Richard L. Parish

Comparison of Spreader Pattern Evaluation Methods

TWELVE methods of collecting samples for spreader pattern tests were evaluated in the laboratory using one spreader and two materials. The results indicated that there can be significant differences in the apparent rate, optimum swath width, amount of skewing, coefficient of variation of the overlapped pattern, and minimum and maximum points in the overlapped pattern resulting from the choice of collection methods. In this test, traditional baffled collection pans (as specified by ASAE S341.1) yielded coefficients of variation of 8 to 22% compared to coefficients of variation of 27 to 57% for the same spreader and materials using long, narrow pans and 21 to 41% for floor collection. Differences in minimum/maximum points in the patterns and degree of skewing were also very pronounced.

A Computer Program for Spreader Pattern Analysis

A computer program for analysis of the distribution patterns from granular applicators has been developed. The program, originally a research tool, was revised to make it versatile enough to handle the full range of granular applicators and testing conditions, and easy for non-technical people to use. The program can be used for any size of applicator from lawn spreaders through large agricultural and aerial applicators. Although the program is most helpful in evaluating the pattern from rotary spreaders, it works equally well for other spreader types such as full-width drop-type spreaders. The program facilitates data analysis using ASAE Standard S341.1, Test Procedure for Dry Fertilizer Spreaders. The program is written in Advanced BASIC and runs on IBM PC or compatible computers. It provides a printed record of relevant data on the spreader, product tested, and test conditions. It prints out the distribution pattern and then a table of rate, coefficient of variation, and extremes in the overlapped swath at different swath widths. A plot of coefficient of variation as a function of swath width is provided. Plots of overlapped patterns at different swath widths are optional.

The Effect of Speed on Performance of a Rotary Spreader for Turf

THE speed of a rotary spreader is known to affect the application rate and the pattern—particularly when the spreader has a ground-driven impeller. A laboratory study of spreader rate and pattern parameters at varying speeds indicates that pattern quality may not be as susceptible to speed changes as has been assumed. The critical parameters of an overlapped pattern—coefficient of variation and the minimum and maximum points in the pattern—were not significantly changed in the test until the speed had been decreased at least 25%. These parameters were not significantly changed with speed increases of as much as 50%. Thus, from the pattern standpoint, speed increases are less detrimental than speed decreases, so the operator should try to err on the positive side. Rate, on the other hand, changed significantly with a speed decrease of 25% or a speed increase of only 8%. This test was run with only one material and one spreader, so caution is urged in extrapolation of the data.

Evaluation of a Rotary Spreader with a Helical Cone for Drop Point Control

ABSTRACT A new rotary spreader has recently been introduced that incorporates a helical cone which is rotated to change the drop point of the material onto the impeller, and a new impeller with both straight and forward-curved fins. The new spreader and two conventional spreaders were evaluated using four materials covering the full range of products normally applied with this type of spreader. The new spreader substantially outperformed both of the conventional spreaders. It could be adjusted to deliver an excellent pattern with all of the materials tested. The coefficient of variation for overlapped patterns did not exceed 10% with any of the materials. The spreader was also tested for sensitivity to speed variations and impeller angle. It was no more sensitive than the conventional spreaders.

Technical Notes: Experimental Verification of the Effect of Collection Pan Width on Apparent Spreader Pattern

A theoretical study of the relationship between collection pan width and apparent spreader pattern was published in the Netherlands. The mathematical relationship developed in that study has been compared to the results of an extensive experimental study on the relationship between collection pans and apparent spreader patterns conducted at the Louisiana Agricultural Experiment Station. The experimental data verify the theoretical relationship, and conversely, the theoretical relationship provides a useful explanation of the apparent pattern differences noted in the experimental study.

Speed Effects on Drop-Type Spreader Application Rate

OPERATORS of drop-type fertilizer spreaders often assume that the spreader meters in a volumetric manner; i.e. delivery rate per revolution is constant and independent of speed. At least one major reference work on the subject states that this assumption is true. A test was run at the Louisiana Agricultural Experiment Station using two popular drop-type spreaders and two materials under controlled laboratory conditions. The results clearly show that drop spreader application rate does vary with speed, but is not completely gravimetric; i.e. the flow rate is not constant with respect to time. The application rate of a typical drop-type spreader is variable and falls between volumetric and gravimetric.

Band Application Performance of Single-Disc Rotary Fertilizer Spreaders

Abstract. Single-disc rotary fertilizer spreaders are principally used to obtain a full fertilizer distribution pattern. These spreaders also can be used for banding application if the spreader disc is simultaneously fed by two orifices with the same shape and size. Using two orifices at the opposite angular position of 180° and the proper angular position with respect to travel direction resulted in two bands on opposite sides of the spreader. The single-disc spreader used for this study was evaluated for spreader disc height and PTO speed to control the spacing between the two bands and bandwidths. Spreader disc heights of 38, 56, and 75 cm and PTO speeds of 270, 405, and 540 rpm were used to demonstrate the effects of these variables on band spacing and width. Using triple superphosphate, band spacings from 4 to 11 m and bandwidths from 4 m left/4 m right to 9.5 m left/9.5 m right were obtained. The effect of PTO speed was more pronounced than the effect of spreader disc height for both band spacing and bandwidth. The effect of spreader disc height on both left and right bandwidth was not proportional.

INDUSTRIAL AND AGRICULTURAL TECHNOLOGY—A COMBINED CURRICULUM AT LOUISIANA STATE UNIVERSITY

The Agricultural Mechanization curriculum at Louisiana State University has been combined with the Industrial Technology curriculum to provide one overall program in Industrial and Agricultural Technology with five areas of specialization: Agricultural Systems; Computer Integrated-Manufacturing; Occupational Safety and Health; Electronics and Microcomputers; and Industrial Supervision.

Development of a Marshgrass Transplanting System

A mechanized method of transplanting salt-tolerant species of marshgrass in the bareroot form was explored. Detailed discussions of the design, building, and testing of several different mechanical transplanters to accommodate different soil types and water levels are included. A system consisting of a furrow planter for supportive mineral soils, a dibble planter for soft, organic soils, and a planting aid for areas inaccessible to machines was needed to plant in all the conditions encountered. The performance of the modified furrow planter was satisfactory under the conditions in which it was tested. The performance of the modified dibble planter was not acceptable in its present state of development. A three part planting system was not anticipated at the beginning of the project and more work is needed on the dibble planter and planting aids to make the system complete.

Basic Data on Air Requirements for Cleaning Christmas Trees

A basic study of Christmas tree cleaning with an air blast was conducted. Virginia pine Christmas trees were suspended in a large diameter air stream. Cleaning variables included air velocity, retention time in the air stream, and wet versus dry foliage. Very good cleaning was achieved with an air velocity of 121 km/h (75 mph) and a retention time of 15 s. Wet foliage had no effect on cleaning.