Direct Seeding of Basmati Rice through Improved Drills: Potential and Constraints in Pakistani Farm Settings

Abstract

Abstract.In Pakistan, rice is an important cash crop and is cultivated over 2.75 mha, generally as traditionally transplanted rice (TTPR). High labor costs and water requirements, time intensiveness, low plant populations, and increased methane emissions are problems associated with TTPR. Alternatively, direct seeded rice (DSR) is now being adopted by rice growers for saving of labor cost (1-2 compared to 50-60 person-days/ha for TTPR), for time and water saving (10% to 30%), and most importantly for achieving the optimal plant population. Technical issues in machine design, and direct seeding, lack of farmers’ awareness about the technology, and social issues are the major hurdles in wide scale adoption of this effective intervention. To identify and address these issues, a testing and calibration activity was conducted during 2017 in the eight major basmati rice producing districts of Punjab, Pakistan. Twenty-one DSR drills (model 2017) being used in the field were tested to determine efficiency and farmers’ perceptions of the technology were noted. Plant germination percentage and vegetation vigor were also measured. The drawbacks in design, manufacturing, and assembling were identified in the DSR drills and modifications were made in the new model to improve efficiency. Fifty-three randomly selected modified DSR drills (model 2018) were calibrated in 2018 before the start of the rice-sowing season. In 2017 the study showed large variability in the row-to-row distance, seed rate and distances of individual drills, and resulting seed germination ranged from 20% to 90% sown at different sites. In 2018, the standard deviation (SD) of seed rate was improved from SD = 19.7 to 6.6 g/40 rev/tine while SD of row-to-row distance was reduced from 0.81 to 0.61 cm as compared to 2017 drill. The plant vigor measured in terms of the Normalized Difference Vegetation Index (NDVI) showed a good relationship with the plant population (R2 = 0.66) except at a few locations where weeds dominated. Important social issues identified were farmer’s lack of interest in preparing the land, precision land leveling, seed treatment, timely inputs, and farmer’s traditional thinking. However, farmers were motivated to consider adopting the DSR technology by demonstration plots established in 2017 by the Nuclear Institute for Agriculture & Biology (NIAB) and the Rice Research Institute (RRI), Kala Shah Kaku. Increased DSR machine sales in 2018 indicate the technology is being more widely adopted. Keywords: Direct seeded rice drills, Normalized Difference Vegetation Index (NDVI), Plant population, Precision planting, Traditionally transplanted rice.