Sensor Based Crop Water Stress Index (Cwsi) for Irrigation Scheduling in Subsurface Drip Irrigated MaizeWheat Cropping Sequence

Susanta Das

Sensor Based Crop Water Stress Index (Cwsi) for Irrigation Scheduling in Subsurface Drip Irrigated MaizeWheat Cropping Sequence

Date

2022

Authors

Susanta Das

Publisher

Punjab Agricultural University

Abstract

A study was conducted at Punjab Agricultural University, Ludhiana to develop a canopy temperature-based sensor-system to estimate the crop water stress index (CWSI) for irrigation scheduling in subsurface drip irrigated maize-wheat cropping sequence. Rabi wheat and kharif maize crop was sown for two consecutive years as (2019-20) and (2020-21). The crops were irrigated with different irrigation levels (60, 70, 80, 90 and 100% ETc) and varying irrigation interval (1-day, 2-day, and 3-day) through sub surface drip, installed at 20 cm depth as well as surface drip (100% ETc). Based on the field observations of rabi wheat (2019-20) and kharif maize (2020), the upper and lower baselines of canopy-air temperature were established for computation of Crop Water Stress Index (CWSI). The threshold value of CWSI was determined from the relationship between CWSI, grain yield, water use efficiency. For the entire growing period, a threshold value of CWSI was found to be 0.254, and 0.365 for wheat and maize respectively. Also, growth stagewise CWSI values have been estimated for maize-wheat. An IoT based sensor system was developed and programmed with Arduino for collection of temperature- humidity and cloud-based estimation of CWSI. The developed sensor system was deployed in the field during rabi wheat (2020-21) and kharif maize (2021) and based on the CWSI irrigation has been applied. Growth stage 3 was found, the most crucial stage for both wheat and maize from crop water stress point of view. Irrigation at 90 % of ETc with 3-day irrigation interval found to be the best and was recommended for SDI in maize-wheat cropping system. The irrigation scheduling by IoT based sensor system was found to be beneficial, as it lowers the crop water stress and enhance the yield and water use efficiency. Irrigation water saving by 15.43% and 19.87 % and yield enhancement was observed in 5.2 % and 6.4 % in wheat and maize, respectively as compared to 100 % ETc based sub surface drip irrigation. This developed sensor system has a great scope for adoption and can be calibrated for threshold CWSI for other crops.

Citation

Susanta Das (2022). Sensor Based Crop Water Stress Index (Cwsi) for Irrigation Scheduling in Subsurface Drip Irrigated MaizeWheat Cropping Sequence (Unpublished Ph.D. Dissertation). Punjab Agricultural University, Ludhiana, Punjab, India.