Yield, quality, economic benefit and comprehensive evaluation of film-covered mechanically transplanted rice

Film-covered rice cultivation has been significantly enhanced by the biodegradable films, film-covered mechanical transplanting, and controlled-release fertilizers. Mechanical and simple rice farming can be expected for environmentally friendly and sustainable agriculture. Film-covered mechanical transplanting is increasing in large-scale rice production. The promising approach can also offer to streamline the field operations with low labor inputs for high production efficiency. However, it is still lacking in the impacts of the film-covered cultivation on the rice yield, quality, and economic benefit. In this study, a systematic evaluation was implemented on the yield, quality, and economic benefit of the film-covered mechanically transplanted rice. The experimental materials were taken as the conventional japonica rice, indica-japonica hybrid rice, and hybrid indica rice varieties. Four treatments were also set as the film-covered cultivation with one-time application of controlled-release nitrogen fertilizer (FMCS), film-covered cultivation with multiple applications of conventional nitrogen fertilizer (FMCF), non-film-covered cultivation with one-time application of controlled-release nitrogen fertilizer (NFCS), and non-film-covered cultivation with multiple applications of conventional nitrogen fertilizer (NFCF). Mechanical transplanting was then simulated under farming scenarios. The results indicated that the fertilization significantly impacted the yield performance of the film-covered cultivation. Specifically, the rice yield was ranked as the FMCS, NFCS, NFCF, FMCF. Among them, the FMCS was achieved in the high yield after optimization on the effective panicle numbers and grains per panicle. There was an increase in the total spikelet numbers in order to maintain the high seed-setting rates and thousand-grain weights. In terms of the rice quality, the FMCS increased the head rice rate by 0.8% and 1.5%, respectively, compared with NFCS and NFCF, whereas the chalkiness degree was reduced by 13.6% and 18.7%, respectively. Some significant differences were also observed to improve the processing and appearance qualities. Additionally, the FMCS shared a 0.9% reduction in the protein content, compared with the NFCF. Its taste value score was 2.2% and 1.0% lower than that of FMCF and NFCS, respectively, although there were no statistically significant differences. As such, the taste value of the FMCS remained, compared with the NFCS treatment. The increasing protein and amylose contents were attributed to the better cooking and eating quality of the rice. The economic benefit of FMCS was 525 Yuan/hm2 lower than that of NFCS. Its ratio of output to input was also lower than those of both NFCS and NFCF. The reason was the significant increase in the film and planting costs. Its profitability outstandingly exceeded that of NFCF, due to the suitable variety selection. Furthermore, the evaluation model was integrated with the analytic hierarchy process, the membership function of the optimal indices, and the fuzzy evaluation index. The overall value of FMCS was found to be lower than that of NFCS, but higher than that of NFCF. Its relatively high benefits were then achieved over the conventional cultivation. Therefore, the FMCS mode exhibited considerable potential for application among treatments. Further optimization was also required for cost reduction and efficiency enhancement. Some recommendations were given on the membrane materials to reduce the costs, fertilizer application strategies to optimize the yield and rice quality, and mechanical operations for high efficiency. Additionally, it is critical to the physiological and ecological mechanisms underlying the growth and development of rice under film-covered cultivation. Integrated technologies can also be expected to promote the high-yield, quality, and efficiency film-covered rice cultivation in sustainable agriculture.