Rattan Lal, Ph.D, is professor of soil physics and director of the Carbon Management & Sequestration Center at Ohio State University, Columbus, USA. B.A. Stewart, Ph.D, is distinguished professor of agriculture and director of the Dryland Agriculture Institute, West Texas A&M University, Canyon, USA.

• The Global Phosphorus Cycle. Positive and Negative Effects of Phosphorus Fertilizer on U.S. Agriculture and the Environment. Coupled Cycling of Carbon, Nitrogen, and Phosphorus. Phosphorus in Soil and Plant Relation to Human Nutrition and Health. Phosphorus Management. Phosphorus Effluxes from Lake Sediments. Economic and Policy Issues of Phosphorus Management in Agroecosystems. Phosphorus Fertilization and Management in Soils of Sub-Saharan Africa. Phosphorus and the Environment. Enhancing Efficiency of Phosphorus Fertilizers through Formula Modifications. Soil Phosphorus Cycling in Tropical Soils: An Ultisol and Oxisol Perspective. The Use of Phosphorus Radioisotopes to Investigate Soil Phosphorus Dynamics and Cycling in Soil-Plant Systems. Pathways and Fate of Phosphorus in Agroecosystems.

Rattan Lal, Ph.D, is professor of soil physics and director of the Carbon Management & Sequestration Center at Ohio State University, Columbus, USA. B.A. Stewart, Ph.D, is distinguished professor of agriculture and director of the Dryland Agriculture Institute, West Texas A&M University, Canyon, USA.

• The Global Phosphorus Cycle. Positive and Negative Effects of Phosphorus Fertilizer on U.S. Agriculture and the Environment. Coupled Cycling of Carbon, Nitrogen, and Phosphorus. Phosphorus in Soil and Plant Relation to Human Nutrition and Health. Phosphorus Management. Phosphorus Effluxes from Lake Sediments. Economic and Policy Issues of Phosphorus Management in Agroecosystems. Phosphorus Fertilization and Management in Soils of Sub-Saharan Africa. Phosphorus and the Environment. Enhancing Efficiency of Phosphorus Fertilizers through Formula Modifications. Soil Phosphorus Cycling in Tropical Soils: An Ultisol and Oxisol Perspective. The Use of Phosphorus Radioisotopes to Investigate Soil Phosphorus Dynamics and Cycling in Soil-Plant Systems. Pathways and Fate of Phosphorus in Agroecosystems.

Rattan Lal, Ph.D, is professor of soil physics and director of the Carbon Management & Sequestration Center at Ohio State University, Columbus, USA. B.A. Stewart, Ph.D, is distinguished professor of agriculture and director of the Dryland Agriculture Institute, West Texas A&M University, Canyon, USA.

• The Global Phosphorus Cycle. Positive and Negative Effects of Phosphorus Fertilizer on U.S. Agriculture and the Environment. Coupled Cycling of Carbon, Nitrogen, and Phosphorus. Phosphorus in Soil and Plant Relation to Human Nutrition and Health. Phosphorus Management. Phosphorus Effluxes from Lake Sediments. Economic and Policy Issues of Phosphorus Management in Agroecosystems. Phosphorus Fertilization and Management in Soils of Sub-Saharan Africa. Phosphorus and the Environment. Enhancing Efficiency of Phosphorus Fertilizers through Formula Modifications. Soil Phosphorus Cycling in Tropical Soils: An Ultisol and Oxisol Perspective. The Use of Phosphorus Radioisotopes to Investigate Soil Phosphorus Dynamics and Cycling in Soil-Plant Systems. Pathways and Fate of Phosphorus in Agroecosystems.