Extent of Salt Affected Land in Central Asia: Biosaline Agriculture and Utilization of the Salt-affected Resources

The current status and trends of salinization are discussed with waterlogging of marginal land/plant and water resources problems including strategies for development of integrated biosaline crop-livestock agriculture based system on food-feed crops and forage legumes for better livelihood of poor farmers in Central Asian (Uzbekistan, Kazakhstan, Turkmenistan and Tajikistan). Transfer of technologies and/or methodology of ICBA (International Centre for Biosaline Agriculture) in planting of both perennial and annual valuable halophytes (based on around the world dataset from similar sites and conditions) are a new approach that should be tested in Central Asia. Afforestation, as an option to mitigate land degradation, requires a judicious evaluation and selection of multipurpose tree species (MPTS) to make use of marginal unproductive/salt- affected lands and lower the elevated groundwater table (GWT) via biodrainage. The leading among 21 screened native and introduced tree and shrubs species with regards to survival rate, growth characteristics and adaptability to high saline natural environment proved to be Haloxylon apphyllum, Salsola paletzkiana, S. richteri at the saline sandy deserts, followed by atriplex undulate, Hippophae ramnoides, E. angustifolia, Acacia ampliceps, U. pumila, P. euphratica and P. nigra var. pyramidalis, Robinia pseudoacacia, M. alba, Morus nigra on clay loamy hyromorphic soils, whereas fruit species such as Cynadon oblonga, Armeniaca vulgare, Prunus armeniaca and species of genera Malus, though desirable from the farmer's financial viewpoint, showed low bio drainage potential. Planting herbaceous fodder crops within the inter-spaces of fodder salt tolerant trees and shrubs on intensive agro-forestry plantations could solve the animal feeding problem in the degraded (both by overgrazing and salinity) desert and semidesert marginal areas. Yield data of new varieties of sorghum and pearl millet ICBA/ICRISAT germplasm collected at the conclusion of the 2006-2007 growing seasons indicates considerable adaptability of introduced genetic material to saline soil conditions, when compared to local material. Sorghum and pearl millet crop residues utilization could be an option for bio fuel production in the region.

Rehabilitation of a salt affected wetland

There exists an urgent need to rehabilitate salt-affected and degraded wetlands in the south-west of Western Australia, particularly in water resource catchments. Various rehabilitation techniques have been developed for such areas, which address the problem of integrating water catchment management and surrounding land use. Despite this, there has been limited success in restoring salt affected wetlands in the south west region of Western Australia. This project was established to develop a method for the rehabilitation of wetlands in the south west of Western Australia, using the western Coollangatta Farmland wetland as a case study. This site was chosen because of its broad application in assessing rehabilitation potentials. It is on the western side of the new Collie Power Station, under construction in Collie. The site has been degraded by salinity, grazing and clearing. This study reviews rehabilitation practices in salt-affected wetlands and maps the physical features and vegetation of the catchment. It also examines the hydrology, distribution of salinity, and assesses nutrient sources of the site. Studies showed a deficit of 1189 m3 between inflow and discharge of water in the wetland in July, and discharge exceeded input by 7623.4m3 in August Interpretations of the hydrology of the wetland was made. Mean concentrations of total phosphorus were 21.9ug/L and total nitrogen was 5821.9 ug/L. Sources of the high total nitrogen concentrations were investigated. This study found that the methods used were suitable to prepare a rehabilitation plan within the time frame of this study. Areas that required specific treatment for revegetation were identified and an appropriate plan for separate management areas was formulated. The methods used in this study could be applied to formulate rehabilitation plans for similarly affected wetlands. However each site has its own unique problems and restrictions that need to be addressed. The landowner is very enthusiastic about the rehabilitation of the wetland, and community involvement in the project. The understanding gained by the methods of this study, enabled the development of an appropriate rehabilitation plan, which could be utilised in other areas of the south west of Western Australia

Revegetating salt-affected land with shrubs

The establishment of salt-tolerant shrubs such as saltbush and bluebush on salt-affected land reduces the risk of soil erosion, and can also fit into farm programmes as a profitable enterprise. Salt-tolerant shrubs can be used as forage for sheep in summer and autumn, when the availability of annual pastures is low or annual pastures are just beginning to emerge. This article describes three methods for establishing shrubs on salt-affected land and what affects shrub establishment

