陕西地区苹果叶营养元素标准范围的确定

 对苹果叶营养水平状况研究表明, N、P、K、Ca、Mg、B 等6 种元素的取值遵从正态分布,Cu、Fe、Mn、Zn 近似X² 分布。对于符合正态分布的元素可用4 点5 分段的概率分级法, 使1～5 级分别对应叶营养元素含量标准值中的缺乏、低值、正常值、高值、过高5 个数值范围, 各级出现的叶样概率分别为10 %、20 %、40 %、20 %和10 % , 其中处在第3 级的叶样占总样本的40 % , 叶分析值在( X - 0.5246S )～ ( X + 0.5246S) 可作为标准值中的正常值范围, 这与通过高产水平果园叶分析值制定的正常值非常接近。对于不符合正态分布的元素, 可参考高产水平果园的叶分析值对概率分级法进行矫正。据此制定出陕西苹果叶营养元素含量标准值, 与国内外标准相比, 陕西标准值表现出N、Ca、Mg、Cu 水平高, P、Zn、Fe、K水平低, Mn、B 基本一致的特点。

Studies on the Standard Range of Apple Leaf Nutritional Elements in Shaanxi Province

According to the results of X 2 test,the distributions of N,P,K,Ca,Mg,B content in leaves conformed to the normal distribution, but those of Cu,Fe,Mn,Zn looked rather like X 2 distribution.The values of normally distributed characters could be divided into 5 grades by 4 dividing points(standardized probability grading-SPG method),presented the absence,low value,normal value,high value,excess of standard range of nutritional elements,and the occurrence probability of 1-5 grades is 10%, 20%, 40%, 20% and 10% respectively.The third grade,which valued from(X-0.5246S) to (X 0.5246S),could be the normal value of standard range,rather same to the average value of leaf nutritional elemets in high yield orchards.The values of X 2 distributed characters graded by SPG method could be corrected by the average value of leaf nutritional elemelnts in high yield orchards.Therefor,proposed the standard range of apple leaf nutritional elements of Shaanxi province,compared to the others,the characteristics of N,Ca,Mg,Cu are higher,P,Zn,Fe,K are lower,Mn,B are same to.