A time sex apply fertilizer
apply fertilizer period
Apply fertilizer rationally
Long-term fixed position apply fertilizer
Optimization apply fertilizer the model
Different fertilizer level
higher level fertilizer
application of organic fertilizer combined with chemical fertilizer
Different ratio of cake fertilizer and inorganic fertilizer
Nitrogen fertilizer combined with potassium fertilizer
organic fertilizer and chemical fertilizer
organic fertilizer plus inorganic fertilizer
phosphate fertilizer and potassium fertilizer
4-level frequency modulation (4-level FM)
bi-level programming model with two lower level models