Smart Watering 101

Have you, or your customers, ever wondered what smart watering is or asked why is it important?

In this 5-minute video we present the basics of smart watering

There is a lot more to true smart watering. Scroll below the video to learn about some of the details in our secret sauce.

Smart Watering is the process to automate the creation of watering schedules that uses information about environmental conditions to ensure your plants get the optimum amount of water. Basically, evaporation will draw moisture from your garden, while rainfall and irrigation will add moisture. Understanding these conditions allows B-hyve Pro to decide when the time is right to water.

Why should I use B-hyve Pro Smart Watering?

When soil becomes saturated any additional water applied to the soil will simply runoff, flowing elsewhere and not helping you achieve the desired results for your lawn or other plants. Because of this, you may find that you often water long hours and too often to try to achieve a green lawn or vibrant flowers with varying degrees of success. Instead of watering for one long period of time, the Smart Watering Program will water multiple times for shorter intervals, proven for the type of soil you have, to maximize water absorption while minimizing watering duration. This helps your yard get the water it needs and save water at the same time.

Predictive Watering Smart Watering also includes Water Sense which uses weather forecasting and actual rainfall to predict when to water. For example, as long as your B-hyve Pro timer is properly connected to the internet and the forecast for your timer’s location is at a certain percentage toward rain, your timer will automatically receive a Rain Delay and delay any Smart Watering Programs from running during the specified Rain Delay.

Some cities/locations use watering restrictions to try to ensure available water is used responsibly and maintain availability throughout the entire watering season. Smart Watering can be configured to adhere to water restrictions. Days and times of day can be easily set from the B-hyve application to either water or not water while watering restrictions are in effect.

Definitions

Application Rate (AR) – the depth of water applied by an irrigation system over a certain period of time and is typically expressed in inches per hour (in/hr).

Efficiency (E) – the ratio between irrigation water actually utilized by growing crops and water diverted from a source (as a stream) in order to supply such irrigation water.

Plant Factor (Kp or Kc) – All of the plants in a given hydrozone should have about the same plant factor. Each plant factor is a percentage of the “reference evapotranspiration” (ETo) for the site, in inches per year.

Microclimate Factor (Kmc) – An “average” micro-climate condition is equivalent to reference evapo-transpiration conditions, i.e. an open-field setting without extraordinary winds or heat inputs. A landscape in the low micro-climate category would be one sheltered from typical winds and shaded for several hours each day. A planting in raised concrete planters on a roof terrace would be in the high micro-climate category.

Management Allowed Depletion (MAD) – specifies the maximum amount of soil water the irrigation manager chooses to allow the crop to extract from the active rooting zone between irrigations.

Field Capacity (FC) – the amount of soil moisture or water content held in soil after excess water has drained away and the rate of downward movement has materially decreased, which usually takes place within 2–3 days after a rain or irrigation in pervious soils of uniform structure and texture.

Permanent Wilting Point (PWP) – the minimum amount of water in the soil that the plant requires not to wilt. If the soil water content decreases to this or any lower point a plant wilts and can no longer recover its turgidity when placed in a saturated atmosphere for 12 hours.

Root Zone (RZ) – the depth of soil and oxygen surrounding the roots of a plant.

Allowable Surface Accumulation (ASA) – The maximum height of water that is allowed to accumulate over the soil surface before runoff occurs.

Basic Infiltration Rate (BIR) – the velocity or speed at which water enters into the soil. It is usually measured by the depth (in mm) of the water layer that can enter the soil in one hour. An infiltration rate of 15 mm/hour means that a water layer of 15 mm on the soil surface, will take one hour to infiltrate.

Effective Rainfall – is equal to the difference between total rainfall and actual evapotranspiration.

Drought Factor* – A multiplier applied to the smart watering formula to determine how much water is needed for each day. If there is no drought level selected, then the multiplier is 1. If there is a drought level selected, then the multiplier is applied based on the drought level.

*B-hyve Exclusives

B-hyve Pro Smart Watering Advanced Settings

Only four Advanced Settings actually affect the total amount of water used during a season, and these deserve the greatest understanding, focus and effort in order to optimize both plant performance and water conservation:

Application Rate (AR)
Efficiency (E)
Plant Factor (KP)
Microclimate Factor (KMC)

The remaining Advanced Settings simply affect how often or how long watering occurs in a given day or cycle. Adjusting them may affect plant performance but will not change the total amount of water used in a season.

