scholarly journals Phosphorus forms and their distribution under long-term no tillage systems

2019 ◽  
Vol 65 (No. 1) ◽  
pp. 35-40
Author(s):  
Kai Wei ◽  
Zhenhua Chen ◽  
Xiaoping Zhang ◽  
Lijun Chen
Keyword(s):  
Management Practice ◽  
Crop Growth ◽  
No Tillage ◽  
Soil P ◽  
P Loss ◽  
Phosphorus Forms ◽  
Significant Difference ◽  
Mouldboard Plough ◽  
P Fertilizers

Phosphorus (P) stratification in no-tillage (NT) systems has important implications for crop growth and potential P loss, but little is known about P forms and their distribution when mineral P fertilizers are placed to the depth of 5 cm in NT soil. A 10-year field experiment was used to study the effect of NT and mouldboard plough (MP) on soil P forms at three depths (0–5, 5–10 and 10–20 cm) and their relationship with Fe and Al oxides. The results indicated that stratification of organic P forms occurred under NT treatment, and Fe oxides may have a stronger capacity for adsorbing the P forms. When mineral P fertilizers were placed to the depth of 5 cm under NT treatment, there was no significant difference in P forms or crop yield between NT and MP treatment, and orthophosphate did not show any significant difference under NT treatment between 0–5 cm and 5–10 cm depth. Overall, the agricultural management practice that mineral P fertilizers are placed to the depth of 5 cm under NT treatment could result in stratification of P forms, while the changes in the distribution of P forms in soil profiles might help reduce potential P loss in surface runoff and do not make any difference to crop growth.

Long-term effects of no-tillage management practice on soil organic carbon and its fractions in the northern China

Geoderma ◽  
2014 ◽  
Vol 213 ◽  
pp. 379-384 ◽  
Author(s):  
Enke Liu ◽  
Saba Ghirmai Teclemariam ◽  
Changrong Yan ◽  
Jianmin Yu ◽  
Runsheng Gu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practice ◽  
Northern China ◽  
No Tillage ◽  
Long Term Effects

How Can Soil P Balance Influence Soil Test P? A case study from the Argentinian Pampas

2018 ◽  
Vol 102 (4) ◽  
pp. 11-13
Author(s):  
Florencia Sucunza ◽  
Flavio Gutiérrez Boem ◽  
Fernando García ◽  
Miguel Boxler ◽  
Gerardo Rubio
Keyword(s):  
Soil Test ◽  
Soil P ◽  
Soil Test P ◽  
P Balance ◽  
Study Sites ◽  
Single Response ◽  
The Impact ◽  
P Fertilizers

Data from long-term crop rotation study sites were combined to evaluate the effect of long-term application (and omission) of P fertilizers. The impact of maintaining either a negative or positive P balances on soil test P at five distinct sites was described by single response functions despite a range of differences in soil properties.

Changes in soil phosphorus availability and potential phosphorus loss following cessation of phosphorus fertiliser inputs

Soil Research ◽  
2013 ◽  
Vol 51 (5) ◽  
pp. 427 ◽  
Author(s):  
R. J. Dodd ◽  
R. W. McDowell ◽  
L. M. Condron
Keyword(s):  
Agricultural Soils ◽  
Soil Phosphorus ◽  
Pasture Production ◽  
Soil P ◽  
Olsen P ◽  
P Loss ◽  
P Concentration ◽  
Rate Of Decline ◽  
P Retention

Long-term application of phosphorus (P) fertilisers to agricultural soils can lead to in the accumulation of P in soil. Determining the rate of decline in soil P following the cessation of P fertiliser inputs is critical to evaluating the potential for reducing P loss to surface waters. The aim of this study was to use isotope exchange kinetics to investigate the rate of decline in soil P pools and the distribution of P within these pools in grazed grassland soils following a halt to P fertiliser application. Soils were sourced from three long-term grassland trials in New Zealand, two of which were managed as sheep-grazed pasture and one where the grass was regularly cut and removed. There was no significant change in total soil P over the duration of each trial between any of the treatments, although there was a significant decrease in total inorganic P on two of the sites accompanied by an increase in the organic P pool, suggesting that over time P was becoming occluded within organic matter, reducing the plant availability. An equation was generated using the soil-P concentration exchangeable within 1 min (E1 min) and P retention of the soil to predict the time it would take for the water-extractable P (WEP) concentration to decline to a target value protective of water quality. This was compared with a similar equation generated in the previous study, which used the initial Olsen-P concentration and P retention as a predictor. The use of E1 min in place of Olsen-P did not greatly improve the fit of the model, and we suggest that the use of Olsen-P is sufficient to predict the rate of decline in WEP. Conversely, pasture production data, available for one of the trial sites, suggest that E1 min may be a better predictor of dry matter yield than Olsen-P.

