Effect of crop residue incorporation on soil organic carbon dynamics : changes in carbon stocks and carbon fractions in an Italian long-term field experiment

Increasing the organic matter content in soil improves the soil productivity, its abil-ity to hold water, deliver nutrients and it protects against erosion. It is also a way to sequester carbon (C) as a strategy to mitigate climate change. Straw incorporation is a widespread management practice that can be used for this purpose. However, straw can also be used for other purposes such as feed or bioenergy. The effect of straw incorporation on soil organic carbon (SOC) varies between studies and we need to improve our understanding of the effect of straw incorporation on C dynam-ics in order to use the resource in the best possible way. This study investigates the effect of straw incorporation on SOC stocks as well as C fractions under different nitrogen (N) fertilization levels. By studying different C fractions, and not only the bulk soil, more detailed knowledge is obtained about the C dynamics. For this study, soil samples were taken in 2006 from a long-term field trial in a clay soil in Italy. The results showed that straw incorporation significantly increased the SOC stock with 3.15 Mg ha-1 in the bulk soil. The effect of straw incorporation did de-crease over the years in comparison with earlier results from the long-term experi-ment. The earlier observed effect of N on SOC was no longer present in the bulk soil. After 40 years of treatment, 3.3% of the total C input was retained in the soil. Two fractions were significantly affected by the straw incorporation, the non-resistant C associated with clay and silt particles (SC-rSOC) and the dissolved or-ganic carbon. No significant effect due to residue treatment was found in the other fractions and N fertilization had no significant effect in any of the fractions. The C fraction varying most was the particulate organic matter followed by the fraction of C attached to sand particles and stable aggregates. The resistant fraction did not change with straw incorporation and seems to be insensitive to the treatments in a decadal perspective. Most C was stored in the SC-rSOC fraction and this was also the fraction that showed the highest significant increase after straw incorporation. Since this is believed to be one of the most stable fractions, straw incorporation might lead to a long-term C sequestration even though the absolute amount C se-questered was small

Är kolrika jordar en källa till fosforläckage?

