scholarly journals Microscale Heterogeneous Distribution and Speciation of Phosphorus in Soils Amended with Mineral Fertilizer and Cattle Manure Compost

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 121
Author(s):  
Noriko Yamaguchi ◽  
Toshiaki Ohkura ◽  
Atsuko Hikono ◽  
Yohey Hashimoto ◽  
Aomi Suda ◽  
...  

Global concerns for the sustainability of agriculture have emphasized the need to reduce the use of mineral fertilizer. Although phosphorus (P) is accumulated in farmland soils due to the long-term application of fertilizer, most soil P is not readily available to plants. The chemical speciation of P in soils, which comprise heterogeneous microenvironments, cannot be evaluated with a high degree of specificity using only macroscopic analyses. In this study, we investigated the distribution and speciation of P accumulated in soils by using both macro- and microscopic techniques including chemical extraction, solution and solid-state 31P NMR, bulk- and micro- P K-edge X-ray absorption near edge structure (XANES), and electron probe microanalysis (EPMA). Soil samples were collected from a field in which cabbage was cultivated under three amendment treatments: i) mineral fertilizer (NPK), ii) mineral fertilizer and compost (NPK + compost), and iii) mineral fertilizer plus compost but without nitrogen fertilizer (PK + compost). Macro-scale analyses suggested that accumulated P was predominantly inorganic P and associated with Al-bearing minerals. The repeated application of compost to the soils increased the proportion of P associated with Ca which accounted for 17% in the NPK + compost plot and 40% in the PK + compost plot. At the microscale, hot spots of P were heterogeneously distributed, and P was associated with Fe and Ca in hot spots of the NPK + compost (pH 6) and PK + compost (pH 7) treated samples, respectively. Our results indicate that application of compost contributed to creating diverse microenvironments hosting P in these soils.

Soil Systems ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 11
Author(s):  
Wakene Negassa ◽  
Dirk Michalik ◽  
Wantana Klysubun ◽  
Peter Leinweber

Previous studies, conducted at the inception of rewetting degraded peatlands, reported that rewetting increased phosphorus (P) mobilization but long-term effects of rewetting on the soil P status are unknown. The objectives of this study were to (i) characterize P in the surface and subsurface horizons of long-term drained and rewetted percolation mires, forest, and coastal peatlands and (ii) examine the influence of drainage and rewetting on P speciation and distributions using wet-chemical and advanced spectroscopic analyses. The total P was significantly (p < 0.05) different at the surface horizons. The total concentration of P ranged from 1022 to 2320 mg kg−1 in the surface horizons and decreased by a factor of two to five to the deepest horizons. Results of the chemical, solution 31P nuclear magnetic resonance (NMR), and P K-edge X-ray absorption near-edge structure (XANES) indicated that the major proportions of total P were organic P (Po). In the same peatland types, the relative proportions of Po and stable P fractions were lower in the drained than in the rewetted peatland. The results indicate that long-term rewetting not only locks P in organic matter but also transforms labile P to stable P fractions at the surface horizons of the different peatland types.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Nina Siebers ◽  
Liming Wang ◽  
Theresa Funk ◽  
Sabine von Tucher ◽  
Ines Merbach ◽  
...  

