Technical equipment of the information-advisory system for irrigation management

Technical composition and purpose of the system

The information and advisory system (IAS) is designed to allow the agronomist to promptly adjust irrigation based on real soil and climatic conditions and weather forecasts. This helps to accurately dose water and manage the productivity of irrigated crops. The system makes it possible to avoid soil waterlogging or drought, optimizing the costs of land reclamation.

The technical complex of the system includes three main components. It consists of soil moisture sensors, a professional Vantage Pro2 weather station, and a personal computer. The minimum requirements for the computer are an Intel Pentium III processor with a frequency of at least 750 MHz.

• Sensor polling interval — from 2.5 s
• Interface memory capacity — 2560 records
• Console display size — 150x90 mm
• Sound alerts — 35 functions

Functions and technical specifications of the Vantage Pro2 weather station

The Vantage Pro2 weather station consists of a control console and an Integrated Sensor Suite (ISS). The sensors are combined into a single housing, which significantly simplifies their installation directly in the field. The standard package includes an air humidity sensor, an anemometer for measuring wind speed and direction, as well as a 30 m console cable.

Control of the weather station and reading of information are carried out through the console. The user can switch between built-in operating modes for detailed situation analysis. All necessary statistics are displayed on the built-in screen.

• Current Data — display of current indicators, selection of units of measurement, and instrument calibration.
• High/low — output of maximum and minimum values for the day, month, or year.
• Alarm — configuration of sound alarms when weather parameters reach critical values.
• Graph — creation of up to 100 different types of charts based on stored data.

A set of key weather parameters is displayed on the console screen. The weather station records temperature, humidity, pressure, wind speed, and precipitation level. Based on this data, the system calculates the dew point, moon phases, as well as sunset and sunrise times.

The built-in local weather forecast algorithm takes several factors into account. The system analyzes the geographic coordinates of the field, the current season, pressure dynamics, wind direction, and humidity. This allows for accurate short-term forecasts specifically for your site.

A special scheme for the transmission and accumulation of weather information is used to automatically populate the system's database. There are two ways to transmit the collected data to a computer. This allows for continuous monitoring and saving the history of observations for subsequent analysis.

The first method: meteorological indicators from the weather station sensors are transmitted to the console via a radio channel; in the standard version, the maximum data transmission distance is 100 m. The use of directional antennas installed on the console and the weather station makes it possible to increase the transmission distance to 8 km. Then the data from the console is transmitted to the PC via a USB cable. The WeatherLink program installed on the PC allows you to view the data coming from the weather station in real time. A data archive is also created, which is stored in the C:\WeatherLink\WeatherStation\2009-06.wlk directory.

The second method involves the use of a GSM modem at the weather station. Meteorological information is transmitted via satellite to a server on the Internet, and the transmission distance is unlimited. The information is also stored on the server in a \2009-06.wlk file. The disadvantage of this scheme is the additional costs for Internet payment and server maintenance. After the data is on the server, the WeatherLink program settings are configured. Once the settings are complete, the program accesses the server, the data is downloaded, and displayed on the PC screen.

Fig. 19. Scheme of transmission and accumulation of meteorological information

Since the .wlk file format is not recognized by any standard PC application, the WeatherLink program provides for data export to a .txt file. From the .txt file, the data can be transferred to any other program for analysis or further calculation.

Also, the WeatherLink software allows for preliminary data analysis. All information obtained is displayed in the form of charts,

Fig. 20. Viewing weather station indicators in real-time mode

Fig. 21. Exporting weather data to a .txt file

Using this application makes it possible to comprehensively evaluate all meteorological information and provides the ability to convert data into the necessary format for further information processing.

Soil moisture control. Determination of soil moisture in an irrigated agrobiocenosis is carried out using soil sensors calibrated using the methods and equipment listed in Table 23.