Phosphorus (P) is an essential nutrient but a surplus could lead to eutrophication. Furthermore, the minerals used to produce the mineral phosphate is a non renewable resource. There are in other words several reasons to reduce the leakage of P and the agriculture is one important area to attend. The aim of this work has been to investigate if carbon-rich arable soils content contain more P than arable soils with low carbon content. Moreover it has been calculated if the carbon-rich soils could pose a risk of P leakage by comparing their delivery of P with the plant uptake. The work has consisted of compiling the results from former gathered and analysed soil samples of 130 Swedish arable soils. The fractions of P considered are water soluble P (Pw), ammonium lactate-extractable P (P-AL), hydrochloric acid-soluble P (P-HCl), organic ammonium lactate-extractable P (Porg-AL) and inorganic ammonium lactate-extractable P (Porg-HCl). The P-AL and P-HCl has been analysed both with colorimetric method, which detects the inorganic fraction and ICP, which detects the inorganic as well as the organic fraction. The diference between these values has given the value of Porg-AL and Porg-HCl, respectively. The results show that there is a strong correlation between Pw and P-AL, which implies the possibility to make a realicstic estimation of the amount of P in the soil solution by measuring the P-AL fraction. With the colorimetric method it is also shown not to exist any relation between P and the carbon content, whilst there with the ICP method exists a relation. This suggests that for carbon-rich soils, the colorimetric method could give an defective perception of the P content. It may therefore be advisable to consider other methods for such soils. The majority of the soils investigated present a risk of P leakage. The carbon-rich soils often contain the highest concentration of P, however the soils with low carbon content contain the highest amounts of P. That indicates that the soils with low carbon content might pose a greater risk of leakage. Nevertheless, carbon-rich soils contain more organic carbon, which is a more mobile form of P and therefore is more easily transported to aquatic ecosystems. Based on this work it is difficult to conclude which kind of soil presents the greatest risk of leakage since the leakage is the result of many different processes taking part in complex systems.Fosfor (P) är ett essentiellt närinsämne för alla organismer men kan i överskott leda till övergödning av vattendrag. Dessutom är mineralerna ur vilka mineralfosfat utvinns en icke-förnyelsebar resurs. Det finns alltså flera orsaker till att minska läckaget av P och ett viktigt område att förbättra är jordbruket. Syftet med det här arbetet har dels varit att undersöka om åkerjordar med hög kolhalt innehåller mer P än åkerjordar med låg kolhalt, dels att ta reda på ifall kolrika åkerjordar utgör en risk för P-läckage genom att jämföra P-leveransen med växtupptaget. Arbetet är en sammanställning av resultat från tidigare insamlade och analyserade jordprover från 130 åkerjordar. En marks fosforleverande förmåga påverkas dels av mängden P och dels av hur lättrörlig P är, vilket bland annat beror på i vilken form den förekommer. De P-fraktioner som har undersökts i arbetet är vattenlöslig P (Pw), utbytbar P (P-AL), förråds-P (P-HCl), organisk utbytbar P (Porg-AL) och organisk förråds-P (Porg-HCl). För P-AL och P-HCl har fosforhalten mätts med kolorimetrisk metod, vilken mäter oorganisk P samt med ICP, vilken mäter både oorganisk och organisk P. Skillnaden mellan de båda metoderna har gett värdet på Porg-AL respektive Porg-HCl. Resultaten visar att det finns ett starkt samband mellan Pw och P-AL. Det innebär att det är möjligt att göra en realistisk uppskattning av hur mycket vattenlöslig P jorden leverar genom att mäta P-AL-värdet. Vidare visar studien att P-AL och P-HCl inte ökar med kolhalten om kolorimetrisk analys används medan det däremot syns en ökning när halterna analyseras med ICP. Det tyder på att P-halter mätta med kolorimetrisk metod inte ger en representativ bild av jordarnas P-innehåll vid höga kolhalter. För kolrika jordar bör det därför övervägas att analysera fosforhalten med hjälp av andra metoder. De flesta undersökta jordarna utgör en risk för P-läckage. De kolrika jordarna innehåller i många fall högre koncentration P, men mineraljordarna leverar de största mängderna. Det tyder på att mineraljordarna kan utgöra större risk för P-läckage. Dock innehåller kolrika jordar mer organiskt kol som är mer lättrörligt och därför lättare kan transporteras till olika vattensystem. Utifrån det här arbetet är det svårt att avgöra vilka jordar som utgör störst risk för läckage eftersom det faktiska läckaget påverkas av komplexa system med många påverkande faktorer

Qualitative and quantitative response of soil organic carbon to 40 years of crop residue incorporation under contrasting nitrogen fertilisation regimes

Crop residue incorporation (RI) is recommended to increase soil organic carbon (SOC) stocks. However, the positive effect on SOC is often reported to be relatively low and alternative use of crop residues, e.g. as a bioenergy source, may be more climate smart. In this context, it is important to understand: (i) the response of SOC stocks to long-term crop residue incorporation; and (ii) the qualitative SOC change, in order to judge the sustainability of this measure. We investigated the effect of 40 years of RI combined with five different nitrogen (N) fertilisation levels on SOC stocks and five SOC fractions differing in turnover times on a clay loam soil in Padua, Italy. The average increase in SOC stock in the 0–30cm soil layer was 3.1Mgha–1 or 6.8%, with no difference between N fertilisation rates. Retention coefficients of residues did not exceed 4% and decreased significantly with increasing N rate (R2=0.49). The effect of RI was higher after 20 years (4.6Mgha–1) than after 40 years, indicating that a new equilibrium has been reached and no further gains in SOC can be expected. Most (92%) of the total SOC was stored in the silt and clay fraction and 93% of the accumulated carbon was also found in this fraction, showing the importance of fine mineral particles for SOC storage, stabilisation and sequestration in arable soils. No change was detected in more labile fractions, indicating complete turnover of the annual residue-derived C in these fractions under a warm humid climate and in a highly base-saturated soil. The applied fractionation was thus useful to elucidate drivers and mechanisms of SOC formation and stabilisation. We conclude that residue incorporation is not a significant management practice affecting soil C storage in warm temperate climatic regions

Effects of Solution Elicitation Aids and Need for Cognition on the Generation of Solutions to Ill-Structured Problems

