Smart Wireless Solution Using Weather Stations to Improve Irrigation Scheduling Ali Mah’d Al Shrouf Abu Dhabi Food Control Authority UAE Ali.Alshrouf@adfca.ae
WHY WEATHER STATIONS? • To get real-time micro-climatic information • To compute Evapotranspiration • To use the same data for disease models • To monitor soil moisture • To correlate irrigation with ETo, soil moisture, soil salinity, precipitatin, ground water level, etc. - TO UNDERSTAND WHAT‘S GOING ON - AND TAKE BETTER IRRIGATION DECISIONS!
Disease Solutions • provides the grower with advice via computer regarding the optimum moment at which to use fungicides and which type of fungicide to use.
Irrigation Solution • The right volume at the right moment. determine the optimum time for irrigation. • This prevents both damage due to draught stress and excessive watering.
Insect Solution • provides a grower with advice via his computer regarding the insect's current development stage. This allows the correct moment and the correct type of insecticide to be determined.
Fertilizer Solution • Advises how much and at which point to apply fertilizer.
ADFCA Agri-Metrological Station Objectives: effectiveness evaluation for using the automatic weather station in Irrigation calculation
Weather Stations for Irrigation Improvements • What is todays most important rule for irrigators? • THE RULE OF THUMB • Why do farmers irrigate the way they irrigate? • „because it looks dry“ • „because that‘s how I always did it“ • „because it feels right“ irrigation decision is pure guesswork
Precision Irrigation Irrigation Improvements • Just about all farmers over-irrigate - with rather detrimental consequences: • Wash out of nutrients = increased need of fertilizers • Too much water in the soil > too little oxygen! This • largely affects the plants „metabolism“, reduces growth, • harms micro-organisms, reduces yield. • Pollution of ground- and surface water (nitrates!!) • Unnecessary wear and maintenance of equipment • Waste of energy (electricity, fuel) to run the pumps
8 mm/day 80 mm Temporary slow down of daily crop water use and growth caused by over irrigation. 10 days Irrigation 15 mm/day 45 mm 3 days Irrigation
Precision Irrigation Irrigation Improvements Some farmers under-irrigate - with consequences as fatal: • The plant suffers excessive dry stress = reduced yield, lesser quality crops • Water and fertilizers do not reach the active root zone = reduced yields, lesser quality crops • Water and fertilizers that do NOT reach the active • rootzoneare 100% lost for this crop! And so is the • energy invested for their application!
An Automatic Weather station - Sensor Requirements • at least the sensors required by the ETo Formula according to Penman-Monteith is needed.
A Weather Station‘s Sensors • Data collection - the Sensors (evaluation criteria) • Sufficient Accuracy • Robust • Operate in wide temperature range • Low Power Consumption • Little drift over time • Simple Installation, low maintenance
Data Collection: GPRS GSM Provider Internet Measure once per minute, transmit averages every 15 minutes
Weather Stations for Irrigation Improvements • Which quality / accuracy is required? • Sufficient accuracy for the task! • Low Drift at least within the first five years • Low maintenance requirements • Remote Configuration • Low Power Consumption
Water - the resource of the future • Monitoring needs in the cycle of water • Precipitation • Quantity and quality of irrigation water • Irrigating • Evapotranspiration • Soil moisture (at various levels) • Wind speed and direction
QA/QC Checks • Range • within a reasonable range • Step • maximum allowable change • Persistence • minimum allowable change • Like Sensor • similar value to similar sensors • Spatial • similar value to neighboring stations (parameter dependent)
Range Checks • Three range checks • Valid • Suspect • Invalid • If the data falls within the inner range then it will be marked Valid If it falls in between the outer range and the inner range it will be marked Suspect • If data falls outside the outer range it will be marked as Invalid • If the data is missing it will be marked Missingand then filled
Range Checks: Solar Radiation Invalid Suspect Valid -0 950 Hourly Solar Radiation (W m-2)
Persistence Check valid valid susp. susp. valid Difference of Maximum and Minimum over n steps must be greater than y susp.
Step valid Difference of maximum and minimum over n steps must be at most y susp. valid valid valid valid
Automated Q/C • Every morning, data graphically reviewed • Geographically similar stations grouped • All weather parameters reviewed • Bad data estimated or deleted • Dependent computations (ET) recomputed • Upper and lower limit checks on sensor data • Rate of change between consecutive readings
Other Tests • Like Sensors • Relating wind speed 2M to wind speed 10M • Relating occurrence of precipitation to humidity • Nearest Neighbors