Abstract Background The phosphorus (P) stocks of arable subsoils not only influence crop production but also fertilizer P sequestration. However, the extent of this influence is largely unknown. This study aimed to (i) determine the extent of P sequestration with soil depth, (ii) analyze P speciation after long-term P fertilization, and (iii) compare soil P tests in predicting crop yields. We analyzed four long-term fertilizer trials in Germany to a depth of 90 cm. Treatments received either mineral or organic P, or a combination of both, for 16 to 113 years. We determined inorganic and organic P pools using sequential extraction, and P speciation using 31P nuclear magnetic resonance (NMR) and X-ray absorption near edge structure (XANES) spectroscopy. In addition, we applied three P soil tests, double-lactate (DL), calcium acetate lactate (CAL), and diffusive gradients in thin films (DGT). Results The results suggested that plants are capable of mobilizing P from deeper soil layers when there is a negative P budget of the topsoil. However, fertilization mostly only showed insignificant effects on P pools, which were most pronounced in the topsoil, with a 1.6- to 4.4-fold increase in labile inorganic P (Pi; resin-P, NaHCO3–Pi) after mineral fertilization and a 0- to 1.9-fold increase of organic P (Po; NaHCO3–Po, NaOH–Po) after organic P fertilization. The differences in Po and Pi speciation were mainly controlled by site-specific factors, e.g., soil properties or soil management practice rather than by fertilization. When modeling crop yield response using the Mitscherlich equation, we obtained the highest R2 (R2 = 0.61, P < 0.001) among the soil P tests when using topsoil PDGT. However, the fit became less pronounced when incorporating the subsoil. Conclusion We conclude that if the soil has a good P supply, the majority of P taken up by plants originates from the topsoil and that the DGT method is a mechanistic surrogate of P plant uptake. Thus, DGT is a basis for optimization of P fertilizer recommendation to add as much P fertilizer as required to sustain crop yields but as low as necessary to prevent harmful P leaching of excess fertilizer P.


Author(s):  
Khaled D. Alotaibi ◽  
Melissa Arcand ◽  
Noura Ziadi

Abstract Background Continuous application of phosphorus (P) nutrient in association with its low recovery results in large amounts of P being accumulated in soil in different forms. Use of biochar can be a possible means to mobilize soil legacy P and increase its bioavailability. Therefore, the aim of this study was to identify the potential impact of a range of biochar types on P fractions in a long-term cultivated arid soil with high legacy P content. Methodology The soil was treated with biochar produced from four feedstock sources (BFS): sewage sludge (SSB), olive mill pomace (OPB), chicken manure (CMB), and date palm residues (DRB) pyrolyzed at 300, 500, or 700 °C in addition to an untreated control. The soil biochar mixture was incubated for 1 month followed by soil P fractionations using sequential chemical extraction to separate soil P into: labile (Resin-Pi, NaHCO3-Pi, NaHCO3-Po), moderately labile (NaOH-Pi, NaOH-Po), and non-labile (HCl-Pi and Residual-P) pools. Results Biochar addition clearly influenced most of the soil P fractions; however, the extent of this effect greatly varied depending on BFS and pyrolysis temperature (PT). The most evident biochar impact was observed with labile P pool, with the greatest increase being observed in NaHCO3-Pi fraction in most biochar treatments. Irrespective of PT, SSB and CMB were the most effective biochar type in increasing labile inorganic P; the SSB and CMB increased Resin-Pi by 77 and 206% and NaHCO3-Pi by 200 and 188%, respectively. In contrast, DRB made no changes in any P fraction. Differences in effects of biochar types on labile P is presumably related to the higher content of P in biowaste-based biochar compared to plant-based biochar which have much lower P content. The SSB, CMB, and OPB produced at low temperature reduced HCl-Pi content, indicating that these biochars may have stimulated organic matter decomposition and thereby dissolution of non-labile Ca-associated P to labile P forms. Conclusion Overall, biochar addition appeared to be an effective approach in enhancing legacy P availability in arid soil. However, further studies are necessary to verify these findings in the presence of plant and for a longer period. Graphic abstract


2011 ◽  
Vol 60 (2) ◽  
pp. 343-358
Author(s):  
Péter Csathó ◽  
Marianna Magyar ◽  
Erzsébet Osztoics ◽  
Katalin Debreczeni ◽  
Katalin Sárdi

