There are two kinds of theoretical defects export in the diagnosis and recommendationintegrated system (DRIS): the distribution of nutrient elements ratios with two normaldistribution displays an abnormal distribution...There are two kinds of theoretical defects export in the diagnosis and recommendationintegrated system (DRIS): the distribution of nutrient elements ratios with two normaldistribution displays an abnormal distribution of positive skewness; there is a blinddiagnostic area by DRIS on the occasion of the nutrient elements with equal ratios butwithout equal quantity. In the light of the quadratic form theory of multidimensionalnormal distribution and the view of balance of equal probability, the balance diagnosisand recommendation integrated system (BDRIS) was developed in this paper, which issuperior to DRIS and its diagnosis method is unified to critical value diagnosis. Whenthe correlation matrix of nutrient elements R=I(identity matrix), i.e., the effects ofelements antagonism is disregarded, BDRIS will be simplified into the critical valuediagnosis. In addition, the diagnosis program written in SAS language was also providedin this paper.展开更多
Maize is one of the most nutrient demanding staple crops. Tissue nutrient diagnosis of maize is currently conducted using critical nutrient concentration or dual ratio ranges, but such diagnoses are pathological as bi...Maize is one of the most nutrient demanding staple crops. Tissue nutrient diagnosis of maize is currently conducted using critical nutrient concentration or dual ratio ranges, but such diagnoses are pathological as biased by data redundancy, sub-compositional incoherence and non-normal distribution. The use of orthogonal balances, a compositional data analysis technique, avoids such biases. Our objective was to develop foliar nutrient balance standards for maize. We collected 758 grain yields (15.5% moisture content) and foliar samples at silk stage in maize fields of southern Quebec, Canada, and analyzed ten nutrients in tissues (N, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe). Nutrients were arranged into ad hoc balances and computed as isometric log ratios (ilr). An optimized binary classification performed by a customized receiver operating characteristic procedure showed that a critical Mahalanobis distance of 4.21 separated balanced from imbalanced specimens about yield cut-off of 11.83 Mg grain·ha-1 with test performance of 86%. Quebec maize balance standards differed from published standards computed from DRIS norms collected in other agroecosystems. The Redfield N/P ratio in maize leaves was found to be the least variable balance across regions of the world. The DRIS dual ratios and raw concentration values were found to be geometrically inadequate for conducting diagnosis. The unbiased nutrient balance diagnosis combined the critical Mahalanobis distance and a mobile representation of nutrient balances with ilr means of true negative (TN) specimens centered at fulcrums and back-transformed ilr values of TN specimens into raw concentrations loading the buckets below. Nutrients can be appreciated as relative shortage, adequacy or excess in the concentration domain following statistical analysis and diagnosis in the unbiased balance domain.展开更多
文摘There are two kinds of theoretical defects export in the diagnosis and recommendationintegrated system (DRIS): the distribution of nutrient elements ratios with two normaldistribution displays an abnormal distribution of positive skewness; there is a blinddiagnostic area by DRIS on the occasion of the nutrient elements with equal ratios butwithout equal quantity. In the light of the quadratic form theory of multidimensionalnormal distribution and the view of balance of equal probability, the balance diagnosisand recommendation integrated system (BDRIS) was developed in this paper, which issuperior to DRIS and its diagnosis method is unified to critical value diagnosis. Whenthe correlation matrix of nutrient elements R=I(identity matrix), i.e., the effects ofelements antagonism is disregarded, BDRIS will be simplified into the critical valuediagnosis. In addition, the diagnosis program written in SAS language was also providedin this paper.
文摘Maize is one of the most nutrient demanding staple crops. Tissue nutrient diagnosis of maize is currently conducted using critical nutrient concentration or dual ratio ranges, but such diagnoses are pathological as biased by data redundancy, sub-compositional incoherence and non-normal distribution. The use of orthogonal balances, a compositional data analysis technique, avoids such biases. Our objective was to develop foliar nutrient balance standards for maize. We collected 758 grain yields (15.5% moisture content) and foliar samples at silk stage in maize fields of southern Quebec, Canada, and analyzed ten nutrients in tissues (N, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe). Nutrients were arranged into ad hoc balances and computed as isometric log ratios (ilr). An optimized binary classification performed by a customized receiver operating characteristic procedure showed that a critical Mahalanobis distance of 4.21 separated balanced from imbalanced specimens about yield cut-off of 11.83 Mg grain·ha-1 with test performance of 86%. Quebec maize balance standards differed from published standards computed from DRIS norms collected in other agroecosystems. The Redfield N/P ratio in maize leaves was found to be the least variable balance across regions of the world. The DRIS dual ratios and raw concentration values were found to be geometrically inadequate for conducting diagnosis. The unbiased nutrient balance diagnosis combined the critical Mahalanobis distance and a mobile representation of nutrient balances with ilr means of true negative (TN) specimens centered at fulcrums and back-transformed ilr values of TN specimens into raw concentrations loading the buckets below. Nutrients can be appreciated as relative shortage, adequacy or excess in the concentration domain following statistical analysis and diagnosis in the unbiased balance domain.
