施钾量对高产甜菜光合特性、干物质积累和产量的影响

Effects of potassium fertilizer on main physiological characteristics,dry matter accumulation and yield of high yield sugar beet

以甜菜品种KWS7156为材料,通过不同施钾水平的大田试验,研究了施钾量对高产甜菜光合特性、干物质积累及产量的调控效应.结果表明:施用钾肥可显著提高甜菜的株高和叶面积指数,全生育期甜菜叶片可溶性糖含量呈先升高后降低的趋势;钾肥促进了甜菜叶片的净光合速率,从块根分化形成期至收获期,施钾量90,180,270和360kg/hm^2的处理平均净光合速率较未施钾肥的对照分别提高1.4,3.2,3.8和1.2μmol/(m^2·s)(CO_2).全生育期所有处理甜菜植株干重表现为施钾量270kg/hm^2>360kg/hm^2>180kg/hm^2>90kg/hm^2>0kg/hm^2;甜菜根冠比从块根分化形成期的0.2上升至收获期的3.9~4.3,至糖分积累期开始,施钾量360kg/hm^2的处理根冠比显著低于90,180和270kg/hm^2的处理.产量与施钾量的回归分析得出一元二次肥料效应方程y=-0.111x^2+59.02x+79 877(R^2=0.976),施钾肥265.9kg/hm^2甜菜产量可达到最大.

In order to evaluate the effects of different potassium levels on photosynthesis characteristics,dry matter accumulation and yield of high yield sugar beet,a field experiment was carried out.A sugar beet cultivar,KWS7156,was used.The results indicated that potassium fertilizer can significantly increase the sugar beet plant height and leaf area index,and the leaf carbohydrates content increased first and then decreased during the whole growth period;Potassium fertilizer promoted the net photosynthetic rate,and the average net photosynthetic rate of K2O 90,180,270and360kg/hm^2 was increased by 1.4,3.2,3.8and 1.2μmol/（m^2·s）（CO2）than 0kg/hm^2 from root differentiating and forming stage to harvest stage.Plant dry matter showed K2O 270kg/hm^2 360kg/hm^2180kg/hm^290kg/hm^20kg/hm^2 during the whole growth stage;Root to shoot ratio was increased from 0.2to 3.9～4.3during the whole growth stage,and K2O 360kg/hm^2 was significantly lower than 90,180,and 270kg/hm^2 beginning with sugar content accumulated stage.Regression analysis of yield and potassium estimate the unary quadratic equation：y=-0.111x2＋59.02x＋79 877（R^2=0.976）,and sugar beet yield can reach the maximum while the application of potassium fertilizer is265.9kg/hm^2.