Editable Settings

Application Rate (AR)

The amount of water applied per hour and expressed as inches per hour. Application rates for nozzles and emitters vary widely depending on the type, brand and installation parameters so it is important to evaluate your unique system. The most reliable way to measure Application Rate is to perform a catch cup test. The more cups used in the test the more accurate the measurement, but even a test with just a few cups will improve scheduling efficiency. Changing the Sprinkler Type setting will change this value. Performing a catch cup test will also change this value and will override the Sprinkler Type default setting with the more accurate data.

increase: Decreases the total runtime per day and total water used; may also decrease the number of watering cycles depending on Maximum Runtime.
decrease: Increases the total runtime per day and total water used; may also increase the number of watering cycles depending on Maximum Runtime.
Efficiency (E)

Efficiency measures the ability of an irrigation system to apply water efficiently and uniformly to a zone, and it is one of the most important factors in water conservation. Causes of low water application efficiency include overwatering, evaporation, wind drift, and poor application uniformity. Application uniformity is a measure of the variation in water applied to locations within a zone. A simple catch cup test performed in a zone will identify opportunities to improve uniformity. By making equipment adjustments to reduce water in cups with abnormally high volumes and to increase water in cups with abnormally low volumes, measurable improvements in uniformity and overall efficiency can be achieved. Target Efficiency is 75% for sprays and rotors and 95% for drip. This value can only be changed in Advanced Settings.

Plant Factor (KP or KC)

The fraction of Reference Evapotranspiration (ETo) required for acceptable plant appearance. When multiplied by Reference Evapotranspiration, the Plant Factor and Microclimate Factor estimate the depth of water required by plants. Typical plant factors are 0.8 for cool season turf and annual flowers, 0.7 for humid-climate perennials, shrubs and trees, 0.6 for dry-climate perennials, shrubs and trees, 0.6 for warm season turf and 0.3 for desert plants. In zones with plants having more than one Plant Factor, best management practice is to schedule according to the plant with the highest factor. Changing the Plant Type setting will change this value.

increase: Increases the total runtime per day and total water used; may also increase the number of watering cycles depending on Maximum Runtime.
decrease: Decreases the total runtime per day and total water used; may also decrease the number of watering cycles depending on Maximum Runtime.

Microclimate Factor (KMC)

Site-specific environmental factors such as buildings, pavement, and trees create unique sunlight and temperature variations which in turn affect the rate at which plants in a zone use water. When multiplied by Reference Evapotranspiration, the Plant Factor and Microclimate Factor estimate the depth of water required by plants. Full sun means the zone receives sun all day long. Part shade means the zone receives less than six hours of direct sun. Full shade means the zone receives little or no direct sun. Typical microclimate factors are 1.00 for full sun, 0.75 for part shade, and 0.50 for full shade. Where a zone gets too much water, adjust the Microclimate Factor down incrementally to create shorter runtimes. When a zone is too dry, increase the Microclimate Factor to increase the amount of water applied to the zone. Changing the Sun/Shade setting will change this value.

Management Allowed Depletion (MAD)

The soil water content deficit percentage at the time of next watering. The B-hyve will water before this percentage of Plant Available Water is depleted from the soil, unless water restrictions are in place which prevent watering. Adjusting Management Allowed Depletion is a helpful way to increase or decrease intervals between watering days. 50% is a smart allowed depletion for most soil types. Sandy soils could be as high as 60%. Clay soils could be as low as 40%. This value can only be changed in Advanced Settings.

increase: Increases the intervals between watering days and increases the total runtime per day; may also increase the number of watering cycles depending on Maximum Runtime.

decrease: Decreases the intervals between watering days and decreases the total runtime per day; may also decrease the number of watering cycles depending on Maximum Runtime.

Field Capacity (FC)

Percentage soil water content in the Root Zone after gravity drainage is complete. In sandy soils the larger pores drain quickly and gravity drainage may take just a few hours. In clay soils gravity drainage may take two to three days. Smart Watering refills soil water content to a maximum of Field Capacity which minimizes wasted water due to gravity drainage. The percentage of soil water content at Field Capacity is generally 10 to 20% for sandy soils, 20 to 30% for loam soils, and 30 to 40% for clay soils. Changing the Soil Type setting will change this value.

increase: Increases the intervals between watering days and increases the total runtime per day; may increase the number of watering cycles depending on Maximum Runtime.

decrease: Decreases the intervals between watering days and decreases the total runtime per day; may decrease the number of watering cycles depending on Maximum Runtime.

Permanent Wilting Point (PWP)

Percentage soil water content in the Root Zone when the plant irreversibly loses internal pressure.. Typical soil water content at Permanent Wilting Point is 5 to 10% for sandy soils, 10 to 15% for loam soils, and 15 to 30% for clay soils. Clay has higher moisture content at Permanent Wilting Point because water holds tightly to fine soil particles. Smart Watering ensures that watering occurs far enough above Permanent Wilting Point that plants do not experience undue stress. Changing the Soil Type setting will change this value.

increase: Decreases the intervals between watering days and decreases the total runtime per day; may decrease the number of watering cycles depending on Maximum Runtime.
decrease: Increases the intervals between watering days and increases the total runtime per day; may increase the number of watering cycles depending on Maximum Runtime.

