Terms of sowing forage crops for haylage production under the conditions of Central Yakutia

In recent years the agricultural production in the Republic of Sakha (Yakutia) has been introducing the technology of haylage production, which can replace part of the silage and hay in the ration of animals. However, stable raw materials of herbage are not enough for the technology of haylage production in Yakutia. Natural forage lands cannot provide a new technology of haylage production with herbage, since the entire area of haymaking goes to hay harvesting. Therefore, the selection of forage crops to create a reliable raw material base for haylage is a very relevant research topic. The purpose of the research was to study the terms of sowing forage crops for haylage production under the conditions in the Central Yakutia. The research has been carried out in the research and production permanent out-station in the M. G. Safronov Yakut Scientifi c Research Institute of Agriculture for three years. The experimental site was located on the second above-fl oodplain terrace of the Lena River Valley. The objects of research were the following varieties of zoned annual crops – oats of Pokrovsky variety 9, peas of Capital variety, spring vetch of Priobskaya variety 25, barley of Tammy variety. It has been found as a result of research that in the soil and climatic conditions in the Central Yakutia for the production of haylage for plant growth and development, dynamics of accumulation of dry matter, yield and nutritional qualities, the most effective mixtures are: vetch (1,2 million pcs/ha) + oats (2,5 million pcs/ha) and peas (0,8 million pcs/ha) + oats (2,5 million pcs/ha) germinating seeds. As the result of the conducted research, the optimal terms for sowing annual grasses for haylage have been established such as the 1st term (sowing in the third decade of May, harvesting in the first decade of August), the 2nd term (sowing in the second decade of June, harvesting in the third decade of August), the 3rd term (sowing in the first decade of July, harvesting in the first decade of September) in the phase of milk-wax ripeness in cereals and in the phase of fruit formation in legumes.

Thermokarst Landscape Development Detected by Multiple-Geospatial Data in Churapcha, Eastern Siberia

Thermokarst is a typical process that indicates widespread permafrost degradation in yedoma landscapes. The Lena-Aldan interfluvial area in Central Yakutia in eastern Siberia is now facing extensive landscape changes with surface subsidence due to thermokarst development during the past few decades. To clarify the spatial extent and rate of subsidence, multiple spatial datasets, including GIS and remote sensing observations, were used to analyze the Churapcha rural locality, which has a typical yedoma landscape in Central Yakutia. Land cover classification maps for 1945 and 2009 provide basic information on anthropogenic disturbance to the natural landscape of boreal forest and dry grassland. Interferometric synthetic aperture radar (InSAR) with ALOS-2/PALSAR-2 data revealed activated surface subsidence of 2 cm/yr in the disturbed area, comprising mainly abandoned agricultural fields. Remote sensing with an unmanned aerial system also provided high-resolution information on polygonal relief formed by thermokarst development at a disused airfield where InSAR analysis exhibited extensive subsidence. It is worth noting that some historically deforested areas have likely recovered to the original landscape without further thermokarst development. Spatial information on historical land-use change is helpful because most areas with thermokarst development correspond to locations where land was used by humans in the past. Going forward, the integrated analysis of geospatial information will be essential for assessing permafrost degradation.

Cryosols from Tundra and Taiga Zones of Yakutia: Properties, Clay Mineralogy, and Problems of Classification

Abstract— Data on major properties and clay mineralogy in the profiles of slightly differentiated Cryosols forming in cold ultracontinental climate of Yakutia are discussed. The particular objects are represented by the cryozems of tundra, forest-tundra, and northern taiga of the Anabar and Alazeya plateaus and by the palevaya (pale) soil of middle taiga in Central Yakutia. The differentiation of clay minerals in the vertical soil profiles is poorly pronounced because of the strong homogenizing impact of cryoturbation processes. The profile of pale soil displays minor differences in clay mineralogy despite the strong difference in acid–base conditions of the upper and lower horizons. However, the obtained data suggest that mineral weathering in pale soils of Central Yakutia is more advanced than it was concluded in the 1970s on the basis of data on the absence of pronounced trends in the vertical distribution of clay minerals in their profiles. This is in good agreement with the presence of a sufficiently thick upper humus horizon in these soils, which is typical of the soils of more humid regions. It is suggested that pale soils of Central Yakutia should be classified as soddy pale soils.

THE EFFECT OF ALFALFA INOCULATION BY NODULE BACTERIA STRAINS ON HE AGROCHEMICAL COMPOSITION OF PERMAFROST SOILS OF CENTRAL YAKUTIA

The long-term experimental data of studies on the influence of nodule bacteria strains on alfalfa yield, improving the quality of the resulting product, increasing agrochemical indicators of permafrost soils of Central Yakutia are presented.

Influence of Rainfall Changes on the Temperature Regime of Permafrost in Central Yakutia

Climate change effects, such as melting of glaciers and sea ice in response to rising temperatures, may lead to an increase in global water availability and thus in precipitation. In Central Yakutia, as one of the possible options for climate change, an increase in rainfall is possible, which makes up more than 60% of the annual precipitation. Rainfall is a highly variable meteorological parameter both spatially and temporally. In order to assess its effect on the ground temperature regime in Central Yakutia, we conducted manipulation and numerical experiments with increased rainfall. The manipulation experiment results suggest that a significant (three-fold) increase in rainfall can lower the mean annual ground temperatures locally. The long-term simulation predicts that a 50% increase in rainfall would have a warming effect on the ground thermal regime on a regional scale. For Central Yakutia, infiltration of increased precipitation has been shown to have both warming and cooling effect depending on the area affected.