Numerical analysis and laboratory testing of seed spacing uniformity performance for vacuum-cylinder precision seeder

Seed-metering system is an important component in row-crop planters in terms of uniform seed distribution. Numerous field and laboratory methods have been developed and used for evaluation of planter performance; each method having its own advantages and shortcomings. In the present study, a digital camera (Nikon, D70) was used for laboratory evaluation of vertical-rotor seed-metering device performance, indices such as multiple planting, feeding quality, miss planting and seed space uniformity being the major criteria. To validate the results from image processing method, the more conventional, grease-belt method, was used. The experiments were conducted on the basis of factorial randomized complete design with two types of seed-metering devices, with different numbers of cells and four levels of seed-metering speeds in three replications. Captured images were transferred to the computer via USB port and were processed by program written in MATLAB software environment. The results from two methods, namely, image processing and grease belt methods were in good agreement and analysis of variances showed that seed-metering device with 15 cells in 40 rpm performed better than seed-metering device with 21 cells and in other speeds. Comparison of the number of spaces that fell in normal domain in different seed-metering speeds showed that image processing method had higher value than grease-belt method. Since the initial falling velocity of seed and angle of its exit from metering device was unknown, thus the precision of space index was different in two methods.

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Laboratory Evaluation of Seed Metering Device Using Image Processing Method

Videogrammetric technique for three-dimensional structural progressive collapse measurement

For a furrow opener of a seeder, the ability to place seed at a given sowing depth in the soil is an important factor in evaluating its performance. Furrow openers directly affect sowing depth and lateral seed scatter of seeds. The aim of this study was to compare the performance of furrow openers by characterizing the spatial distribution of seeds within the seedbed. A newly developed criterion, distribution area of seeds, characterized both sowing depth and lateral seed scatter (standard deviation from row centre) of seeds. A field experiment was conducted to determine the effect of furrow opener type (shoe, hoe, single disc and double disc) on sowing uniformity according to conventional and developed evaluation criteria. Distribution area of seeds was calculated by ellipse and integral criteria. Ellipse criterion gave detailed information about the effectiveness of lateral seed scatter and variation in sowing depth on seed distribution area. Sowing uniformity was affected by furrow openers according to both conventional and newly developed evaluation criteria. The newly developed seed distribution evaluation procedures will better describe seed distribution in a two-dimensional way in a vertical plane. Therefore, these procedures will help improve furrow openers for effective seed placement.

M. Wiesehoff

Papers

Laboratory measurement of seed drill seed spacing and velocity of fall of seeds using high-speed camera system