Mechanical transplanting and urea fertilizer deep placement into soil simultaneously with a walk behind type mechanical transplanter increased yield and benefit of wetland rice (Oryza sativa L.) cultivation in Bangladesh

Abstract

Abstract

A research was conducted to evaluate the BRRI developed rice transplanter cum prilled urea applicator (RTPUA) during Boro 2017-2018. Urea fertilizer deep placement mechanism successfully incorporated in the walk behind type rice transplanter (ARP-4UM). Engine power available at high rpm (more than 1800 rpm of the walking type rice transplanter) was conveyed to the applicator with the arrangement of a belt-pulley, worm gearing, shaft-bearing, chain-sprocket and bevel gear with engage-disengage facility resulting 22 rpm of the applicator main shaft considering transplanting speed of the transplanter. Impellor type mechanism was connected with the main shaft of the applicator to dispense the prilled urea fertilizer to the output channel. Field experiments were conducted on a silty loam soil in Gopalgonj, clay loam soil in Kushtia, silty clay loam soil in Gazipur and on a clay soil in Netrakona. Four transplanting and urea fertilizer treatments were T₁ = Mechanical transplanting (MT) along with urea deep placement together (70% urea), T₂= MT + hand broadcasting of urea (UHB) at three equal split, T₃ = Hand transplanting (HT) and UHB at three equal split and T₄ = Control (-N). In four locations, theoretical and actual field capacity of the rice transplanter was found higher to some extent without fertilizer deep placement mechanism during transplanting due to extra fertilizer re-filling time and slow of operation. Field capacity was found more in clay and clay loam soil. Average of four locations and three replications, actual field capacity of the rice transplanter was found 0.119 ha hr^-1. In the field, saving percentage of urea fertilizer varied from 25.1 to 28.5% against the calibration of 30% of urea saving due to variation of the machine, operational speed and more penetration of the driving wheel in the field during operation etc. It was also observed that grain yield varied with the mode and rate of urea fertilizer application. Mechanical transplanting along with urea fertilizer deep placement (70% of recommended dose) gave significantly higher yield compared to manual transplanting and hand broadcasting of urea as well as higher benefit-cost ratio (BCR). Mechanized transplanting along with urea fertilizer deep placement in wet land rice establishment is thus a promising technology for rice farmers in Bangladesh as well as in Asia.