The invention relates to the technical field of environment monitoring, in particular to a water-salt ratio
dynamic monitoring method and
system for farmland, and the method comprises the following steps: collecting multi-point tension and
conductivity data, carrying out the ratio judgment, delaying the collection if a threshold value is exceeded, synchronously updating a
data set, converting salt, calculating the change of the water-salt ratio, and fitting a trend to obtain change information. Evaluating
water stress in combination with
crop parameters, judging a
water demand period, superposing predicted rainfall to generate an interference result, and calculating a water-salt change acceleration recognition intervention point. According to the method, through the
water stress index constructed by fusing the
transpiration potential base value of the
crop and the
water content of the root layer, accurate identification of the
water demand period of the
crop is realized, comparison with the predicted rainfall time interval is carried out, and trend key points influenced by rainwater disturbance are screened; a continuous acceleration change section is identified through a water-salt ratio acceleration sequence formed by a change
rate difference value, and an intervention
demand point is marked in time under the condition that a continuous trend is enhanced.