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

ObjectiveThe 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.MethodAccording 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.ResultThe 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.ConclusionAccording 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.