The activity of cellulolitic microorganisms in sod-podzolic soil in crop rotation
Vladykina N.I., PhD, head of sector
The Udmurt Agricultural Research Institute, Pervomajskij, Russia
The analysis of the biological activity of sod-podzolic soil in the third biologizing rotation (2004-2012) was held. At the beginning of rotation the content of humus and nutrients are increased, the soil became more acidic; types of fallow have differences. Two-factor experiment showed that the use of pure fallow with manuring increases the activity of cellulolytic microorganisms to 8.7 and 10.6% (least significant difference = 2.2) at the beginning of crop rotation in comparison with the control without manure (6.4%). In rotation with full fallow it was significant declines by 4.8 % (up to 1.6%). Our studies have shown that favorable conditions for the decomposition of cellulose in this rotation formed only at the end of crop rotation, thereby increasing the yield of only three of its past crops. There was a high correlation of yield from cellulose decomposition intensity (r = 0.75 and r = 0.80). Joint use of straw and manure (10 t/ha of crop rotation area) in a pure fallow optimizes soil biological activity, thereby enabling maintain soil fertility and receive consistently high crop yields throughout the rotation. Replacing the annual plowing to the annual moldboardless or shallow soil cultivation in crop rotation reduces soil biological activity (34.4%, respectively, 27.9% and 30.0 % at the least significant difference = 4.2) due to compaction of the lower layer 10-20 cm and plowing layer in general. Combined small-moldboard tillage system provides bulk density of topsoil (1.34 g/cm3), and biological activity (31.4%) at the level of plowing (1.33 g/cm3 and 34.4%).
Keywords: fallow (pure, green-manure, full), manure, straw, plowing, shallow cultivation, moldboard less, combined, biological activity, compaction of soil layer, yield