Background:
Depletion of water resources in agriculture has been a serious cause of concern. In most of the farmers' fields, particularly in sugarcane fields, efficient irrigation management practices such as irrigation scheduling, based on soil moisture status is rarely in practice. In an effort to save water and to facilitate irrigation scheduling, ICAR-SBI has developed this gadget a handy and user-friendly electronic moisture indicating device, named “Soil Moisture Indicator (SMI)”. :
Technology Details:
Under Indian situations, the irrigation scheduling based on soil moisture is not in vogue due to the non-availability of simple, easy to use, rugged, effective and inexpensive soil moisture indicators. From farmers experience, it was found that tensiometer (generally used for irrigation scheduling) has many inherent problems like permanent installation of multiple units (about 10 per hectare) in different spots of the field, blocking of ceramic cup, regular filling of water in the reservoir tube immediately after irrigation, vacuum leakage problems, chances for breaking the ceramic cup of the tensiometer and expensive (each unit costing about Rs. 6000/-). Thus, this tensiometer is not being preferred / used by farmers. This has necessitated the innovation of a novel device that can be used easily by the farmer to assess the status of soil moisture before scheduling irrigation. Soil moisture indicator was tested and found better than tensiometer in assessing the moisture status and helped farmers to decide when to irrigate. It was found that scheduling irrigations based on soil moisture status considerably reduce the number of irrigations required for cultivating crops, thereby saving precious water without affecting productivity. About the SMI: SMI comprises of sensor made up of metal rod(s) and a plastic casing. There are either two metal sensor rods (two individual rods spaced at a distance of 3 to 5 cm) or a combined rod. The rods are preferably made up of stainless steel. The casing houses an electronic printed circuit board with an integrated circuit, electronic components, LEDs, provision for 3V DC supply (two AA or AAA cells) and a control switch. To assess the soil moisture, the sensor rods are to be inserted into the soil. Turn on or press the switch, the device indicates the soil moisture status by glow of any one coloured LED out of the 10 LEDs. Blue LED glow indicates ample moisture available in the soil, while green for sufficient, orange for caution (indicating a need for irrigation) and red for low moisture or dry condition. Fine tuning can be carried out by adjusting the presets to suit different soil conditions and crops (soil moisture indicator manual enclosed herewith)