EXTENT OF MINERALIZATION ORGANIC FERTILIZER ON SALT AFFECTED SOIL AND THAT IMPLEMENTATION ON TOMATO

Mineralization of organic fertilizers in saline soil is determined by the level of soil salinity. The higher levels of soil salinity, the lower the ability of organic matter mineralization. Evaluation mineralization levels assessed by the content of N, P, K, C-org in organic fertilizer. Research objectives were to assess the ability of the various formulas of mineralization of organic fertilizer to provide nutrients and suppress soil salinity. Nutritional NPK fertilizers are classified by grade. The results showed that the formula with high-grade organic fertilizer was obtained from a mixture of manure, compost, guano, and straw. High-grade organic fertilizer is not always effective as the controlling soil salinity and aggregate stability, but can increase the CEC and the availability of N, N Ammonium inhibits volatilization, decrese soil EC, but soil pH was increased. Mineralization rate of organic fertilizer on clay-textured soil (Rungkut and Sedati) more slowly than sandy soil (Buduran). Keywords: grade, mineralization, NPK, organic fertilizers, soil salinit

Reclamation of salt-affected land: A review

Reclamation of salt-affected soil has been identified by the FAO as being critical to meet the needs to increase agricultural productivity. This paper reviews commonly used reclamation methods for salt-affected soils, and provides critical identifiers for an effective reclamation practice of salt-affected soil. There are widely used methods to reduce salinity and sodicity of salt-affected soils, including salt leaching, addition of amendments, revegetation using halophytes and salt scrapping. Not all reclamation techniques are suitable for salt-affected land. The reclamation strategy must be tailored to the site, and based on understanding the soil, plant and climate interactions. On some occasions, a combination of techniques may be required for reclamation. This can include salt scrapping to remove salts from the surface soil, the addition of physical amendments to improve soil pore systems and enhance salt leaching, followed by amelioration of soil by chemical amendments to preserve soil physical conditions, and then halophyte establishment to expand the desalinization zone. This study reveals that soil hydro-geochemical models are effective predictive tools to ascertain the best reclamation practice tailored to salt-affected land. However, models need to be calibrated and validated to the conditions of the land before being applied as a tool to combat soil salinity

Why are Chloris gayana leaves shorter in salt-affected plants? Analyses in the elongation zone

Reduced hydraulic conductance calculated from growth data was suggested to be the main reason for reduced leaf expansion in salt-stressed Chloris gayana (Rhodes grass). In this work, xylem vessel cross-sections and wall enzyme activities were analysed to re-examine the effects of salinity on leaf growth in this species. Maximal segmental growth rates were 20% lower and the growth zone was 23% shorter in leaves from salinized plants than in controls; however, growth rates between 0 mm and 15 mm from the ligule were similar in both types of leaves. Xylem cross-sectional areas in this region were about 65% smaller in leaves of salinized plants, suggesting that hydraulic restrictions in the leaves of salinized plants were much higher than overall growth reductions. Extractable xyloglucan endotransglucosylase activity in this zone was twice as high in leaves of salinized plants as in leaves of controls. Nevertheless, the activity of the extracted enzyme was not affected by up to 1 M NaCl added to the reaction medium. Therefore, increased xyloglucan endotransglucosylase activity under salinity may be due to a promotion of transcription of XTH (xyloglucan endotransglucosylase/hydrolases) genes and/or translation of preformed transcripts. These results suggest that, as in drought stress, increased activity of cell wall enzymes associated with wall loosening may contribute to the maintenance of growth under saline conditions despite hydraulic restrictions.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Ortega, Leandro Ismael. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); ArgentinaFil: Fry, Stephen C. University of Edinburgh. Institute of Molecular Plant Sciences. The Edinburgh Cell Wall Group; Gran BretañaFil: Taleisnik, Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales (ex IFFIVE); Argentina

Plant cover for bare and salt affected land

The contributions made by this State to land reclamation were recognised at an international level last year. Mr. C. V. Malcolm, a research officer with the Soils Division, presented a paper entitled Establishing Shrubs in Saline Environments at a symposium on Useful Wildland Shrubs, Their Biology and Utilisation, at Utah State University, Logan, Utah. The conclusion to Mr. Malcolm\u27s review, set out below, summarises much of what is known about shrub establishment in saline areas