Aging characteristics of drip irrigation belt in Xinjiang cotton fields and their effects on its recovery and recycling

Abstract

The old drip irrigation belts in Xinjiang cotton fields are prone to damage and have low recovering efficiency when being mechanically recovered, as well as poor mechanical performance and short service life of the old materials used in the production of various new products. Therefore, experiments were carried out from the macroscopic mechanical properties and microscopic chemical composition changes of the old drip irrigation belt to explore how the changes in its mechanical and chemical properties affect the recovery and recycling of the old drip irrigation belt. Mechanical properties of the old drip irrigation belts were tested by statics and dynamics test methods. The experiment results of indicators about mechanical properties showed that the tensile strength, elongation at break, natural rebound rate, impact strength and other mechanical parameters of the old drip irrigation belt samples were significantly lower than the corresponding values of the new ones. Which will affect the tensile capacity of the drip irrigation belt when it is recovered in the field. Furthermore, X-ray energy spectrum and infrared spectrum methods were used to analyse the chemical composition changes of the old drip irrigation belt. The determination results of X-ray energy spectrum showed that the oxygen content of the new drip irrigation belt samples was 1.73%, while that of old drip irrigation belt samples reached 12.15% ~ 15.27%. Then, the infrared spectrum experiment results showed that there were significantly more carbon groups in the old drip irrigation belt samples than that in the new ones. In addition, the correlation between the mechanical properties and oxidation degree of drip irrigation belt samples was analyzed, results showed that there was a significant negative correlation between them. This study results can provide basic data and theoretical guidance for the research and development of drip irrigation belt recovery equipment in Xinjiang cotton field, the research of rapid detection method of drip irrigation belt aging, the manufacture of anti-aging drip irrigation belt and the cyclic utilization of old materials.

Design of a New Drip Irrigation Belt Recovery Machine with Anti Breakage Function

“…Therefore, in this study, only the torque generated by the tension of drip irrigation belts was considered. The national standard stipulates that the tensile strength of qualified drip irrigation belts shall not be less than 130 N. However, according to our experimental research on the mechanical properties of the most commonly used maze drip irrigation belts in Xinjiang [10], the tensile strength range of the old drip irrigation belts is approximately 18.96~23.56 MPa. The maximum tensile range before the rupture of the drip irrigation belt is approximately 129.02~150.78 N. Therefore, we set the tensile force that the old drip irrigation belt can withstand to 120 N, and the maximum radius of the winding mechanism is 0.25 m. According to Equation (3), the maximum torque generated by the tension of the drip irrigation belts shall not exceed 30 N•m.…”

“…In this way, the drip irrigation belt can be evenly wound around the winding mechanism. The schematic diagram of the movement of the crank slide mechanism is shown in Figure 5b, and the kinematic equation of the drip irrigation belt conveyor mechanism in the horizontal direction satisfies Equation (10).…”

“…In theory, the movement speed of the drip irrigation belt arrangement mechanism should satisfy the first equation in Equation (11). However, according to Equation (10), it can be seen that the motion speed of the drip irrigation belt arrangement mechanism varies continuously according to a harmonic function. Therefore, when determining the specific motion speed of the drip irrigation belt arrangement mechanism, the effective speed (v' X ) is used instead of its actual speed (v x ).…”

“…Its price is low, and it is highly accepted by farmers. However, its mechanical properties will show a significant decrease after one year of use [10]. In addition, after the crops are harvested, there are many pieces of straw and weeds, plastic film, and soil blocks in the field.…”

<strong>Technological Advancements in Cotton Agronomy: A Review and Prospects</strong>

“…Because of their high water-use efficiency, which supports the sustainability drive, there are recent research efforts to utilize these irrigation systems for autonomous variable rate fertigation using low-cost electronics and controllers and to enhance their satisfactory performance and prospects [53] . Also, in China, where they irrigate about 3.33 million ha of farmland with drip irrigation, continuous research studies are being conducted to improve the irrigation technique for durability and higher performance [54] . And because most cotton farms are still furrow-irrigated in many countries (especially in developing economies), the combination of these new more water-efficient irrigation systems with machine learning algorithms, biodegradable PM, vegetation indices computed in real-time with remotely sensed data, and modern electronics presents hope/near-term solution for cotton water sustainability drive [53] .…”