Aims A field experiment was conducted to investigate the effect of biochar on maize yield and greenhouse gases (GHGs) in a calcareous loamy soil poor in organic carbon from Henan, central great ...plain, China. Methods Biochar was applied at rates of 0, 20 and 40 tha−1 with or without N fertilization. With N fertilization, urea was applied at 300 kg N ha−1, of which 60% was applied as basal fertilizer and 40% as supplementary fertilizer during crop growth. Soil emissions of CO2, CH4 and N2O were monitored using closed chambers at 7 days intervals throughout the whole maize growing season (WMGS). Results Biochar amendments significantly increased maize production but decreased GHGs. Maize yield was increased by 15.8% and 7.3% without N fertilization, and by 8.8% and 12.1% with N fertilization under biochar amendment at 20 tha−1 and 40 tha−1, respectively. Total N2O emission was decreased by 10.7% and by 41.8% under biochar amendment at 20 tha−1 and 40 tha−1 compared to no biochar amendment with N fertilization. The high rate of biochar (40 tha−1) increased the total CO2 emission by 12% without N fertilization. Overall, biochar amendments of 20 tha−1 and 40 tha−1 decreased the total global warming potential (GWP) of CH4 and N2O by 9.8% and by 41.5% without N fertilization, and by 23.8% and 47.6% with N fertilization, respectively. Biochar amendments also decreased soil bulk density and increased soil total N contents but had no effect on soil mineral N. Conclusions These results suggest that application of biochar to calcareous and infertile dry croplands poor in soil organic carbon will enhance crop productivity and reduce GHGs emissions.
In ASIACCS 2015, Nuñez, et al. proposed a proxy re-encryption scheme, named NTRUReEncrypt, based on NTRU, which allows a proxy to translate ciphertext under the delegator’s public key into a ...re-encrypted ciphertext that can be decrypted correctly by delegatee’s private key. Because of the potential resistance to quantum algorithm, high efficiency and various applications in real life, NTRUReEncrypt has drawn lots of attention and its security has been widely discussed and analyzed. In PQCrypto2019, Liu, et al. proposed two key recovery attacks against it. However, their first attack heavily relies on a weaken decryption oracle, and the second attack needs to collect about 2
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ciphertexts from the same message by theoretical analysis, which makes both of the attacks unrealistic. In this paper, inspired by the broadcast attack against NTRU, the authors find out that for NTRUReEncrypt the delegator and the delegatee can efficiently recover each other’s private key in polynomial time without any unrealistic assumptions. In addition, the authors also show how to fix NTRUReEncrypt to resist the proposed attacks. As a by-product, the authors also show how to commit broadcast attacks against NTRU 2001 with even
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, which was thought infeasible before.
▶ Biochar increased rice yield at 10% while N fertilization could be saved for a rice yield of 9t/ha. ▶ Biochar increased methane emission but reduced N2O emission. ▶ Biochar significantly reduced ...emission factor of N fertilizer.
A field trial was performed to investigate the effect of biochar at rates of 0, 10 and 40tha−1 on rice yield and CH4 and N2O emissions with or without N fertilization in a rice paddy from Tai Lake plain, China. The paddy was cultivated with rice (Oryza sativa L., cv. Wuyunjing 7) under a conventional water regime. Soil emissions of CH4 and N2O were monitored with a closed chamber method throughout the whole rice growing season (WRGS) at 10 day intervals. Biochar amendments of 10tha−1 and 40tha−1 increased rice yields by 12% and 14% in unfertilized soils, and by 8.8% and 12.1% in soils with N fertilization, respectively. Total soil CH4-C emissions were increased by 34% and 41% in soils amended with biochar at 40tha−1 compared to the treatments without biochar and with or without N fertilization, respectively. However, total N2O emissions were sharply decreased by 40–51% and by 21–28%, respectively in biochar amended soils with or without N fertilization. The emission factor (EF) was reduced from 0.0042kgN2O-Nkg−1 N fertilized with no biochar to 0.0013kgN2O-Nkg−1 N fertilized with biochar at 40tha−1. The results show that biochar significantly increased rice yields and decreased N2O emission, but increased total CH4 emissions. Summary calculations based on this experiment data set provide a basis for estimating the potential reductions in GHG emissions that may be achieved by incorporating biochar into rice paddy soils in south-eastern China.
► Biochar amendment of 10tha−1, 20tha−1 and 40tha−1 increased rice productivity in both rice cropping cycles. ► Biochar amendment seemed no effect on soil respiration in two cycles, decreased nitrous ...oxide emission but increased methane emission which significantly decreased in the second cycle compared to that of in the first cycle. ► Biochar amendment decreased global warming potential and C intensity of rice production in the second cycle but in the first cycle.
