Early Crop Establishment of Rainfed Lowland Rice by Slit Seeding
Herbert T. Manaligod1
Direct seeding of rice using a Vertical Metering Slit Seeder (VMSS) was tested in tilled and non-tilled plots and at depths of 0-10mm (shallow) and 60-70mm (deep) in rainfed lowland fields of Victoria, Tarlac, Philippines in 1993, 1994 and 1995, to study its potential of establishing rice crop early in the wet season.
Seeds used in the experiment were exposed to drought periods of 12 d and 17 d then seeded during the early onset of rainy season (WS) of 1993 and 1995. The germinated seeds of slit-seeded plots gave a sustained crop establishment during the drought period while the germinated seeds for the broadcast seeded plots were not able to survive. The crop establishment in the slit-seeded plots was attributed to the sustained supply of residual moisture present in the sub-surface of the soil.
In all the treatments, deep slit-seeded plots in tilled soil enabled the germinated seeds to survive during drought periods within the rainy season and gave consistently the highest yields of 4.8 tons/ha in 1993 and 3.2 tons/ha in 1995. The heavy weed infestation was the drawback of non-tilled plots. There was drier weed weight matter collected in non-tilled than in the tilled and the broadcast seeded plots. The cost of manual weeding factored out the slight yield advantage on non-tilled plots from the tilled plots. On the other hand, the row seeded plots provided better access to manual weeding and also allowed labor saving methods like use of mechanical or chemical weeders for weed control compared to the broadcast seeded plots.
1Assistant Professor, Department of Industrial Engineering, College of Engineering and Agro-Industrial Technology, University of the Philippines Los Baños, 4031 College, Laguna, Philippines.