Phosphorus levels in croplands of the European Union with implications for P fertilizer use

tIn the frame of the Land Use/Land Cover Area Frame Survey sampling of topsoil was carried out on around22,000 points in 25 EU Member States in 2009 and in additional 2 Member States in 2012. Besidesother basic soil properties soil phosphorus (P) content of the samples were also measured in a singlelaboratory in both years. Based on the results of the LUCAS topsoil survey we performed an assessmentof plant available P status of European croplands. Higher P levels can be observed in regions where highercrop yields can be expected and where high fertilizer P inputs are reported. Plant available phosphoruslevels were determined using two selected fertilizer recommendation systems: one from Hungary andone from the United Kingdom. The fertilizer recommendation system of the UK does not recommendadditional fertilizer use on croplands with highest P supply, which covers regions mostly in Belgiumand the Netherlands. According to a Hungarian advisory system there is a need for fertilizer P input inall regions of the EU. We established a P fertilizer need map based on integrating results from the twosystems. Based on data from 2009 and 2012, P input demand of croplands in the European Union wasestimated to 3, 849, 873 tons(P2O5)/year. Meanwhile we found disparities of calculated input need andreported fertilizer statistics both on local (country) scale and EU level. The first ever uniform topsoilP survey of the EU highlights the contradictions between soil P management of different countries ofthe Union and the inconsistencies between reported P fertilizer consumption and advised P doses. Ouranalysis shows a status of a baseline period of the years 2009 and 2012, while a repeated LUCAS topsoilsurvey can be a useful tool to monitor future changes of nutrient levels, including P in soils of the EU

Biogeochemistry of Icelandic Andosols

Studying biological parameters of northern latitude soils is of importance because of their high capacity to sequester organic matter. A consequence of climate change and the resulting increasing temperatures in the Arctic may be the shift from such soils being carbon sinks to becoming unmanageable carbon sources. Despite the relative harshness of the climate and the limited growing season, Icelandic soils are productive when cultivated and there is evidence of the emergence of a warmer and wetter climate. A key issue will be a consideration of the impact of intensive cultivation on the soils, landscape and general environmental parameters. This thesis studied the effect of climate, land use, fertilisation and soil pedological properties on Icelandic Andosols biology. Icelandic agricultural soils biological parameters were affected by land use were fertilisation seamed to suppress nitrogen mineralisation in cultivated fields. Furthermore, there were indications that an increase in soil moisture content promoted either nitrogen immobilisation or denitrification limiting inorganic N availability to the standing vegetation. They were adapted to perform around the freezing point. Soil respiration and enzymatic activities were measured down to a soil temperature of -10°C. Around the freezing point enzymatic activities and soil respiration was governed by availability of labile carbon. The soil microbial biomass carbon pool was not affected by different climatic variables (rainfall, air and soil temperatures) or fertilisation treatments. In comparison to other soils sampled in Scotland, Icelandic soils had a considerably larger microbial biomass carbon pools but their biological activity was significantly lower. This was mainly related to their pedological properties promoting high carbon sequestration and low C availability to microorganisms.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Phosphorus levels in croplands of the European Union with implications for P fertilizer use

In the frame of the Land Use/Land Cover Area Frame Survey sampling of topsoil was carried out on around 22.000 points in 25 EU Member States in 2009 and in additional 2 member States in 2012. Beside other basic soil properties soil phosphorus (P) content of the samples were also measured in a single laboratory in both years. Based on the results of the LUCAS Topsoil survey we performed an assessment of plant available P status of European croplands. Higher P levels can be observed in regions where higher crop yields can be expected and where high fertiliser P inputs are reported. Plant available phosphorus levels were determined using two selected fertilizer recommendation systems; one from Hungary and one from the United Kingdom. The fertiliser recommendation system of the UK does not recommend additional fertiliser use on croplands with highest P supply, which covers regions mostly in Belgium and the Netherlands. According to a Hungarian advisory system there is a need for fertilizer P input in all regions of the EU. We established a P fertiliser need map based on integrating results from the two systems. Based on data from 2009 and 2012, P input demand of croplands in the European Union was estimated to 3,849,873 tons(P2O5)/year. In the meanwhile we found disparities of calculated input need and reported fertiliser statistics both on local (country) scale and on EU level. The first ever uniform topsoil P survey of the EU highlights the contradictions between soil P management of different countries of the Union while also highlights the inconsistencies between reported P fertiliser consumption and advised P doses. Our analysis shows a status of a baseline period of the years 2009 and 2012, while a repeated LUCAS topsoil survey can be a useful tool to monitor future changes of nutrient levels, including P in soils of the EU.JRC.H.5-Land Resources Managemen

