Research Of Detecting System For Component Of Soil Based On NIRS

As an important part of Precision Agriculture, Precision Fertilization aim at scientific directions for N, P, K, organic fertilizer and many kinds of trace element which may promote the crops grow are mixed by suitable proportion, according to the different area, the different soil type, the crops category as well as the nutrient and lacking situation of each element in the soil. The component of soil measured quickly is the premise of Precision Fertilization.The conventional soil analysis is processed in chemistry laboratory, which needs lots of time and high cost. Besides,many instrument is too large to move. Near Infrared Spectrum (NIRS) analysis is characteristic of fast speed, no need of chemistry reagent, and many component analyzed at the same time. In this paper, based on NIRS, author designs a measuring system of soil to realize total nitrogen and organic matter measured quickly in the field.The main research works are as follows:(1)Researched the feasibility of using NIRS to measure soil in the field.(2)Based on experiments, the calibration model is established to predict the content of the organic matter and total nitrogen in the unknown soil sample.(3)The hardware is designed for the detecting system, which is composed of light path and circuit. The grating is used in the single light path, the measuring technique of feeble signal is adopted to acquire the spectrum data in the circuit.(4)The software design for the whole system include: the calbrating zero in system, the driving of step motor, data sampling, data smoothness, differential coefficient and so on.