized soil biogeochemical properties (e.g., C, N, moisture, and pH) and rates of microbial enzyme activities associated with C, N, and P acquisition. We found significantly correlated increases in estimated richness and high species turnover in all soil groups along the chronosequence. These shifts in soil communities were significantly correlated with microbial enzyme activities and measures of C, N, moisture, and pH. Stoichiometric comparisons of enzyme activities showed phosphorus (P) and carbon (C) limitation of microbial activity across the entire chronosequence with no hint of nitrogen (N) limitation. Taken together, the observed shifts in soil communities and biogeochemistry indicate coordinated increases in trophic complexity and ecosystem functioning during the initial 90 yr of microbial succession along the post-glacial chronosequence of the Puca Glacier.

BACKGROUND: In a field experiment conducted in a Mediterranean area of inner Sicily, durum wheat was inoculated with plant growth–promoting rhizobacteria (PGPR), with arbuscular mycorrhizal fungi (AMF), or with both to evaluate their effects on nutrient uptake, plant growth, and the expression of key transporter genes involved in nitrogen (N) and phosphorus (P) uptake. These biotic associations were studied under either low N availability (unfertilised plots) and supplying the soil with an easily mineralizable organic fertiliser. Regardless of N fertilisation, at the tillering stage, inoculation with AMF alone or in combination with PGPR increased the aboveground biomass yield compared to the uninoculated control. Inoculation with PGPR enhanced the aboveground biomass yield compared to the control, but only when N fertiliser was added. At the heading stage, inoculation with all microorganisms increased the aboveground biomass and N. Inoculation with PGPR and AMF+PGPR resulted in significantly higher aboveground P compared to the control and inoculation with AMF only when organic N was applied. The role of microbe inoculation in N uptake was elucidated by the expression of nitrate transporter genes. NRT1.1, NRT2, and NAR2.2 were significantly upregulated by inoculation with AMF and AMF+PGPR in the absence of organic N. A significant down-regulation of the same genes was observed when organic N was added. The ammonium (NH4+) transporter genes AMT1.2 showed an expression pattern similar to that of the NO3- transporters. Finally, in the absence of organic N, the transcript abundance of P transporters Pht1 and Pht2;1 was increased by inoculation with AMF+PGPR, and inoculation with AMF upregulated Pht2 compared to the uninoculated control. These results indicate the soil inoculation with AMF and PGPR (alone or in combination) as a valuable option for farmers to improve yield, nutrient uptake, and the sustainability of the agro-ecosystem.

Plants employ a range of strategies to increase phosphorus (P) availability in soil. Current soil P extraction
methods (e.g. Olsen P), however, often fail to capture the potential importance of rhizosphere processes
in supplying P to the plant. This has led to criticism of these standard approaches, especially in nonagricultural
soils of low P status and when comparing soil types across diverse landscapes. Similarly,
more complex soil P extraction protocols (e.g. Hedley sequential fractionation) lack functional significance
from a plant ecology perspective. In response to this, we present a novel procedure using a suite of
established extraction protocols to explore the concept of a protocol that characterizes P pools available
via plant and microbial P acquisition mechanisms. The biologically based P (BBP) extraction was conducted
by using four extractions in parallel: (1) 10 mM CaCl2 (soluble P); (2) 10 mM citric acid (chelate
extractable P); (3) phytase and phosphatase solution (enzyme extractable organic P); (4) 1 M HCl
(mineral occluded P). To test the protocol, we conducted the analyses on a total of 204 soil samples
collected as part of a UK national ecosystem survey (Countryside Survey) in 1998 and repeated again in
2007. In the survey, Olsen P showed a net decline in national soil P levels during this 10 year period. In
agreement with these results, soluble P, citrate extractable P and mineral occluded P were all found to
decrease over the 10 year study period. In contrast, enzyme extractable organic P increased over the
same period likely due to the accumulation of organic P in the mineral soil. The method illustrates a
noted shift in P pools over the 10 year period, but no net loss of P from the system. This new method is
simple and inexpensive and therefore has the potential to greatly improve our ability to characterise and
understand changes in soil P status across complex landscapes.

