in order to quantify and simulate the response of lemon balm (melissa officinalis l.) plants to cadmium (cd) concentrations in the soil, a pot experiment was conducted using completely randomized design (crd) with three replicates during 2014. the treatment consisted of twelve cd concentrations from 0 to 300 mg kg-1 of cd in the soil which was mixed with the experimental soil before planting. l...

Expected changes in precipitation over large regions of the world under global climate change will have profound effects on terrestrial ecosystems in arid and semiarid regions. To explore how changes in the amount of precipitation in the growing season would affect soil nitrogen (N) availability in a semiarid ecosystem, we established rainout shelters and irrigation systems by simulating 30% re...

Citrus seedlings were grown in soil columns in which the root system was hydraulically separated into two equal layers; this enabled us to maintain roots in the upper layer without water for 110 d. The columns were placed into waterbaths modified so that soil temperatures in the top layer could be maintained at 25 °C or at 35 °C, while temperature in the bottom layer was maintained at 25 °C. We...

Boron (B) is essential to growth at low concentrations and limits growth and yield when in excess. Little is known regarding plant response to excess B and salinity occurring simultaneously. In this study, two models of Leibig-Sprengel (LS) and Mitscherlich-Baule (MB), originally proposed to explain plant response to nutrients only, were modified to evaluate canola yield response to combined le...

The magnitude and direction of water transport by the roots of eight dominant Brazilian savanna (Cerrado) woody species were determined with a heat pulse system that allowed bidirectional measurements of sap flow. The patterns of sap flow observed during the dry season in species with dimorphic root systems were consistent with the occurrence of hydraulic redistribution of soil water, the movem...

The photolytic degradations of imidacloprid, carbofuran, diazinon, chlorpyrifos, pyridaben, propoxur, and esfenvalerate were independently compared in both moist (75% field moisture capacity at 0.33 bar) and air-dry microbially viable soils at 5 microg/g. All compounds were applied to sandy soil except for propoxur, which was applied to sandy loam soil. Diazinon was applied to both sandy soil a...

Skidding operations can cause considerable and wide spread soil disturbance. The objective of this study was to evaluate the effects of ground skidding operations on soil compaction, moisture content, and total porosity at different levels of slope and traffic frequency. Four levels of traffic intensity (3, 8, 13, and >13 passes of a Crawler Tractor Onezhets ? 110) and three levels of slope ( ...