Seeder and Precise Granular Fertilizer Application
Control System for Zero-Tillage Crop Cultivation
Chair of Biomass Conversion Unit of Biomass Control Systems Engineering
Burce Marlowe Edgar Cortes
Introduction
Zero-tillage cultivation is a type of tillage system where the crops are cultivated in narrowslots or tilled strips leaving an undisturbed soil. Conventional tillage cultivation is thetraditional plowing of the field. Compared to conventional tillage cultivation, zero-tillage
reduces: soil erosion, air pollution, machine wear, soil compaction, and saves a lot of time andmoney especially during field preparation. Zero-tillage crop cultivation requires seeding andfertilizing mechanisms to be able to handle residue, penetrate hard soil, regulate seeding depth,
cover seeds, and provide sufficient soil-seed contact. Thus, zero-tillage seeder is heavier andstronger than conventional tillage seeders but in some instances conventional tillage seeders
can be converted into a zero-tillage seeder.
The objective of this study was to add new functionality to the fertilizer application and seed
depth mechanisms of a conventional tillage air seeder so that it is ready for zero-tillage
cultivation. Functionality and performance test on the effects made by the converted seeder oncrop yields for both the conventional tillage and zero-tillage cultivation of soybean and sugar
beet was conducted.
MethodA pneumatic air seeder (TABATA, TJEV-4LR) with granular fertilizer application system
was tested in this study. This is a 4 row seeder that is commonly used in Japan. The fertilizer
application system was custom-built for flow rate control. An experimental cylindrical hopper,a flow rate sensor, a flow rate actuator, a tractor speed sensor, and a control unit wereinstalled on the fertilizer application system. One of the four seeder units was custom-built tocontrol seeder’s position to keep uniform seeding depth. The seeder unit was installed with ahydraulic cylinder, an electro-hydraulic valve, seeding depth sensors, and a control unit.
Laboratory and field test were conducted on both control system to test its functionality. For
crop cultivation, two experimental silt-clay-loam residue-free fields, one for each crop, eachfield measuring 162 m × 3 m divided into 9 plots. Three field conditions (1 rotary tilled, 2 untilled with high and low soil strength) at three replications each, were prepared randomly on
the 9 plots. The crops were cultivated on the field (all applied with similar crop management)
for two cultivation seasons (2007-2008) having one controlled row and 3 un-controlled rows.
Crop samples and crop yield parameters were monitored and statistically evaluated.
Results and Discussion
Results showed that the developed fertilizer application control system effectively controlled
fertilizer application within ±5% error of the target fertilizer application rates above 900kg/ha at 3 m/s tractor speed. The developed seed depth control system effectively regulated
seeding depth at 1 m/s tractor speed at ±75 mm soil surface undulations with 2 m periodic
distance. Statistical test on soybean seedling emergence count showed significant differenceat p<0.01. Statistical results on crop yield parameters for both sugar beet and soybean in 2007
and 2008 showed no significant difference in the yield parameters between the three field
conditions applied.
Conclusion
The converted fertilizer and seeder was successfully working. It was demonstrated that
residue-free zero-tillage cultivation of soybean and sugar beet can be possibly applied inHokkaido at minimal effects to original crop yields to help reduce field preparation time.