[Genesis and reclaiming of solonetz complexes]

The book reportes that there are more than 30 million hectares in the Russian Federation where solonetzic soils (SS) are either continuous or form mixtures with the zone soils within a mapping unit. About 20 million hectares of SS and complex soils have been introduced into intensive agricultural use during the past years. Ameliorated SS can produce 2-5 times higher yield than natural non-meliorated areas. Melioration costs have been compensated within 2-3 years, while the effect of amelioration can last more than 8-10 years. Nowadays the amelioration of complex chernozem or chesnut SS is almost stopped away. In agricultural use there are of about 10 million hectares of SS that requires the repeated amelioration. The present monography is summing up the results of the long-term investigations on the genesis, amelioration and cultivation of the SS. It is suggested that the genesis of SS and solonetzic horizons has been formed by the influence of exchangeable Mn, hydrophilic siliceous and complex organic-siliceous compounds. The new data is received that proves the high stability of soil colloids under the small amount of exchangeable sodium in the soil exchange complex. It is investigated that the mobile organic and non-organic hydrophilic and highly dispersed compounds of different origin play almost an important role in the SS genesis as the exchangeable sodium does. This phenomenon provides wide diversity of native SS . Natural zeolites improve ecological conditions of chemical amelioration being applied together with by-products such as phosphogypsum highly This can be due to the ability of natural zeolite to absorb some of heavy metals which have brought with phosphogypsum and thus reduce its content in soil solution and uptake by plants. Use of radioactive isotopes of Ca45 is very important when we want to estimate the effectiveness of different types of ameliorative cultivation practices. The evolution of both virgin and ameliorated SS is a subject of interesting discussion. In arid conditions characterized by warm and sunny climate the reclamation of SS should be economically effective unless water resources are easily accessible. In this case the partly amelioration of SS spots within complex soil areas should conduct before their irrigation