Sediment fingerprinting techniques can provide valuable information on sources of suspended sediment to facilitate effective targeting of best management practices. Research was conducted in the Pleasant Valley watershed (50 km 2 ) in South Central Wisconsin to identify sources of suspended sediment during cropping season and snowmelt periods at a subwatershed scale. Results show that both stream banks and agriculture are important sources of suspended sediment. The contribution from agriculture and stream banks to suspended sediment at the watershed outlet ranged from 45 to 97% and from 3 to 47%, respectively. During periods of high sediment loading agriculture was the important source of suspended sediment at the majority of sites within this watershed, with the exception of snowmelt runoff, when stream banks were the dominant source of suspended sediment at the watershed outlet. The average annual erosion rates in croplands and pasture land-use determined from the Revised Universal Soil Loss Equation 2 (RUSLE 2) ranged from 0 to 0.00509 t m −2 yr −1 , indicating significant variability among fields. Conservation practices in this watershed should be targeted to stream banks or agriculture (prioritize fields based on RUSLE 2 average annual erosion rates) depending on the dominant source of suspended sediment within a subwatershed. The results of this study show that both temporal and spatial variability in suspended sediment sources should be considered to develop management strategies and sampling only at the watershed outlet or capturing a few storms might not be sufficient to target locations for best management practices.

Fosfátová analýza je v současné době patrně nejuniverzálnější a také nejvyužívanější geochemickou metodou v archeologii i etnoarcheologii či experimentální geoarcheologii. Fosfátové půdní analýzy je již od konce 40. let 20. století využíváno také k výzkumu hrobových nálezů: kromě prospekce pohřebišť ji lze využít i k detekci totálně rozložených či druhotně přemístěných pozůstatků, čehož může být využito jako podpůrné evidence při zkoumání variability pohřebního ritu .

We explore the application of an inexpensive and less-invasive method of discovering community patterning at a series of complex sites in the glacio-lacustrine region of northern Ohio. In this pilot study we employ systematic soil phosphate (SP) and soil magnetic susceptibility (MS) analyses on these three northeast Ohio archaeological sites. This is the first such effort in the Lake Erie Basin to combine SP and MS surveys to understand site activity structure. We investigate activity patterning at three northern Ohio habitation sites: White Fort (33Ln2), a multicomponent, Late Prehistoric (Sandusky Tradition) site in Lorain County; Burrell Orchard (33Ln15), a multicomponent site with a substantial Late Archaic component in Lorain County; and Heckelman (33Er14), a multi-component Woodland Period enclosure and habitation in Erie County. The analysis of SP was complicated by extremely high values, in one case reaching an apparent saturation point, and complex occupation histories. The combination of both MS and P makes for a robust survey strategy to identify details of activity structure even at places with complex and overlapping use histories. We demonstrate the promise and problems of this analytical technique and shed light on the applicability of this method of prospection to the glacio-lacustrine region of Ohio. Especially when used in a multi-pronged research design, soil analysis is a powerful supplement to traditional techniques that enables whole-site analysis without full excavation.

How multiple, interacting components of complex soil communities assemble within forefields of receding glaciers is still largely unknown, especially at high-elevation sites (>5000 m a.s.l.) where plant succession is very slow. To examine succession of soil communities across different trophic levels, we investigated four major soil groups: bacteria, fungi, nematodes, and other non-fungal non-nematode microbial eukaryotes at the Puca Glacier in the Peruvian Andes spanning 9-, 24-, and 89-year-old deglaciated soils. This is the first study of microbial communities, other than bacteria, at a high-elevation chronosequence in the Andes Mountains. In addition, we characterized soil biogeochemical properties (e.g., C, N, moisture, and pH) and rates of microbial enzyme activities associated with C, N, and P acquisition. We found significantly correlated increases in estimated richness and high species turnover in all soil groups along the chronosequence. These shifts in soil communities were significantly correlated with microbial enzyme activities and measures of C, N, moisture, and pH. Stoichiometric comparisons of enzyme activities showed phosphorus (P) and carbon (C) limitation of microbial activity across the entire chronosequence with no hint of nitrogen (N) limitation. Taken together, the observed shifts in soil communities and biogeochemistry indicate coordinated increases in trophic complexity and ecosystem functioning during the initial 90 yr of microbial succession along the post-glacial chronosequence of the Puca Glacier.

