Aiming at precise evaluation of the performance of soybean seed metering devices, a photoelectric sensor-based real-time monitoring system was designed. The proposed system mainly included a photoelectric sensor module for seeding signal collecting, Hall sensors speeding module, microcontroller unit (MCU), light and sound alarm module, human–machine interface (HMI), and other parts. The indexes of miss, multiples, flow rate, and application rate were estimated on the basis of seeder speed, seed metering disk rotation rate, photoelectric sensor signals, and clock signals. These real-time statistics of the seeding process were recorded by seeding management system. The laboratory results showed that the detection errors of seeding quantity of both big- and small-diameter soybeans were less than 2.0%. Miss and multiples index estimated by this system were 0.4% and 0.5% than that of seeding image monitoring platform (SIMP), respectively. In field tests, miss and multiples index can be used to evaluate the performance of seed metering device, and big-diameter seeds can be detected more precisely than small ones by these photoelectric sensors. This system can provide support for evaluation of working performance of seed metering devices and have a positive effect on seeding monitoring technology.

Soil penetration resistance (SPR) is one of the major indicators of soil physical properties. Crop residue managements, tillage practices and their interactions exert significant effects on the SPR. However, rare information is available in the sloping farmland of Mollisols. Field experiments were conducted to investigate the variations of the SPR as affected by crop residue managements and tillage practices on the sloping land in Northeast China from 2015 to 2019. The split-plot experiment was arranged with two crop residue managements (removed, REM and retained, RET), and three tillage practices (no tillage, NT; rotary tillage, RT; plow tillage, PT). SPR data in 0-80 cm soil depth was measured at the end of harvest of maize monoculture. Results showed that the two crop residue managements induced significant variations in the SPR at 0-15 cm, 15-30 cm and 0-80 cm soil depths under NT, RT, and PT treatments, respectively. In comparison with RET treatment, the average values of the SPR under REM treatment were 10.9% and 8.9% higher in 45-60 cm and 60-80 cm soil depths, respectively. The average values of the SPR under PT treatment were 12.4% and 14.1% lower in 0-15 cm soil depth, and 23.9% and 10.4% lower in 15-30 cm soil depth than those under NT and RT treatments. However, the average value of the SPR under PT treatment was 11.2% and 22.0% higher in 60-80 cm soil depth than those under NT and RT treatments, respectively. The SPR generally decreased with the slope position declined in the deeper soil depth (except for the NT+RET treatment). The findings from this research can provide a scientific reference for the establishment of rational cultivation and the sustainable development of productivity on the sloping land of Mollisols in cold regions. Keywords: soil penetration resistance, crop residue management, tillage practice, slope position, soil depth, Mollisols DOI: 10.25165/j.ijabe.20221501.6526 Citation: Wang Y J, Qiao J Y, Ji W Y, Sun J, Huo D X, Liu Y P, et al. Effects of crop residue managements and tillage practices on variations of soil penetration resistance in sloping farmland of Mollisols. Int J Agric & Biol Eng, 2022; 15(1): 164–171.

After corn mechanical harvest in autumn in the cold region of northeast China, straw mulching leads to high soil topsoil water content and slow ground temperature rise in the spring sowing season, which may result in a no-tillage planter being unable to operate in time, delayed sowing date, poor seedling emergence quality, and low grain yield. Based on the problems of high moisture content and low temperature in soil topsoil in the spring sowing season in conservation tillage with straw mulching, an experimental study on timely sowing in the spring sowing season was carried out from the perspective of combination optimization of attribute parameters of straw mechanical treatment. Taking the four mechanical treatment attributes as experimental factors, including straw length, straw shape, mulching form (surface covering, inter-ridge covering, and inter-ridge mixed soil covering), and stubble height after corn harvest in autumn of 2019 as experimental factors, and soil topsoil moisture content and temperature during spring sowing in 2020 as evaluation indexes, a field plot experiment was carried out by four factors and three levels of orthogonal combination test method. The results showed that all the factors had significant influence on soil topsoil moisture content and soil topsoil temperature (p < 0.05). It is helpful to reduce the moisture content of soil topsoil and increase the temperature of soil topsoil by increasing the length of corn stalk, breaking the stalk moderately, covering the stalk between ridges, and increasing the stubble height of stalk. Design-Expert software was used to optimize the parameters. The results showed that when the length of straw was 150 mm, the shape of straw was half-cut (dividing straw into two parts evenly along the axis), the mulch was between ridges, and the stubble height was 600 mm, the moisture content of soil topsoil was 22~24% and the temperature of soil topsoil was higher than 8 °C during spring sowing. After corn harvest in autumn of 2021, corn stalks were treated in that year according to the results of parameter optimization combination. The soil topsoil moisture content and temperature were measured to be 24.4% and 8.2 °C, respectively, in the spring sowing season of 2022, which proved that the optimization results in this experiment were credible. The experimental results provide a technical reference for the implementation of conservation tillage with straw surface mulching in the cold region of northeast China.