A szabadföldi trágyázási (tartam)kísérletek eredményeit talaj-, illetve diagnosztikai célú növényvizsgálatok segítségével tudjuk kiterjeszteni, általánosítani – figyelembe véve természetesen a kiterjesztés korlátait is. Célszerűnek láttuk ezen túl a talaj könnyen oldható tápelem-, közöttük P-tartalmát is meghatározni a hazánkban hivatalosan elfogadott AL- (ammónium-laktátos) módszer mellett az Európai Unióban és Észak-Amerikában alkalmazott P-tesztekkel is (CaCl2-, H2O-, Olsen-, Bray1-, LE-, Mehlich3- stb.) a hazai OMTK kísérletek talajmintáiban. A kísérleti helyek talajtulajdonságaiban megnyilvánuló jelentős különbségek lehetőséget adnak rá, hogy a talaj P-teszteket – és a növényi P-felvételt – jellegzetes hazai talajokon, sokszor szélsőséges talajparaméterek mellett vizsgáljuk. Az egyes P-szintek között a 28 év átlagában mintegy évi 50 kg P2O5·ha-1volt a különbség. A P0-szinten mért P-tartalmak jól jelezték az egyes kísérleti helyek talajának eltérő P-ellátottságát, illetve, közvetve, fizikai féleségében, pH és mészállapotában meglévő különbségeket. A P2-szinten – a hazai talajokra, P-igényes növényekre a hazai szabadföldi P-trágyázási tartamkísérleti adatbázisban talált összefüggésekre alapozott – új AL-P határértékek szerint csupán a bicsérdi csernozjom barna erdőtalajon nem javult a P-ellátottság legalább a „jó” szintig. Vizsgálataink megerősítették az AL-módszer függőségét a CaCO3-tartalomtól: a Mehlich3 módszerrel való összefüggésben a karbonátmentes és a karbonátos talajok csoportja erőteljesen elkülönült egymástól. Az AL-P korrekció elvégzése, azaz az AL-P értékeknek egy standard talajtulajdonság-sorra való konvertálása (KA: 36; pH(KCl): 6,8; CaCO3: 0,1%) látványosan csökkentette az AL-módszernek a talaj CaCO3-tartalmától való függőségét. Az AL-P és Olsen-P, valamint a korrigált AL-P és Olsen-P tartalmak összehasonlításában ugynakkor ugyanez az összefüggés nem volt állapítható, ami arra utal, hogy az Olsen módszer bizonyos fokig szintén pH- és mészállapot függő. Kísérleti eredményeink megerősítették a Sarkadi-féle AL-P korrekciós modell helytálló voltát. Fenti megállapításunkat ugyanakkor a növényi P-tartalmakkal való összefüggéseknek is igazolniuk kell. Szükséges tehát a talajvizsgálati eredményeknek a diagnosztikai célú növényvizsgálatokkal, valamint a terméseredményekkel való összevetése. A tartamkísérletek talajai lehetőséget nyújtanak a környezetvédelmi célú P-vizsgálatok értékelésére, a talaj P-feltöltöttsége környezeti kockázatának becslésére. Ezekkel a kérdésekkel a cikksorozat további részeiben kívánunk foglalkozni.


