Template-Type: ReDIF-Article 1.0 Author-Name: O.N. Silva Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: A.K.S. Lobato Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: F.W. Ávila Author-Workplace-Name: Center for Agriculture and Health, Cornell University, Ithaca, USA Author-Name: R.C.L. Costa Author-Workplace-Name: Laboratory of the Physiology Advanced, University Federal Rural of the Amazon, Belém, Author-Name: C.F. Oliveira Neto Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: B.G. Santos Filho Author-Workplace-Name: Laboratory of the Physiology Advanced, University Federal Rural of the Amazon, Belém, Author-Name: A.P. Martins Filho Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: R.P. Lemos Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: J.M. Pinho Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: M.B.C.L. Medeiros Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: M.S. Cardoso Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Author-Name: I.P. Andrade Author-Workplace-Name: Nucleus of Basic and Applied Plant Research, University Federal Rural of the Amazon, Paragominas, Brazil Title: Silicon-induced increase in chlorophyll is modulated by the leaf water potential in two water-deficient tomato cultivars Abstract: This study aims to explain the effects of silicon on chlorophyll and to measure gas exchange and carbohydrate levels in two Lycopersicon esculentum cultivars that are exposed to drought. The experimental design used in this study was a randomised combination of five different water and silicon conditions (control, water deficit + 0.00 μmol Si, water deficit + 0.25 μmol Si, water deficit + 1.00 μmol Si, and water deficit + 1.75 μmol Si) applied to the two cultivars (Super Marmante and Santa Cruz). Parameters measured were gas exchanges, chlorophylls, and total soluble carbohydrates. Silicon at concentrations of 0.25, 1.00, and 1.75 μmol induced a gradual increase in the total chlorophyll levels. A correlation analysis revealed a linear, positive interaction between the leaf water potential and the total chlorophyll (r = 0.71; P < 0.05). This study confirmed the hypothesis that silicon has a beneficial effect with regard to chlorophyll. Under water-deficient conditions, both cultivars showed an increase in chlorophyll a when treated with silicon in addition to changes in the total chlorophyll levels. These results were supported by the change in leaf water potential. In addition, a reduction of the effects of water restriction was also observed in the transpiration rate, the stomatal conductance and in the levels of total carbohydrates. Keywords: Lycopersicon esculentum Mill., water deficit, Si, photosynthetic pigments Journal: Plant, Soil and Environment Pages: 481-486 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/213/2012-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/213/2012-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0001.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:213-2012-PSE Template-Type: ReDIF-Article 1.0 Author-Name: Z.X. Niu Author-Workplace-Name: Key Laboratory of Regional Environment and Eco-remediation, Shenyang University, P.R. China Author-Workplace-Name: Environmental Simulation and Pollution Control State Key Joint Laboratory, Beijing Normal University, Beijing, P.R. China Author-Name: X.D. Li Author-Workplace-Name: Liaoning Province Academic of Environmental Science, Shenyang, P.R. China Author-Name: L.N. Sun Author-Workplace-Name: Key Laboratory of Regional Environment and Eco-remediation, Shenyang University, P.R. China Author-Name: T.H. Sun Author-Workplace-Name: Key Laboratory of Regional Environment and Eco-remediation, Shenyang University, P.R. China Author-Workplace-Name: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, P.R. China Title: Changes of three organic acids in the process of Cd and Pb phytoextraction by Helianthus annuus L. Abstract: In the present study, sunflower was used to enrich the cadmium (Cd) and lead (Pb) in sand culture, and the changes of metals uptake, organic acids, pH, and redox potential were investigated. Results showed that the Cd and Pb accumulation was dissimilar in treatments. In single treatments of Cd or Pb, the amount of glutaric and lactic acids decreased with concentrations; the secretion of glutaric and glycolic acids in 5 mg/L Cd treatments were the highest at the 90th day. In the mixed treatments of Cd and Pb, glutaric acids in cultures with Cd 5 mg/L + Pb 50 mg/L and Cd 10 mg/L + Pb 100 mg/L were higher than those in other treatments. Both lactic and glycolic acids reached the highest values in Cd 10 mg/L + Pb 100 mg/L treatments at the end of experiment. Besides, the Cd or Pb uptake showed various correlations with pH, redox potential, and organic acids, the reason might be that the presence of Cd or Pb influenced the organic acids exudation, and alterations of rhizosphere, including acidity, redox potential, and organic acids, impacted the bioavailability and phytoextraction of toxic metals conversely. Keywords: sunflower, bioaccumulation, root exudates, heavy metals Journal: Plant, Soil and Environment Pages: 487-494 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/230/2012-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/230/2012-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0002.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:230-2012-PSE Template-Type: ReDIF-Article 1.0 Author-Name: T.