Fig 4 -

Diagram of spiral blades (a) Spiral line diorama; (b) Spiral expansion diagram. Among them, r is the radius of the trenching knife; h is the height of point f; β is the helix angle at c; γ is the helix angle at f.</p

Technical parameters of the machine.

Technical parameters of the machine.</p

Performance test of the double screw trencher and fertilizer.

Performance test of the double screw trencher and fertilizer.</p

Structure of the double screw trencher and fertilizer.

(a) Front view; (b) Top view. 1. tractor 2. drive shaft cover 3. fertilizer box frame 4. fertilizer discharge device 5. fertilizer box 6. fertilizer delivery pipe 7. scraper 8. trenching shaft 9. spiral blade 10. fertilizer discharge hole 11. profiled ground wheel 12. spiral fertilizer discharge device 13. tea garden.</p

Experimental design scheme and test results.

Experimental design scheme and test results.</p

Response surface for the effect of each factor on the coefficient of variation.

(a) Open trenching and fertilizing mechanism at 480 r/min; (b) Spiral fertilizer discharge at 90 mm diameter; (c) Spiral fertilizer discharge at 60 r/min.</p

Hydraulic system schematics.

Hydraulic system schematics.</p

Structure of the trenching and fertilizing mechanism.

1. hydraulic motor 2. fertilizer discharge screw conveyor 3. fertilizer inlet hole 4. shaft cover 5. auger blade 6. fertilizer discharge hole 7. auger tip.</p

Key design parameters of the trenching and fertilizing mechanism.

Key design parameters of the trenching and fertilizing mechanism.</p

Test factors and levels.

Test factors and levels.</p