The controls of soluble Al concentration were examined in three situations of acid sulfate conditions: 1)experimental acid sulfate conditions by addition of varying amounts of Al(OH)3 (gibbsite) into a sequenceof H2SO...The controls of soluble Al concentration were examined in three situations of acid sulfate conditions: 1)experimental acid sulfate conditions by addition of varying amounts of Al(OH)3 (gibbsite) into a sequenceof H2SO4 solutions; 2) experimental acid sulfate conditions by addition of the same sequence of H2SO4solutions into two non-acid sulfate soil samples with known amounts of acid oxalate extractable Al; and3) actual acid sulfate soil conditions. The experiment using gibbsite as an Al-bearing mineral showed thatincrease in the concentration of H2SO4 solution increased the soluble Al concentration, accompanied bya decrease in the solution pH. Increasing amount of gibbsite added to the H2SO4 solutions also increasedsoluble Al concentration, but resulted in an increase in solution pH. Within the H2SO4 concentration rangeof 0.0005~0.5 mol L-1 and the Al(OH)3 range of 0.01~0.5g (in 25 mL of H2SO4 solutions), the input ofH2SO4 had the major control on soluble Al concentration and pH. The availability of Al(OH)3, however, wasresponsible for the spread of the various sample points, with a tendency that the samples containing moregibbsite had a higher soluble Al concentration than those containing less gibbsite at equivalent pH levels.The experimental results from treatment of soil samples with H2SO4 solutions and the analytical results ofacid sulfate soils also showed the similar trend.展开更多
Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antiox...Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antioxidant system of Jatropha curcas L.seedling.The results showed that with the Al^(3+)treatment being applied,protein content increased first,then decreased and finally increased with the increase of Al^(3+)concentration;the soluble sugar content increased first and then decreased with the increase of Al^(3+)concentration.Under low concentration of Al^(3+)treatment,Pro content,MDA content and POD activity of Jatropha curcas L.seedling leaves changed a little,while under high concentration of Al^(3+)treatment,Pro and MDA content of Jatropha curcas L.seedling leaves rapidly accumulated,POD activity increased and they showed a trend of increase with the increase of Al^(3+)concentration;From the perspective of Al^(3+)stress time,protein content,soluble sugar content,MDA content and POD activity increased with stress time being prolonged,while Pro content decreased with stress time being prolonged.These results indicated that the leaves of Jatropha curcas L.seedlings had certain self-protection and remediation abilities under Al^(3+)stress.展开更多
文摘The controls of soluble Al concentration were examined in three situations of acid sulfate conditions: 1)experimental acid sulfate conditions by addition of varying amounts of Al(OH)3 (gibbsite) into a sequenceof H2SO4 solutions; 2) experimental acid sulfate conditions by addition of the same sequence of H2SO4solutions into two non-acid sulfate soil samples with known amounts of acid oxalate extractable Al; and3) actual acid sulfate soil conditions. The experiment using gibbsite as an Al-bearing mineral showed thatincrease in the concentration of H2SO4 solution increased the soluble Al concentration, accompanied bya decrease in the solution pH. Increasing amount of gibbsite added to the H2SO4 solutions also increasedsoluble Al concentration, but resulted in an increase in solution pH. Within the H2SO4 concentration rangeof 0.0005~0.5 mol L-1 and the Al(OH)3 range of 0.01~0.5g (in 25 mL of H2SO4 solutions), the input ofH2SO4 had the major control on soluble Al concentration and pH. The availability of Al(OH)3, however, wasresponsible for the spread of the various sample points, with a tendency that the samples containing moregibbsite had a higher soluble Al concentration than those containing less gibbsite at equivalent pH levels.The experimental results from treatment of soil samples with H2SO4 solutions and the analytical results ofacid sulfate soils also showed the similar trend.
文摘Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antioxidant system of Jatropha curcas L.seedling.The results showed that with the Al^(3+)treatment being applied,protein content increased first,then decreased and finally increased with the increase of Al^(3+)concentration;the soluble sugar content increased first and then decreased with the increase of Al^(3+)concentration.Under low concentration of Al^(3+)treatment,Pro content,MDA content and POD activity of Jatropha curcas L.seedling leaves changed a little,while under high concentration of Al^(3+)treatment,Pro and MDA content of Jatropha curcas L.seedling leaves rapidly accumulated,POD activity increased and they showed a trend of increase with the increase of Al^(3+)concentration;From the perspective of Al^(3+)stress time,protein content,soluble sugar content,MDA content and POD activity increased with stress time being prolonged,while Pro content decreased with stress time being prolonged.These results indicated that the leaves of Jatropha curcas L.seedlings had certain self-protection and remediation abilities under Al^(3+)stress.