Numerous techniques have been proposed to assist problem solvers in the solution generation process. We empirically examined the effectiveness of a solution elicitation technique based on the presentation of problem objectives and also examined whether the technique was effective across individual differences in need for cognition (NC). We found that when two conflicting objectives were presented successively, more solutions, more categories of solutions, and more effective solutions were generated than when the same two objectives were presented simultaneously or not at all. However, the results indicated that effective solutions may be more efficiently generated by considering objectives simultaneously. Need for cognition was positively related to measures of divergent thinking, and the presentation of objectives was particularly effective as a solution elicitation aid for individuals with low NC. Implications for creative problem-solving research and practice are discussed

Self-Reported Leadership Experiences in Relation to Inventoried Social and Emotional Intelligence

Leadership has both social and emotional components. Social intelligence appears to tap the social component found in leadership. Recently, emotional intelligence has surfaced as a stable individual difference variable and appears to tap the emotional component of leadership. Mayer and Salovey (1993) suggested that the emotional intelligence and social intelligence constructs overlap. This study examined the power of both emotional and social intelligence to account for variance in self-reported leadership experiences. One hundred ninety-two university students completed measures of social and emotional intelligence and a measure of leadership experiences. Regression analyses showed that both social intelligence and emotional intelligence accounted for variance in leadership experiences. Although emotional intelligence was found to account for variance in leadership, it did not add unique variance beyond social intelligence. Social intelligence appears to play a principal role in leadership

Conscientiousness Is Not Always a Good Predictor of Performance: The Case of Creativity

Meta-analyses investigating the relationship between Conscientiousness and performance suggest a positive relationship for a variety of criteria. However, recently it has been argued that Conscientiousness is not always a good predictor of performance, particularly for creative performance. Additionally, it has been suggested that Conscientiousness includes two distinct components, achievement and dependability, which may have different relationships with criterion measures. Two studies were conducted to determine whether the components of Conscientiousness predict creativity better than the full factor. Students in each study completed a measure of the Five Factor Model and a measure of creative performance. In the first study, creative accomplishments were measured and in the second study, creative problem solving was measured. As predicted, both studies revealed a cooperative suppression effect when analyzing the conscientiousness components together such that achievement was positively related and dependability negatively related to creative performance. Also, both studies showed that the overall Conscientiousness factor was not related to creativity

The Future of the Public Trust: The Muddied Waters of Rockweed Management in Maine

Seaweeds, or more properly, intertidal macroalgae have never been easy to classify—by law or by science: they are not part of the animal kingdom, nor part of the plant kingdom (and scientific controversies about their phylogenetic placement abound), they are not completely on terra firma, nor completely submerged in ocean water. One such organism that exists at the space in between land and sea—the brown alga commonly known as Rockweed (Ascophyllum nodosum) presents an intriguing legal question with implications that extend far beyond the shoreline. Recently, in Ross v. Acadian Seaplants Ltd. , the Supreme Judicial Court of Maine (Court) ruled that Rockweed located within the intertidal zone is the property of the adjacent upland property owner, and therefore the public cannot enter intertidal lands to harvest Rockweed as a matter of right—a right that has been preserved for the harvest of shellfish species, fish species, and bird species. The legal status of Rockweed is important to the scientists that study its ecological benefits, the harvesters that collect it for commercial purposes, the state agency concerned with its sustainable management as a marine resource, and the coastal landowners that assert that seaweed is their private property. This article explores the legal justification for—and practical resource management issues associated with—the Court’s decision to treat a marine organism such as Rockweed that derives its nutrients from ocean water and not through a root system as private property

Self-sampling tools to increase cancer screening among underserved patients: A pilot randomized controlled trial

