Wednesday, August 6, 2008 - 10:40 AM

SYMP 11-8: Sustainable agriculture practices and effects of global climate change

Rattan Lal, The Ohio State University

Background/Question/Methods Agricultural sustainability, meeting the needs of present and future generations while enhancing quality of natural resources and the environment, is a dynamic concept because the issues and strategic foci change over time by the changing aspirations of population.  Global issues of the 21st century are: (i) increase in atmospheric concentration of CO2 by 36% since 1750 with the present rate of enrichment 2ppm/yr, (ii) global energy demand of 425 EJ/yr and increasing at 1-2%/yr, (iii) soil degradation of about 2 billion ha and increasing by 5 to 10 million ha/yr, (iv) present global cereal yield of 2.6 Mg/ha to be increased to 3.6 Mg/ha by 2025 and 4.3 Mg/ha by 2050 with present dietary needs, and 4.4 Mg/ha by 2025 and 6.0 Mg/ha by 2050 with change in diet, (v) food-insecure population of 854 million in 2007 and increasing because of the increase in risks of soil degradation, climate change and price increase, and (vi)water scarcity for population in 30 countries by 2025 exacerbated by pollution and eutrophication.  This articles deliberates the impact of climate change, and how adoption of sustainable agricultural practices can address global issues.  The focus is on the processes, properties and practices of C sequestration in soils and terrestrial ecosystems, and making agriculture an important solution to environmental and food security issues.

Results/Conclusions The strategy of achieving agricultural sustainability depends on the biophysical (soils, climate, farming system, terrain) and the human dimensions (population, economic, social, gender and policy factors) developing countries (e.g., Sub-Saharan Africa) must adapt to climate change by increasing agronomic productivity, enhancing use efficiency of input, (e.g., fertilizer, irrigation, energy) and decreasing losses (e.g., erosion, leaching, volatilization).  Restoring degraded soils is important to sequester C within the terrestrial biosphere, increase productivity, improve the environment and mitigate climate change.  Judicious use of modern technology (GM crops, fertigation, drip sub-irrigation, no-till/conservation tillage, nano-enhanced fertilizers and amendments) can increase production without jeopardizing the environment.  However, over fertilization, unnecessary plowing, abuse of pesticides, excessive irrigation and use of extractive farming practices (e.g., residue removal, excessive grazing, use of dung for fuel rather than as manure) have caused severe problems of soil and environmental degradation emission of greenhouse gases into the atmosphere.  Sustainable management of soil and water resources is a win-win strategy of advancing food security, mitigating climate change and improving the environment.