Fertilizer Sulfur And Food Production

Fertilizer is a vital component of strategies for expanding foodproduction. The rapid growth in population and the widening food deficits inmany tropical countries ofAsia, Africa, and Latin America call attention to those aspects of fertilization that have been neglected but are expected to yield large economic payoffs in the future. Fertilizer sulfur falls into this category. In the past fertilizer sulfur received little attention from researchers and policymakers since sulfur deficiency was not considered a serious problem. It was not a problem because of low crop yields, extensive cropping, and the incidental supply of sulfur through rain, irrigation water, manures, and sulfurcontaining fertilizers. However, the situation has changed in the last three decades. Moder nagriculture based on high crop yields, intensive cropping, improved crop varieties, and greater use of sulfur-free fertilizers and environmental regula tions restricting sulfur emissions are creating large gaps between sulfur sup ply and sulfur requirements. Sulfur deficiencies are widespread and grow ing. Consequently, the full potential of a modern agricultural system in tropical countries is not being realized. This research effort results from the recognition of the seriousness of the sulfur problem and its adverse impact on food production as well as IFDC's dedication to the development and transfer of economically ef ficient fertilizer technology to tropical countries. This study represents a comprehensive analysis ofthe technical and economic linkages between fer tilizer sulfur and food production, and it provides guidelines for future directions in fertilizer sulfur research and public policy.

Sulfur forms and cycling processes in soil and their relationship to sulfur fertility / Jeff J. Schoenau and Sukhdev S. Malhi -- Sulfur nutrition of crops in the Indo-Gangetic plains of South Asia / M.P.S. Khurana, U.S. Sandana and Bijay-Singh -- Soil sulfur cycling temperate agricultural systems / Jørgen Eriksen -- History of sulfur deficiency in crops / Silvia Haneklaus, Elke Bloem and Ewald Schnug -- Availability of sulfur to crops from soil and other sources / Warren A. Dick, David Kost and Liming Chen -- Sulfur and cysteine metabolism / Rainer Hoefgen and Holger Hesse -- Sulfur response based on crop, source, and landscape position / Dave Franzen and Cynthia A. Grant -- Sulfur management for soybean production / Kiyoko Hitsuda [and others] -- Sulfur in a fertilizer program for corn / George W. Rehm and John G. Clapp -- Sulfur nutrition and wheat quality / Hamid A. Naeem -- Sulfur and marketable yield of potato / Alexander D. Pavlista -- Sulfur, its role in onion production and related alliums / George E. Boyhan -- Sulfur and the production of rice in wetland and dryland ecosystems / Richard W. Bell -- Evaluation of the relative significance of sulfur and other essential mineral elements in oilseed rape, cereals, and sugar beet production / Ewald Schnug and Silvia Haneklaus -- Improving the sulfur-containing amino acids of soybean to enhance its nutritional value in animal feed / Hari B. Krishnan -- Methionine metabolism in plants / Rachel Amir and Yael Hacham -- Plant sulfur compounds and human health / Joseph M. Jez and Naomi K. Fukagawa -- A future crop biotechnology view of sulfur and selenium / Muhammad Sayyar Khan and Rüdiger Hell.

This is the second volume in the series Nutrients in Ecosystems. Sulphur as an essential plant nutrient has received little attention. This is explained by the facts that sulphur was obviously in sufficient supply from the atmosphere, from soil and as a by-product in mineral fertilizers. Increases in the yield potential and thus in the nutrient requirement of modern crops, however, as well as remarkable changes in SO2 emissions by private households, power stations and industry, associated with legislative measures to reduce air and water pollution, have altered the situation to a large extent. In particular the public concerns about forest decline and pollution-induced climatic changes have initiated extensive research programs on the physiological functions of sulphur in plants, on the occurrence and plant availability of sulphur in agricultural and forest soils and on the chemistry of sulphur compounds in the tropo- and stratosphere. This book cannot be an encylcopedia of sulphur in all the media mentioned nor in all ecozones of the globe. However, it aims to give an overview of our present knowledge with a special focus on the sulphur situation in agrosystems of industrialised Western Europe. The ecological trends for sulphur observed in this region during recent decades are likely to be mirrored wherever industrialisation and urbanisation take place and where an increasing standard of living demands clean air, good drinking water and nutritious food. Agricultural production systems, therefore, require well-founded information on the actual sulphur nutrition and potential sulphur-fertilizer requirement of crops and soils respectively. It is hoped that this book will provide this information and will encourage further research where open questions still exist.

Sulphur (S) plays a pivotal role in various plant growth and development processes being a constituent of sulphur-containing amino acids, cysteine and methionine, and other metabolites viz., glutathione and phytochelatins, co-factor of enzymes which contribute to stress repair and amelioration of heavy metal toxicity. Besides, a number of S-containing components are biologically active and, thus, a source for use as medicinal value. The basic global issue before the agricultural scientist and world community is to evolve cultivars and develop methodologies for efficient use of inputs to enhance agricultural productivity. This is particularly true of the developing countries which are going to see maximum rise in population with changing food demands and declining availability of land. Amongst the inputs, nutrients play a crucial role. The major requirement is for N, P and K followed by several micro-nutrients. In this context reports of world-wide S deficiency in the agricultural systems are relevant. The reasons are many. Broadly speaking reduction inS emission, use of S-free N, P and K fertilizers and higher biomass production contributed the maximum. Despite the need for sulphur as an essential plant nutrient and the substantial returns expected from its use, very little attention has been given to fill the gap between supply and demand of S.