Conventional soil-tool interaction has been upgraded to straw-soil-tool interaction due to plenty of straw remains in the field after harvesting. Understanding the straw-soil-tool interaction relationship and quantifying the straw movement and distribution characteristics at various tillage operation parameters is critical for straw management and the design of tillage tools. Here, in order to investigate the interactive effects of key operation parameters on the displacement and burial of straw, a specific field test rig was developed to perform straw movement test. According to the singe-factor test and multifactor interactive experiment, we investigated the effect of straw length, tillage depth and rotary speed on straw movement, and established a mathematical model between operation parameters and straw movement. The results showed that the significant order of the influence on the displacement and burial of straw was as follows: the tillage depth, the straw length, the rotary speed. As determined by response surface analysis, the optimal combination of parameters for straw incorporation was straw length of 5 cm, tillage depth of 13 cm, and rotary speed of 320 rpm, and the corresponding straw burial rate and straw displacement were 95.5% and 27.6 cm, respectively. The relative errors of the optimization results are less than 5%. These results indicated that the mathematical model can be used to predict and evaluate straw movement. Therefore, it is feasible to enhance the straw incorporation performance by a reasonable setting of operation parameters, which may provide a comprehensive strategy to improve the working quality of tillage tools.

High-yielding agriculture in an intensive rice–wheat rotation system leads to plenty of residues left in the field after harvest, which is detrimental to seeding operation, seed germination, and early plant growth. Some residue thus needs to be incorporated into the soil. Providing the relationship between tillage operations and residue incorporation and establishing a mathematical model play important roles in residue management and the design of tillage machinery. In order to obtain detailed data on the interaction between residue incorporation and tillage operations, a multifunctional field-testing bench with precise parameter control was developed to assess residue incorporation characteristics of rotary tillage, and we investigated the effects of straw length, stubble height and rotary speed on residue incorporation. Three experimental factors affecting residue incorporation performance were studied, i.e., six lengths of straw (30–150 mm), four heights of stubble (50–200 mm), and three rotary speeds (240–320 rpm). Chopped straw and stubble with certain sizes were prepared for the test, and we measured the burying rate and distribution uniformity of residue after rotary tillage. The results indicated that straw length, stubble height, and rotary speed all impact residue incorporation quality. The burying rate and distribution uniformity of residue decreased with the increase in straw length and stubble height; a lower rotary speed parameter buried less residue and distributed it with worse uniformity than a higher one. It is suggested that farmers determine the straw length and stubble height at the stage of harvest according to the required burying rate and distribution uniformity of residue.

A rotary tiller is a common tillage tool for straw incorporation in an intensive tillage system. However, rotary tillage for seedbed preparation in dense-straw mulching conditions experiences high torque and poor performance of straw incorporation. Nowadays, a great deal of studies have been focused on mimicking the morphological features of low-resistance animals to improve the performance of soil-engaging tools. Accordingly, the present study investigated the performance of three C-type rotary blades (i.e., conventional, serrated, and biomimetic) under three straw lengths (50, 100, and 150 mm) for incorporation of straw into the field using an in situ field tillage testing bench. Compared to the conventional and serrated blades, the biomimetic blade had lower straw displacement (decreased by an average of 50 mm and 7 mm, respectively), higher straw burying rate (increased by an average of 5.2% and 7.8%, respectively), better straw distribution (decreased by an average of 9.1% and 10.4% on the coefficient of variation, respectively), as well as lower torque and power (decreased by an average of 3.3 N·m and 4.4 N·m, respectively) under all straw lengths. The improved performance of the biomimetic blade could be attributed to the fact that its typical teeth configuration was designed by mimicking the smooth arc of the mole-rat’s claw. These results demonstrated that the biomimetic-designed blade could be a better option for incorporating dense straw into the field conditions.

The uniformity of the cultivation environment in a micro-plant factory plays a critical role in ensuring the consistent growth of seedlings, and an optimal airflow pattern is the key to maintaining environmental uniformity. This study applied computational fluid dynamics (CFD) modeling to compare the effects of six different ventilation modes on the microclimate within the cultivation space. In cases 1 and 2, the inlet was positioned at the top, while the outlets were located at both the bottom and the top of the side walls. For cases 3 to 6, a side-inlet and side-outlet ventilation system was employed across the three cultivation layers. Case 4 maintained consistent inlet and outlet airflow speeds, whereas cases 3, 5, and 6 featured airflow settings that either increased or decreased progressively from the top layer to the bottom. Notably, case 6 was characterized by a more compact arrangement of cultivation racks within the space, which were positioned closer to the outlet than in the other cases. In case 1, the air inlets were positioned at the top, while the outlets were located on both side walls at the lower layer of cultivation. In contrast, case 6 used a side-inlet and side-outlet ventilation strategy, in which the airflow speed of the inlets decreases progressively from the top to the bottom of the cultivation layers. Additionally, the cultivation racks in case 6 were arranged more compactly and positioned closer to the outlet of the cultivation space. The relative standard deviation (RSD) was used to evaluate the uniformity of the airflow velocity (m/s), temperature (K), and relative humidity (%) within the crop-growing area. The results indicated that, among all the scenarios, case 6 demonstrated the lowest RSD values for the airflow velocity, temperature, and relative humidity, with reductions of 18.34%, 0.12%, and 2.05%, respectively, compared to the control group (case 1). Based on the ventilation design of case 6, a micro-plant factory was developed featuring a bidirectional flow fan, air conditioning, and PWM fans for the coordinated control of air circulation within the seedling cultivation space, along with adjustable cultivation layer heights and shelf spacing. The accuracy of the CFD model for the micro-plant factory was validated with normalized root mean square error (NMSE) for cultivation layer heights of 250 mm, 300 mm, and 350 mm. The NMSE values comparing the simulated and measured results for the airflow velocity, temperature, and relative humidity were found to be 0.032, 0.0020, and 0.0022; 0.031, 0.0021, and 0.0018; and 0.046, 0.0021, and 0.0021, respectively. These findings indicate that the established CFD model can reliably predict the microenvironment within the micro-plant factory.

As an advanced agricultural production technology, conservation tillage has been developed rapidly and adopted widely for many crops all over the world, but challenges remain with regard to dealing with excessive residues, especially for intensive rice–wheat rotation systems. Most studies to date have been based on a single type of tool and the indoor bin test to explore its performance. Accurate field test data on the tillage performance of different types of tools for conservation tillage are lacking in this area. In this study, five tillage tools were tested in a paddy field with plenty of crop residues to compare their performance. They were three vertical discs with plain disc (PD), notched disc (ND), and rippled disc (RD) and two disc coulters with plain disc coulter (PDC) and notched disc coulter (NDC). All five tools were tested using a specific field test rig at two different working depths of 70 and 100 mm. Tillage forces, straw cutting efficiency, soil disturbance width, and soil cutting depth were measured. The results showed that tool geometry and working depth had a significant impact on tillage performance. The vertical disc performed a higher average straw cutting efficiency, as well as lower tillage forces and lower soil disturbance width than the disc coulter. For straw handling and furrowing operations, RD had the highest straw cutting efficiency, moderate tillage force, and appropriate soil disturbance width among the five tools. For all five tools, the 100 mm working depth results in 40% higher draught force, 39% greater vertical force, and 18% higher straw cutting efficiency on average. For no-tillage seeding in the intensive rice–wheat rotation system, the RD would be a more suitable rotary tool for conservation tillage practice.