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
coupling mechanism between upper level and low level jet
fiscal system at county level and township level
interaction between upper level and lower level
municipal level and county level