Plant, Soil and Environment, 2012 (vol. 58), issue 11
Silicon-induced increase in chlorophyll is modulated by the leaf water potential in two water-deficient tomato cultivars
O.N. Silva, A.K.S. Lobato, F.W. Ávila, R.C.L. Costa, C.F. Oliveira Neto, B.G. Santos Filho, A.P. Martins Filho, R.P. Lemos, J.M. Pinho, M.B.C.L. Medeiros, M.S. Cardoso, I.P. Andrade
Plant Soil Environ., 2012, 58(11):481-486 | DOI: 10.17221/213/2012-PSE 
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...
Changes of three organic acids in the process of Cd and Pb phytoextraction by Helianthus annuus L.
Z.X. Niu, X.D. Li, L.N. Sun, T.H. Sun
Plant Soil Environ., 2012, 58(11):487-494 | DOI: 10.17221/230/2012-PSE
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...
Effects of compost on water availability and gas exchange in tomato during drought and recovery
T.-T. Nguyen, S. Fuentes, P. Marschner
Plant Soil Environ., 2012, 58(11):495-502 | DOI: 10.17221/403/2012-PSE
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,...
Percolation in macropores and performance of large time-domain reflectometry sensors
F. Doležal, S. Matula, J.M. Moreira Barradas
Plant Soil Environ., 2012, 58(11):503-507 | DOI: 10.17221/6372-PSE
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...
Influence of injection nitrogen fertilization on yield and seed composition of winter oilseed rape (Brassica napus L.)
L. Peklová, J. Balík, O. Kozlovský, O. Sedlář, K. Kubešová
Plant Soil Environ., 2012, 58(11):508-513 | DOI: 10.17221/455/2012-PSE
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...
Prediction of crude protein content in rice grain with canopy spectral reflectance
H. Zhang, T.Q. Song, K.L. Wang, G.X. Wang, H. Hu, F.P. Zeng
Plant Soil Environ., 2012, 58(11):514-520 | DOI: 10.17221/526/2012-PSE
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...
Response of brachiaria grass to selenium forms applied in a tropical soil
S.J. Ramos, F.W. Ávila, P.F. Boldrin, F.J. Pereira, E.M. Castro, V. Faquin, A.R. Reis, L.R.G. Guilherme
Plant Soil Environ., 2012, 58(11):521-527 | DOI: 10.17221/559/2012-PSE
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...