Effects Of Different Soil Moisture And Potassium Fertilizer On The Absorption,Distribution And Circulation Of Potassium In Flue-cured Tobacco

Experiments in pot were carried out to study the effect of different soil moisture and potassium amount on the absorption,distribution and circulation of potassium in flue-cured tobacco with K326 and soil from Henan Xiangcheng town at Henan Agricultural university experiment field from 2002 to 2003. The results are as follow:1 Effect of different soil moisture and potassium amount on the absorption of potassium in flue-cured tobacco During three growth periods, higher soil moisture(FC≥80%) and potassium amount(N/K≥1/3) could increase root activities and ATPase activities, decrease plasma membrane permeability and K+ leakage, add the whole absorption amount of potassium in tobacco,accumulation amount of potassium in root and shoot of tobacco and potassium content , decrease ratio of accumulation amount of potassium in root and accumulation amount of potassium in shoot. With the rising of soil moisture and potassium amount, the contents of quick-acting and slow acting potassium of rhizosphere were added, however, the content of quick-acting potassium of non-rhizosphere was on decreasing trend, the influence strength for slow acting potassium of non-rhizosphere was smaller; higher soil moisture(FC≥80%) and potassium amount(N/K≥1/3) could add the contents of quick-acting and slow acting potassium in every growth period, the intense of influence of soil moisture for quick-acting potassium was fast growing stage>topping>ripe stage, adding potassium amount, the intense was ripe stage>topping>fast growing stage.2 Effect of different soil moisture and potassium amount on the distribution of potassium in flue-cured tobacco Higher soil moisture(FC≥80%) and potassium amount(N/K≥1/3) could increase weight of dry matter in every growth period, promoted the accumulation and distribution of potassium for shoot, added the gradient of potassium content between middle-upper stalk and lower stalk, increase potassium content of different tobacco leaves. For potassium contents of lamina tissue, in fast growing stage, both upper and middle leaves were palisade tissue >spongy tissue>upper and lower epidermis; in topping, upper leaves was spongy tissue>palisade tissue>lower epidermis>upper epidermis; in ripe stage, both upper and middle leaves were palisade tissue >spongy tissue, lower epidermis>upper epidermis. Soil moisture and potassium amount could improve potassium content of palisade tissue and spongy tissue. For potassium contents of vein tissue, in fast growing stage, upper leaves was far-stalk parenchyma cells>near-stalk sclerenchyma cells>phloem>xylem, middle leaves was phloem>xylem> far-stalk parenchyma cells>near-stalk sclerenchyma cells; in topping, upper leaves in a whole was phloem>xylem> far-stalk parenchyma cells>near-stalk sclerenchyma cells, the potassium content of phloem was highest; middle leaves was near-stalk sclerenchyma cells,near-stalk sclerenchyma cells>phloem>xylem; in ripe stage, upper leaves in a whole was near-stalk sclerenchyma cells>xylem> far-stalk parenchyma cells>phloem, middle leaves was far-stalk parenchyma cells> phloem> near-stalk sclerenchyma cells>xylem. Soil moisture and potassium amount could increase potassium content of vein tissue, decreased gradient of potassium content among vein tissue. For stalk tissue, in fast growing stage, the potassium content of cortex,phloem and pith were highest in middle stalk, however , the potassium content of xylem was on rising with the height of stalk; in topping, the most obvious character was that the potassium content of lower stalk decreased significantly; however, the potassium contents of middle and upper stalk were a little down; in ripe stage, potassium content of middle stalk tissue was highest, potassium content of every tissue was middle stalk>upper stalk>lower stalk; higher soil moisture(FC≥80%) and potassium amount(N/K≥1/3) could increase potassium of middle and upper stalk tissue, decrease potassium content of lower stalk tissue of the lowest soil moisture content treatment.In a who...