Сельское хозяйство/3. Земледелие, грунтоведение и агрохимия

Candidate of agricultural sciences Shilov M.P., second year magistrand Zinchenko A.V.

RSE " Kostanai State University A.Baitursynov " Kazakhstan

The qualitative composition of humus and technologies resting dark chestnut soils

Preservation and restoration of soil fertility is the main task of the zonal system of agriculture. Along with the increase of humus content should also improve the quality of its staff. The most acute problem facing conservation farming in Northern Kazakhstan, where the saturation of crops, limited sources of humus and a high proportion of complete fallow in the structure of crop rotation substantially complicate the solution.

Of the whole complex of cultural practices to improve soil fertility, highlight the technology bastard fallow. Its use in combination with good moisture-accumulating activities, fertilizers and modern herbicides can significantly increase the productivity of crop rotation and the accumulation of organic matter in the soil zone.

The experiments were conducted in 2009-2012. On dark chestnut soils of Akmola region. We studied 4-dipole grain - fallow rotation with alternating crops: fallow (complete, bastard) - wheat - wheat - wheat. Crop rotation is mastered through time and space, the studies were carried out in the third rotation. Complete fallow preparing to area technology. In a bastard fallow, July 5-10, sown pea - oat mixture for green mass with the cleaning at the end of September. Methods main processing fallow field shown in Table 1 under the second and third blade loosening wheat conducted by 10 - 12 and 20 - 22 cm. Of fertilizer in the fallow field superphosphate applied at a dose of P₈₀ kg active ingredient on 1 ha, the first wheat on the background of the employed pair N₃₀P₂₀. Total humus was determined by the method of Tyurin, faction-group composition in the modification Ponomariova and Plotnikovoa. Experience laid in 4 replicates, soil samples were collected from 2 non-adjacent repetitions on all fields of crop rotation at the beginning and end of the rotation. The studies found that in a short period of time various technologies fallow had a marked influence on the mode of organic matter. So, the technology is complete fallow that promotes active mineralization and deep processing of post-harvest residues to finished products, significantly reduces the amount of substrate for humus formation. Against the background of a lack of energy material exposed to microbial decomposition and the actual soil humic substances. Under the subsequent crop rotation humification processes are unable to compensate for the current and initial (fallow), the loss of soil organic matter. So by the end of crop rotation with complete fallowgoing well pronounced negative balance of humus. During 4 years of its content in the plow layer is reduced by 0.12 - 0.18%, or 3.2 - 4.8% of the initial amount and the annual loss reaches 0.72 - 1.08 t/ha.

More efficient use of soil organic fund in the rotation with a busy ferry. The presence of technology will shorten the fallow fitoperiod unregulated mineralization and release to land cut - samle residues pea – oat mixture compensates for the loss of humus. Activation of microbiological activity under spring wheat is limited to organic matter decomposition of plant matter, actually humic substances are weakly affected. Therefore, mobilization of soil fertility is going on here in much smaller amounts than in the rotation with complete fallow. At the end of the rotation, the humus content is stabilized almost at baseline. His loss of topsoil was only 0.03 - 0.06%, while the annual rate of mineralization decreased by more than 2-3 times.

The tendency in the mode of organic matter is accompanied by changes in the structure and composition of humus (Table 1). Complete fallowtechnology reduces the amount of carbon cycle and mobilized as an energy material humus soil mix. First of all mineralization is exposed the most active and valuable part of the humus - humic acid. A one-way direction of the process of degradation is manifested in all variants of its basic processing.

Table 1

Physical and fractional composition of humus in the soil layer 0 - 20 cm, depending on the method of the vapor content and methods of its main processing, % *

View pair	The overall "C" in the soil	Humic acid				Fulvic acids (the sum of 4 fractions)	Fail hydrolyzable remainder	Сгк Сфк
		1	2	3	sum
Blade loosening by 25 - 27 cm at the end of the fallow (control)
Comlete fallow	2,10	0,16 7,62	0,50 23,81	0,14 6,67	0,80 38,09	0,46 21,91	0,84 40,0	1,74
Bastard fallow	2,16	0,20 9,26	0,53 24,54	0,13 6,02	0,86 39,81	0,47 21,76	0,83 38,43	1,83
Plowing at 25 - 27 cm in the middle of fallow
Comlete fallow	2,07	0,13 6,28	0,48 23,19	0,17 8,21	0,78 37,68	0,47 22,70	0,82 39,61	1,66
Bastard fallow	2,14	0,18 8,41	0,52 24,30	0,15 7,01	0,85 39,72	0,48 22,43	0,81 37,85	1,77

* numerator - the weight of the carbon content of the soil, the denominator - the total organic carbon of the soil.

Bastard fallow better preserves the mobile part of the organic matter and significantly improves the quality of humus. By the end of the rotation amount of humic acids than with complete fallow rotation average of 7.5 - 9.0% by weight of soil. In their structure increases the proportion of free humic acids and associated with moving a half oxides, and humic acids associated with calcium. The content of the first fraction increases more significantly, by 25.0 - 38.5%, the second increase is only about 6.0 - 8.3%. As a result, the ratio of carbon humic and fulvic acids expands from 1.66 - 1.74 to 1.77 - 1.83. The accumulation of brown and black humic acids should be considered not only as a source of nutrients, they play a decisive role in structuring soil, increase water-stable aggregates and improving its anti-erosion resistance.

Stable condition in experience was typical for the insoluble residue and the third fraction of humic acids strongly related to mineral soil. The inaccessibility of these compounds and the short period of studies limit their participation in the processes of mineralization and biological cycles. Amount of fulvic acid fractions also remained unchanged, but its persistence has been associated with the redistribution of carbon humic acids during their decomposition. Some of the differences in the content of humus components between the main methods of processing fallow predecessors explains the movement of individual layers of the arable layer in cultural plowing.

The investigations must be concluded that the bastard fallow provides for more favorable treatment of organic matter in the rotation. Reducing the period of complete fallow soil enrichment plant material, reducing its biogenesis can get virtually non-deficit balance of humus. Complete fallow technology results in mobilization of soil fertility with intense mineralization of organic matter of plant residues and humus compounds of the soil itself. As a result, reduces the amount of humus formation, reducing its content, quality deteriorates.