Productivity of mechanically disturbed soils and its relation with some abiotic factors

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Nizhny Novgorod State Agricultural Academy

Productivity of mechanically disturbed soils and its relation with some abiotic factors

Postgraduate student Shakhov S.S.

Doctor of Agricultural Sciences Titova V.I.

Abstract

This article examines the productivity of mechanically disturbed soils of main zonal types of Nizhny Novgorod region (sod-podzolic, light gray forest, podzolized chernozem ones). On the basis of the Pearson correlation coefficient, the effects of some abiotic factors (pH, the content of carbon, phosphorus, and potassium) on the white mustard's yield were found and analyzed for their relation with the value of the yield.

Keywords: mechanically disturbed soils, light gray forest soil, sod-podzolic soil, podzolized chernozem, productivity, correlation

Аннотация

В статье рассматривается продуктивность механически нарушенных почв основных зональных типов Нижегородской области (дерново-подзолистая, светло-серая лесная, чернозём оподзоленный). На основе коэффициента корреляции Пирсона найдена зависимость урожайности от некоторых абиотических факторов (реакция среды, содержание углерода, фосфора и калия) и определена степень их связи с величиной урожайности.

Ключевые слова: механически нарушенные почвы, светло-серая лесная почва, дерново-подзолистая почва, чернозём оподзоленный, продуктивность, корреляция

Intensive growth of anthropogenic load on natural objects around us, including the soil, increases every year, resulting in adverse effects such as degradation or complete destruction of the soil cover [2]. The soils that disturbed by the construction of various infrastructures needed to return to the original level of fertility of their arable layer and, sometimes, the whole soil profile [1]. In the Nizhny Novgorod region during the construction of pipelines, highways, power transmission lines, polygons, quarrying and other infrastructure annually getting mechanically broken about 14,000 hectares of agricultural lands. [3] For this reason, the problem of anthropogenic disturbance of lands and their recultivation is very urgent.

The productivity of such soils has been studied in a model vegetation-field trial on the zonal soils of the Nizhniy Novgorod region (sod-podzolic sandy loam soil, light-gray forest loamy soil, podzolized loamy chernozem soil), where in the process of modeling the soil of different degrees of disturbance were created with using of original undisturbed soil (variant 1, control ). Other options include mechanically disturbed soils in which the arable layer is mixed with the subsoil layers in proportions of 1: 1 and 1: 2 (variants 2 and 3, respectively). White mustard can be a good crop for these soils, cause it usually grows at a slightly acidic, poor soils, and its root secretions contribute to the increase of mobility of nutrients, enshrined in the soil.

Our findings about the yield of white mustard in a model vegetation-field trial on the mechanically disturbed soils indicate the adverse impact of anthropogenic factors on the soil productivity (table 1).

Table 1. Productivity of white mustard (Sinapis alba) on the mechanically disturbed soils

Note: ^* - the coefficient of variation,%; ^** - Range of feature oscillation, g / pot; ^*** - the average error of the mean and characteristic, g / pot. The amount of variation series -- 9.

The clear trend to a reduction in yields observed in all the studied soils after their mechanical disturbances, and the productivity of disturbed soils in all cases is inversely proportional to the degree of anthropogenic changes in them: the more soil is disturbed, the lower is yield of the crop. Yields on mechanically disturbed sod-podzolic sandy loam soil in variants with a ratio of arable layer to the subsurface of 1: 1 and 1: 2 were 89% and 75% of yield on control one, on light gray forest loamy soil - 92% and 78%, on podzolized chernozem loamy soil - 88% and 76%, respectively. disturbed soil productivity abiotic

Based on the determination of the physico-chemical and agrochemical characteristics, it can be argued that the main factors, limiting the productivity of mechanically disturbed soils, are nutrient content and soil pH. The content of biogenic elements will directly affect the quality and quantity of production, while the pH value will determine the level of favorable conditions for the growth of crop.

To evaluate the relation of yield of these soils with the value of pH and the content of nutrients in the soil we used a linear correlation coefficient (or Pearson's correlation coefficient), which characterizes the degree of linear dependence between the variables. The resulting correlation coefficients are given in Table 2.

Table 2. The correlation coefficients of white mustard yield and some abiotic environmental factors during mechanical disturbance

After analysis of the correlation coefficients, we can conclude that our assumption about the direct impact of the deterioration of agrochemical and physico-chemical factors on the productivity of mechanically disturbed soil is right. The only dropping out of the general trend factor is mobile phosphorus content during process of soil disturbance: the smallest in absolute values of all other ones, it is less likely is directly related with the level of productivity, and the negative sign of the value indicates an inverse connection between the content of mobile phosphorus and reduction of yields. This, however, may be due to significant fluctuations in the levels of phosphorus in the various layers of the original sod-podzolic soil. In other cases, there is a direct, close to functional, dependence of productivity from degradation of abiotic factors, and by the numerical values we can be find limiting ones. For the sod-podzolic soil after its disturbance the limiting factor is the carbon content, for light gray forest soils and podzolized chernozem soil - content of mobile phosphorus.

Thus, the productivity of mechanically disturbed soils is lower compared with stable agrobiocenoses, and all the negative consequences of the degradation of the soil profile, such as changing the physical, chemical and agrochemical properties, would adversely affect the yield of crops. In this study, given that the during mechanical soil disturbance the significant part of their potential productivity is lost, the crop yields can be regarded as one of the objects of agricultural land monitoring.

References

1. Dabahova E.V. Assessing the impact of the work on laying the main pipeline on the properties of the soil / Dabahova E.V., Pyatakov L.P., Vetchinnikov A.A. // Proceedings of the V All-Russian Congress. Soil Science Society of V.V. Dokuchaev. - Rostov-on-Don, 2008. - P. 465.

2. Dashkovsky I. Progress of degradation // Farming equipment and technologies: the Internet magazine. 2009. №1. URL: http://www.agroinvestor.ru/technologies/article/14825-progress-degradatsii/(the date of usage: 08/26/2015)

3. Titova V.I. Influence of construction and repair work on the pipeline in the ecological and agrochemical characteristics of the soil / V.I. Titova, A.A. Vetchinnikov // Agrochemical Gazette. - 2009. - № 2. - . P. 13-15.

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