Automatic irrigation control method based on water balance model

Abstract

The invention discloses an automatic irrigation control method based on a water balance model. The method comprises the steps of A, initializing parameters, wherein the type and the planting date of the planted crops are determined, and a corresponding crop coefficient Kc is obtained; the soil type is determined, and corresponding wilting water content WP, field capacity WHC and irrigation threshold value IT are obtained; B, calculating current soil water content FCs; C, calculating effective water content AWC of current soil; D, calculating actual evapotranspiration ETc; E, calculating soil real-time effective water content delta AWC; F, judging whether the soil real-time effective water content delta AWC is lower than the irrigation threshold value IT, if the soil real-time effective water content delta AWC is lower than the irrigation threshold value IT, conducting irrigation; if the soil real-time effective water content delta AWC is not lower than the irrigation threshold value IT, turning to the step E to continue calculation. According to the automatic irrigation control method based on the water balance model, defects of the prior art can be overcome, and precision and flexibility of the irrigation control can be improved.

Description

technical field [0001] The invention relates to the technical field of agricultural automatic irrigation, in particular to an automatic irrigation control method based on a water balance model. Background technique [0002] The current automatic irrigation control is basically divided into the following categories, one is timing irrigation, that is, the irrigation schedule is set in advance, and the timing starts and ends at a fixed time; the other is irrigation based on crop transpiration, that is, according to a specific calculation formula. Calculation of crop transpiration, irrigate when a certain set value is reached, and determine the amount of irrigation according to the calculation data; one is to irrigate according to sensor data, that is, real-time detection by soil moisture sensors inserted or buried in the soil Changes in soil humidity, irrigate when a certain set value is reached, and determine the irrigation stop time based on the sensor detection data; there i...

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Problems solved by technology

[0003] There are certain defects and deficiencies in the above-mentioned multiple automatic irrigation control methods: one, the irrigation system is static in the regular irrigation mode, and the required irrigation water volume and irrigation time of the crops are determined by prior estimation, but the crop growth and its environment It is dynamic, and the amount of irrigation required for crop growth is also constantly changing. This method cannot accurately provide the amount of water required for crop growth. There is a phenomenon of over-irrigation or under-irrigation, and it cannot be flexibly changed according to meteorological conditions. According to the situation, irrigation control will still be carried out according to the schedule. If the weather is particularly dry during a certain period of time and has not been estimated in advance, it will cause crop water shortage

2. Irrigation based on crop transpiration Generally, crop transpiration is estimated based on meteorological information, and irrigation control is carried out accordingly. Although relative to regular irrigation, the degree of flexibility has been improved, but it is still estimated based on external soil environmental parameters. Understand the moisture change inside the soil, and it is impossible to avoid the situation of performing irrigation under the condition of precipitation, and when the irrigation pipes, drippers, sprinklers, etc. are blocked, whether the crops have received the irrigation water they should get, cannot be determined according to the soil. Feedback on internal moisture changes

First, whether the sensor data is always accurate cannot be guaranteed; second, it cannot be flexibly adjusted according to specific meteorological conditions. For example, there will be precipitation soon, but the current sensor data shows that irrigation should be carried out. Precipitation, then to a certain extent caused the waste of water resources

4. Comprehensive use of various meteorological parameters and soil parameters for irrigation control. Although compared with other methods, this kind of control mostly uses some intelligent algorithms to establish models, and then performs irrigation control according to the models, and the establishment of models requires a lot of data, otherwise the control accuracy cannot be guaranteed

If this kind of control method is used, it needs to be trained in advance based on a large amount of previous data in the area to establish a relatively accurate control model, which has poor versatility. If the previous environmental parameters such as weather and soil in the area cannot be obtained, it is difficult to use this and if there are too few parameters affecting the model, even if there is a large amount of data, the accuracy of the model cannot be guaranteed. If there are too many parameters, such as using air temperature, air humidity, light, soil temperature, soil humidity, wind speed, and rainfall Monitoring and many other parameters not only increase the data flow, but also cause the model training speed to be too slow, and there may be some contradictory data among various parameters. At the same time, multi-parameters and large data volumes also have data redundancy. directly affects the calculation speed of the control model

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