Fig. 22. Graphical display of meteorological information

Continuation of Table 23

Indicator name Determination method Measuring instruments, devices

Hydro-physical properties Field (minimum) Flooded plot method Water container, scales, drying oven field moisture capacity, % Soil moisture of the Thermostat-weighing Auger, weighing bottles, scales, drying oven arable horizon, % method Maximum hygroscopic GOST 28268-89 Drying oven, desiccator, glass weighing bottles, moisture and permanent analytical scales wilting moisture, %

Physico-chemical properties pH Ion meter, laboratory scales, glassware, standard titrants Organic Muffle furnace, crucibles, GOST 26483-85 substance, % drying oven Hydrolytic Ion meter, laboratory acidity, mg-eq per 100 g glassware Exchangeable GOST 26489-85 Photocolorimeter ammonium, mg/kg (by CIPAO method) Nitrates, mg/100 g of soil GOST 26951-86 Ion meter, electrodes, (ionometric) chemical glassware, reagents

Total nutrient content Nitrogen, mg/100 g of soil GOST 26107-84 Sireneva instrument

Mobile (available to plants) forms Hydrolyzable nitrogen, Tyurin and Kononova Kjeldahl instrument, reagents, laboratory glassware mg/100 g of soil method Mobile phosphorus, Spectrophotocolorimeter mg/100 g of soil

GOST 26207-91 Exchangeable potassium, Flame photometer mg/100 g of soil

Indicator name Determination method Measuring instruments, devices Magnesium, mg/100 g of soil Burettes, laboratory glassware, reagents GOST 26487-85 Calcium, mg/100 g of soil Sodium, mg/100 g of soil GOST 26426-85 Ion meter, electrodes, chemical glassware, reagents Yield, cwt/ha Total harvest method Scales, computing equipment (sample plot method)

Computer program for operational irrigation planning

The computer program, one of the modes of which performs calculations for the IIS (the "Calculate Season" mode), was developed at the All-Russian Scientific Research Institute "Raduga" in 2008 based on existing methods and programs, taking into account modern requirements and using mathematical apparatus. State registration number 2008615169, working title "Calculation of the dynamics of agroclimatic resources and their regulation (Raduga Irrigation)".

The software suite operates in the following modes:

Adding new weather stations (weather data) and crops that are not yet included in the program's working database;

Calculation of the dynamics of heat and moisture availability over a multi-year period for crops and weather stations included in the working database. A calculation of the bioclimatic potential (BCP) has been introduced, characterizing the potential productivity of the climate. BCP values can vary from 1 to 5.2 under sufficient moisture conditions and from 0.6 to 4.68 under insufficient moisture conditions;

Mode for operational calculation of soil moisture reserves and irrigation rates for one season (year) based on actual and newly entered data with a calculation period (or step) of one hour. The calculation is carried out from the beginning of the growing season to any specified date for a specific agricultural crop using forecasted weather data;

The analytical section is used for mathematical processing of calculation results and construction of spline functions.

Adding new weather stations and crops (Add Data)

Fig. 23. Add Data mode panel

Crops included in the working database of the program are recommended to be described in advance in an additional (auxiliary) "Crops" file, conveniently formatted in Excel.

The following order of information placement is proposed in the file for generating the program's working database:

• The first four tables of the file ("General" sheet) — values of the Kb coefficient by zones for the BD OSN region, which unites the European part of the agricultural territory. The coefficient values are provided in accordance with the sums of temperatures from the beginning of the growing season with a step of 200°C. When transferring data to specific Excel sheets (the sheet is organized for each crop), the order of zones is as follows: dry steppe, temperate steppe, forest-steppe, forest zone.
• The next four tables are the values of the Kb coefficient by zones for the BD URAL region, which includes the agricultural territory of the Urals, Trans-Urals, and Western Siberia.
• The next two tables are the dependence of the root zone depth hk (m) of agricultural crops on the sum of average daily air temperatures Ef for BD OSN for arid and humid zones, respectively.
• The next two tables are the dependence of the root zone depth hk (m) of agricultural crops on the sum of average daily air temperatures Ef for BD URAL for arid and humid zones, respectively.

All listed tables can be supplemented as needed (for crops not yet included in the program's working database).