A comparison of tillage, direct drilling and lime on springtail communities in a long-term field trial in poland

2017 ◽  
Vol 63 (2) ◽  
pp. 17-24
Author(s):  
Izabella Olejniczak ◽  
Stanisław Lenart
Keyword(s):  
Spring Barley ◽  
Relative Proportion ◽  
Conventional Tillage ◽  
Research Station ◽  
No Tillage ◽  
Clear Trend ◽  
Growing Seasons ◽  
Collembolan Species ◽  
Mouldboard Plough

In 2009 and 2010, we examined the effects of different tillage systems on springtail communities. The study was established on the experimental field, in which tillage and no-tillage cultivation had been conducted since 1975, of the Research Station of the Warsaw University of Life Sciences’ Department of Agronomy, located at Chylice, near Warsaw (52005’N, 20033’E).The treatments considered were conventional tillage with a mouldboard plough (CT) and no-tillage (NT), and each method was divided between with and without liming. In 2009, the fields were sown with winter wheat, and spring barley was planted the following year. During both growing seasons, collembolan densities were higher under NT than CT, but the reverse was true after harvest. However, the time of the season had a significant effect on collembolan densities not only over the whole study period but also in particular years. Additionally, in fields that were limed, collembolan densities varied, with no clear trend. The dominant collembolan species in the CT and NT fields was Isotoma viridis Bourlet, 1839, while Paristoma notabilis (Schäffer, 1896) was prevalent when liming was used. The relative proportion of each of the two species in springtail communities was at least 20 percent. The species diversity of collembolan communities was similar in both study years, and it was higher in CT than in NT fields.The study was financially supported as part of the MNiSW project No. N N305171136.

Relation between soil P test values and mobilization of dissolved and particulate P from the plough layer of typical Danish soils from a long-term field experiment with applied P fertilizers

2013 ◽  
Vol 29 (3) ◽  
pp. 297-305 ◽  
Author(s):  
N. Glaesner ◽  
C. Kjaergaard ◽  
G. H. Rubaek ◽  
J. Magid
Keyword(s):  
Field Experiment ◽  
Soil P ◽  
Soil P Test ◽  
Plough Layer ◽  
P Fertilizers ◽  
Term Field

scholarly journals Effects and Mechanisms of Phosphate Activation in Paddy Soil by Phosphorus Activators

2020 ◽  
Vol 12 (9) ◽  
pp. 3917
Author(s):  
Huanli Yao ◽  
Xian Chen ◽  
Junying Yang ◽  
Jihong Li ◽  
Jiale Hong ◽  
...  
Keyword(s):  
Humic Acid ◽  
Paddy Soil ◽  
Field Experiments ◽  
Rice Yield ◽  
Alpha Diversity ◽  
Water Soluble ◽  
Utilization Efficiency ◽  
Soil P ◽  
P Loss ◽  
P Fertilizers

Phosphorus (P) build-up in agricultural soils as a consequence of excessive P fertilizer application necessitates the exploration of soil P pool for crop supply. We conducted a soil incubation experiment, pot experiments, and field experiments to study the effects of different P activators (Pas) (humic acid, lignosulfonate sodium, and biochemical humic acid) on soil phosphate fraction, rice yield, and P loss. Through chemical analyses and microbial community structure measurement, we found that Pas significantly increased paddy soil water-soluble P (WSP), available P, Fe-P, and relative abundances of P-mineralizing and P-solubilizing microorganisms, whereas they decreased Al-P and microbial alpha diversity. Our pot experiment results showed that the application of Pas significantly reduced soil P loss and resulted in grain yield comparable to those obtained by fertilization with P fertilizers, and significantly higher than those in the control plants. The results of the field experiment suggested that Pas are able to increase rice yield more significantly than P fertilizers and improve the P utilization efficiency of rice plants. We conclude that application of Pas was more effective in reducing P leaching, soil total P, WSP, and Olsen P than P fertilizers during rice harvest.

