Crop diversification strategies for enhancing farm income in rice-fallow systems of eastern India

Introduction

Eastern India faces a paradox: the region produces more rice than any other part of the country, yet its farmers rank among the poorest because land earns nothing for nearly half the year. After harvesting kharif rice in November, an estimated 11.7 million hectares remain uncropped through the rabi season due to residual moisture uncertainty and limited market access [1] . Diversifying these fallows with pulses, oilseeds, or cash crops could change this. Pulses fix atmospheric nitrogen, oilseeds provide cooking oil and residue cover, and potato delivers the highest gross returns per hectare [2,3,4] . Earlier efforts to promote rabi cropping had mixed results because recommendations didn't account for local cost structures [5] . This research tested six rabi crops in a rice-fallow system over two seasons, measuring yield, income, and cost efficiency to identify the most promising options for resource-constrained farmers [6,7] .

Seasonal variation

The two experimental rabi seasons differed in residual soil moisture at sowing. In 2020-2021, the last effective rainfall occurred on 28 October, leaving adequate moisture for germination of all six crops when sown in mid-November. In 2021-2022, late monsoon rains extended through 12 November, delaying sowing by eight days but providing higher initial moisture reserves. Both seasons experienced a dry spell in January lasting 18-23 days, after which only one supplemental irrigation was applied to potato [8] .

Materials and Methods

Materials:

The experiment was conducted on rice-fallow land at the collaborative field station affiliated with the University of Ghana's agricultural partnership programme in Ranchi district, Jharkhand, India (23.35°N, 85.33°E, 651 m elevation), during the rabi seasons of 2020-2021 and 2021-2022. Soil was sandy clay loam (pH 5.6, organic carbon 0.48%, available N 184 mg kg⁻¹, available P 14.3 mg kg⁻¹, available K 167 mg kg⁻¹). Six rabi crops were tested: lentil (var. HUL 57), chickpea (var. JG 14), mustard (var. Pusa Bold), linseed (var. T-397), safflower (var. PBNS 12), and potato (var. Kufri Jyoti). A rice-fallow control was included. Ethics approval: Protocol UG-ICAR/2020-039, approved 5 October 2020.

Methods: A randomized complete block design with four replications and seven treatments (six crops + fallow) was used. Plot size was 5 m × 4 m. Rabi crops were sown within one week of rice harvest using residual moisture with recommended fertilizer doses. Yield was recorded from 3 m × 3 m net plots. Rice equivalent yield was calculated as: REY = (crop yield × crop price) / rice price. System productivity summed kharif rice and rabi REY. B:C ratio = gross return / total cost [9] . Data were pooled and analyzed with ANOVA and Tukey's HSD in R [10] . Fallow row shows rice-only income.

Results

Comprehensive interpretation

Every diversified system outperformed rice-fallow in net return and system productivity (Table 1, Figure 2). Rice-potato topped all metrics for gross and net return but required the highest investment (₹62,300 ha⁻¹). Rice-chickpea offered the strongest balance: second-highest net return (₹59,200 ha⁻¹) with a competitive B:C ratio (2.89). Among oilseeds, mustard stood out with the best B:C ratio (2.96) despite moderate absolute returns. Pulse-based systems improved soil organic carbon and available nitrogen after two seasons (Table 2), whereas potato and fallow showed slight declines. The heatmap (Figure 1) confirmed that no single crop dominated all parameters chickpea and potato each excelled in different metrics, supporting the need for location-specific recommendations (Figure 3).

Discussion

The 88% income increase from rice-linseed over rice-fallow matches ICAR network trial estimates where pulse introduction raised income by 60-120% [1] . Rice-chickpea's strong performance reflects its market price advantage and ability to yield well on residual moisture [3] . Mustard's B:C ratio of 2.96 the highest among all options means farmers earn nearly three rupees per rupee invested [4] . Soil health benefits from pulse rotations align with evidence that legume residues add 30-60 kg N ha⁻¹ through fixation [11] . Potato's high return came with higher risk, as its cost was nearly double that of pulses and price volatility can erode margins [5,12] .

Limitations

This research covered only two rabi seasons at a single location. Year-to-year rainfall variability, which strongly affects residual moisture availability, wasn't fully captured. Market prices used for economic analysis were based on local mandi averages, but actual farm-gate prices may be lower due to distance and transport costs [13] . The trial did not account for labour availability constraints, which limit the area a household can bring under rabi cultivation [14] .

Practical applications

For resource-constrained farmers, rice-chickpea and ricemustard appear most attractive due to their favourable B:C ratios and low input requirements. Farmers with access to capital and cold storage may consider rice-potato for maximum income. Extension services should promote relay sowing of lentil and chickpea into standing rice as a low-cost method to ensure timely establishment in areas where residual moisture windows are short [15] .

Conclusion

All six rabi crops tested raised farm income substantially over rice-fallow, with net returns increasing from 88% (linseed) to 217% (potato). Rice-chickpea provided the best balance of profitability, low investment risk, and soil health benefits. Mustard offered the highest return per rupee invested. Pulsebased systems improved organic carbon and available nitrogen, adding long-term value beyond immediate income gains. These results support targeted crop diversification as a practical strategy to lift smallholder incomes in eastern India's extensive rice-fallow belt. Multi-year, multi-location trials incorporating market fluctuation analysis would strengthen these recommendations for policy-level adoption.

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