Biomass Productivity-Based Mapping of Global Land Degradation Hotspots

Land degradation is a global problem affecting negatively the livelihoods and food security of billions of people, especially farmers and pastoralists in the developing countries. Eradicating extreme poverty without adequately addressing land degradation is highly unlikely. Given the importance and magnitude of the problem, there have been recurring efforts by the international community to identify the extent and severity of land degradation in global scale. As discussed in this paper, many previous studies were challenged by lack of appropriate data or shortcomings of their methodological approaches. In this paper, using global level remotely sensed vegetation index data, we identify the hotspots of land degradation in the world across major land cover types. In doing so, we use the long-term trend of inter-annual vegetation index as an indicator of biomass production decline or improvement. Besides the elimination of technical factors, confounding the relationship between the indicator and the biomass production of the land, we apply a methodology which accounts for masking effects of both inter-annual rainfall variation and atmospheric fertilization. We also delineate the areas where chemical fertilization could be hiding the inherent land degradation processes. Our findings show that land degradation hotpots cover about 29% of global land area and are happening in all agro-ecologies and land cover types. Land degradation is especially massive in grasslands. About 3.2 billion people reside in these degrading areas. However, the number of people affected by land degradation is likely to be higher as more people depend on the continuous flow of ecosystem goods and services from these affected areas. As we note in the paper, this figure, although, does not include all possible areas with degraded lands, it identifies those areas where land degradation is most acute and requires priority actions in both in-depth research and management measures to combat land degradation. Our findings indicate that, in fact, land improvement has also occurred in about 2.7% of global land area during the last three decades, providing a support that with appropriate actions land degradation trend could be reversed, and that the efforts to address land degradation need to be substantially increased, at least by a factor, to attain the vision of Zero Net Land Degradation. We also identify concrete aspects in which these results should be interpreted with caution, the limitations of this work and the key areas for future research

Impact of Land Degradation on Future World Food Production

Land degradation will likely curb agricultural production increases in the developing countries of Africa, Asia, and Central and South America. Growing populations and weak economies in many countries will seriously hamper efforts to bring new land under cultivation. Forty percent of the world's available land is being farmed, representing the best soils, but cultivating the remaining sparsely populated and often marginal 60 percent of land will require expensive farming techniques and new technology. Improved land management will likely spur per capita food increases in the developed countries

Irrigation well waters of New Mexico: Chemical characteristics, quality, and use

Factors affecting water quality; Principal cations; Principal anions; Other ions; Characteristics affecting water quality; Analysis and classification of irrigation well waters; Factors affecting salt accumulation; Factors affecting sodium accumulation; Relation of conductivity to sodium hazard; Relation to conductivity to dissolved solids; Relation of conductivity to cation content; Definitions and conversion factors; Literature citedBulletin containing the results of analyses of representative waters from the main pump-irrigated areas in New Mexico

Crop moisture index

Research report containing the results of an evaluation of preciptation and temperature factors in the success of crops in areas of New Mexico where irrigation is not practiced

Salt-fertilizer-specific ion interactions in soil

Literature review; Procedures; Salt and fertilizer interactions; Specific ion effects; Results and discussion; Salt and fertilizer interactions; Specific ion effects; Summary and conclusions; Literature citedBulletin containing the results of experiments to determine the viability of ion antagonism and salt-fertilizer interactions as alternatives to leaching for reducing soil salinity

Fertilizer consumption trends in New Mexico

Press bulletin containing detailed information on the consumption of fertilizer in New Mexico over an approximate 20 year period

Prediction of crop yields from quantity and salinity of irrigation water

Assumptions; Average soil salinity; Salt tolerance; Water requirement; Salinity and water effects on yield; Maintaining maximum yields with saline irrigation water; Summary and conclusions; AppendixBulletin containing the results of a study to determine the most economical crops to produce for varying irrigation water and soil salinity levels

Irrigation water quality and the leaching requirement

Literature review; Procedures; Results and discussion; Leaching percentage; Sodium adsorption; Conclusions; Appendix; Literature citedBulletin containing the results of studies into the effect lime and gypsum in certain types of soils on the leaching requirement of carbonate and sulfate irrigation waters