-T. Nguyen Author-Workplace-Name: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia Author-Name: S. Fuentes Author-Workplace-Name: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia Author-Name: P. Marschner Author-Workplace-Name: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia Title: Effects of compost on water availability and gas exchange in tomato during drought and recovery Abstract: Compost can increase soil water availability and nutrient uptake by plants, but it is not clear whether it can also improve the ability of plants to recover after drought stress. Tomato plants (Lycopersicon esculentum L.) were grown in sandy soil without compost or with compost either incorporated or mulched. There were two water treatments: (i) plants grown under sufficient water supply throughout the experiment and (ii) plants grown with sufficient water supply until day 33 after which water was withheld until stomatal conductance was close to zero. Compost addition increased water content at both field capacity and permanent wilting point, but only incorporated compost increased total available water. Compost addition increased shoot and root growth under well-watered and drought stressed conditions with a greater effect by incorporated compost. At sufficient water supply, the rates of photosynthesis and transpiration were similar in all treatments. Drought stressed plants with incorporated compost wilted earlier than control plants, whereas mulched compost increased water availability to plants and hence the number of days until wilting. Photosynthesis and transpiration recovered faster in plants grown with incorporated compost compared to other treatments. The rapid recovery of plants after drought with incorporated compost could be due to their greater root length. Keywords: organic amendment, re-watering, stomatal conductance, transpiration, water stress Journal: Plant, Soil and Environment Pages: 495-502 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/403/2012-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/403/2012-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0003.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:403-2012-PSE Template-Type: ReDIF-Article 1.0 Author-Name: F. Doležal Author-Workplace-Name: Department of Water Resources, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences in Prague, Prague, Czech Republic Author-Name: S. Matula Author-Workplace-Name: Department of Water Resources, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences in Prague, Prague, Czech Republic Author-Name: J.M. Moreira Barradas Author-Workplace-Name: Department of Water Resources, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences in Prague, Prague, Czech Republic Title: Percolation in macropores and performance of large time-domain reflectometry sensors Abstract: The large-diameter time-domain reflectometry soil water sensors placed horizontally in a structured loamy soil are very sensitive to rapid preferential percolation events. Their readings on these occasions rise considerably, often becoming higher than the native soil's porosity. The effect is caused by gaps between the native soil and the sensors. The geometry of the gaps, even if filled with soil slurry at installation, is not exactly reproducible, which leads to sensor-to-sensor variability of readings. Field calibration in percolation-free periods lead to non-unique trajectories rather than monotonous calibration curves, which can be commented in terms of soil heterogeneity and the dual porosity theory. Data of two typical percolation events are presented. Sensors of this type can be used for detection of preferential flux. Keywords: TDR, soil water, installation, calibration, preferential flow Journal: Plant, Soil and Environment Pages: 503-507 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/6372-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/6372-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0004.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:6372-PSE Template-Type: ReDIF-Article 1.0 Author-Name: L. Peklová Author-Workplace-Name: Department of Agro-environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources Prague, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: J. Balík Author-Workplace-Name: Department of Agro-environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources Prague, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: O. Kozlovský Author-Workplace-Name: Department of Agro-environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources Prague, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: O. Sedlář Author-Workplace-Name: Department of Agro-environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources Prague, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: K. Kubešová Author-Workplace-Name: Department of Agro-environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources Prague, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Influence of injection nitrogen fertilization on yield and seed composition of winter oilseed rape (Brassica napus L.) Abstract: Influence of the nitrogen injection fertilization 'controlled uptake long term ammonium nutrition' (CULTAN) on winter rape yield and seed composition was studied in 2009 and 2010 at two sites with different soil-climatic conditions in the Czech Republic. Two conventional treatments consisted of fertilization using the system of divided doses applied on soil surface. Two CULTAN treatments used injection fertilization with the whole dose of nitrogen applied once in the vegetation period, in early spring at the BBCH 26 stage (6 side shoots detectable). The trial compared conventional and CULTAN treatments. The overall dose of nitrogen was 200 kg N/ha in each treatment. The seed yield in a two-year average was 4.83 t/ha at conventional and 4.80 t/ha at the CULTAN treatment. This difference was not statistically significant. The higher nitrogen content in seed was recorded mainly at CULTAN treatments at the Hněvčeves site in 2009. An inconclusively higher phosphorus content was recorded in winter rape seed fertilized with the CULTAN method at both sites in 2010. Content of K, Ca, Mg and S did not show statistically significant differences between the two treatments during both experimental years. In oiliness no differences between conventional and CULTAN methods were observed. Keywords: ammonium nitrogen, winter rape, injection, macroelements, oiliness Journal: Plant, Soil and Environment Pages: 508-513 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/455/2012-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/455/2012-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0005.