Potato is an important food crop in China, and its planting area and output rank first in the world. Due to the labor intensity and low efficiency of manual harvesting, mechanized harvesting has become an inevitable solution for the development of the potato industry. In this paper, on the basis of elaborating on mechanized harvesting operation modes for potatoes, the research progress of key technologies, such as top-killing potato seedlings, low-loss digging with reduced obstruction, limiting the depths of rows, high-efficiency separation, sorting tons of packages, and intelligent harvesting in China and abroad, is analyzed. By comparing the basic structure and technical characteristics of both domestic mechanized potato-harvesting equipment and that used abroad, this paper identifies the gaps between domestic equipment’s performance, intelligence level, and adaptability and those of equipment in European and American countries and also identifies bottlenecks, such as large regional variability, the lack of high-efficiency and low-loss separating devices, and the difficulty of breaking through key “chokepoint” technologies. On this basis, this paper proposes that the future development direction of domestic mechanized potato harvesting should focus on the synergistic development of multiple modes, on the research and development of flexible and low-loss separation equipment, and on the integration of intelligent technology; it also gives specific suggestions, aiming to provide references for the future progress of mechanized potato harvesting.

The uneven sowing of wheat on ground covered with rice straw in the rice–wheat rotation area in the middle and lower reaches of the Yangtze River has become a serious problem. Therefore, a test bed for throwing soil after sowing with a wide wheat seed belt was designed, which could complete the functions of straw crushing, straw lateral concentration and uniform sowing at one time. The discrete element simulation model of throwing soil after sowing with a wide wheat seed belt was established with rotary blade shaft speed, soil guide plate angle and soil retaining plate angle as variables. Taking the variation coefficient of wheat sowing depth and variation coefficient of sowing lateral uniformity as evaluation indexes, the effects of three variables on sowing uniformity were analyzed by single factor test and Box–Behnken test. The results of single factor test observed that when the rotating speed of rotary blade shaft was 260–300 rpm, the angle of soil guide plate was 36°–48°, the angle of soil retaining plate was 58°–74° and the experiment of utilizing a soil throwing and covering device with a wide seed belt after sowing revealed a good consistency of sowing depth and lateral uniformity effect. The Box–Behnken simulation experiment showed that the primary and secondary factors affecting the variation coefficient of wheat sowing lateral uniformity were the angle of soil guide plate, the rotation speed of rotary blade shaft, the angle of soil retaining plate and the angle of soil guide plate. When the rotation speed of rotary blade shaft, the angle of soil guide plate and the angle of soil retaining plate were 282.1 rpm, 42.4° and 65.5°, respectively, the soil throwing and covering device after sowing has the best seed-homogenizing effect. At this time, the variation coefficients of sowing depth and lateral uniformity in simulation test and field verification test were 4.35% and 4.57%, respectively, and 12.46% and 12.73%, respectively. The results of field verification test were basically consistent with those of the simulation test, which proved that the results of applying discrete element methods to optimize the soil-throwing device after sowing with a wide seed belt were credible. This study could provide a theoretical reference for the structure optimization of a soil-throwing device after sowing with a wide seed belt.

Aiming at the problems of high missed-pickup rate and crushed rate caused by different types of peanut harvester pickup drums, by tracking a field comparative experiment from 2020 to 2021, the missed-pickup rate, missed-pickup quality distribution, crushed rate and quality distribution rule of pods with different degrees of crushing observed in two peanut varieties with different pickup drums were studied. Three kinds of pod-pickup drums were set up: axial flow (T1), tangential flow (T2) and tangential–axial flow (T3), and they were installed on the pickup harvester to form three kinds of pickup and harvest test stands. At the same time, a control test stand (CK) without pod-pickup drums was set up. Peanut varieties “Shanhua 9” and “Huayu22” and 10 water content levels were used. Using Origin2018 software, the missed-pickup rate, missed-pickup quality distribution, crushed rate and the quality distribution of pods with different degrees of crushing were statistically analyzed for the two peanut varieties harvested by different pickup drums. The results showed that the average missed-pickup rate was T1, T2 and T3, in order from small to large. The order of pickup quality from more to less was small pods, medium pods and large pods, which indicated that small pods were more likely to be missed. The average pod crushed rates for T1, T2 and T3 for Shanhua 9 were 2.06%, 2.19% and 2.45%, and those of T1, T2 and T3 for Huayu22 were 1.74%, 1.91% and 2.23%, so the order of pod crushed rates from small to large was T1, T2 and T3. At the same time, the crushed rate of T1, T2 and T3 to the two varieties decreased obviously with the decrease in water content. After the T1 test, the proportion of medium and severely crushed pods was the least, followed by T2, and the highest was T3. At the same time, the higher the water content, the higher the proportion of medium and severely crushed pods, and the proportion of medium and severely crushed pods after the Huayu22 test was less than that of the Shanhua 9 test.

