The non-judicious use of water at the farm level in traditional irrigation application methods is a present-day concern across the world that can be resolved by enhancing application efficiency through the adoption of advanced irrigation techniques. Sprinkler irrigation is a method that has high application efficiency, which can be further increased when coupled with automation toward precision irrigation. The objectives of this review are to summarize the main aspects of sprinkler and precision irrigation and their development, scope, and future prospects specifically in Asian countries. In this paper, a modified methodology, inspired by PRISMA guidelines, was used to explore the available literature to summarize the existing knowledge in the field. Regarding the technological aspects of the analyzed works, it became evident that sprinkler systems are an efficient method to not only irrigate crops (with 39% water saving) but also for the application of fertilizers with higher efficiency (>35%) and water productivity (>14.1%) compared with gravity irrigation systems. Moreover, this paper highlights the prominent features of precision irrigation for maximizing agricultural productivity. The use of sprinkler irrigation with precision applications using automation with a sensor-based mechanism for field data collection, data transformation, data analysis, and operation of IoT-based automatic solenoid valves can save 20–30% more irrigation water and increase crop yield by 20–27%. An analytical understanding and knowledge of the field were used to draw conclusions that are thought-provoking for scientists, researchers, and other stakeholders.

Anaerobic fermentation of organic waste, such as livestock manure, in biogas projects is an environmentally friendly and effective treatment method. The resulting biogas, mainly composed of methane, is a combustible gas with energy properties, while the digestate, containing nutrients such as nitrogen (N), phosphorus (P), potassium (K), and other organic matter, can be used for agricultural irrigation. This article analyzes the current situation of resource utilization of livestock manure in various countries and the progress of biogas projects. It introduces the process, composition, and commonly used filtration methods before applying the digestate to farmland. The summary focuses on the improvement of crop quality, enhancement of soil fertility and the risks of pollution, and environmental hazards associated with the utilization of biogas slurry. The limitations and corresponding solutions for the agricultural utilization of livestock digestate are discussed, and recommendations are made for the technology of digestate irrigation and application to farmland.

Water saving is an essential part of sprinkler irrigation owing to the impact of climate change and rising energy costs. This review highlights the technologies that are emerging in sprinkler irrigation to optimize crop production. While there have been notable advances in irrigation, the continued progress has occurred by the combination of current status with the postulation of new ideas such as conversion of high-pressure sprinkler to low-pressure ones, incorporation of smart controllers in sprinkler irrigation systems. To enhance the adoption of these technologies, research on the dispersion device is needed to improve the performance of impact sprinklers to efficiently operate at low-pressure conditions. It is also important to study how water savings estimates based on water use, irrigated area, longevity of saving, and level of wasteful irrigation prior to the retrofit obtained from field trials can be extrapolated to other areas with different conditions. Research in the development of optimized method for irrigation scheduling is necessary. This review emphasizes that the status of technologies should be considered a continuum, building on earlier knowledge and progress, and hopefully leading toward optimized crop production in sprinkler irrigated areas. Keywords: sprinkler irrigation technologies, smart controllers, crop water demand, crop production DOI: 10.25165/j.ijabe.20191203.4310 Citation: Li H, Issaka Z, Jiang Y, Tang P, Chen C. Overview of emerging technologies in sprinkler irrigation to optimize crop production. Int J Agric & Biol Eng, 2019; 12(3): 1–9.