Cutting is a significant part of agricultural material processing, and the cutting technology determines the quality of agricultural products. Water jet cutting technology is a non-contact and cold cutting technology suitable for cutting agricultural materials. It can realize an environmentally friendly cutting process avoiding such problems as heat generation, sharpening and cleaning blades, and microbial cross-contamination. This paper reviews the current status of water jet cutting of six kinds of agricultural materials, including vegetables, fruits, meats, woods, stems, and soils. By analyzing how to complete different cutting operations, improve cutting ability, or control post-cutting influences, the problems and solutions of water jet cutting of each material are summarized. Then, combined with the application requirements, some suggestions are put forward for developing water jet cutting technology. The results would help researchers determine key information required by cutting agricultural materials and provide a reference for further research on water jet cutting technology in agricultural engineering.

To solve the problem of low straw-cutting efficiency of single-disc openers of no-till planters under conditions of high soil moisture content, a single-disc furrowing and straw-cutting device was designed based on the support-cutting principle. To improve the straw-cutting ability of the disc opener when it operates under high-moisture-content soil conditions and to make sure that the straw that is not cut by the disc coulter can be cut smoothly by the disc opener, the support shovel was designed, and the operation mechanism of the support shovel device was analyzed. The soil moisture content, the support shovel’s entry angle, the support shovel’s entry gap angle, and the support shovel’s tip margin were identified as the factors influencing the device design through the theoretical analysis of the furrowing and straw-cutting device. Through the discrete element method (DEM), a single-factor simulation test was first conducted to analyze how different soil moisture contents affected the device’s ability to cut straw, and the results showed that the number of broken bonds was lowest when the soil moisture content was 20 ± 1%, and the time taken for the straw to be wholly cut off was also the longest. Then, a quadratic orthogonal simulation test was conducted to construct a regression model and optimize the parameters at the soil moisture content of 20 ± 1%, and the results revealed that the significant order of each factor’s influence on the number of broken bonds is as follows: entry gap angle, entry angle, and shovel tip margin. In addition, the device’s overall operation quality was better when the entry angle was 49°, the entry gap angle was 0°, and the shovel tip margin was 10 mm. At this time, the number of broken bonds was predicted to be 506. Finally, the simulation validation test was run, and the number of broken bonds was obtained to be 478, with a relative error of 5.6% from the predicted value. According to the optimal parameters to complete the device trial production and field test, the results show that the average cut-off rate of the device is 71.7%, the stability coefficient of the furrowing depth is 90.87%, and the performance of the furrow opening is excellent, which meets the requirements of a no-tillage seeding operation. This study can provide a reference for the design and improvement of no-tillage seeding machines under conditions of high soil moisture content.

A direct-injection straw deep-burial method was proposed to address the issues of insufficient depth and compaction during the process of straw deep burial. Based on the working principle of oblique cutting, an in situ soil-lifting shovel is designed for oblique cutting of soil and in situ lifting of soil, forming a deep burial space for straw. Elaborating on the working principle of the in situ soil-lifting shovel, we analyzed the stress situation of each stage during the operation process and determined the structural parameter values of the in situ soil-lifting shovel. Using the DEM simulation analysis method, the regression orthogonal simulation test is carried out with the soil-opening angle, the soil-lifting angle, and the camber angle of the in situ soil-lifting shovel as the test indicators, and the number of straws deeply buried and the operational resistance as the evaluation indicators. The regression equation and the response surface mathematical model were established to analyze the influence of the interaction of various factors on the operational performance of the in situ soil-lifting shovel. The simulation results showed that the significant order of effect on the number of straws buried deeply and the operational resistance was camber angle > soil-opening angle > soil-lifting angle. After optimization, the structural parameters were soil-opening angle of 17°, soil-lifting angle of 37°, camber angle of 30°, the corresponding number of straw buried was 228.29, and the operating resistance was 2840.45 N. The average value of operational resistance obtained from the field validation test was 3145.95 N, and the error with the simulation results was only 11%. The quantity of straw buried deeply was 90.21%. The straw deep burial experiment further indicates that the operation effect meets the agronomic requirements of straw deep burial.

Cutting maize stalks using water jet cutting technology is a new method of stalk management before no-tillage sowing. Aiming to cut off the maize stalks (stems and stem nodes), we conducted an all-factor cutting experiment on stems and single-factor cutting experiments on stem nodes under different cutting parameters. The results showed that the cutoff ratio of the stems and stem nodes increased with water jet pressure and decreased with target distance and traverse speed. For cutting off the stems with a maximum traverse speed, the parameters were 120 MPa water jet pressure, 10 mm target distance, and 1371 mm/min traverse speed. When the target distance was 30 mm, the traverse speed was 4000 mm/min, and the water jet pressure was greater than or equal to 160 MPa, the cutoff ratio of stem nodes was 100%. Therefore, the water jet pressure ≥ 160 MPa, the target distance ≤ 10 mm, and the traverse speed ≤ 1371 mm/min were needed to cut off both. Moreover, bottom burrs, surface stripes, and cutting residue might appear due to the divergent and lagging characteristics of water jets. The results could provide basic data and technical support for cutting maize stalks with water jets.