基于DRIS法的樟树人工林营养诊断

[目的]开展基于诊断施肥综合法(DRIS)的樟树人工林营养诊断,为培育高效樟树人工林提供参考依据.[方法]依据DRIS图解法求得樟树叶片各营养元素诊断参数最适比范围及低产组需肥紧迫程度排序,依据DRIS指数法求得各样地樟树需肥紧迫程度排序及养分不平衡指数(NII),初步制定樟树营养元素DRIS指数分级标准.[结果]樟树人工林营养诊断的各营养元素比最适范围:氮/磷为3.795~5.689,钾/磷为1.761~2.405,钾/氮为0.396~0.510,氮/钙为0.677~0.856,镁/氮为1.022~1.306,钙/磷为5.255~7.167,镁/磷为4.516~6.222,钾/钙为0.305~0.373,镁/钾为2.371~2.819,镁/钙为0.788~0.957.根据低产组各营养元素比偏离最适范围的程度,得出樟树人工林低产组需肥紧迫程度排序为磷>钙>氮>钾>镁,其中磷、钙和氮养分处于缺乏状态,镁含量相对过剩;高产组和低产组樟树的平均NII分别为3.748和7.540,高产组樟树各营养元素相对平衡.DRIS指数初步分级结果表明,樟树的氮、磷、钾、钙和镁DRIS指数最适范围分别为-0.838~0.185、-0.903~0.602、-0.154~0.941、-0.790~0.329和-0.357~0.985.[结论]根据DRIS诊断,江西省丰城市樟树人工林的氮、磷和钙养分含量均呈缺乏状态,镁含量相对过剩,且以诊断的需肥紧迫程度排序及制定的指数分级标准能直观判断樟树树体各营养元素的平衡状况,可用于生产上指导樟树人工林进行及时合理施肥.

Nutrient diagnosis of Cinnamomum camphora(L.)Presl plantation based on DRIS

[Objective]The nutrient diagnosis of Cinnamomum camphora(L.)Presl plantation was carried out by dia-gnosis and recommendation integrated system(DRIS)to provide reference for high-efficiency cultivation of C.camphora plantation.[Method]According to DRIS graphic method,the optimal range for each nutrient diagnostic parameter and or-der of nutrients requirement urgency in low yield group were obtained.And the order of nutrients requirement urgency and nutrient imbalance index(NII)of C. camphora in various sites were obtained by DRIS index. Based on the results,C. camphora DRIS index grading standards for nutrient elements were initially developed.[Result]The optimum ranges for nutrient diagnosis of C.camphora plantation were as follows:N/P 3.795-5.689,K/P 1.761-2.405,K/N 0.396-0.510,N/Ca 0.677-0.856,Mg/N 1.022-1.306,Ca/P 5.255-7.167,Mg/P 4.516-6.222,K/Ca 0.305-0.373,Mg/K 2.371-2.819 and Mg/Ca 0.788-0.957.According to the gap between ratios of various nutrient elements in low yield group and the optimal range,the order of nutrients requirement urgency of C.camphora low yield group was P>Ca>N>K>Mg.P,Ca and N con-tents were deficient,but Mg content was excessive.Average NII values of high yield group and low yield group were 3.748 and 7.540 respectively,nutrients in the high yield group was relatively balanced.According to DRIS preliminary classification norms,the suitable ranges of DRIS indexes for N,P,K,Ca and Mg were-0.838-0.185,-0.903-0.602,-0.154-0.941,-0.790-0.329 and-0.357-0.985 respectively.[Conclusion]According to DRIS diagnosis,N,P and Ca contents in C. camphora plantation in cities of Jiangxi are deficient,and Mg content is excessive. Through diagnosis of order of nu-trients requirement urgency and the established DRIS index classification norms,balance of nutrition in C. camphora plantation can be diagnosed,and provide guidance for fertilizing of C.camphora plantation in production.