Based on these tables, data files in a specified format are generated for each crop (to update the program's working database) and transferred to the program's working fields during calculation. Each crop is placed on a separate sheet of the "Crops" Excel file, the name of which, for convenience, matches the name of the crop.

The sheet filling format is as follows:

• In rows 1-6 for BD OSN, starting from column A, crop information is sequentially copied: the first row is for deserts, the second for semi-deserts (if these zones are not involved in calculations, rows up to position S1 are filled with zeros); the third for the dry steppe zone: temperature of the beginning of the growing season (AZ); sum of temperatures of the crop's growing season (VZ); C3-R3 — values of the biological coefficient Kb in accordance with the sums of temperatures from the beginning of the growing season with a step of 200°С; S3 — coefficient of actual moisture saturation ju.
• Then, from position A4 (fourth row), similar information is copied for the temperate steppe zone, from A5 — for the forest-steppe zone, and from A6 — for the forest zone.
• From position A7, the depth of the root zone hk (m) of agricultural crops is copied depending on the sum of average daily air temperatures Ef for BD OSN, respectively, for the arid zone; from position A8 — similar information for the humid zone.
• Then all information (rows 1-8) is repeated for BD URAL (rows 9-16 are filled).

After the sheet is formed, the crop can be included in the program's working database using the Add Data mode.

To do this, you must:

1. Copy the entire sheet.
2. Place it in the field suggested by the program when the Add Data mode is on.
3. Enter the crop name in the suggested window and click the "Add Crop" button.

It is possible to enter data into the suggested window manually, while observing the placement of data and entry rules (t — tab for input from a specified position, / — number separator, h — transition to a new line).

Meteorological data are inserted similarly. The format, quantity, and order of data entry match the format from the previous ROSK program. After filling the fields with data while the Add Data mode is on, click the "Add Weather Station" button. The weather station with meteorological data will be added to the working database.

The software module in the "Calculate for many" mode is developed based on the methodology for the ROSK program, which has been in operation since 2004 (in this version, it has been improved and expanded).

Calculation via the program is carried out after clicking the button 1, but it is necessary to set the correct information in the windows beforehand as follows:

• First window — select the name of the weather station for which the calculation is being performed from the drop-down menu. If the weather station is missing from the suggested menu, it means it is not in the working database. You should enter the program's Add Data mode and enter the weather station according to the instructions in clause 1);
• Second window — select the name of the crop for the calculation. If the required crop is not among those listed, enter the program's Add Data mode and enter the crop according to the instructions;
• Third window — assign one of the suggested regions: European Part (BD OSN) or Siberian Part (BD URAL) for the program to select the array of Kb coefficients;
• Fourth window — selection of a humid or arid zone for calculating the dynamics of the root zone kk.

Then the user enters the values:

Next, below the windows, a comment "Sampling by..." is displayed, i.e., the value of the calculation period in hours: 24 — daily, 240 — 10-day, etc.

In the comment "Used for analysis... %" — indicate the probability value selected by the user using the suggested scale: 25% — medium-wet, 50 — average year, 75% — medium-dry, etc.

Next, the windows indicate (or clarify) the temperature values of the beginning and end of the growing season (KY T_s and KY Т_е respectively), required for calculating the integral indicator Ku.

Then you need to check the correctness of the set settings and start the program by clicking the buttonL.

Copy (Ctrl-A, Сtrl-Ins) the information obtained as a result of the calculation and paste (Shift-Ins) it into a blank Excel sheet for ease of reading and printing.

In the "Calculate Season" mode for operational irrigation management (OIM), an operational calculation of soil moisture reserves and irrigation requirement deficit is performed.

Operation in this mode for a specific crop is always conducted from the beginning of the growing season. The last few lines of meteorological data may represent forecast values for several days ahead, which are replaced by actual data in subsequent calculations.

At the beginning of the work, in the first upper window, select the name of the weather station (or field) for which the calculation will be performed from the drop-down menu. After selecting the desired name, click the adjacent "Load Weather Station" button.

