[Effects of Biochar and Straw on Soil N2O Emission from a Wheat Maize Rotation System].

The effects of biochar and straw return on soil N2O emissions were studied in the winter wheat-summer maize rotation system of intensively farmed land in North China to provide a theoretical basis for N2O emission reduction and the efficient straw utilization. The experiment included the following four treatments:① Control (CK); ② Biochar application at a rate of 9.0 t·(hm2·a)-1 (C); ③ Straw return (SR); and ④ Straw return plus biochar application at a rate of 9.0 t·(hm2·a)-1 (C+SR). The results showed that in the wheat season, the CK treatment showed a slight decrease in soil N2O emission while the SR and C+SR treatments promoted soil N2O emission by 47.4% and 71.8%, respectively. In the maize-growing season, the CK treatment reduced soil N2O emission by 29.8% while the SR and C+SR treatments increased soil N2O emission by 13.4% and 35.8%, respectively. During the wheat-growing season, the soil water, NH4+-N, and MBN content were the main environmental factors affecting N2O emissions; during the maize-growing season, NO3--N, NH4+-N, and MBC content were the main environmental factors affecting emissions. Based on our results, the application of biochar to cropland is an effective option for mitigating greenhouse gas emissions, whereas direct straw return to fields might not be an effective strategy. More research is now needed to examine the effect of the return of straw of different maturity on N2O emissions.

[Effects of Interference with UCA1 and Inhibition of miR-185-5p on Activation, Autophagy and Survival of ß-Catenin Pathway in Non-small Cell Lung Cancer].

OBJECTIVE: To investigate the effect on ß-Catenin pathway by lncRNA urothelial carcinoma associated 1 (UCA1) targeting regulated miR-185-5p in human lung adenocarcinoma A549 cell line. METHODS: A549 cell was selected as the study model and were divided into four groups, blank control group, sh-scramble negative control group (sh-scramble), sh-UCA1 interference group (sh-UCA1), miR-185 inhibitor group (miR-185 inhibitor) and sh-UCA1+ inhibitor group (sh-UCA1+inhibitor). The proliferation-, apoptosis- and autophagy- related protein levels were determined by Western blot. qRT-PCR was employed to detect the mRNA levels of UCA1 and miR-185-5p. The relationship between lnRNA UCA1 and miR-185-5p was validated by bioinformatics analysis and luciferase reporter system assays. BrdU staining was used to detect the cell growth, and immunofluorence staining was performed to measure the content of LC3+ cells. RESULTS: sh-UCA1 significantly decreased UCA1 expression and increased miR-185-5p expression in A549 cells, and inhibited the cell growth and autophagy, while promoted the cell apoptosis (P<0.01). Bioinformatics analysis and luciferase reporter system assays demonstrated that lncRNA UCA1 and miR-185-5 can combine effectively, indicating that they have a targating relationship. sh-UCA1 also significantly inhibited the protein levels of ß-Catenin/TCF-4, Beclin 1 and LC3 Ⅱ, and decreased the cell growth and autophagy by the miR-185-5p; and down-regulated the LC3 expression (P<0.01). CONCLUSION: The effect of UCA1 inhibition for miR-185-5p was decreased by lncRNA UCA1 inference, and released the ß-Catenin/TCF-4, Beclin 1 and LC3 Ⅱ, and further reduced the autophagy and growth in A549 cells.

[Effects of Biochar on Nitrous Oxide Fluxes and the Abundance of Related Functional Genes from Agriculture Soil in the North China Plain].

To explore the effect and mechanism of biochar application in reducing nitrous oxide (N2O) content in agricultural soil, from March 27 to June 5 2015, pot experiments were conducted to study the effects of biochar application rates (CK, C1:5%, C2:10%, C3:15%, and C4:30%) (mass fraction) on soil N2O fluxes and the functional marker genes ammonia monooxygenase (amoA), nirK, nirS, and nosZ, which are responsible for nitrification and denitrification. The results revealed the following. ①The application of low doses of biochar (5%) promoted N2O emission. The application of middle and high doses of biochar reduced N2O emission. Furthermore, the application of biochar (15%) was found to be the best practice to reduce N2O emission. ② At the beginning of the experiment, biochar had a significant effect on the abundance of soil amoA and denitrification bacteria gene. Furthermore, the abundance of AOA and nirS had a significant positive correlation with the biochar rate, and the abundance of nirK gene and biochar rate were significant. There was a significant negative correlation between AOB and nosZ gene abundance and biochar rate. At the end of the experiment, AOA abundance correlated negatively with biochar rate, while there was a significantly positive relationship between AOB abundance and biochar rate. ③ At the beginning of the experiment, the N2O fluxes exhibited a significant negative correlation with AOA and nirS gene, indicating that N2O production was controlled by the abundance of AOA and nirS gene under high soil moisture content. At the end of the experiment, there was a significant positive correlation between N2O flux and nosZ gene, indicating that the production of N2O was regulated by the abundance of nosZ gene under low soil water content. The results of this study showed that the application of biochar altered the abundance of amoA and denitrification bacteria genes, and reduced N2O emission. These results provide a theoretical basis for a rational application of biochar in farmland.

