Introduction
DSR is a resource conservation technology which involves sowing of seeds directly into the main field using seed drill rather than transplanting seedlings.
Field Preparation
DSR can be done on the same field as in the case of puddled transplanted rice but good leveling must be done for conserving the moisture, better crop emergence and better yield. The seeds can either be sown under conservation tillage or zero till method depending on site-specific factors.
Sowing
One can sow the seeds by two methods: 1) In moist soil condition and 2) In dry soil condition. It depends on the weather condition and the irrigation facility available. Since the seed quality greatly influences the germination rate, it is recommended to use the certified seeds at a seed rate 20-30 kg/ha having germination percentage >95%. The seeding depth is critical and the seeds must be sown at 1-2 cm and not deeper than 3 cm.
Varieties
Short duration varieties like Radha 4, Hardinath 2, Sukkha dhan 1, Tara,etc. are suitable only for the upland condition. Medium and Long duration varieties like Ramdhan, Sabitri, Loktantra, Mithila, Sukkha 4, etc. can also be used for the lowland condition.
Seed Treatment
Seed treatment such as priming i.e. soaking the seeds for 10-12 hours in a gunny bag, accelerates the crop emergence. The seed is then air dried and incubated and it must be sown into moist soil. Sowing into dry soil may adversely affect the emergence of pre-germinated seeds. Also seed treatment with fungicides can be done to manage the diseases such as rice blast, brown spot, false smut, etc.
Fertilizer Application
All fertilizers except urea should be applied at sowing. N dose varies depending on variety from 80-120kg/ha and applied in at least 3 minimum split doses. The requirement for other fertilizers is P₂O5 at 60 kg/ha, K₂O at 60 kg/ha and ZnSO4 at 25 kg/ha. DAP should be used with seed drill while sowing.
Weed Management
Since the weed infestation is high in case of DSR, it is necessary to manage the weeds either by preparing stale seedbed, or by manual hand/tool weeding or by use of chemical weedicides.
Irrigation
Irrigation is critical during first three weeks. It is required during tillering to flowering stage. There should be no water stress during Panicle Initiation and Grain filling Stage. It is crucial to have a better drainage facility for DSR.