BACKGROUND: Screening can reduce cancer mortality, but uptake is suboptimal and characterized by disparities. Home-based self-sampling can facilitate screening for colorectal cancer (with stool tests, eg, fecal immunochemical tests) and for cervical cancer (with self-collected human papillomavirus tests), especially among patients who face barriers to accessing health care. Additional data are needed on feasibility and potential effects of self-sampling tools for cancer screening among underserved patients. METHODS: We conducted a pilot randomized controlled trial with patients (female, ages 50-65 years, out of date with colorectal and cervical cancer screening) recruited from federally qualified health centers in rural and racially segregated counties in Pennsylvania. Participants in the standard-of-care arm (n = 24) received screening reminder letters. Participants in the self-sampling arm (n = 24) received self-sampling tools for fecal immunochemical tests and human papillomavirus testing. We assessed uptake of screening (10-week follow-up), self-sampling screening outcomes, and psychosocial variables. Analyses used Fisher exact tests to assess the effect of study arm on outcomes. RESULTS: Cancer screening was higher in the self-sampling arm than the standard-of-care arm (colorectal: 75% vs 13%, respectively, odds ratio = 31.32, 95% confidence interval = 5.20 to 289.33; cervical: 79% vs 8%, odds ratio = 72.03, 95% confidence interval = 9.15 to 1141.41). Among participants who returned the self-sampling tools, the prevalence of abnormal findings was 24% for colorectal and 18% for cervical cancer screening. Cancer screening knowledge was positively associated with uptake (P \u3c .05). CONCLUSIONS: Self-sampling tools can increase colorectal and cervical cancer screening among unscreened, underserved patients. Increasing the use of self-sampling tools can improve primary care and cancer detection among underserved patients. CLINICAL TRIALS REGISTRATION NUMBER: STUDY00015480

Emerging implications of policies on malaria treatment: genetic changes in the Pfmdr-1 gene affecting susceptibility to artemether-lumefantrine and artesunate-amodiaquine in Africa.

Artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ) are the most commonly used artemisinin-based combination therapies (ACT) for treatment of Plasmodium falciparum in Africa. Both treatments remain efficacious, but single nucleotide polymorphisms (SNPs) in the Plasmodium falciparum multidrug resistance 1 (Pfmdr1) gene may compromise sensitivity. AL and AS-AQ exert opposing selective pressures: parasites with genotype 86Y, Y184 and 1246Y are partially resistant to AS-AQ treatment, while N86, 184 F and D1246 are favoured by AL treatment. Through a systematic review, we identified 397 surveys measuring the prevalence of Pfmdr1 polymorphisms at positions 86 184 or 1246 in 30 countries in Africa. Temporal trends in SNP frequencies after introduction of AL or AS-AQ as first-line treatment were analysed in 32 locations, and selection coefficients estimated. We examined associations between antimalarial policies, consumption, transmission intensity and rate of SNP selection. 1246Y frequency decreased on average more rapidly in locations where national policy recommended AL (median selection coefficient(s) of -0.083), compared with policies of AS-AQ or both AL and AS-AQ (median s=-0.035 and 0.021, p<0.001 respectively). 86Y frequency declined markedly after ACT policy introduction, with a borderline significant trend for a more rapid decline in countries with AL policies (p=0.055). However, these trends could also be explained by a difference in initial SNP frequencies at the time of ACT introduction. There were non-significant trends for faster selection of N86 and D1246 in areas with higher AL consumption and no trend with transmission intensity. Recorded consumption of AS-AQ was low in the locations and times Pfmdr1 data were collected. SNP trends in countries with AL policies suggest a broad increase in sensitivity of parasites to AS-AQ, by 7-10 years after AL introduction. Observed rates of selection have implications for planning strategies to cycle drugs or use multiple first-line therapies to maintain drug efficacy

Recanalization strategies in childhood stroke in Germany

Childhood arterial ischemic stroke (CAIS) is a rare event. Diverse etiologies, risk factors, symptoms and stroke mimics hamper obtaining a fast diagnosis and implementing immediate recanalization strategies. Over a period of 3~years (2015-2017), the data of 164 pediatric patients (> 28~days of life-18~years) with a first episode of AIS were submitted to a hospital-based nationwide surveillance system for rare disorders (ESPED). We report a subgroup analysis of patients who have undergone recanalization therapy and compare these data with those of the whole group. Twenty-eight patients (17%) with a median age of 12.2~years (range 3.3-16.9) received recanalization therapy. Hemiparesis, facial weakness and speech disturbance were the main presenting symptoms. The time from onset of symptoms to confirmation of diagnosis was significantly shorter in the intervention group (4.1~h vs. 20.4~h, p ≤ 0.0001). Only in one patient occurred a minor bleed. Cardiac disease as predisposing risk factor was more common in the recanalization group. Recanalization therapies are feasible and increasingly applied in children with AIS. High awareness, timely diagnosis and a large amount of expertise may improve time to treatment and make hyperacute therapy an option for more patients