Сельское хозяйство/3. Земледелие, почвоведение и агрохимия

Candidate of agricultural sciences, Shilov M.P.,

2nd year student of ABF, Chervyak A.N.

RSE «Kostanai State University named after A.Baitursynov», Kazakhstan

THE DYNAMICS OF ADDITION DENSITY SOUTHERN BLACK SOILS OF NORTHERN KAZAKHSTAN.

Density of addition is a leading indicator of agro physical condition of soil, providing direct and indirect impact on many soil processes, and also on the growth, development and productivity of grain crops [1]. Parameters of density have for black soils of steppe zones, which define the conditions of accumulation, preservation and rational use of soil moisture [2]. That is why the constant control in the arid zone of is required for the formation and dynamics of soil bulk density.

Research works were on the southern black soil of Kostanay region on the level of crop rotation fallow (bare, seed) - spring wheat – spring wheat using different methods of main soil cultivation.

It was found that the southern chernozems of granulometric structure has the highest level of effective fertility with the density of the arable layer within 1,05-1,20 g/cm³ [3]. Creation and maintenance of an optimal addition is achieved by treating the soil. However, the choice of techniques and depth of processing depends on characteristics of each soil difference. They included the availability of the dense (1,47 g/cm³) illuvies horizon B₁ with sodium salt enriched silt particles (43 %), and also strongly carbonate horizon B₂ with volumetric mass of 1,52 g/cm³.

Research works showed that by the moment of planting of wheat the influence of steam predecessors on the average density of the layer of 0-30 cm was the same (table 1). Its values were within the optimal range and accounted for by personnel of the steam 1,13-1,19, the busy – 1,11-1.17 g/cm³. Some decrease in density is explained later in the duration of the main treatments (for a month). Reduction of the period of seal reduces the volume mass of the individual layers on 0,02-0,03 g/cm³.

Table 1
Density of the soils before planting wheat in connection with a variety of technologies fallow (average for the 2008-2012), g/cm³

Kind of fallow	Soil layer, cm							Average in the layer of 0-30 cm
	0-10		10-20		20-30		30-40
Loosening at 25-27 cm at the end of fallow (control)
Bare fallow	1,07	1,15		1,18		1,36		1,13
Seed fallow	1,05	1,12		1,16		1,35		1,11
Processing 10-12 cm at the end of fallow
Bare fallow	1,08	1,18		1,30		1,39		1,19
Seed fallow	1,05	1,17		1,29		1,40		1,17
Loosening at 20-22 cm at the end of fallow
Bare fallow	1,09	1,14		1,25		1,39		1,16
Seed fallow	1,06	1,12		1,24		1,41		1,14
Loosening racks "Paraplaw" on 33-35 cm at the end of fallow
Bare fallow	1,10	1,14		1,18		1,32		1,14
Seed fallow	1,07	1,11		1,15		1,30		1,11
Ploughing on 25-27 cm in the middle of fallow
Bare fallow	1,07	1,15		1,26		1,38		1,16
Seed fallow	1,06	1,14		1,25		1,40		1,15
LSD05	0,07	0,04		0,03		0,02		0,05

Density changes under the influence of techniques core processing were in full accordance with the above mentioned peculiarities of the black earth structure. Till the depth of 20-30 cm great differences were not found between them only in the layer of 10-20 cm on small loosening there some seal to 1,17-1,18 g/cm³ was mentioned. Differentiation of the methods of processing begins with depth illuvies horizon (20-30 cm). During loosening it remains out of reach, and its bulk density is larger than the upper limit of the optimal values - 1,29-1,30 g/cm³. Processing of 20-22 cm has similar situation although the magnitude of seals decreased on 0,05 g/cm³. Good degree of loosening achieved by deep tillage. On these versions of soil structure does not exceed acceptable levels and is within 1,15-1,18g/cm³. The postponement of the main processing to mid-fallow increases the time of shrinkage. Therefore, the variant with deep plowing in comparison with the autumn loosening at the same depth density increases to 0,08-0,09 g/cm³. This fact indicates the high ability of horizon to self condense horizon with sodium salt.

On the composition of the soil layer 30-40 cm from studied techniques processing racks of "Paraplaw" impacted at the depth of 33-35 cm. Some changes are observed on the variant with a deep loosening.

Methods effect of processing on the density of the arable layer is short-lived. By the end of vegetation differences between them are equal, and the equilibrium density indicates a strong soil compaction. The range of its changes during the period from sowing to harvesting reaches 0,22-0,30 g/cm³, or 17,5-25,0 % from the first initial level. Individual layers of arable horizon have the density is typical to the lower part of soil profile 10-20cm - 1,36-1,40, 20-30 cm – 1,45-1,50 g/cm³.

High degree of compaction of topsoil and the absence of the preceding treatments differentiate techniques autumn processing under repeated sowing of wheat (table 2).

Table 2

Soil density before the second wheat sowing after fallow in connection with autumn processing (average for the period 2009-2012)*, g/cm³

Treatment option	Soil layer, cm						Average in the layer 0-30 cm
	0-10		10-20			20-30
In a couple of subsurface cultivator loosening 25-27cm at the end of fallow (control)
1. Without processing		1,10		1,24	1,30		1,21
2. Subsurface cultivator on 10-12cm		1,09		1,17	1,28		1,18
3 Subsurface cultivator on 20-22cm см		1,07		1,14	1,23		1,15
In a couple of subsurface cultivator processing 10-12 cm
1. Without processing		1,11		1,25	1,32		1,23
2. Subsurface cultivator on 10-12 сm		1,07		1,19	1,30		1,19
3. Subsurface cultivator on 25-27 сm		1,08		1,12	1,17		1,12
In a couple of subsurface cultivator loosening 20-22 cm
1. Subsurface cultivator on 25-27 cm		1,05		1,13	1,16		1,11
2. Chisel cultivator on 25-25 cm		1,09		1,15	1,19		1,13
LSD05		0,08		0,04	0,03		0,05

Indicative variant is a "zero" option showing a weak ability of self- solidifying black soil with sodium salt. For the period of wheat sowing in 10-20 cm layer density exceeds the upper limit on 0,04-0,05 g/cm³, and increases to 1,30-1,32 g/cm³ in the lower part. Small processing i also saves lower overcrowded horizon and creates high density - 1,17-1,19 g/cm³ at the depth of 10-20 cm. Deep loosening forms the soil structure closer to optimum than the average processing does. It is noticeable in the whole horizon (1,12-1,14 g/cm³) and in its parts (20-30 cm). Some density increase at the depth of 20-30 cm loosening processing (0,03 g/cm³) was due to the design features inclined racks, not creating solid border pruning of the processed layer.

Thus, researched works revealed a high ability of solonetzic chernozems, for compacting of which the alternations of annual deep and medium treatments are necessary.

Literature
1. Medvedev V.V. Density of addition of soils (genetic, ecological and agronomic aspects) [Text] / V.V. Medvedev, I.E. Lydina, T.N. Laktionova. Kharkov : 2004.–244p.
2. Slesarev V.N. Agro-physical basis for improvement of the basic treatment of black soils of Western Siberia [Text] : Authoref. … doct. agricultural sciences: 06.01.01. Omsk, 1985. – 36p.
3. Zinchenko S.I. Agrophysical basis of soil efficiency processing of chernozems of Central Kazakhstan hills. Authoref. … doct. agricultural sciences: 06.01.01. Omsk, 2000. - 32 p.