1) In this experiment, a seed-shooting device including a saw-toothed disc was designed and developed as part of a new direct-sowing system for rice seed under submerged paddy field condition.
2) The saw-toothed disc is 190mm in diameter in size and 20mm in thickness, with 32 surrounding teeth. Elastic expanded-rubber is a suitable disc material.
3) The disc case consists of both supplying and shooting tubes, and the space between the disc case and the tip of the saw-toothed disc has to be adjusted within a width of 1 to 3mm.
4) The rate of revolution of the saw-toothed disc is automatically controlled in the velocity range of 100 to 1, 500rpm. Rice seeds are shot onto the soil surface of a paddy field in proportion to the velocity of the disc. The seed-shooting system applied in this experiment was well adaptable for use with soft soil immediately after puddling during land preparation.
5) Hill-seeding could be easily performed by the intermittent transference of several seeds using the supplying tube of the seed-shooting device.

View full abstract

Turning operation and adjusting of moisture content are indispensable process in the composting of tree pruning chips. From our previous study, reduction of the composing period to 90 days was observed as a result of the 60% moisture control by turning operation. Moreover, the higher aeration rate required higher amount of additional water by turning operations.
In this study secondary crushing process of pruning chips were examined to simplify composting methods without turning and adjusting of moisture content in 1m 3 reactors equipped with air pipes. Three aeration conditions were also examined to seek suitable methods for a moisture control. A flywheel cutter type chipper was used for the primary crushing and screw pressure type crusher was used for the secondary crushing. The aeration conditions of reactors were the continuos aeration, the intermittent aeration (30 minuets on and 60 minuets off) and the daytime aeration (8 hours during daytime on and 16 hours off) reactors and aeration rates were 15m³/day.
The results were followings:
1) The moisture contents of secondary processed chips held above 40% during more 56 days in composing process.
2) Secondary crush chips with the intermittent aeration fermented without turning operations.
3) The intermitting aeration reduced the composing period to 56 days.
4) The fermentation temperatures did not reach to suitable range in the daytime aeration reactor.

View full abstract

1. A prototype combined seeder comprised of a forage harvester, a rotary tiller, a fertilizer and a seeder for dentcorn·sorghum-barley·rye double cropping systems was developed. The working hour of combined seeder for dentcorn harvesting and rye seeding work in test field (30a) was 12.2a/h.
2. Using the combined seeder, dentcorn-rye cropping system and sorghum-barley cropping system showed maximum average yields of 2.7t/10a (DM). The forage crops were improved in qualities as silage materials because of longer culture periods by the combined seeder.
3. The simulation results of 11 years (1985-1995) using precipitation data of Morioka in field area of 5ha show that the combined seeder with the work efficiency 12a/h completed 5ha of dentcorn·sorghum-rye·barley cropping systems same as forage-harvester with the work efficiency of 24a/h did. And the combined seeder will finish rye or barley seeding work earlier than individual harvesting and seeding works do. The combined seeder shows merits of efficient works and better forage crop qualities in northern Tohoku Area.

View full abstract

The working efficiency and rice yield of large-scale paddies were investigated in a flat plane in Niigata. Large-scale paddies (40 a and 60 a) were created by removal of levees, without further mechanical land consolidation, and cv. Koshihikari was produced from May to September in 1998 and 1999. The newly created large-scale paddies were flat, as the standard deviation (SD) of ground height in the original paddies was within the standard level set by Ministry of Agriculture, Forestry and Fisheries. Transplantation of rice seedlings and irrigation were performed smoothly. The efficiency of human labor such as fertilizer application decreased in the large-scale paddies. On the other hand, the efficiency of mechanical work such as tillage, pudding and harvest increased and fuel consumption decreased clearly in the large-scale paddies. The direction in which the drain was made in the paddy did not affect the efficiency of irrigation during midseason drainage. There was not a significant difference in the rice yield among the 20 a, 40 a and 60 a-paddies.

View full abstract