【摘要】 以赤红壤为研究对象,通过甘蔗盆栽试验,利用Olsen和Mehlich3方法,研究甘蔗土壤速效磷的临界值及丰缺情况。结果表明:当土壤Olsen-P含量低于13.7mg/kg或Mehlich3-P含量低于15.4mg/kg时,甘蔗植株的生长量随土壤速效磷含量的增加而显著增加。甘蔗地上部干物质相对产量与土壤速效磷含量的关系可以用一元二次响应方程来拟合,Olsen-P的响应方程为:y=-0.3198x2+12.263x-15.471,决定系数R=0.9767**;Mehlich3-P的响应方程为:y=-0.2366x2+10.532x-12.794,R=0.9758**。以最高产量的95%作为临界产量,计算得到蔗园土壤Olsen-P和Mehlich3-P丰缺临界值分别为14.5、16.0mg/kg。更多还原

【Abstract】 Under pot sugar culture conditions, soil available P content was determined by using Olsen and Mehlich3 methods. When the soil Olsen -P content was lower than 13.7 mg/kg or the soil Mehlich3 P content lower than 15.7 mg/kg, the growth of sugarcane was increased significantly with an increase in the soil available P content. The relationship of the dry matter weight of sugarcane above the ground and the soil available P content was fit by univariate quadratic equations. The equation for Olsen-P content was y= -0.319 8x2 + 12.263x 15.471, and the coefficient was R=0.976 7. The equation for Mehlich3-P content was y= -0.236 6x2 + 10.532x 12.794, and the coefficient was R=0.975 8. Considering 95% of the optimum yield was the critical yield, the critical level of Olsen P content was 14.5 mg/kg, and the critical level of Mehlich3 P content was 16.0 mg/kg.更多还原