[Effects of Biochar and Organic Fertilizer on Saline-alkali Soil N2 O Emission in the North China Plain].

Based on the winter wheat-summer maize rotation field experiment, the effects of biochar and organic fertilizer on saline-alkali soil N2O emissions in the summer maize season were studied in Binzhou in the Shandong Province to provide a theoretical basis for reducing N2O emissions from saline-alkali soil. The experiment includes six treatments with three replications:CK[N:0.2 t·(hm2·a)-1, P2O5:0.12 t·(hm2·a)-1, K2O:0.2 t·(hm2·a)-1], C1[5 t·(hm2·a)-1biochar], C2[10 t·(hm2·a)-1 biochar], C3[20 t·(hm2·a)-1 biochar], M1[7.5 t·(hm2·a)-1 organic fertilizer], and M2[10 t·(hm2·a)-1 organic fertilizer]. The same nitrogen, phosphorus, and potassium fertilizer was applied for each treatment. The results showed that the dynamic trend of the soil N2O fluxes among different treatments were similar. The peak N2O emissions occurred after fertilization (base fertilizer and topdressing). The N2O cumulative emission fluxes accounted for nearly half of the emissions during the whole growth period, and the N2O emissions of the C1, C2, and C3 treatments were lower than that of CK after fertilization. Compared with CK, the N2O cumulative emissions from C1 and C2 were reduced by 45.3% and 31.6%, respectively, but C3, M1, and M2 increased by 17.3%, 37.4%, and 27.6%, respectively. Biochar and organic fertilizer both affected N2O emission fluxes. Applying biochar can reduce N2O emissions, while organic fertilizer can increase N2O emissions. In summary, biochar has a great advantage in reducing N2O emissions in the farmland.

Effects of Simulated Nitrogen Deposition on Soil Net Nitrogen Mineralization in the Meadow Steppe of Inner Mongolia, China.

Effects of simulated nitrogen (N) deposition on soil net nitrogen mineralization (NNM) were examined in situ during two growing seasons, using the resin-core technique in the semiarid meadow steppe in Inner Mongolia, China. The aim of this study is to clarify the effect of N levels (0, 10, and 20 kg N ha-1yr-1) and forms (NH4+ and NO3-) on soil mineral N and NNM. Our results showed that N levels had no significant differences on soil mineral N and NNM. In the first year, three N treatments ((NH4)2SO4, NH4Cl and KNO3) increased soil NH4+ concentrations but had no significant effects on soil NO3- concentrations. In the second year, (NH4)2SO4 treatment increased soil NO3- concentrations, NH4Cl and KNO3 treatments decreased them. Three N treatments significantly decreased soil NH4+ concentrations in the later stages of the second year. As for the soil NNM, three N treatments had no significant effects on the rates of soil NNM (Rm) and net nitrification (Rn) in the first year, but significantly decreased them in the second year. The contribution of N addition to Rm was higher from (NH4)2SO4 than from NH4Cl and KNO3. However, Soil Rm was mainly affected by soil water content (SWC), accumulated temperature (Ta), and soil total N (TN). These results suggest that the short-term atmospheric N deposition may inhibit soil NNM in the meadow steppe of Inner Mongolia.

Effects of biochar on soil microbial biomass after four years of consecutive application in the north China Plain.

The long term effect of biochar application on soil microbial biomass is not well understood. We measured soil microbial biomass carbon (MBC) and nitrogen (MBN) in a field experiment during a winter wheat growing season after four consecutive years of no (CK), 4.5 (B4.5) and 9.0 t biochar ha(-1) yr(-1) (B9.0) applied. For comparison, a treatment with wheat straw residue incorporation (SR) was also included. Results showed that biochar application increased soil MBC significantly compared to the CK treatment, and that the effect size increased with biochar application rate. The B9.0 treatment showed the same effect on MBC as the SR treatment. Treatments effects on soil MBN were less strong than for MBC. The microbial biomass C∶N ratio was significantly increased by biochar. Biochar might decrease the fraction of biomass N mineralized (KN), which would make the soil MBN for biochar treatments underestimated, and microbial biomass C∶N ratios overestimated. Seasonal fluctuation in MBC was less for biochar amended soils than for CK and SR treatments, suggesting that biochar induced a less extreme environment for microorganisms throughout the season. There was a significant positive correlation between MBC and soil water content (SWC), but there was no significant correlation between MBC and soil temperature. Biochar amendments may therefore reduce temporal variability in environmental conditions for microbial growth in this system thereby reducing temporal fluctuations in C and N dynamics.

