Advances in Soil Science

1. Front Matter

   Pages i-xiv

   PDF

2. Improving the Sustainability of Dryland Farming Systems: A Global Perspective

   • J. F. Parr, B. A. Stewart, S. B. Hornick, R. P. Singh

   Pages 1-8

3. Agroclimatology of Semiarid Lands

   • J. L. Hatfield

   Pages 9-26

4. Conservation Tillage Systems

   • P. W. Unger

   Pages 27-68

5. Tillage and Residue Management Effects on Soil Organic Matter Dynamics in Semiarid Regions

   • J. L. Smith, L. F. Elliott

   Pages 69-88

6. Tillage Systems and Equipment for Dryland Farming

   • O. R. Jones, R. R. Allen, P. W. Unger

   Pages 89-130

7. Fertility Management and Nutrient Cycling

   • J. F. Power

   Pages 131-149

8. Water-Use Efficiency

   • B. A. Stewart, J. L. Steiner

   Pages 151-173

9. Water Erosion and Water Quality

   • D. K. McCool, K. G. Renard

   Pages 175-185

10. Wind Erosion: Mechanics, Prediction, and Control

    • D. W. Fryrear

    Pages 187-199

11. Methods for Removing Spatial Variability from Field Research Trials

    • D. J. Mulla, A. U. Bhatti, R. Kunkel

    Pages 201-213

12. Diseases Caused by Root-Infecting Pathogens in Dryland Agriculture

    • R. J. Cook

    Pages 215-239

13. The Role of Soil Biodiversity in Sustainable Dryland Farming Systems

    • C. S. Potter, R. E. Meyer

    Pages 241-251

14. Managing Crop Residues to Optimize Crop/Livestock Production Systems for Dryland Agriculture

    • R. I. Papendick, J. F. Parr, R. E. Meyer

    Pages 253-272

15. Agroclimatic Approaches for Improving Agricultural Productivity in Semiarid Tropics

    • E. T. Kanemasu, J. I. Stewart, S. J. van Donk, S. M. Virmani

    Pages 273-309

16. An Economic Analysis of Farm Management Practices and Improved Technologies in the Sahel

    • J. C. Day, W. R. Butcher, D. W. Hughes

    Pages 311-332

17. Use of Crop Simulation Models in Dryland Agriculture

    • C. A. Jones

    Pages 333-345

18. Strategies for Increasing the Productivity and Stability of Dryland Farming Systems

    • C. E. Whitman, R. E. Meyer

    Pages 347-358

19. Back Matter

    Pages 359-373

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From the beginning of agriculture until about 1950, increased food production came almost entirely from expanding the cropland base. Since 1950, however, the yield per unit of land area for major crops has increased dramatically. Much of the increase in yields was because of increased inputs of energy. Between 1950 and 1985, the farm tractor fleet quadrupled, world irrigated area tripled, and use of fertilizer increased ninefold. Between 1950 and 1985, the total energy used in world agriculture increased 6. 9 times. Irrigation played a particularly important role in the rapid increase in food production between 1950 and 1985. The world's irrigated land in 1950 totaled 94 million hectares but increased to 140 million by 1960, to 198 million by 1970, and to 271 million hectares in 1985. However, the current rate of expansion has slowed to less than 1 % per year. The world population continues to increase and agricultural production by the year 2000 will have to be 50 to 60% greater than in 1980 to meet demands. This continued demand for food and fiber, coupled with the sharp decline in the growth rate of irrigation development, means that much of the additional agricultural production in future years must come from cultivated land that is not irrigated. Agricultural production will be expanded in the arid and semiarid regions because these regions make up vast areas in developing countries where populations are rapidly rising.

• Infiltration
• Pathogen
• Soil fertility
• biodiversity
• climatology
• growth
• plant disease
• simulation
• soil science
• wind

• Indian Council of Agricultural Research, Hyderabad, India

  R. P. Singh

• USDA Agricultural Research Service, Beltsville, USA

  J. F. Parr

• USDA Conservation & Production Laboratory, Bushland, USA

  B. A. Stewart

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