Success of precision Citriculture largely depends upon the correctness to which, the spatial variability in soil fertility is addressed as a major production constraint. Redressal of such spatial variability in soil is, therefore, important to identify the nutrient constraint zones vis-à-vis production zones to rationalize the nutrient use and optimize the factor productivity.
Attempts were made to address these issues with the help of spatial technology like geographical information system (GIS). An extensive exploration of ‘Khasi’ mandarin (Citrus reticulata Blanco) (geographical indicator) growing belts across seven sister states of northeast India, Sikkim and West Bengal was carried out covering 108 orchards from 52 sites (grid points) of different geographical origins. These grid sampling sites were georeferenced and digitized. Voluminous databank was generated with respect to leaf nutrient composition (Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Iron, Manganese, Copper, and Zinc) and fruit yield. The data, hence produced, were subjected to analysis through two diverse kinds of software-based decision support systems in two tiers of interpretation. These included: (i) analysis through diagnosis and recommendation integrated system (DRIS) to determine leaf nutrient optima and (ii) mapping of spatial variability in nutrient constraints nutrientwise and productionwise using the nutrient optima. The nutrientwise maps produced were superimposed over each other to identify different production zones displaying high fruit yield and lowest frequency of nutrient constraint.
Such production zones are of huge advantage for performance-based development of citrus industry under any geographical unit.
(Source: NAIP sub project on Mass Media Mobilization, DIPA based on inputs from A.K.Srivastava and Shyam Singh, National Research Centre for Citrus, Nagpur 440 010, Maharashtra)