2001年-世界发展银行全球_Productivity_Growth_and_Sustainability_in_Post-Green_Revolution_Agriculture___The_Case_of_the_Indian_and_Pakistan_Punjabs_20页_596kb

Summary of Productivity Growth and Sustainability in Post-Green Revolution Agriculture: The Case of the Indian and Pakistan Punjabs

Core Content

This article examines the long-term productivity and sustainability of irrigated agriculture in the Indian and Pakistan Punjabs, focusing on the impact of Green Revolution technologies and subsequent intensification on output growth and resource degradation. The study uses total factor productivity (TFP) measurements to assess performance over three distinct periods: the Green Revolution period (1966–74), the input intensification period (1975–85 in India, 1975–84 in Pakistan), and the post-Green Revolution period (1986–94 in India, 1985–94 in Pakistan).

Main Findings

1. Spatial and Temporal Variations in Productivity Growth:

   • Output growth and crop yields were significantly higher in the Indian Punjab compared to the Pakistan Punjab.
   • Productivity growth was relatively modest, with the lowest gains occurring during the initial Green Revolution period.
   • The wheat-rice system showed the lowest productivity growth in both regions.

2. Input Growth as a Major Driver:

   • Input growth accounted for most of the output growth in both Punjabs.
   • The TFP growth was relatively low during the Green Revolution period, but increased significantly in the input intensification period.

3. Resource Degradation:

   • Intensification, particularly in the wheat-rice system, led to significant resource degradation, including soil and water quality deterioration, salinization, and groundwater overexploitation.
   • In Pakistan, resource degradation reduced overall productivity growth by one-third, affecting both technical change and public investments in education and infrastructure.

Key Information

• TFP Calculation: The study uses the chain-linked Tornqvist-Theil index to measure TFP, which accounts for changes in output and input indices, including the revenue share of output and the cost share of inputs.
• Data Sources: District-level data on inputs (land, labor, water, machinery, fertilizer, pesticides), outputs (crops, livestock), and prices were used to calculate TFP and analyze productivity trends.
• Cropping Systems: The Punjabs were divided into different cropping systems, such as wheat-rice, wheat-cotton, wheat-maize, and wheat-mungbean, to assess productivity and degradation patterns.
• Policy Implications: The study suggests that public investments in education, roads, and research and extension are essential for promoting agricultural productivity and sustainability. Additionally, policies should aim to reduce resource degradation by eliminating or modifying subsidies that encourage input intensification.

Methodology Overview

• Three Periods of Analysis:
  1. Green Revolution (1966–74): Rapid adoption of modern wheat and rice varieties.
  2. Input Intensification (1975–85 in India, 1975–84 in Pakistan): Increase in fertilizer and capital inputs.
  3. Post-Green Revolution (1986–94 in India, 1985–94 in Pakistan): Stabilization or decline in input use, with increased focus on sustainability.
• TFP Decomposition: The study decomposes productivity growth into contributions from technological change, human and physical infrastructure improvements, and resource degradation using a cost function approach.

Cropping System Performance

Cropping System	Output Growth (%)	Input Growth (%)	TFP Growth (%)
Indian Punjab
Wheat-Rice	5.1	3.7	1.4
Wheat-Cotton	5.0	2.5	2.5
Wheat-Maize	3.6	1.2	2.4
Overall Indian Punjab	5.5	3.0	1.9
Pakistan Punjab
Wheat-Rice	2.4	2.3	0.1
Wheat-Cotton	4.1	2.1	1.9
Wheat-Mungbean	4.3	2.3	2.0
Wheat-Mix	2.6	1.6	1.0
Overall Pakistan Punjab	3.2	1.9	1.5

Policy Recommendations

• Promote public investments in education, roads, and research and extension to support agricultural productivity.
• Reduce subsidies that encourage input intensification to mitigate resource degradation.
• Encourage sustainable cropping systems and diversification to avoid over-reliance on resource-intensive systems like wheat-rice.
• Address market distortions that may limit the adoption of new technologies and influence productivity outcomes.

Conclusion

The study highlights the importance of understanding the relationship between productivity growth, resource degradation, and policy interventions in the context of the Green Revolution. While the initial period saw significant output growth, the long-term sustainability of agricultural systems in the Indo-Gangetic Plain remains a critical concern. The findings underscore the need for balanced agricultural policies that enhance productivity while preserving natural resources.