Q7.What are the major reasons for declining rice and wheat yield in the cropping system? How crop diversification is helpful to stabilise the yield of the crop in the system?

The intensive rice-wheat cropping system, dominant in many regions, faces significant challenges leading to a decline in productivity and sustainability. This monoculture approach has detrimental effects on soil health and resource utilization.

• Soil Degradation: Continuous monoculture of rice and wheat depletes specific nutrients, reduces soil organic matter, and degrades soil structure, leading to lower fertility and reduced water retention capacity.
• Groundwater Depletion: Both crops are highly water-intensive. Their over-reliance, especially in non-native regions, leads to excessive groundwater extraction, increasing irrigation costs and threatening water security.
• Pest and Disease Build-up: The lack of crop rotation creates a conducive environment for specific pests and diseases to proliferate, necessitating increased pesticide use, which in turn fosters resistance and environmental concerns.

• Improved Soil Health: Introducing legumes (e.g., pulses) fixes atmospheric nitrogen, enriching soil fertility. Diversification also increases organic carbon content and promotes better nutrient cycling, enhancing overall soil structure and health.
• Pest and Disease Management: Varied cropping systems disrupt the life cycles of specific pests and pathogens associated with rice and wheat, naturally reducing their incidence and the need for chemical interventions.
• Enhanced Water Use Efficiency: Diversifying with less water-intensive crops (e.g., millets, oilseeds) reduces overall water demand. It also builds resilience against climate variability, ensuring more stable yields even with erratic rainfall.

Crop diversification is crucial for mitigating the adverse impacts of monoculture, promoting ecological balance, and ensuring the long-term stability and sustainability of agricultural yields in the face of environmental challenges.