Abstract: The system and method of watering crops with a variable rate irrigation system provides a means to formulate a watering prescription map even when some required input data is unavailable. In the preferred embodiment, the unavailable input data is measured canopy temperature data from infrared thermometers mounted on a center pivot irrigation pipe. The system is the irrigation scheduling supervisory control and data acquisition system (ISSCADAS) and the method is an Artificial Neural Network (ANN) modeling method that substitutes data from trained existing data sets to estimate the unavailable variable when actual variable measurements are missing or invalid.

Abstract: Plant canopy images and temperature are acquired with a wireless computer vision instrument, and the temperature data are qualified and pixels within the image are classified. The instrument includes sensors for measuring plant radiation due to canopy temperature and an imaging sensor which collects data over four bands, a microprocessor to receive and store and process measured data from the sensors, and a wireless transmitter for transmitting data from the microprocessor to a remote receiver. The data are used to detect plant stress and canopy cover percentage and to qualify temperature data accordingly. The data from the sensors provide information for decision support algorithms related to the initiation of automatic irrigation scheduling as a function of crop canopy cover and water stress, the qualification of temperature data used in automatic irrigation scheduling algorithms, and the detection of diseased crops for the purpose of withholding irrigations when yield potential is compromised.

Abstract: Plant canopy temperature and multi-spectral reflectance are measured with a wireless multi-band sensor, and the temperature data are qualified and the spectral reflectance measurements are classified. The multi-band sensor includes sensors for measuring plant canopy temperature radiation and spectral reflectance over five bands, a microprocessor to receive and store measured data, and a wireless transmitter for transmitting data from the microprocessor to a remote receiver, all enclosed within a single housing. The data are used to detect variations in spectral signature due to plant stress (e.g., disease, water stress) and due to soil background and to qualify temperature data accordingly.

Abstract: Soil water content and bulk electrical conductivity may be determined by time domain reflectometry at multiple depths in the soil such that the entire soil profile from the surface to a user-selected depth may be characterized. A short rise-time pulse is passed into an electrode and the reflected pulse is captured at multiple times. A waveform of reflection coefficient versus time is determined, which may be used to determine the pulse travel time, effective frequency and reflection coefficients at times necessary for the determination of the soil water content and bulk electrical conductivity.

Abstract: Irrigation of plants or crops is effected using plant canopy temperature measurements. The process and device include an irrigation scheduling algorithm based on an integrated water stress index (WSI) and an integrated WSI set-point. A WSI is calculated at repeated time intervals and compared to an encoded threshold WSI value that is crop and region specific. If the calculated WSI is greater than the encoded WSI value, a unit of integrated WSI (IWSI) is accumulated. If the time integral exceeds the encoded value for a 24 hour period, an irrigation signal is produced, directing the irrigation system where, when and how much to irrigate. The process and device will automatically schedule crop irrigations when the crop is water stressed and may control a moving or static irrigation system to apply the irrigation. Moreover, irrigation applications can be selectively varied over specified control areas or management zones.