A fixed-amount and variable-rate fertilizer applicator based on pulse width modulation

Fertilizer plays a significant role in increasing crops quality. When fertilizer users use inappropriate fertilization practices in fields, it brings nutrient waste, large investment and residue in soil. The purpose of the present paper is to develop a fixed-amount and variable-rate fertilizer applicator with a vertical spiral conveyor to minimize this risk. As for row replacement, high accurate and uniform application patterns from a reliable fertilizer applicator for precision farming are required. This applicator includes a speed measure unit and a fixed-amount and variable-rate Pulse Width Modulation control system. In order to evaluate our fertilizer applicator, its performance was tested in both laboratory and field. The findings of this study suggest that the applicator with a vertical spiral conveyor and a variable-rate pulse width modulation control system makes fewer errors during application. To guarantee the degree of accuracy of this applicator, the linearity between travel speed and amount of fertilizer is essential. Both of the applicator tests revealed that using the applicator was a positive experience because it can preset expected consumption by operator and always keep amount of fertilizer uniform and accurate while traveling, and it will be widely used in Southwest China.