Two experiments were conducted about the effect of the application of phosphorus (P) or silicon (Si) on the arsenic (As) contents of Japanese mustard spinach (JMS) (Brassica rapa var. perviridis) grown on As contaminated soil (30.6 mg As kg -1 ). The P was applied with four different P fertilizers derived from both organic or inorganic sources viz. chicken manure (CM), bone powder (BP), fused magnesium phosphate (FMP), and super phosphate (SP). The P was applied at two rates (50 and 100 kg citrate soluble P 2 O 5 ha -1 ). The As contents (mg kg -1 dry weight [DW] and/or µg plant -1 ) in the edible part of JMS reduced significantly as compared to the As contents in control plant with the application of P, irrespective of the form of fertilizer and to the application rate of P. There was no significant difference among the P fertilizers as well as the rate of P application in reducing As contents in the plant. The growth of the plant and P concentration in the plant part increased significantly with the application of P. In the Si application experiment, Si was applied from three different sources viz. potassium silicate (PS), magnesium trisilicate pentahydrate (MTP) and lherzolite (LE). Silicon was applied at the rate of 1,050 114 kg SiO 2 ha -1 . The As contents in the edible part of JMS increased, but not significantly, as compared to the As contents in control plant with the application of Si irrespective of the source of Si. There was no significant difference in the As contents in the edible part of the plant among the Si sources. The magnesium content in the plant part was increased significantly with the application of MTP and LE. The growth of the plant and the other mineral concentrations in the plant part was statistically similar as compared to the control plant. The results of two experiments indicated that the application of P could reduce the As contents in the edible part of JMS whereas Si had no effect to reduce As content in JMS under the employed condition.

Tropical forests are the most carbon (C)-rich ecosystems on Earth, containing 25–40% of global terrestrial C stocks. While large-scale quantifi-cation of aboveground biomass in tropical forests has improved recently, soil C dynamics remain one of the largest sources of uncertainty in Earth system models, which inhibits our ability to predict future climate. Globally, soil texture and climate predict B 30% of the variation in soil C stocks, so ecosystem models often predict soil C using measures of aboveground plant growth. However, this approach can underestimate tropical soil C stocks, and has proven inaccurate when compared with data for soil C in data-rich northern ecosystems. By quantifying soil organic C stocks to 1 m depth for 48 humid tropical forest plots across gradients of rainfall and soil fertility in Panama, we show that soil C does not correlate with common predictors used in models, such as plant biomass or litter production. Instead, a structural equation model including base cations, soil clay content, and rainfall as exogenous factors and root biomass as an endoge-nous factor predicted nearly 50% of the variation in tropical soil C stocks, indicating a strong indirect effect of base cation availability on tropical soil C storage. Including soil base cations in C cycle models, and thus emphasizing mechanistic links among nutrients , root biomass, and soil C stocks, will improve prediction of climate-soil feedbacks in tropical forests.

2011. Temporal trends of risk of water contamination by phosphorus from agricultural land in the Great Lakes Watersheds of Canada. Can. J. Soil Sci. 91: 1Á11. The indicator of risk of water contamination by phosphorus (IROWC_P) was designed to estimate the level of risk of P contamination in water and how the level of risk has changed over 25 yr (1981Á2006) in agricultural watersheds of Canada. IROWC_P allows for a qualitative assessment of this risk in comparison with other regions of eastern and western Canada, and the identification of high to very high risk watersheds may require on-site assessment and the development of remedial action plans. This study presents an in-depth analysis of IROWC_P results in the major Great Lakes watersheds of Canada. The risk of water contamination by P remains acceptable (very low to moderate) in most Great Lakes watersheds, but better management practices (e.g., reduced fertilization and manure application rates) and improved control of surface runoff may be required in watersheds which are at increased risk. The Canadian watersheds of the Great Lakes basin showed a 39% reduction in their P applications in excess of crop requirements between 1981 and 2006 bringing the Ontario provincial P-balance close to equilibrium in 2006. Vulnerable areas were found south of Kitchener in the Lower Grand River watershed and east of Lake Simcoe.

The main source cause pollution in urban storm water are urban landscape runoff (fertilizer, animal waste and plant waste), inappropriately operation of septic systems. Alum sludge from waterworks has been occupied as a low cost phosphate removal. The dewatered alum sludge has content of aluminum being discharge to landfill and it can reduce the landfill lifespan. Over disposal of alum sludge can generate the massive dumping costing to the country. This study investigates the green technology for the preservation of the environment and to enhance the phosphate treatment. This finding attempts to determine the effectiveness of dewatered water treatment alum sludge as a filter media to remove phosphate from wastewater. The vertical column test approach with constant flow rate was used in this study. Alum sludge was prepared in 2.36 mm sieve size in dry condition and three different variations of water, i.e. river water, water from wastewater treatment plant and phosphate solution water. The test was monitored over one month and measured the phosphate residual with standard method. The results indicated removal phosphorus in beginning of contact time at 30% -90 %. The maximum percentage removal is 91% -98 % in various condition. From the result, Malaysian alum sludge has potential for phosphate removal in storm water and surface runoff application.