[Prediction of winter wheat yield based on crop biomass estimation at regional scale].

Based on the 2004 in situ data of crop yield, remote sensing inversed photosynthetically active radiation (PAR), fraction of photosynthetically active radiation (f(PAR)), climate, and soil moisture in 83 typical winter wheat sampling field of 45 counties in Shijiazhuang, Hengshui, and Xingtai of Hebei Province, a simplified model for calculating the light use efficiency (epsilon) of winter wheat in Huanghuaihai Plain was established. According to the crop accumulated biomass from March to May and corrected by harvest index, the quantitative relationship between crop biomass and crop yield for winter wheat was set up, and applied in the 235 counties in Huanghuaihai Plain region of Hebei Province and Shandong Province and validated by the official crop statistical data at county level in 2004. The results showed that the root mean square error (RMSE) of predicted winter wheat yield in study area was 238.5 kg x hm(-2), and the relative error was 4.28%, suggesting that it was feasible to predict winter wheat yield by crop biomass estimation based on remote sensing data.

[Soil net nitrogen mineralization in the typical temperate grassland].

Soil net nitrogen mineralization rate of three types temperate grassland in Inner Mongolia, China was studied using the resin-core technique. The major results include: the net nitrogen mineralization rate of the Stipa baicalensis meadow grassland, the Aneulolepidum Chinense grassland and the Stipa krylovii grassland were 0.333 kg x (hm2 x d)(-1), 0.316 kg x (hm2 x d)(-1) and 0.211 kg x (hm2 x d)(-1) respectively during the field incubation period of July to October, 2005; Soil net nitrogen mineralization accumulation and rates was remarkably different between phase incubation and continuous incubation during the same field incubation period; Rainfall was one of the main factors affecting nitrogen mineralization. The net nitrogen mineralization rate was correlated with the change of soil moisture in all of the measured sites, the correlation coefficient was 0.80, 0.61 and 0.56.

[Calculation of optical parameters and investigation of luminescence spectra in Sm3+ doped borate glasses].

In the present paper, Sm3+ doped borate glasses (LBLB) with high effective visible fluorescence emission have been synthesized. The absorption and fluorescence spectra of this glass were measured and analyzed. The absorption spectra were fitted by J-O theory, and the intensity parameters omega = (2, 4, 6) were found to be 6.81 x 10(-20), 4.43 x 10(-20), and 2.58 x 10(-20) cm2, respectively, then the relative intensity of spectral lines of every energy level transition, radiative transition probabilities, radiative lifetimes, and fluorescence branching ratio were calculated. Under the excitation of UV light, Sm3+ doped borate glasses (LBLB) emit bright salmon pink light. The excitation spectra indicate that argon laser is an effective excitation source in Sm3+ doped LBLB glasses.

Emission characteristics of carbon dioxide in the semiarid Stipa grandis steppe in Inner Mongolia, China.

Using the static opaque chamber method, the soil respiration rates (SR) were measured through the continuous experiments in situ in semiarid Stipa grandis steppe in Xilin River Basin of Inner Mongolia, China from June 2001 to June 2003, in parallel, the difference between the SR and the ecosystem respiration rates (TER) were compared. The results indicated that the seasonal variations of the SR and TER were obvious with higher emissions in growing season and a relatively low efflux level in non-growing season, furthermore, the negative effluxes were found in the observation site in winter; the annual CO2 efflux of total ecosystem ranged from 160.5 gC/(m2 x a) to 162.8 gC/(m2 x a) and that of soil ranged from 118.7 gC/(m2 x a) to 152.3 gC/(m2 x a). The annual SR accounted for about 74.0% to 93.5% of the annual TER, but the results of Analysis of Variance (ANOVA) indicated that the difference between the annual average TER and SR did not reach the significance level of 0.05. The TER was under similar environmental controls as SR, in growing seasons of drought years, the variations of soil moisture at 0-10 cm and 10-20 cm depth could account for 79.1%-95.6% of the changes of the SR and TER, but in non-growing season, more than 75% of the variations of the SR and TER could be explained by the changes of the ground temperature of soil surface layers.

[Luminescence properties of Pr(3+) and energy transfer characteristics of Pr(3+)-->Gd(3+) in CaSiO3].

The excitation spectrum and the emission spectrum of Pr3+ in CaSiO3 under the room temperature were studied. The emission spectrum was constituted of three emission bands, corresponding to the emissions of the lowest 4f5d states to the 3H4, 3H6, 1G4 of the 4f2 states. The emission of the 3P0 and 1D2 were not observed. The concentration quenching of Pr3+ was due to the radiative and nonradiative energy transfer. There was energy transfer from Pr3+ to Gd3+, with the transfer rate of 10% of the Pr3+ emission rate.