scholarly journals Chemical, Biological, and Biochemical Parameters of the Soil P Cycle After Long-Term Pig Slurry Application in No-Tillage System

2017 ◽  
Vol 41 (0) ◽  
Author(s):  
Tales Tiecher ◽  
Tadeu Luis Tiecher ◽  
Fábio Joel Kochem Mallmann ◽  
Mohsin Zafar ◽  
Carlos Alberto Ceretta ◽  
...  
Keyword(s):  
Biochemical Parameters ◽  
Pig Slurry ◽  
No Tillage ◽  
Soil P ◽  
Tillage System ◽  
P Cycle

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Calibration of methods for soil and diagnostic plant analysis in the Hungarian National Fertilization Long-term Trials. I. Comparison of soil P tests for agronomic purposes in the soils of long-term experiments

2011 ◽  
Vol 60 (2) ◽  
pp. 343-358
Author(s):  
Péter Csathó ◽  
Marianna Magyar ◽  
Erzsébet Osztoics ◽  
Katalin Debreczeni ◽  
Katalin Sárdi
Keyword(s):  
Plant Analysis ◽  
Soil P ◽  
Olsen P ◽  
Long Term Experiments ◽  
Soil P Tests

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.

Percutaneous glycerol rhizotomy for trigeminal neuralgia in patients with multiple sclerosis: a long-term retrospective cohort study

2020 ◽  
Vol 132 (5) ◽  
pp. 1405-1413 ◽  
Author(s):  
Michael D. Staudt ◽  
Holger Joswig ◽  
Gwynedd E. Pickett ◽  
Keith W. MacDougall ◽  
Andrew G. Parrent
Keyword(s):  
Multiple Sclerosis ◽  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Retrospective Chart Review ◽  
Medication Usage ◽  
Free Response ◽  
Free Survival ◽  
Time To Recurrence ◽  
Significant Difference

OBJECTIVEThe prevalence of trigeminal neuralgia (TN) in patients with multiple sclerosis (MS-TN) is higher than in the general population (idiopathic TN [ITN]). Glycerol rhizotomy (GR) is a percutaneous lesioning surgery commonly performed for the treatment of medically refractory TN. While treatment for acute pain relief is excellent, long-term pain relief is poorer. The object of this study was to assess the efficacy of percutaneous retrogasserian GR for the treatment of MS-TN versus ITN.METHODSA retrospective chart review was performed, identifying 219 patients who had undergone 401 GR procedures from 1983 to 2018 at a single academic institution. All patients were diagnosed with medically refractory MS-TN (182 procedures) or ITN (219 procedures). The primary outcome measures of interest were immediate pain relief and time to pain recurrence following initial and repeat GR procedures. Secondary outcomes included medication usage and presence of periprocedural hypesthesia.RESULTSThe initial pain-free response rate was similar between groups (p = 0.726): MS-TN initial GR 89.6%; MS-TN repeat GR 91.9%; ITN initial GR 89.6%; ITN repeat GR 87.0%. The median time to recurrence after initial GR was similar between MS-TN (2.7 ± 1.3 years) and ITN (2.1 ± 0.6 years) patients (p = 0.87). However, there was a statistically significant difference in the time to recurrence after repeat GR between MS-TN (2.3 ± 0.5 years) and ITN patients (1.2 ± 0.2 years; p < 0.05). The presence of periprocedural hypesthesia was highly predictive of pain-free survival (p < 0.01).CONCLUSIONSPatients with MS-TN achieve meaningful pain relief following GR, with an efficacy comparable to that following GR in patients with ITN. Initial and subsequent GR procedures are equally efficacious.

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