Phosphorus levels in croplands of the European Union withimplications for P fertilizer use

tIn the frame of the Land Use/Land Cover Area Frame Survey sampling of topsoil was carried out on around22,000 points in 25 EU Member States in 2009 and in additional 2 Member States in 2012. Besidesother basic soil properties soil phosphorus (P) content of the samples were also measured in a singlelaboratory in both years. Based on the results of the LUCAS topsoil survey we performed an assessmentof plant available P status of European croplands. Higher P levels can be observed in regions where highercrop yields can be expected and where high fertilizer P inputs are reported. Plant available phosphoruslevels were determined using two selected fertilizer recommendation systems: one from Hungary andone from the United Kingdom. The fertilizer recommendation system of the UK does not recommendadditional fertilizer use on croplands with highest P supply, which covers regions mostly in Belgiumand the Netherlands. According to a Hungarian advisory system there is a need for fertilizer P input inall regions of the EU. We established a P fertilizer need map based on integrating results from the twosystems. Based on data from 2009 and 2012, P input demand of croplands in the European Union wasestimated to 3, 849, 873 tons(P2O5)/year. Meanwhile we found disparities of calculated input need andreported fertilizer statistics both on local (country) scale and EU level. The first ever uniform topsoilP survey of the EU highlights the contradictions between soil P management of different countries ofthe Union and the inconsistencies between reported P fertilizer consumption and advised P doses. Ouranalysis shows a status of a baseline period of the years 2009 and 2012, while a repeated LUCAS topsoilsurvey can be a useful tool to monitor future changes of nutrient levels, including P in soils of the EU.JRC.H.5-Land Resources Managemen

The effect of season and management practices on soil microbial activities undergoing nitrogen treatments - interpretation from microcosm to field scale

The warming of Arctic regions is causing higher winter and spring temperatures, less snow cover and intensifying seasonal patterns, which in turn have led to a longer growing season in colder regions. In Iceland the climate has become warmer and wetter with lengthening of the growing season and a corresponding increase in arable production. The aim of this study was to assess the effect of seasons and management practices on soil microbial biomass, nitrification, enzymatic activities and labile C availability. A parallel soil microcosms study was conducted to identify the key drivers in a controlled environment. Seasons had a more pronounced effect on soil microbial attributes (dehydrogenase activity, soil microbial biomass and labile C) than soil management with microbial attributes being greater in warmer summer months. This was an indication that continuing climate change and corresponding increase in dehydrogenase activity and soil microbial biomass in soils may increase carbon decomposition and hence loss of organic carbon from cultivated soils in Iceland. Management had a greater impact on soil N dynamics than seasons. There was evidence that precipitation promoted immobilisation of NO3 - -N in soils suggesting that the wetter climate developing in Iceland might reduce the availability of NO3 - -N to crops. Labile C was a governing factor in soil microbial activity as was demonstrated both in the field and the laboratory.Loftlagsbreytingar á norðurhveli jarðar hafa aukið hitastig bæði yfir vetrar og sumarmánuði, skerpt skil milli árstíða, minnkað snjóhulu, og þar með aukið landnýtingarmöguleika á norðlægum slóðum. Svipaðar breytingar hafa verið að þróast hér á landi þar sem hita- og rakastig í andrúmslofti hefur hækkað og lengt vaxtatímabilið auk þess sem hlutdeild ræktarlands stækkar. Megin markmið þessarar rannsóknar var að rannsaka áhrif árstíða og landnýtingar á jarðvegslífmassa, umsetningu niturs, virkni ensíma og aðgengilegt, auðbrjótanlegt lífrænt kolefni í jarðvegi en allir þessir þættir gegna veigamiklu hlutverki í næringarefnahringrás jarðvegs. Samhliða tilraunum við náttúrulegar aðstæður voru gerðar tilraunir við staðlaðar aðstæður inn á rannsóknastofu til að öðlast dýpri skilning á umhverfisbreytum á borð við árstíðabundnar hitastigsbreytingar sem og breytilegum styrk auðbrjótanlegs kolefnis frá plönturótum við náttúrulegar aðstæður. Í heildina höfðu árstíðir meiri áhrif á virkni vetnissvipta ensíma, heildar lífmassa og auðleysanlegt kolefni en landnýting, en einnig var virknin meiri yfir hlýrri sumarmánuði. Þetta telst vera vísbending um að hlýnandi veðurfar hér á landi gæti aukið niðurbrot lífrænna efna í jarðvegi og þar með aukið losun kolefnis út í umhverfið. Landnýting hafði hins vegar afgerandi áhrif á niturhringrás (umsetningu og bindingu) jarðvegsins í samanburði við árstíðir. Aukin úrkoma benti til þess að binding NO3 - -N jókst innan lífmassa jarðvegsins en aukin úrkoma í tengslum við hlýnandi veðurfar á Íslandi gæti þar með minnkað aðgengi ræktarplantna á NO3 - -N. Örveruvirkni jarðvegsins var háð framboði auðleysanlegs kolefnis í jarðveginum en bæði mælingar við náttúrulegar og staðlaðar aðstæður sannreyndu þá niðurstöðu

