From UPSC perspective, the following things are important :
Prelims level : Not Much
Mains level : Paddy cultivation in India
Farmers are now being encouraged to adopt ‘direct seeding of rice’ (DSR) in place of conventional transplanting due to lack of labourers, who are stranded due to lockdown.
Recall the classification of cropping seasons on India based on onset and retreat of Monsoon.
The kharif crops include rice, maize, sorghum, pearl millet/bajra, finger millet/ragi (cereals), arhar (pulses), soyabean, groundnut (oilseeds), cotton etc. The rabi crops include wheat, barley, oats (cereals), chickpea/gram (pulses), linseed, mustard (oilseeds) etc. Kindly make a note of this.
What is ‘Direct Seeding of Rice’ (DSR)?
- In transplanting, farmers prepare nurseries where the paddy seeds are first sown and raised into young plants.
- These seedlings are then uprooted and replanted 25-35 days later in the main field.
- Paddy seedlings are transplanted on fields that are “puddled” or tilled in standing water using tractor-drawn disc harrows.
- In DSR, there is no nursery preparation or transplantation. The seeds are instead directly drilled into the field by a tractor-powered machine.
How is the question of herbicides addressed in DSR?
- Paddy being very much water-intensive is compromised by weeds that compete for nutrition, sunlight and water.
- Water prevents the growth of weeds by denying them oxygen in the submerged stage, whereas the soft ‘aerenchyma tissues’ in paddy plants allow air to penetrate through their roots.
- Water, thus, acts as a herbicide for paddy. The threat from weeds recedes once tillering is over; so does the need to flood the fields.
- In DSR, water is replaced by real chemical herbicides. Farmers have to only level their land and give one pre-sowing irrigation or rauni.
- Once the field has good soil moisture, they need to do two rounds of ploughing and planking (smoothening of soil surface), which is followed by the sowing of the seeds and spraying of herbicides.
What are these herbicides?
- There are two kinds. The first is called pre-emergent, i.e. applied before germination. In this case, the pre-emergent herbicide used is Pendimethalin.
- The second set of herbicides is post-emergent, sprayed 20-25 days after sowing, depending upon the type of weeds appearing.
- They include Bispyribac-sodium (Rs 600-700 at 100 ml/acre) and Fenoxaprop-p-ethyl (Rs 700-800 at 400 ml/acre).
What is the main advantage of DSR?
- The most obvious one is water savings. The first irrigation (apart from the pre-sowing rauni) under DSR is necessary only 21 days after sowing.
- This is unlike in transplanted paddy, where watering has to be done practically daily to ensure submerged/flooded conditions in the first three weeks.
- The second savings, relevant in the present context, is that of labour. About three labourers are required to transplant one acre of paddy at almost Rs 2,400 per acre.
- As against this, the cost of herbicides under DSR will not exceed Rs 2,000 per acre.
Limitations of DSR
- The main issue is the availability of herbicides.
- The seed requirement for DSR is also higher, at 8-10 kg/acre, compared to 4-5 kg in transplanting.
- Further, laser land levelling, which costs Rs 1,000/acre, is compulsory in DSR. This is not so in transplanting.
- The yields are as good as from normal transplanting, but one need to sow by the first fortnight of June. The plants have to come out properly before the monsoon rains arrive.
- There is no such problem in transplanting, where the saplings have already been raised in the nursery.