Root Zone (RZ)

Effective root depth which is generally considered the top 50% of the maximum root depth. Typical Root Zone is 4-6 inches for annual flowers and ground covers, 4-8 inches for cool season turf, 6-12 inches for shrubs and warm season turf, and 12-24 inches for trees. In the case of new plants with undeveloped root zones, it often makes sense to set the Root Zone at a “target” depth which encourages roots to expand downward. Changing the Plant Type setting will change this value.

increase: Increases the intervals between watering days and increases the total runtime per day; may also increase the number of watering cycles depending on Maximum Runtime.
decrease: Decreases the intervals between watering days and decreases the total runtime per day; may also decrease the number of watering cycles depending on Maximum Runtime.

Allowable Surface Accumulation (ASA)

Free standing water which forms on top of the soil surface by application rates that exceed soil intake rates that is generally restrained from running off by the combined effects of surface detention and the presence of the crop canopy, thatch layer, or accumulated plant waste. Allowable Surface Accumulation decreases as the amount of slope of the landscape increases and typically ranges from 0.1 to 0.4. Changing the Slope setting will change this value.

increase: Increases the Maximum Runtime for a zone which decreases the number of watering cycles per day, increasing the risk of runoff.
decrease: Decreases the Maximum Runtime for a zone which increases the number of watering cycles per day, decreasing the risk of runoff.

Basic (Steady) Infiltration Rate (BIR)

A measurement of the depth of the water layer that can enter the soil in one hour. In dry soil, water infiltrates rapidly. This is the initial infiltration rate. As more water replaces the air in the pores the water from the soil surface infiltrates more slowly and eventually reaches a steady rate. This is the Basic Infiltration Rate (BIR). The Basic Infiltration Rate depends on soil texture (the size of the soil particles) and soil structure (the arrangement of the soil particles). Typical basic infiltration rates range from 0.1 for clay soils to 0.6 for sandy soils. Changing the Soil Type setting will change this value.

Computed Non-Editable Settings

Available Water (AW)

Total inches of water per inch of soil between Field Capacity and Permanent Wilting Point. AW = FC – PWP

Field Capacity Depth (FCD)

Total inches of water in the Root Zone after gravity drainage. FCD = FC x RD

Permanent Wilting Point Depth (PWPD)

Total inches of water in the Root Zone when the plant irreversibly loses internal pressure. PWPD = PWP x RD

Plant Available Water (PAW)

Total inches of Available Water in the Root Zone. PAW = FCD – PWPD or AW x RZ

Readily Available Water (RAW)

Total inches of water readily available to the plant at Field Capacity. As soil water content decreases osmotic pressure decreases and water becomes less and less available to the plant. Readily Available Water is Management Allowed Depletion expressed in inches of water. RAW = PAW x MAD

Refill Point (RP)

Total inches of soil water content at which Readily Available Water is fully depleted. In the absence of water restrictions next watering will occur at or above this point so that the plants do not experience stress. RP = FC – RAW

Standard Runtime (STDRT)

Measurement of how long a zone must water in order to refill the soil water content from the Refill Point (0% Readily Available Water) to Field Capacity (100% Readily Available Water). STDRT = (RAW / AR) x SM (or divided by E if not using Scheduling Multiplier)

Maximum Runtime Before Runoff (MAXRT)

Measurement of how long a zone can water before runoff starts to occur. Runoff represents wasted water since it does not reach the intended Root Zone of the plants. To minimize runoff Smart Watering divides the total runtime equally into cycles that are shorter than the Maximum Runtime which is why a zone may water more than one time in a day. MAXRT = (60 x ASA) / (AR-BIR)

Reference Evapotranspiration (ETo)

Estimate of total water use for uniform surface of dense actively growing vegetation similar to clipped cool season turf, with approximate height of 0.12 meter, not short of water, and representative of a large expanse of same or similar vegetation.

Landscape Coefficient (KL)

Factor that represents the combined effect of Plant Factor and Microclimate Factor on the landscape water requirement. KL = KP x KMC.

Landscape Evapotranspiration (ETL)

Estimate of total water use for a specific plant type in a specific microclimate. ETL = ETO x KL.

Current Moisture Balance (MBC)

Soil water content in the Root Zone, expressed in inches of water, that is readily available for use by plants. Current Moisture Balance decreases between 09:00 and 21:00 local time at the rate of Landscape Evapotranspiration, reflecting the fact that most plant water use occurs during daylight hours. Between 21:00 and 09:00 any Effective Rainfall (RE) and Effective Irrigation (IE) which occurred during the past 24 hours are added to the Current Moisture Balance, establishing the Initial Moisture Balance for the new day (MBI). The soil moisture bubble in Smart Watering shows the Current Moisture Balance in percentage terms ranging from full (100% Readily Available Water) to empty (0% Readily Available Water). MBC = MBI – ETL + RE + IE