Background:
Nitrogen is broadcasted prior to transplanting in wetland rice. This practice is subject to extensive losses of nitrogen due to ammonia volatilization, denitrification, and build-up of ammonium (NH4+)-N in the floodwater, which leads to losses through leaching and runoff. Many research studies in rice-producing countries proved that deep placement of fertilizer for wetland rice is highly beneficial to farmers, economically as well as environmentally aspect. Some of the manually operated deep placement fertilizer applicators for USG, prilled urea, and urea solution are developed to increase the nitrogen use efficiency and minimize gaseous emission of N to the atmosphere. These machines were discontinued due to the high torque required for efficient operation of the machine, clogging problem, and labor intensive. The non-availability of appropriate machines leads to the discard of proven deep placement technology in the farmer field. Most of the fertilizer applicators developed are relying entirely on manual operation and all these machines failed due to poor performance, labor shortage, and drudgery in manual deep placement. Combining deep placement of fertilizer with multi-row rice transplanters seems to be more practical and presents a bright prospect since rice transplanter is getting popular among most farmers in India due to their economical and timely operation. Hence it was felt to design and develop a deep placement fertilizer applicator as an attachment to walking behind the rice transplanter.:
Technology Details:
Deep placement fertilizer applicator as an attachment to a walk-behind rice transplanter has developed. The unit consists of a hopper, electronic control metering system, air blower soil float with furrow opener. The electronic metering mechanism system consists of an auger-metering mechanism, proximity sensor, digital hour meter counter, and solenoid actuator for fertilizer placement. The auger-metering mechanism is operated by optimized speed using a 12 V DC motor to meter the required amount of fertilizer. A proximity sensor with a relay is used to actuate the linear solenoid attached opener. A single proximity sensor is attached near the planting unit to detect the planting arm. When the planting arm is detected by the sensor, it sends the signal to the digital hour meter counter. Digital hour meter counter actuates linear solenoid attached opener to drop the fertilizer at the alternative hill in between rows so that it ensures nutrient supply to four hills. The battery is used to power the electronic control system. The air-assist system using an air blower is attached to the fertilizer unit to avoid blockage in the delivery tube end. The developed deep-placement fertilizer applicator will be evaluated in the rice field. The circuit diagram of deep placement fertilizer applicator as an attachment to walk-behind rice transplanter (band placement). The field capacity, field efficiency, and fertilizer application efficiency of the developed unit were 0.16 ha h-1, 72 %, and 94 % respectively. The approximate cost of the developed deep placement fertilizer applicator attachment to walking behind the rice transplanter is ? 25,000/-. The equipment saves about 20 % in cost when compared to the conventional method (Broadcasting).