A novel methodology for using digital cameras to calculate spectral parameters

Abstract

Nitrogen and Phosphorus, two of the most vital soil nutrients required by plants, should be present in a ratio of 4:1 to ensure a healthy growth of the plant. However, the current scenario for India sees a ratio of 24:1. This is due to over fertilization of the fields. Precision Agriculture can lead to better yield, reduced expenditure on fertilizers, and thus greater outputs for the farmer. The laboratory methods used for soil analysis are too tedious and time-consuming. The proposed solution entails the use of digital cameras for calculating spectral parameters like NDVI (Normalized Difference Vegetation Index) which can help determine the leaf nitrogen content. Albeit, digital cameras have been used in the past, a new methodology has been proposed, with arguments explaining why the earlier findings were erroneous in nature. An implementation of the proposed methodology has been compared with Greenseeker's Handheld Crop Sensor for determining the value of NDVI. Statistical analysis revealed a non-significant difference (t=-0.348) in the mean values calculated by the two devices; evidently, the performance of the proposed methodology is at par and can be used for the determination of NDVI. Also, the pilot implementation of the methodology cost 40 times less than the Greenseeker's Handheld Crop Sensor, hence catering to the important demand of economically viable alternatives for soil testing analysis.