As the complex terrain in hilly areas is not conducive to corn mid-tillage precision fertilization, a corn-overlapped strip fertilizer spreader was designed without an external power source. By configuring a passive overlapping spreading method with a three-branch split chamber structure, the uniform spreading of fertilizer in strips was achieved. A horizontal and vertical movement model of fertilizer spreading was developed to determine the angle of the fertilizer extending tube, the width of fattening small plates, and the height of the fertilizer spread as the main factors affecting the fertilizer distribution pattern. The single-factor ternary orthogonal rotational combination response surface simulation test was carried out with pendulum angle, width, and height as test factors and the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient as test indicators. The test results showed that the pendulum angle, height, and width had significant effects (p < 0.05) on the transversal fertilizer uniformity coefficient, and the pendulum angle and width had a considerable impact (p < 0.05) on the longitudinal fertilizer uniformity coefficient. In the optimal combination of parameters, swing angle 52°, height 400 mm, and width 50 mm operation, the coefficients of uniformity of both the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient were less than 0.15%. A verification test was carried out under the optimal combination of parameters for the simulation tests with the simulation conditions as the standard. The test results were consistent with the simulation results within the error range. The deviation values of the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient were 8.11% and 9.01%, respectively. The corn-overlapped strip fertilizer spreader was able to complete the fertilizer spreading operation smoothly. This study provides evidence for further optimizing the performance of the corn mid-tillage fertilizer applicator.

Aiming at the problems of large soil disturbance, high power consumption and strong vibration during the operation of the 2BMFJ series straw clearing and mulching no-tillage precision planter with rigid teeth, an elastic tooth type lateral straw clearing roller was designed and the key parameters and values affecting the operation performance of the device were determined through theoretical analysis. Orthogonal test method was adopted to implement parameter combination improvement test with the length of tooth rod, the clearance of roller center from ground, the circumferential number of elastic teeth and the angular velocity of roller as test factors and straw clearing rate, power consumption and vibration intensity as performance evaluation indexes. The results showed that: all the factors had extremely significant effects on the straw clearing rate and power consumption performance evaluation indexes, except the clearance of roller center from ground had no significant effect on the vibration intensity performance evaluation indexes, the other factors have significant effects. Parameter optimization combination: At the planter forward speed of 7.2 km/h, the length of toothed rod was 270 mm, the clearance of roller center from ground was 360 mm, the circumferential number of elastic teeth was 8, the angular velocity of roller was 52 rad/s and the performance evaluation indexes were as follows: straw clearing rate was more than 90%, power consumption was less than 1.7 kW and vibration intensity was less than 85 m/s². Through the comparative test of the elastic tooth and rigid tooth type lateral straw clearing roller, there was no significant difference in the straw clearing rate between the two, but there were significant differences in the power consumption and vibration intensity. The elastic tooth type lateral straw cleaning roller reduced power consumption by 63.3% and vibration intensity by 43.2%.

Knowledge about the frictional characteristics of materials is required for equipment design, either to exploit the friction or to overcome it. This paper deals with studying the coefficients of sliding friction of non-treated and extrusion-exploded wheat straw and rice straw on mild steel and aluminum surfaces and the effects of several factors, including the moisture content (at five levels 35, 45, 55, 65, and 75%), normal pressure (at the following five levels: 2, 4, 6, 8, and 10 kPa), and length (at the following five levels: 30, 60, 90, 120, and 150 mm). Through the use of a statistical analysis method, we found that the moisture content, normal pressure, and interactions between them had statistically significant effects on the coefficient of sliding friction (p < 0.01). The coefficient of sliding friction was much larger than that of rice straw on both contact surfaces, and the coefficient values of both straw samples on the aluminum surface were notably higher than those on mild steel. A significantly higher value was found for the coefficient of sliding friction of extrusion-exploded straw compared with that of untreated straw on both surfaces. As the normal pressure increased from 2 to 10 kPa, the coefficient of sliding friction decreased first, and then increased sharply, finally fluctuating slowly for both kinds of straw and on both tested surfaces, with the maximum value was observed at a normal pressure of 6 kPa. When the length increased from 30 to 150 mm, a slightly linear upward trend was observed for the coefficient of sliding friction of untreated wheat straw, and the coefficient of sliding friction of untreated rice straw initially increased and then decreased.