Bioremediation trial on aged PCB polluted soils - A bench study in Iceland

Polychlorinated biphenyls (PCBs) pose a threat to the envuronment due to their high adsorption capacity to soil organic matter, stability and low reactivity, low water solubility, toxicity and ability to accumulate. With Icelandic soils, research on contamination issies has been very limited, and no data has been reported either on PCB degradation potential or rate. The goals of this research were to assess the bioavailability of aged PBCs in the soils of the old NATO facility in Keflavík, Iceland, and to find the best feasable biostimulation method to decrease the pollution. The effectiveness of different iostimulation additives at different temperatures and oxygen levels were tested. PCB bioavailability to soil fauna was assessed with earthworms (Eisenia foetia). PCBs were biovailable to earthworms, with less chlorinated congeners showing higher bioaccumulation factors than highly chlorinated congeners. Biostimulation with pine needles at 10 degrees under aerobic conditions resulted in nearly 38% degradation of total PCBs after two months incubation. Detection of aerobic PCB degrading bphA gene supports the indigenous capability of the soils to aerobically degrade PCBs.JRC.H.5-Land Resources Managemen

The lithium isotope response to the variable weathering of soils in Iceland

This study has analysed Li isotopes ratios from well-studied soil and pore water profiles from Iceland that have the same parent material but have experienced different degrees of chemical weathering. Thus, from least to most weathered, we have analysed vitrosols (V), gleyic andosols (GA), brown andosols (BA), Histosols (H) and Histic Andosols (HA). Although the most weathered H and HA soils have the highest content in clay-sized material, they have the least fractionated δ7Lipore water values. In contrast, the least weathered GA and BA pore waters are most fractionated for Li isotopes. Given that Li isotope ratios are fractionated by clay mineral formation, this appears counter-intuitive. A single trend for all samples of δ7Li as a function of Li/Na ratios suggests that they are all controlled by a process with a single fractionation factor, in this case likely the formation of poorly-crystalline allophane, which dominates in the “least weathered” soils. This rapidly forming secondary mineral dominates Li isotope fractionation over more slowly-forming crystalline clays. The fractionation along a single path shows that the key process here in controlling the Li isotope ratio of surface waters is the degree of Li uptake by secondary minerals. This does not necessarily correspond to the amount of clay minerals present in the soil, but to the amount of clay minerals that are being newly formed in a single passage of the pore water through the soil, or are in equilibrium with soil solutions at the time of sampling