After this, the next window on the panel is activated; enter the start date of the season into it, and confirm by clicking the "Select Season" button.

To enter a new season (or change the start date of the calculation), use the "Add S" button, clicking which allows correcting the date in the adjacent (right) window.

After this, by clicking the "Select Data" button, load the information selected for the season from the weather station file or an auxiliary file.

To calculate based on operational and forecast data, which are selected from an auxiliary file organized according to the specified format, they should be copied, pasted into the empty working window, and then click the "Select Data" button.

Table 24

              Sequence of data arrangement
                     in the auxiliary file
 Time
                  T         A         P         V         HF       AddP
 interval
     24         11.65      68.7      0.3       0.9        12         0
     24         9.45        81        4        1.6        12         0
     24         9.85       77.1       0        U          12         0
     24         11.45      70.3       0        0.9        12         0
     24         15.85       61        0          1        12         0
     24         16.25      67.2       0         1.6       12         0
     24         13.45       71        0        1.75       12         0
     24         13.55      72.3       10        3         12         0
     24         15.85      82.9       2         1.9       12         0
     24         12.55      71.5       6        3.25       12         0
     24         12.25      69.2      0.3        1.6       12         0

Note. T - temperature, A - air humidity, P - precipitation, V - wind speed, HF - vane height, AddP - added water (irrigation, mm).

Clicking the "Select Season" button activates the following menu:

• "Display Data" - the loaded information will appear in the panel field. If you need to delete several recent records (for example, forecast information), specify the required quantity in the window next to the "Delete N last records" button and confirm by clicking the button. After that, give the "Display Data" command again to verify the operation performed;

MC - microclimatic coefficient.

M Irrigation % - set irrigation, in % of the maximum.

M Drainage/Day - rate of excess water removal from the field, mm/day (to ignore this parameter, set a value intentionally higher than the maximum irrigation rate).

M in % - minimum permissible threshold of soil moisture, from which irrigation should begin;

• select the crop for calculation from the proposed list contained in the program's working database;

• select the start date of the growing season - specify in the adjacent window;

• click the "Calculate" button. Copy the calculation results to a clean Excel sheet.

Rows with a positive deficit correspond to days when irrigation is necessary.

Appendix AZ presents the 2007 season calculation (May-September) based on actual daily meteorological data from the Kolomna weather station for the alfalfa crop of previous years. The calculation conditions are set by the user and reflected on the working panel. Rows with a positive deficit correspond to days when irrigation is necessary.

A negative deficit value indicates excess moisture (mm), resulting in surface runoff.

At a zero deficit value, irrigation is not needed.

Operation in the "Analytical Section" mode

Construction of the spline function is carried out according to the following algorithm:

F(t) = a0 + a1t + a2t + aklcos(tw1) + ak2cos(tw2) + ak3cos(tw3) +

+bklsin(tW1) + bk2sin(tW2)+ bk3sin(tw3). 1. Launch the "Raduga Irrigation" program. 2. Select the "Analytical Section" mode. Previously, organize series in Excel:

Year (starting from zero) Indicator values (e.g., Ky)

Copy these two columns and paste them into the "Analytical Section" window field.

Fill in the proposed windows of the first row (opposite the label T1 (first period): in the first window - starting year (this is 0), in the second - final year (by number of observation years), in the third - calculation step (0.5 is most appropriate).

Click the "1 period" button.

Copy the results obtained after the calculation to an Excel sheet.

Select three rows with the lowest value in the Sigma*2 column in the copied array. Accordingly, select three period values in the adjacent T column.

Return to the "Analytical Section". In the windows for rows T1, T2, and T3, specify respectively the boundaries of each of the three periods (± two units) and the calculation step (also 0.5). Copy the series into the window (as in clause 3). Click the "3 periods" button.

In the results obtained, copied to Excel, find the row with the minimum Sigma*2 value.

Insert the coefficients of the corresponding row into the formula and calculate for all indicator values from clause 3.

Based on the obtained results, plot a spline function graph.

6, METHODOLOGICAL FEATURES