In high-elevation lakes of the Sierra Nevada (California), increases in phosphorus (P) supply have been inferred from changes in phytoplankton growth during summer. To quantify rates of sediment P release to highelevation Sierran lakes, we performed incubations of sediment cores under ambient and reducing conditions at Emerald Lake and analyzed long-term records of lake chemistry for Emerald and Pear lakes. We also measured concentrations of individual P forms in sediments from 50 Sierra Nevada lakes using a sequential fractionation procedure to examine landscape controls on P forms in sediments. On average, the sediments contained 1,445 lg P g -1 , of which 5 % was freely exchangeable, 13 % associated with reducible metal hydroxides, 68 % associated with Al hydroxides, and the remaining 14 % stabilized in recalcitrant pools. Multiple linear regression analysis indicated that sediment P fractions were not well correlated with soluble P concentrations. In general, sediments behaved as net sinks for P even under reducing conditions. Our findings suggest that internal P loading does not explain the increase in P availability observed in highelevation Sierran lakes. Rather, increased atmospheric P inputs and increased P supply via dissolved organic C leaching from soils may be driving the observed changes in P biogeochemistry.

The amount, quality, and turnover of soil P is influenced by climate and changes in soil management. The objectives of this study were to evaluate the influence of edaphic properties, mean annual precipitation, and P-fertilization on soil organic P. 31 P-NMR spectroscopy was applied to investigate P forms of forest soils of the Central Western Spain. The concentrations of NaOHextractable inorganic-P were significantly higher in fertilized than in natural soils. Monoester-P was the dominant organic-P species in both natural and fertilized soils, representing between 19 and 54% of NaOH-extractable P. The highest concentrations of monoester-P were observed in the soil with higher content of Fe oxides. The high charge density of monoester-P allows rapid adsorption on soil minerals and extensive interaction with sesquioxides that protect inositols from degradation. Diester-P represented between 3 and 17% of alkali-extractable P, reflecting a relatively low microbial activity in the soils on schists with a high content of Al and Fe oxides.

Appropriate management of phosphorus (P) in soil will lead to higher yields and sustainability for sugarcane production. Our study evaluated the importance of differences in root structure and function, and the differential composition of the bacterial community in four sugarcane cultivars, in relation to the efficiency for P uptake and also to assess changes in soil P with distance from the rhizoplane. Experiments were performed in pot trials using a sandy clay loam Ferralsol. In the first experiment, the effect of P application (78.4 mg P kg-1 soil astriple superphosphate) on sugarcane cultivars RB92-579; RB85-5156; RB86-7515 and RB96-6928 was investigated. Secondly, we evaluated P rates of 0; 9.8; 19.6; 39.2 and 78.4 mg kg-1 soil using cultivar RB96-6928 which was shown to be one of the more growth responsive cultivars. The cultivar RB96-6928 exhibited the highest root dry matter and root surface area, while the bacterial communities found in the rhizosphere of these plants were not different from other cultivars, as determined by PCR-DGGE. From the P dose-dependent experiment for this cultivar, optimal plant performance occurred at a P supply up to 38.5 mg P kg-1 soil. Collectively, our results indicate that P efficiency in sugarcane was predominantly associated with the generation of high root biomass and surface area.

Information on the different forms and availability of P following compost addition to soil may help to better manage manure in respect to plant growth and the environment. An experiment was conducted to investigate through a sequential extraction procedure the availability of P of fresh dairy manure and several on-farm compost-soil mixtures after a 13 wk incubation in glass jars at 35°C. Materials were mixed at a rate of 200 mg N kg–1 with an Arago sandy loam (Humo-Ferric
Podzol), supplying from 64 to 301 mg P kg–1. Fresh dairy manure gave the highest net increase of resin-P and labile P fractions in terms of percentage of total P added, whereas poultry litter compost was the most efficient in increasing NaHCO3-inorganic P (-Pi). Among compost materials, poultry litter, vegetable residue and sheep manure increased labile P fraction the most. The contribution of the young dairy manure compost to this fraction was largely negative, and lower than those of fresh manure or partially and well-decomposed manure composts. A large part of added P was found in the moderately labile P fraction. The organic P (Po) fractions in the soil were less affected by manure or compost addition. This study indicated that the material P availability was reduced by composting, and was more affected by the origin of residue than by manure management.