Biochar production and application from crop straw had been proposed as one effective countermeasure to mitigate climate change. We conducted a 2-year consecutive field experiment in 2009 and 2010 in rice paddy to gain insight into the consistency over years of biochar effects on rice production and greenhouse gases emissions. Biochar was amended in 2009 before rice transplanting at rates of 0, 10, 20 and 40tha−1, soil emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) were monitored with closed chamber method at 7 days interval throughout the whole rice growing season (WRGS) both in 2009 and 2010. The results showed that biochar amendment increased rice productivity, soil pH, soil organic carbon, total nitrogen but decreased soil bulk density in both cycles of rice growth. Soil respiration observed no significant difference between biochar amendment and the corresponding control both in the first and second cycle, respectively. However, biochar amendment decreased nitrous oxide emission but increased methane emission in both cycles. No significant difference in carbon intensity of rice production (GHGI) and global warming potential (GWP) were observed between the biochar amendment at the rate of 10tha−1 and 40tha−1 and control though the GWP and GHGI was increased by 39% and 26% at the rate of 20tha−1 respectively, in the first cycle. However, in the second cycle, both of overall GWP and GHGI were observed significantly decreased under biochar amendment as compared to control, ranging from 7.1% to 18.7% and from 12.4% to 34.8%, respectively. The biochar effect intensity on global warming potential were observed from −2.5% to 39.2% in the first cycle, and from −18.7% to −7.1% in the second cycle. However, the biochar effect intensity on C intensity of rice production was observed from −10.2% to 25.8% in the first cycle, and from −36.9% to −18.6% in the second cycle. Therefore, biochar effect on reducing the overall C intensity of rice production could become stronger in the subsequent cycles than that in the first cycle though a consistently strong effect on reducing N2O emission in a single crop cycle after biochar amendment. Nevertheless, these effects were not found in proportional to biochar amendment rates and a high rice yield but lowest C intensity was achieved under biochar amendment at 10tha−1 in both cycles of the rice paddy in the present study.
•We reported changes in bacterial community under biochar amendment in three fields.•Biochar consistently increased soil pH, SOC and microbial biomass in three paddies.•Biochar consistently increased ...bacterial abundance and diversity in three paddies.•Changes in bacterial community structure were inconsistent across the three paddies.•Biochar is suggested to potentially affect the soil C and N cycling of the rice soil ecosystem.
Biochar functionality related to soil microbial community changes has not yet been fully understood. In this study, we present a cross site field experiment on bacterial community changes of rice paddies among three sites (Jiangxi province, JX; Hunan province, HN; and Sichuan province, SC) from South China with biochar amended (BSA) at 0, 20 and 40t ha−1 before rice plantation in 2010. Changes in bacterial abundance and diversity of topsoil (0-15cm) sampled at rice harvest were assessed. Increases in soil pH, soil organic carbon, total N, soil microbial biomass, as well as bacterial gene copy numbers and diversity indices (phylogenetic diversity, Shannon, Chao1 and OTU richness) were consistently observed under BSA at 40t ha−1, though generally insignificant at 20tha−1 across the sites. Cluster analysis of both terminal restriction fragment length polymorphism (T-RFLP) profiles and pyrosequencing of the 16S gene indicated a strong impact of biochar on bacterial community composition, though the changes were variable across the sites. In particular, BSA at 20 and 40tha−1 greatly increased the relative abundance of Betaproteobacteria (by 54% and 80%) and Deltaproteobacteria (by 164% and 151%) in JX while decreased Betaproteobacteria (by 46% and 52%) and increased Chloroflexi (by 27% and 61%) in SC site, respectively. However, no significant changes were detected in HN site. In addition, some significant but variable changes were observed in the abundance of nitrifying, denitrifying and N-fixing bacteria groups with biochar addition among sites. This study suggested a potential role of biochar in enhancing bacterial abundance, community diversity and modifying the community compositions, particularly of the bacteria involved in N cycling. However, changes in soil microbial structure and functioning related to biochar treatment deserve further studies.
•We reported changes in microbial community under biochar amendment in a field study.•Biochar soil amendment (BSA) increased bacterial but decreased fungal gene abundance.•Both bacterial and fungal ...community structure were clearly affected by BSA.•Changes in soil enzyme activities could partially support the above findings.•BSA could potentially affect the soil C and N cycling of the rice soil ecosystem.
Biochar’s role on greenhouse gas emission and plant growth has been well addressed. However, there have been few studies on changes in soil microbial community and activities with biochar soil amendment (BSA) in croplands. In a field experiment, biochar was amended at rates of 0, 20 and 40tha−1 (C0, C1 and C2, respectively) in May 2010 before rice transplantation in a rice paddy from Sichuan, China. Topsoil (0–15cm) was collected from the rice paddy while rice harvest in late October 2011. Soil physico-chemical properties and microbial biomass carbon (MBC) and nitrogen (MBN) as well as selected soil enzyme activities were determined. Based on 16S rRNA and 18S rRNA gene, bacterial and fungal community structure and abundance were characterized using terminal-restriction fragment length polymorphism (T-RFLP) combined with clone library analysis, denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR assay (qPCR). Contents of SOC and total N and soil pH were increased but bulk density decreased significantly. While no changes in MBC and MBN, gene copy numbers of bacterial 16S rRNA was shown significantly increased by 28% and 64% and that of fungal 18S rRNA significantly decreased by 35% and 46% under BSA at 20 and 40tha−1 respectively over control. Moreover, there was a significant decrease by 70% in abundance of Methylophilaceae and of Hydrogenophilaceae with an increase by 45% in Anaerolineae abundance under BSA at 40tha−1 over control. Whereas, using sequencing DGGE bands of fungal 18S rRNA gene, some bands affiliated with Ascomycota and Glomeromycota were shown inhibited by BSA at rate of 40tha−1. Significant increases in activities of dehydrogenase, alkaline phosphatases while decreased β-glucosidase were also observed under BSA. The results here indicated a shift toward a bacterial dominated microbial community in the rice paddy with BSA.