Preharvest bagging is a key agricultural technology in the process of the growth and development of young fruits. It can effectively improve the appearance quality of fruits, reduce pesticide residues on the surface of fruits and prevent pests and birds from harming fruits. China is one of the world’s major fruit producers. It is also the country that uses the most fruit cultivating bags. At present, the fruit cultivating bags used in Chinese orchards are mostly paper. Ways to recycle and reuse the waste fruit cultivating bags should be paid attention to. Therefore, this paper comprehensively uses the methods of data analysis and literature research to summarize and analyze. The data mainly comes from the China Rural Statistical Yearbook, a national public service platform for standard information, China’s national knowledge internet and the web of science. The topics discussed include the current situation of fruit production in China, the overview of fruit bagging technology, the production and use of fruit cultivating bags and the recycling strategy of waste fruit cultivating bags. It is hoped that this study can provide some references to the development of fruit bagging technology and the resource reuse and recycling of waste fruit cultivating bags in China and the world in the future.

China’s carrot planting area and total output rank first in the world, but China’s mechanized carrot harvesting level is relatively backward. There are many problems in the existing machine operation process, among which the problems of a high leakage rate and high damage rate are the main difficulties faced. In order to study this problem, a test platform composed of clamping and pulling devices and conveying devices is designed, and it can complete the experiments of clamping, pulling and conveying carrot plants and collecting carrot stalks at one time. During the test, the clamping speed was divided into four test levels: 0.40 m/s (T1), 0.85 m/s (T2), 1.30 m/s (T3), and control test (CK), and each test level was carried out three times at different forward speeds. Finally, the leakage rate and damage rate were statistically analyzed. The results show that the average damage rate of Xiahong2 is 6.13%, 3.53%, and 9.36% and that of Sanhong is 6.22%, 3.76%, and 9.88% under the clamping and conveying speeds of T1, T2, and T3 in two years. The average carrot missed-pulling rate of two consecutive years corresponding to two carrot varieties, Xiaohong2 and Sanhong, was 3.68% and 4.14%, respectively. The carrot missed-pulling rate of CK in the control group of two carrot varieties, Xiaohong2 and Sanhong, was high and stable at 96.2% to 97.5%. At the same time, T1, T2, and T3 had similar overall trends of high carrot leakage rates for two carrot varieties at different clamping and conveying speeds. This control experiment also proves that the experimental arrangement is scientific and accurate. The average carrot leakage rate of T1, T2, and T3 for Xiahong2 is 3.91%, 3.42%, and 6.22%, and that of T1, T2, and T3 for Sanhong is 4.06%. The research results can provide a theoretical basis and reference for the optimization and improvement of carrot clamping and conveying devices, and this research can provide a reference for how to reduce the harvest loss of carrot combine harvesters in China.

When sowing with a wide boundary under full rice straw retention in the rice–wheat rotation area of China, conventional fertilization methods have some problems, such as a low fertilizer utilization rate, heap soil around a buried fertilizer device, or blocked fertilizing orifice. Firstly, combined with theoretical analysis, discrete element numerical simulation technology, and central composite test method, the wide-boundary fertilization device for wheat wide-boundary sowing was designed. Then, with the coefficient of variation for particle uniformity (CVPU) as the response value, the central composite experiment was carried out on the key structural parameters (focal length coefficient, lateral span, tilt angle, and ground clearance) of the wide-boundary fertilization device by EDEM software. Finally, the influential rules of core factors of the device on the CVPU were analyzed by Design-Expert software; then, the optimal parameter combination was determined and verified by a field test. The results showed that all factors had significant effects on the CVPU. The primary and secondary factors affecting the CVPU were the tilt angle, lateral span, focal length coefficient, ground clearance, tilt angle × ground clearance, and lateral span × ground clearance, in which there were certain interactions between the tilt angle and ground clearance and lateral span and ground clearance. When the focal length coefficient, lateral span, tilt angle, and ground clearance were 1.5, 60 mm, 30°, and 192 mm, respectively, the lateral was minimum. In this case, the theoretical value and field test value were 14.11% and 17.63%, respectively. The field test value is consistent with the theoretical calculation value. This study could provide references for the design of a fertilizer-spreading device with a wide boundary.