Information on the forms and bioavailability of P from composts applied to horticultural crops under organic production are required to promote soil quality and plant growth while protecting the environment. Seven composts were selected and characterized for their chemical composition. The composts were mostly mature and the total P contained 73 to 96% as inorganic P (Pi), although the total P concentration and P fractions varied amongst the materials selected for this study. These composts along with an inorganic P (KH2PO4) alone were added to three soils with contrasting chemical properties at a rate equivalent to 65 kg P ha-1 and incubated in the dark at 25°C. An unfertilized control was included to estimate soil P contribution. The amount and relative solubility of P from these compost-soil mixtures were evaluated by a modified Hedley fractionation after 2 and 16 wk of incubation. Results indicated that P added with composts was preferentially found in the Pi portion of soil labile pools after 2 and 16 wk. Except for the dairy cattle manure compost, all composts resulted in the same amounts of labile P (51-58%) and total Pi (61-98%) in soils, which were significantly lower than the labile P (82%) and close to the total Pi (108%) from inorganic KH2PO4 alone. Unlike the other composts, the potato residue compost produced a significant increase in the organic P fraction (Po) extractable with NaHCO3. This study indicated that Pi was the most important form of P in these composts and in the compost-amended soils. Nevertheless, it remains difficult to predict the availability of compost P following its application to soil.

Forests growing on highly weathered soils
are often phosphorus (P) limited and competition
between geochemical and biological sinks affects
their soil P dynamics. In an attempt to elucidate the
factors controlling the relative importance of these
two sinks, we investigated the relationship of between
soil microbial growth kinetics and soil chemical
properties following amendments with C, N and P
in six South African forest soils. Microbial growth kinetics were determined from respiration curves
derived from measurements of CO2 effluxes from
soil samples in laboratory incubations. We found that
microbial growth rates after C + N additions were
positively related to NaOH-extractable P and decreased
with soil depth, whereas the lag time (the time
between substrate addition and exponential growth)
was negatively related to extractable P. However, the
growth rate and lag time were unrelated to the soil’s
sorption properties or Al and Fe contents. Our results
indicate that at least some of the NaOH-extractable
inorganic P may be biologically available within a
relatively short time (days to weeks) and might be
more labile than previously thought. Our results also
show that microbial utilization of C + N only seemed
to be constrained by P in the deeper part of the soil
profiles.

Based on the assumption that silicate application can raise soil P availability
for crops, the aim of this research was to compare the effect of silicate application
on soil P desorption with that of liming, in evaluations based on two extractors and
plant growth. The experiment was carried out in randomized blocks with four
replications, in a 3 × 3 × 5 factorial design, in which three soil types, three P rates,
and four soil acidity correctives were evaluated in 180 experimental plots. Trials
were performed in a greenhouse using corn plants in 20-dm3 pots. Three P rates (0,
50 and 150 mg dm-3) were applied in the form of powder triple superphosphate
and the soil was incubated for 90 days. After this period, soil samples were collected
for routine chemical analysis and P content determination by the extraction
methods resin, Mehlich-1 and remaining P. Based on the results, acidity correctives
were applied at rates calculated for base saturation increased to 70 %, with
subsequent incubation for 60 more days, when P content was determined again.
The acidity correctives consisted of: dolomitic lime, steelmaking slag, ladle furnace
slag, and wollastonite. Therefore, our results showed that slags raised the soil P
content more than lime, suggesting a positive correlation between P and Si in soil.
Silicon did not affect the extractor choice since both Mehlich-1 and resin had the
same behavior regarding extracted P when silicon was applied to the soil. For all
evaluated plant parameters, there was significant interaction between P rates
and correctives; highest values were obtained with silicate.

We explore the application of an inexpensive and less-invasive method of discovering community patterning at a series of complex sites in the glacio-lacustrine region of northern Ohio. In this pilot study we employ systematic soil phosphate (SP) and soil magnetic susceptibility (MS) analysis on these three northeast Ohio archaeological sites. This is the first such effort in the Lake Erie basin to combine SP and MS surveys to understand site activity structure. We investigate activity
patterning at three northern Ohio habitation sites: White Fort (33Ln2), a multi-component, Late Prehistoric (Sandusky Tradition) site in Lorain County; Burrell Orchard (33Ln15), a multi-component site with a substantial Late Archaic component in Lorain County; and Heckelman (33Er14), a multicomponent Woodland Period enclosure and habitation in Erie County. The analysis of SP was complicated by extremely high values, in one case reaching an apparent saturation point, and complex occupation histories. The combination of both MS and P makes for a robust survey strategy to identify details of activity structure even at places with complex and overlapping use histories. We demonstrate the promise and problems of this analytical technique and shed light on the applicability
of this method of prospection to the glacio-lacustrine region of Ohio. Especially when used in a multipronged research design, soil analysis is a powerful supplement to traditional techniques that enables whole-site analysis without full excavation.