2010 ◽  
Vol 59 (2) ◽  
pp. 295-314 ◽  
Author(s):  
Imre Kádár

Egy műtrágyázási tartamkísérlet 32. évében, 2005-ben vizsgáltuk az eltérő N-, P- és K-ellátottsági szintek és kombinációik hatását a réti csenkesz (Festuca pratensis) vezérnövényű, nyolckomponensű, pillangós nélküli gyepkeverék termésére, fejlődésére és elemtartalmára. A termőhely mészlepedékes csernozjom talaja a szántott rétegben mintegy 3% humuszt, 3–5% CaCO3-ot és 20–22% agyagot tartalmazott, N és K elemekben közepesen, P és Zn elemekben gyengén ellátottnak minősült. A kísérlet 4N×4P×4K = 64 kezelést×2 ismétlést = 128 parcellát foglalt magában. A talajvíz 13–15 m mélyen helyezkedik el, a terület aszályérzékeny. A vizsgált 2005. évben azonban kielégítő mennyiségű (649 mm) csapadék hullott és annak eloszlása is kedvező volt. A gyep telepítése spenót elővetemény után 2000. szeptember 20-án történt gabona sortávra 60 kg·ha–1 vetőmaggal, amelynek 25%-át (15 kg) a réti csenkesz (Festuca pratensis); 21–21%-át (12,6 kg) a nádképű csenkesz (Festuca arundinacea) és az angol perje (Lolium perenne); 9%-át (5,4 kg) a taréjos búzafű (Agropyron cristatum), valamint 6–6%-át (3,6 kg) a vörös csenkesz (Festuca rubra), a réti komócsin (Phleum pratense), a zöld pántlikafű (Phalaris arundinacea) és a csomós ebír (Dactylis glomerata) tette ki. Főbb eredményeink: – A meghatározó N-trágyázás nyomán a szénatermés 5-szörösére emelkedett a két kaszálással a N-kontrollhoz viszonyítva. A maximális 10 t·ha–1 körüli légszáraz szénahozamokat a 300 kg N·ha–1·év–1 N-adag, valamint a 150 mg·kg–1 körüli AL-P2O5-, illetve 150 mg·kg–1 feletti AL-K2O-tartalom biztosította. Növénydiagnosztikai szempontból a nagy terméshez kötődő optimális elemtartalom 2% körüli N- és K-, illetve 0,2–0,3% P-koncentráció volt a szénában. – A két kaszálással felvett minimum (a 2 t·ha–1 körüli szénatermést adó N-kontroll) és maximum (a 10 t·ha–1 körüli szénahozamú, nitrogénnel és PK-vel jól ellátott talajok) elemmennyiségek a következőképpen alakultak: N 21–196 kg, K 39–188 kg, Ca 9–48 kg, Mg 4–22 kg, P 6–21 kg. – Az N×P és N×K kölcsönhatások kifejezettebbé váltak a 2. kaszálás idején. A P 0,18–0,55%, a NO3-N 86–1582 mg·kg–1, a Cu 4,7–7,4 mg·kg–1, a Mo 0,7–4,1 mg·kg–1 extrém értékeket jelzett az N×P kezelések függvényében. Az N×K kezelésekben a K 1,44–2,73%, a Mg 0,26–0,39%, a Na 71–2178 mg·kg–1, a Ba 4,1–9,6 mg·kg–1, a Cd 15–44 µg·kg–1 szélsőértékekkel volt jellemezhető. A Sr a 10–26 mg·kg–1 koncentrációtartományban módosult a P×K-ellátottság nyomán. Élettani, takarmányozástani szempontból az indukált kölcsönhatások nyomon követése elengedhetetlen, amennyiben olyan mérvű tápelemhiányok, illetve aránytalanságok jöhetnek létre, melyek anyagcserezavarokat okozhatnak a növényt fogyasztó állatban.


2021 ◽  
pp. 088626052098781
Author(s):  
Marin R. Wenger ◽  
Brendan Lantz

Prior research suggests that many crime types are spatially concentrated and stable over time. Hate crime, however, is a unique crime type that is etiologically distinct from others. As such, examination of hate crime from a spatial and temporal perspective offers an opportunity to understand hate crime and the spatial concentration of crime more generally. The current study examines the spatial stability of hate crimes reported to the police in Washington, D.C., from 2012 through 2018 using street segments, intersections, and block groups as units of analysis. Findings reveal that hate crime is spatially concentrated, with less than 4% of street segments and intersections experiencing hate crime over the study period. Results reveal a high degree of spatial stability, both year-to-year and over the long term even when restricting the analysis to units that experienced at least one hate crime.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 903 ◽  
Author(s):  
Ivan Trifonov ◽  
Dmitry Trukhan ◽  
Yury Koshlich ◽  
Valeriy Prasolov ◽  
Beata Ślusarczyk

In this study we aimed to determine the extent to which changes in the share of renewable energy sources, their structural complex, and the level of energy security in Eastern Europe, Caucasus and Central Asia (EECCA) countries in the medium- and long-term are interconnected. The study was performed through modeling and determination of the structural characteristics of energy security in the countries. The methodology of the approach to modeling was based on solving the problem of nonlinear optimization by selecting a certain scenario. For the study, the data of EECCA countries were used. The ability of EECCA countries to benefit from long-term indirect and induced advantages of the transformation period depends on the extent to which their domestic supply chains facilitate the deployment of energy transformation and induced economic activity. This study provides an opportunity to assess the degree of influence of renewable energy sources on the level of energy security of countries in the context of energy resource diversification. The high degree of influence of renewable energy sources on energy security in the EECCA countries has been proven in the implementation of the developed scenarios for its increase. Energy security is growing. At the same time, its level depends not only on an increase in the share of renewable sources but also on the structure of energy resources complex of countries, and the development of various renewable energy sources. Therefore, today the EECCA countries are forced not only to increase the share of renewable energy sources but also to attach strategic importance to the structural content of their energy complex.


