The Application and Development of Pesticide Precision in Japan

The agricultural working population has been decreasing in Japan. On the other  hand, the average age of farmers has been increasing. These factors have caused farmland to be consolidated, though agricultural management hierarchy is becoming polarized. To solve these problem, a national project in the agricultural machinery field, entitled “Smart Agriculture”, has been started. The purpose of “Smart Agriculture” is to increase working efficiency and reduce labor costs by using robotic techniques, as well as information and communication technology.
                                                                                  
Yamabiko Corporation is one of the leading companies manufacturing crop protection equipment in Japan. Yamabiko Corporation has been encouraged to create  smart agriculture by producing crop protection equipment, such as spraying equipment for UAVs and self-propelled boom sprayers for paddy rice.

The main crop in Japan is paddy rice, occupying 38% of the cultivated areas. It’s very important for the Japanese agricultural machinery manufacturer to take care of paddy rice cultivation. Many types of machines are used in rice fields. In small fields, farmers use knapsack type sprayers and power sprayers. In this case, farmers need to spray by hand. Farmers who have big fields, for example, the size of some 5 ha, want to use high performance machines, such as self-propelled boom sprayers and industrial multi-rotors. Helicopter applications offer the most efficiency for spraying applications. Recently, farmers were willing to use multi-rotors for spraying applications, since multi-rotors are cheaper than helicopters and easier to use.

Japanese agricultural began using UAV’s  in 1990. Yamaha motor began to sell the single rotor helicopter R50 in the Japanese market. Some 30 years ago  Yamaha motor modified aircraft introduced the latest technology. The latest generation YF390 and FAZER are driven by 4-stroke gasoline engines, and implement the turn assisted system and auto-cruise control system. Before using UAVs, manned aircraft were used for agri-chemical spraying in Japan. And then, aerial machines switched to unmanned helicopters for spraying applications for paddy rice fields. In 2018 May, the number of certified helicopters in the country is 2,788. The number of licensed operators is about 10 thousand. Regarding the share of helicopters, 40 % of paddy rice fields are sprayed by unmanned helicopters in Japan.

Regarding industrial multi-rotors,  there are a variety of multi-rotors produced by the Japanese and Chinese manufacturers. The multi-rotors is a new technology for spraying applications, and the practical use in the agricultural field is just starting. Japanese farmer are very interesting for using this unique aircraft in their field. The number of the certified multi-rotor in 2018 May is 889, and the number of operators who have license is over 3,600.

In the management schemes for UAV’s agricultural applications, UAV manufacturers are needed to take certification tests conducted by the Japanese agricultural ministry. If they pass the test, manufacturers can release the machines for use in Japanese markets. For operators, including farmers and teachers in the training school, they need licenses to operate UAVs in paddy fields. For practical use, there are some rules for spraying applications. Farmers need to have the notification of spraying plans for the year, which include information, such as when to spray, where to spray, who is spraying, and so on. When finishing the spraying season, every UAV, including spraying equipment, needs to be taken for inspection and maintenance. When any accidents unfortunately happen, farmers need to submit accident report to UAV manufacturers and the government.

Japan has a variety of types of high performance self-propelled boom sprayers. Farmers can control all the boom movements, such as tilt up/down, lift up/down and flapping out/in. Japanese boom sprayers have unique structures in their “telescopic boom”. Farmer can adjust the working width according to field shape by using switch lever operations from 9.3m to 15.9m. Basically, sprayers have boom control systems to maintain the boom horizontally. Self-propelled boom sprayers can turn at a minimum rotation cycle of 2.5m at the end of field.

Self-propelled boom sprayer has kind of flow rate control system. This can realize to keep the flow rate per area constant. Thanks to these high quality functions, sprayer can realize very high working efficiency. If farmer use knapsack type sprayer in the field with 30 area, it takes 60 minutes to work. Regarding self-propelled sprayer, it takes only 8 minutes.

In the current solution for self-propelled boom sprayers in paddy fields, Yamabiko self-propelled boom sprayers use GPS assisted guidance systems and automatic steering systems for the vehicle. In the paddy field,  it is difficult for farmers to drive the vehicle to avoid driving on rice rows. Auto steering systems  handle steering automatically by using GPS signals. This high performance system will contribute to optimize spray operations and saving labor by farmers. To use very high accuracy GPS signal by RTK system, tracking accuracy will be 2 - 3cm during spray operations. Self-propelled boom sprayers can drive and trace pre-programmed tracks automatically, which greatly improve spraying efficiency and productivity. Farmer can also use LCD touch panel monitors. The area sprayed is displayed on the monitor and is effective in preventing duplication or skipping. Turning points are shown on the monitor and helps to achieve smallest turns.

The benefit of the auto steering system for self-propelled boom sprayers is that the sprayer can drive automatically from point A to point B, which are set in advance, without steering. Sprayers can drive according to rice rows, thus avoid damage to rice. At the end of field, farmers steer the handle wheel, sprayers can drive to the next truck by watching the sprayed area on spray monitors. Auto steering systems for self-propelled boom sprayers can realize easy operation of vehicles during spaying operations with high efficiency, high accuracy and high performance.