Treatment quality assessment of sunflower inter-row widths with asymmetric joining of cultivator to tractor

Abstract

Almost all existing units for mechanical processing of inter-row widths of row crops (corn, sunflower, soybeans, etc.) are symmetrical. In this case, the ratio of the tractor track to the row crop’s inter-row widths is an even integer (k). This article presents the study results of a machine-tractor unit in which the value k equals 3; that is, it is odd. As a result, an asymmetric unit was obtained, in which the cultivator is displaced in the transverse direction relative to the tractor symmetry axis by half the inter-row width, equal to 70 cm. The width fluctuations of sunflower plant protective zone formed by such machine-tractor unit are rather low-frequency. At a speed of 1.9 m·s-1, the main variance spectrum of these oscillations is concentrated in the frequency range 0-0.9 m-1 or 0-0.27 Hz. With an increase in the unit movement speed to 2.4 m·s-1, this diapason narrows to 0-0.6 m-1 (0-0.23 Hz). At the same time, an increase in the movement speed of the studied unit from 1.9 to 2.4 m·s-1 did not lead to a significant change in the mean of the width and variance of the sunflower row protective zone oscillations. The actual difference between the means of this zone (0.6 cm) turned out to be less than LSD05, equal to 0.8 cm. In addition to this, the null hypothesis about the equality of the compared of this parameter fluctuation variances was confirmed. Calculations have established that the possible deviation frequency of the sunflower plant protective zone width actual value of ± 1 cm from the established one can reach 0.007 m-1 or one release per 143 m of the path travelled by the unit at a speed of 1.9 m·s-1. When the machine-tractor unit moves in the sunflower inter-row widths at a speed of 2.4 m·s-1, the value of this indicator is 0.009 m-1 or one release per 111 m of the path. According to the results of experimental studies, real damage (cutting) of sunflower plants for both unit operation modes did not exceed 0.9%. The weed destruction in the inter-row widths of this crop was 98.5%.