Author(s):  
Behnam Jahangiri ◽  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
William G. Buttlar

Various agencies have begun to research and introduce performance-related specifications (PRS) for the design of modern asphalt paving mixtures. The focus of most recent studies has been directed toward simplified cracking test development and evaluation. In some cases, development and validation of PRS has been performed, building on these new tests, often by comparison of test values to accelerated pavement test studies and/or to limited field data. This study describes the findings of a comprehensive research project conducted at Illinois Tollway, leading to a PRS for the design of mainline and shoulder asphalt mixtures. A novel approach was developed, involving the systematic establishment of specification requirements based on: 1) selection of baseline values based on minimally acceptable field performance thresholds; 2) elevation of thresholds to account for differences between short-term lab aging and expected long-term field aging; 3) further elevation of thresholds to account for variability in lab testing, plus variability in the testing of field cores; and 4) final adjustment and rounding of thresholds based on a consensus process. After a thorough evaluation of different candidate cracking tests in the course of the project, the Disk-shaped Compact Tension—DC(T)—test was chosen to be retained in the Illinois Tollway PRS and to be presented in this study for the design of crack-resistant mixtures. The DC(T) test was selected because of its high degree of correlation with field results and its excellent repeatability. Tailored Hamburg rut depth and stripping inflection point thresholds were also established for mainline and shoulder mixes.


2021 ◽  
pp. 205789112110192
Author(s):  
Peng Lin

Engaging in disaster relief and, more recently, post-disaster reconstruction in developing countries with critical geoeconomic and geopolitical interests has become an increasingly regular and institutionalized component of China’s evolving humanitarian diplomacy over the past decade. Drawn upon novel evidence from China’s growing disaster-related humanitarian assistance to Nepal and unprecedented engagement in Nepal’s long-term post-earthquake rebuild since 2015, this article explores the dynamics behind China’s transforming humanitarian diplomacy. The findings of this article suggest that: 1) geopolitical and geoeconomic interests, represented by the Belt-and-Road Initiative, serve as a critical driver for the development of China’s bilateral partnership with other countries in the disaster sector; 2) long-term cooperation with underdeveloped countries like Nepal provides China, both government and non-state actors (NSAs), with an effective channel to engage with the international humanitarian community and to internalize humanitarian norms; 3) although humanitarian missions remain contingent and instrumental in China’s international relations, they are laying the foundations for a specialized humanitarian policy area with more relevant normative assets, more professional actors, and more sophisticated institutions; 4) NSAs, represented by private foundations and civil NGOs, have played active roles in the state-dominant cooperation in disaster management. This article also suggests that intensified geopolitical confrontations, such as military clashes between India and China along their disputed borders over the past year, would lead to a high degree of politicization of humanitarian missions and partnerships counter-conducive to humanitarian goals.


2021 ◽  
pp. 38-55
Author(s):  
A. V. Vlasenko ◽  
E. A. Evdokimov ◽  
E. P. Rodionov

The paper summarizes data on modern approaches to the diagnosis, prevention and treatment of severe acute parenchymal respiratory failure of various origins, including ARDS due to bacterial viral pneumonia. The work is based on the data of modern well-organized studies, analysis of international clinical guidelines with a high degree of evidence, as well as the results of our own long-term experimental studies and clinical observations of the treatment of patients with ARDS of various origins, including viral pneumonia of 2009, 2016, 2020. Scientifically grounded algorithms for prevention, differential diagnosis and personalized therapy of severe acute respiratory failure using innovative medical technologies and a wide range of respiratory and adjuvant treatment methods have been formulated. The authors tried to adapt as much as possible the existing current recommendations for the daily clinical practice of anesthesiologists and resuscitators.


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