•A two-year field experiment was conducted in rainfed maize cropland.•Balanced fertilization and biochar addition increased maize yield greatly.•Balanced fertilization reduced N2O emission.•It is a ...low carbon agriculture with balanced fertilization and biochar amendment.
Maize production plays an important role in global food security, especially in arid and poor-soil regions. Its production is also increasing in China in terms of both planting area and yield. However, maize productivity in rainfed croplands is constrained by low soil fertility and moisture insufficiency. To increase the maize yield, local farmers use NPK fertilizer. However, the fertilization regime (CF) they practice is unbalanced with too much nitrogen in proportion to both phosphorus and potassium, which has led to low fertilizer use efficiency and excessive greenhouse gases emissions. A two-year field experiment was conducted to assess whether a high yielding but low greenhouse gases emission system could be developed by the combination of balanced fertilization (BF) and biochar amendment in a rainfed farmland located in the Northern region of China. Biochar was applied at rates of 0, 20, and 40t/ha. Results show that BF and biochar increased maize yield and partial nutrient productivity and decreased nitrous oxide (N2O) emission. Under BF the maize yield was 23.7% greater than under CF. N2O emissions under BF were less than half that under CF due to a reduced N fertilizer application rate. Biochar amendment decreased N2O by more than 31% under CF, while it had no effect on N2O emissions under BF. Thus BF was effective at maintaining a high maize yield and reducing greenhouse gases emissions. If combined with biochar amendment, BF would be a good way of sustaining low carbon agriculture in rainfed areas.
Postoperative delirium (POD) is a very common complication in elderly patients with gastric cancer (GC) and associated with poor prognosis. MicroRNAs (miRNAs) serve as key post-transcriptional ...regulators of gene expression via targeting mRNAs and play important roles in the nervous system. This study aimed to investigate the potential predictive role of miRNAs for POD.
Elderly GC patients who were scheduled to undergo elective curative resection were consequently enrolled in this study. POD was assessed at 1 day before surgery and 1-7 days after surgery following the guidance of the 5th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM V, 2013). The demographics, clinicopathologic characteristics and preoperative circulating miRNAs by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were compared between patients with or without POD. Risk factors for POD were assessed via univariate and multivariate logistic regression analyses.
A total of 370 participants were enrolled, of which 63 had suffered from POD within postoperative 7 days with an incidence of 17.0%. Preoperative miR-210 was a predictor for POD with an area under the curve (AUC) of 0.921, a cut-off value of 1.67, a sensitivity of 95.11%, and a specificity of 92.06%, (P<0.001). In the multivariate logistic regression model, the relative expression of serum miR-210 was an independent risk factor for POD (OR: 3.37, 95%CI: 1.98-5.87, P=0.003).
In conclusion, the present study highlighted that preoperative miR-210 could serve as a potential predictor for POD in elderly GC patients undergoing curative resection.
•Biochar treatment at 20–40tha−1 reduced rice Cd by 20%–90% from metal polluted rice fields.•Grain Cd under biochar treatment fell in a safe level by 0.4mgkg−1 in soils with Cd in range ...0.16–4.83mgkg−1.•Biochar amendment caused Cd immobilization primarily due to the liming effect by biochar.
Cadmium contamination in croplands has been a serious concern because of its high health risk through soil-food chain transfer. A sudden emergence of Cd-tainted rice from the South China market urged countermeasures to prevent Cd uptake and accumulation in rice grains from Cd-contaminated rice paddies. A cross-site field experiment with biochar soil amendment (BSA) at rates from 20 to 40tha−1 in metal polluted rice fields was conducted across South China during 2010–2011. Samples both of topsoil and rice grains under BSA treatment were collected after rice harvest and soil extractable Cd pool and rice grain Cd level were analyzed. Across the sites, BSA treatment greatly reduced (by 20–90%) rice grain Cd content, and enabled a safe Cd level (<0.4mgkg−1) of rice grain from all these Cd-contaminated rice fields using a 40tha−1 biochar application except in one site where soil had a Cd content over 20mgkg−1. This could be explained by a reduction in the extractable Cd pool in the biochar treated soil, which was closely correlated to the rise in soil pH with BSA treatment. This study demonstrated a promising role of BSA in preventing dangerous Cd accumulation by rice grain in contaminated rice paddies.
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