Block K, North Bihar: Cropping Plan Under Flood and Falling Water Tables
Block K lies in the north Bihar plains. It receives about 1,480 mm of rain a year, but 82 per cent of it falls between mid-June and September. Of its cultivated area of roughly 14,000 hectares, 71 per cent is held in plots below one hectare. The canal meant to serve the block reaches only the last two kilometres of it and carries barely 40 per cent of its design discharge in the rabi season. In three of the last five years the eastern half stayed under water for three to six weeks in August. Farmers there grow paddy from July to October and then wheat from November to March, watering it four to five times from private tubewells. In the western half the water table has been falling about 0.3 metres a year. A sugar mill 22 km away is offering cane contracts, and a dal mill 9 km away will buy pulses, but only in lots of at least two quintals. The Block Agriculture Officer must propose a three-year cropping plan for the flood-prone eastern half and a water policy for the western half.
1. Recommend a kharif and a rabi crop for the eastern half, and name one crop you would refuse to recommend there. Justify each choice from the physical and economic facts given.
Read the worked answer
The binding facts for the eastern half are the August flood window (three to six weeks in three of five years), the unreliable canal, and tiny holdings that cannot absorb risk. Kharif: an early-duration or submergence-tolerant paddy transplanted early enough to be harvested or at least past its vulnerable stage before the August peak, rather than a long-duration variety that stands in water.
Rabi: a pulse such as gram or lentil sown on residual soil moisture, needing one or two light irrigations instead of four or five wheat waterings, with a guaranteed buyer 9 km away - short transport, no cold chain, and a two-quintal lot size that a one-hectare farmer can meet by pooling with neighbours.
Refuse: sugarcane. It stands 12 to 18 months and cannot survive three to six weeks of submergence, it needs heavy irrigation the canal cannot supply, and the mill is 22 km away, so the transport cost falls on a 0.6-hectare plot. A long-duration, water-hungry, distant-market crop is the worst fit for this half of the block.
2. In the western half the water table is falling about 0.3 metres a year and the canal is unreliable. Choose one change you would prioritise, and state two measurements over three years that would show whether it is working.
Read the worked answer
Prioritise reducing the demand peak rather than adding supply: replace the four-to-five-irrigation wheat rotation with a lower-water rabi crop plus field-level water saving (land levelling and ridge-and-furrow or sprinkler for the remaining wheat), and use the canal's limited rabi discharge on a smaller commanded area at full intensity instead of spreading it thin.
Measurements: (1) pre-monsoon water level in a fixed set of observation wells, read in the same month each year - the trend, not a single reading, is the evidence; (2) pumping hours or electricity units per hectare used for irrigation, as a proxy for actual extraction, since metered volumes rarely exist. Add yield and net income per hectare as a safeguard, because a policy that stops the fall by making farmers poorer has not succeeded.
The honest caveat: rainfall varies, so compare with a similar unaltered patch nearby; otherwise a good monsoon will be mistaken for a successful policy.