Amelioration of saline-sodic soils through land preparation with three tillage implements （disc plow, rotavator and cultivator） each followed by application of sulfuric acid at 20% of gypsum （CaSO4-2H2O） requireme...Amelioration of saline-sodic soils through land preparation with three tillage implements （disc plow, rotavator and cultivator） each followed by application of sulfuric acid at 20% of gypsum （CaSO4-2H2O） requirement or no sulfuric acid application during crop growth period was evaluated in a field study for 2.5 years at three sites, i.e., Jhottianwala, Gabrika （Thabal）, and Thatta Langar, in Tehsil Pindi Bhattian, Hafizahad District, Pakistan. Within 2.5 years, there was a decrease in the salinity parameters measured （electrical conductivity, pH, and sodium adsorption ratio）, with a gradual increase in rice and wheat grain yields. It was observed that the disc plow, which not only ensured favorable yields but also helped improve soil health at all the three sites, was the most effective tillage implement. Also, application of sulfuric acid resulted in higher yields and promoted rapid amelioration of the saline-sodic soils.展开更多
Soil parameters have significant influence on the performance of tillage machines for various kinds of tillage operations, such as soil movement by tillage tool, soil cutting, soil turning, soil pulverization, and man...Soil parameters have significant influence on the performance of tillage machines for various kinds of tillage operations, such as soil movement by tillage tool, soil cutting, soil turning, soil pulverization, and manure injections, etc. This paper attempts to provide a clear overview of soil physical properties and soil strength, and their effects on the performance of tillage machines. Furthermore; it includes the descriptions and characteristics of these parameters, and last developed equipment and procedure for evaluating and assessing of these parameters.展开更多
The demand for simple and rapid bioassays in ecotoxicological evaluations is of paramount importance in order to speed up environmental monitoring programs.In this study we performed bioassays with lettuce seeds and t...The demand for simple and rapid bioassays in ecotoxicological evaluations is of paramount importance in order to speed up environmental monitoring programs.In this study we performed bioassays with lettuce seeds and two species of terrestrial isopods (Armadillidium vulgare and Porcellio dilatatus) for the ecotoxicological assessment of a landfarming soil from a petrochemical complex area.The solubilized content of test soil demonstrated a concentration-response type toxic effect on seed germination rate,and a delay on germination,but showed toxic effect on seedlings wet weight only at the highest concentration.Toxic effects were also observed in mortality rate and avoidance behavior of the two woodlice species.These results demonstrated the sensitiveness of the organisms studied,and highlighted the possibility to use these bioassays in environmental monitoring programs in areas contaminated with fossil fuels.展开更多
文摘Amelioration of saline-sodic soils through land preparation with three tillage implements （disc plow, rotavator and cultivator） each followed by application of sulfuric acid at 20% of gypsum （CaSO4-2H2O） requirement or no sulfuric acid application during crop growth period was evaluated in a field study for 2.5 years at three sites, i.e., Jhottianwala, Gabrika （Thabal）, and Thatta Langar, in Tehsil Pindi Bhattian, Hafizahad District, Pakistan. Within 2.5 years, there was a decrease in the salinity parameters measured （electrical conductivity, pH, and sodium adsorption ratio）, with a gradual increase in rice and wheat grain yields. It was observed that the disc plow, which not only ensured favorable yields but also helped improve soil health at all the three sites, was the most effective tillage implement. Also, application of sulfuric acid resulted in higher yields and promoted rapid amelioration of the saline-sodic soils.
文摘Soil parameters have significant influence on the performance of tillage machines for various kinds of tillage operations, such as soil movement by tillage tool, soil cutting, soil turning, soil pulverization, and manure injections, etc. This paper attempts to provide a clear overview of soil physical properties and soil strength, and their effects on the performance of tillage machines. Furthermore; it includes the descriptions and characteristics of these parameters, and last developed equipment and procedure for evaluating and assessing of these parameters.
基金Supported by Brazil National Petroleum Agency and Petrobras(No.PRH-ANP/MME/MCT 27)
文摘The demand for simple and rapid bioassays in ecotoxicological evaluations is of paramount importance in order to speed up environmental monitoring programs.In this study we performed bioassays with lettuce seeds and two species of terrestrial isopods (Armadillidium vulgare and Porcellio dilatatus) for the ecotoxicological assessment of a landfarming soil from a petrochemical complex area.The solubilized content of test soil demonstrated a concentration-response type toxic effect on seed germination rate,and a delay on germination,but showed toxic effect on seedlings wet weight only at the highest concentration.Toxic effects were also observed in mortality rate and avoidance behavior of the two woodlice species.These results demonstrated the sensitiveness of the organisms studied,and highlighted the possibility to use these bioassays in environmental monitoring programs in areas contaminated with fossil fuels.
