RELATIONSHIP BETWEEN SOYBEAN VARIETIES, SPAD502 CHLOROPHYLL METER READINGS, AND RHIZOBIA INOCULATION IN WESTERN SIBERIA - Ecological Consequences of Increasing Crop Productivity - page 91

been the scene of recent large-scale agricultural change [10]. Abandonment of arable
land and changes in the use of permanent grasslands were triggered by the dissolution
of the Soviet Union in 1991 and the following collapse of the state farm system. The
peatlands, forests, and steppe soils of Western Siberia are one of the most important
carbon sinks worldwide [11]. These carbon stocks are, if deteriorated, an important
source of radioactive forcing even in comparison to anthropogenic emissions. This
situation is aggravated by recent and future developments in agricultural land use in
the southern part of Western Siberia. The increase of drought risk in the steppe zone of
Northern Kazakhstan and Southern Siberia will trigger a northward shift of the West
Siberian grain belt into the forest steppe and pre-taiga zone. In conjunction with cli-
mate change, agricultural expansion, and intensification in these regions will increase
the threat of large-scale release of greenhouse gases from reclaimed peat areas.
SASCHA aims to provide management practices to cope with these far-reaching
changes. In particular, as farm-scale strategies are being developed for increased ef-
fi ciencies in crop production systems.

10.3 MATERIALS AND METHODOLOGY
A field trial with soybean varieties from Germany and Siberia was established at the
experimental site “Lake Kuchak” of Tyumen State University in Western Siberia
(57°20'56”N, 66°3'24”E) in May 2013 (Figure 10.2).

FIGURE 10.2 Experimental station “Lake Kuchak”/Tyumen State University in Tyumen/

Western Siberia.

Kuchak shows continental climate with a mean min/max temperature of −2.9/6.9 ° C
(range from −42 to 38 ° C) and yearly average precipitation of 450 mm. The experimen-
tal site (podsolic soil) was irrigated during the trials as required.
Two early/very early varieties from Germany (Augusta, Aveline) and one regional
Siberian (Sibniik315) were grown in completely randomized block design with four
repetitions in two variants: with and without B. japonicum inoculation. The treatment