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:455-2012-PSE Template-Type: ReDIF-Article 1.0 Author-Name: H. Zhang Author-Workplace-Name: Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, P.R. China Author-Workplace-Name: Huanjiang Observation and Research Station for Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, P.R. China Author-Name: T.Q. Song Author-Workplace-Name: Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, P.R. China Author-Workplace-Name: Huanjiang Observation and Research Station for Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, P.R. China Author-Name: K.L. Wang Author-Workplace-Name: Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, P.R. China Author-Workplace-Name: Huanjiang Observation and Research Station for Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, P.R. China Author-Name: G.X. Wang Author-Workplace-Name: Institute of Agricultural Ecological Research, College of Life Sciences, Zhejiang University, Hangzhou, P.R. China Author-Name: H. Hu Author-Workplace-Name: Key Laboratory of Digital Agriculture, Institute of Digital Agricultural Research, Zhejiang Academy of Agricultural Sciences, Hangzhou, P.R. China Author-Name: F.P. Zeng Author-Workplace-Name: Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, P.R. China Author-Workplace-Name: Huanjiang Observation and Research Station for Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, P.R. China Title: Prediction of crude protein content in rice grain with canopy spectral reflectance Abstract: Non-destructive and rapid monitoring methods for crude protein content (CPC) in rice grain are of significance in nitrogen diagnosis and grain quality monitoring, and in enhancing nutritional management and use efficiency. In this study, CPC and canopy spectra in rice were measured based on rice field experiment. Key spectral bands were selected by principal component analysis (PCA) method, and the predicted models were built by multiple linear regressions (MLR), artificial neural network (ANN) and partial least squares regression (PLSR). The results showed that there is a significant correlation between CPC content and key spectral bands. The results of prediction for the three models were in order of PLSR > ANN > MLR with correlation values of 0.96, 0.92 and 0.90, respectively, for the validation data. Therefore, it is implied that CPC in rice (grain quality) could be estimated by canopy spectral data. Keywords: nitrogen content, principal component analysis, partial least squares regression, artificial neural networks, key spectral bands Journal: Plant, Soil and Environment Pages: 514-520 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/526/2012-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/526/2012-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0006.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:526-2012-PSE Template-Type: ReDIF-Article 1.0 Author-Name: S.J. Ramos Author-Workplace-Name: Vale Technological Institute - Mining, Belo Horizonte, Brazil Author-Name: F.W. Ávila Author-Workplace-Name: SoilScience Department, Federal University of Lavras, Lavras, Brazil Author-Name: P.F. Boldrin Author-Workplace-Name: SoilScience Department, Federal University of Lavras, Lavras, Brazil Author-Name: F.J. Pereira Author-Workplace-Name: Biology Department, Federal University of Lavras, Lavras, Brazil Author-Name: E.M. Castro Author-Workplace-Name: Biology Department, Federal University of Lavras, Lavras, Brazil Author-Name: V. Faquin Author-Workplace-Name: SoilScience Department, Federal University of Lavras, Lavras, Brazil Author-Name: A.R. Reis Author-Workplace-Name: Department of Civil and Environmental Engineering, Waseda University, Tokyo, Japan Author-Name: L.R.G. Guilherme Author-Workplace-Name: SoilScience Department, Federal University of Lavras, Lavras, Brazil Title: Response of brachiaria grass to selenium forms applied in a tropical soil Abstract: In Brazil the total area of native and cultivated pasture used for livestock is around 180 million hectares, and selenium (Se) is absent from mineral fertilizer formulas. Nutritional supplementation of this element takes place along with provision of mineral salts in the form of sodium selenite. In the present work, the effects of adding selenate and selenite on Se biofortification, antioxidant activity and anatomy alterations in Brachiaria brizantha were evaluated. The experiments were disposed in a completely randomized design in a 6 × 2 factorial scheme, by means of five levels of Se (0; 0.5; 1.0; 3.0 and 6.0 mg/kg) applied along with grass plant fertilizer, and two Se forms (sodium selenate and sodium selenite), with six replications. The results of the present study suggest that, in tropical soil conditions, the application of Se as selenate at low doses is more appropriate for B. brizantha biofortification than Se as selenite, because it favors a greater shoot Se levels, better activation of the antioxidant system and reduces on lipid peroxidation. Finally, with an increase of Se rates, cellular modifications were observed in internal structures of roots in B. brizantha, with aerenchyma appearing. Keywords: biofortification, forage, antioxidant enzymes, root anatomy, Brachiaria brizantha Journal: Plant, Soil and Environment Pages: 521-527 Volume: 58 Issue: 11 Year: 2012 DOI: 10.17221/559/2012-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/559/2012-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-201211-0007.txt Handle: RePEc:caa:jnlpse:v:58:y:2012:i:11:id:559-2012-PSE