American Journal of Agricultural and Biological Sciences · 2009 · 26 citations · 18 references
AgricultureAgronomyCrop SciencesCrop ManagementNutrient ManagementSite-specific Crop ManagementCrop Nutrient RequirementsNitrogen ManagementNitrogen NutritionSoil Nitrogen SensingSoil Nutrient AvailabilitySoil-plant Nutrient RelationsLaboratory TestingLeaf Nitrogen ContentNitrogen Content AnalysisNitrogen Content EstimationNitrogen Management ZonesSoil Nitrogen AssessmentWithin-field Spatial VariabilityWithin-field Variability
Abstract: Problem statement: Laboratory plant testing is usually time-consuming and high-costing. Hence, plant nutrient variability must be measured rapidly and the information made known to the farmers before the new season starts. Site-specific crop management, well-established in some developed countries, is now being considered in other places such as Malaysia. Approach: The application of site-specific management principles and techniques to diverse crops and small-scale farming systems in Malaysia will present new challenges. Describing within-field variability in typical Malaysian production settings is a fundamental first step toward determining the size of management zones and the inter-relationships between limiting factors, for establishment of site-specific management strategies. Results: Measurements of rice SPAD readings and nitrogen content were obtained in a Malaysian rice paddy field. SPAD reading data was manually collected on 80DAT and measured using a Minolta SPAD 502. Leaf samples were collected at 60 points at the same time to compare results from sampling with SPAD reading values. Samples nitrogen content was analyzed in a laboratory. Analysis of variance, variogram and kriging were conducted to determine the variability of the measured parameters and also their relationship. SPAD reading and nitrogen content maps were created on the interpretation of the data was investigated. Conclusion/Recommendations: Finally the
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Soil mineralogy with environmental applications
Choice Reviews Online · 2003 · 464 citations
Increased N-use efficiency using a chlorophyll meter on high-yielding irrigated rice
Shaobing Peng, F. V. Garcia, Rebecca C. Laza et al. · Field Crops Research · 1996 · 410 citations
Agriculture, Agronomy, Crop Sciences +14