The article considers the history of the work of the Dokuchaev Soil Science Institute researchers in Uzbekistan, conducted jointly with soil scientists from Uzbekistan. These works were started in 1930–1940s. They were especially active during the Great Patriotic War, when the Soil Institute was evacuated to Tashkent. During these years, both Russian and Uzbek soil scientists participated in joint work. Outstanding scientists can be named among Russian researchers: V.A. Kovda, A.A. Rode, A.N. Rozanov and many others who contributed to the study of Uzbekistan soils. The work of the researchers from the Dokuchaev Soil Science Institute, performed on the basis of a station in the Hungry Steppe (Mirzacho'l) in connection with the development of saline lands during the creation of new irrigation systems in Central Asia, is analyzed in particular detail. Various work areas of the station researchers are discussed in the article: issues of ameliorative development of saline soils, salinity mapping based on remote sensing methods, detailed study of the reclaimed soils properties using chemical, micromorphological, mineralogical and other research methods for the determination of salinity and gypsum content of soils in the New Irrigation Zone (NIZ) of Hungry and Jizzakh steppes. The results of the work were presented in a series of publications. In the 1990s, cooperation was temporarily ceased, but at the beginning of the 21st century it was resumed.

The year 2021 is marked by the 175-th anniversary of the birth of Anna Egorovna and Vasiliy Vasilievich Dokuchaevs. This is a wonderful occasion to recall an amazing and remarkably modest woman who played an important role in the life and work of the great Russian natural scientist, the founder of genetic soil science. If many works were written about her outstanding world-wide known husband, films were made, pictures were created, his photos are preserved, then the life of his wife is undeservingly poorly described, and the appearance of this very beautiful woman is depicted in the only one famous portrait. This article, dedicated to the memory of Anna Egorovna Dokuchaeva, is based on both the quotations from the already published memoirs of the follower and the friend of V.V. Dokuchaev – Franz Yulievich Levinson-Lessing, and the excerpts from Anna Egorovna’s letters to Varvara Ippolitovna – the wife of F.Yu. Levinson-Lessing. These letters were collected from the archives of the Academy of Sciences in St. Petersburg and copied by the employee of the V.V. Dokuchaev Soil Science Institute – Sergey Petrovich Lyalin – in the 1980s, and they are now kindly provided by the Central Soil Museum by V.V. Dokuchaev (the Branch of the Federal Research Centre “V.V. Dokuchaev Soil Science Institute” in St. Petersburg).

The analysis of long-term observations in the Kamennaya Steppe (over 125 years) for climatic parameters (air temperature and precipitation), ground water level, vegetation species composition revealed the main trends in their variability. Since 1969 there has been an increase in temperature and a reduction in temperature fluctuation during the year. Over the last 30 years, the difference has reached 1.90, and over the last decade it has grown by 0.40 due to the cold season. The amount of precipitation over the same 50-year period has not changed much. In total, an increase of 45 mm was observed over the decade (1999-2008). In the XXI century, there has been registered an increase in the amount of precipitation in the cold season by 12.7% and a decrease in the warm season, which creates certain prerequisites for climate continentality mitigation during the annual cycle. During the first 70 years of observations, the groundwater level in the well No. 1 was on average at the depth of 6.5 m (5.7-7.3 m). At the end of the XX century and at the beginning of the XXI century, there was marked a pronounced rise in the ground water level, the average depth was 3.8 m, which coincided with the growth of average annual temperature and an increase in total rainfall. In this period changes in the long-term regime of ground and surface soil moisture resultedin expanding the area of wetlands and hydromorphic soils on the territory of the steppe. The period of 2009-2018 is characterized by a continued increase in average annual temperatures and a decrease in precipitation, which may lead to a seasonal change in temperature and precipitation to milder and wetter winters and warmer and drier summers. Transformation of vegetation for 100 years of observations had several stages with a general trend to change the steppe grasslands to meadow-steppe, shrubs and woody species.