Influence of Land Use on the Physical Properties of Chernozems in the Forest-Steppe Zone of Western Siberia

Eurasian Soil Science - The land use type and agricultural practices significantly affect the aggregate state and many physical properties of soils. In this study, we provide a comparative...     

Optimizing the phosphate level of soils in agroecosystems of opolie regions of Central Russia

The regularities of the effectiveness of systematic application of phosphorus fertilzer in various types of crop rotations have been studied in long-term permanent field experiments on gray forest soils of opolie regions of Central Russia. The main factors determining the degree of use by crops of freshly applied and residual phosphates—the level of phosphorus fertilizer in agroecosystems, nitrogen supply of crops, and characteristics of phosphorus nutrition of the crops being grown—have been established. Depending on the character of interaction of these factors, crops over the course of 9 to 23 years have utilized 12–88% of applied fertilizer.     

Dynamics of Soil Properties and Plant Composition during Postagrogenic Evolution in Different Bioclimatic Zones

The postagrogenic dynamics of acidity and some parameters of humus status have been studied in relation to the restoration of zonal vegetation in southern taiga (podzolic and soddy-podzolic soils (Retisols)), coniferous-broadleaved (subtaiga) forest (gray forest soil (Luvic Phaeozem)), and forest-steppe (gray forest soil (Haplic Phaeozem)) subzones. The most significant transformation of the studied properties of soils under changing vegetation has been revealed for poor sandy soils of southern taiga. The degree of changes in the content and stocks of organic carbon, the enrichment of humus in nitrogen, and acidity in the 0- to 20-cm soil layer during the postagrogenic evolution decreases from north to south. The adequate reflection of soil physicochemical properties in changes of plant cover is determined by the climatic zone and the land use pattern. A correlation between the changes in the soil acidity and the portion of acidophilic species in the plant cover is revealed for the southern taiga subzone. A positive relationship is found between the content of organic carbon and the share of species preferring humus-rich soils in the forest-steppe zone.     

Nitrogen budget in agroecosystems on gray forest soils under long-term fertilization

Long-term stationary field experiments were performed to study the efficiency of increased rates of nitrogen fertilizer in crop rotations with cereal crops, perennial grasses, clover, and plow fallow on gray forest soils. It was found that an excess of mineral nitrogen (mainly of nitrates) accumulated in the soil in the case of unbalanced nitrogen fertilization and long-term fallowing creates conditions for the development of unfavorable processes in the nitrogen cycle. Significantly increasing nitrogen losses from the agroecosystem because of leaching and denitrification constitute a depletion hazard for the soil nitrogen pool.     

Ecological and agrochemical aspects of the balanced use of nitrogen fertilizers on gray forest soils of the opolye in Central Russia

As a result of long-term permanent field experiments, it is suggested that one of the criteria of a efficient level of using and providing a highly effective, ecologically balanced action of nitrogen fertilizers on gray forest soils of the opolye is that the amount of applied nitrogen taken up by rotation crops should be commensurate with the amount of this nutrient element used by plants due to mobilization of soil reserves.     

Phosphorus in agroecosystems on gray forest soils in the opolie regions of Central Russia

Long-term stationary field experiments revealed a poor supply of gray forest soils with available phosphorus, which provides no more than half the amount necessary for optimum nutrition of plants. It was found that agricultural crops with different capacities to assimilate phosphates from the soil and fertilizers have strong requirements for phosphorus fertilizers and abruptly increase their utilization in the production process with increasing level of nitrogen nutrition. Crops with the optimum level of nitrogen nutrition uptake a double amount of phosphorus compared to crops depleted in nitrogen. Clover and barley have an increased capacity to mobilize soil phosphates from the lower horizons at an extremely low content of available forms of them in the plow layer. Winter wheat and corn are characterized by an active uptake of phosphorus applied with fertilizer and its efficient utilization in the production process if the nitrogen supply is not a limiting factor. The level of phosphorus nutrition of subsequent rotation crops increases due to the enrichment of the root-inhabited soil layer with phosphorus from clover root and harvest residues. Based on the data about the unacceptably abrupt decrease in the application of mineral fertilizers in Russian agriculture (90% of fertilizers are exported now), it is shown that the export of fertilizers should be limited at the state level, because chemicals, and primarily phosphorus fertilizers, should be considered strategic resources for internal use only.     

The Dynamics of Carbon Pools and Biological Activity of Retic Albic Podzols in Southern Taiga during the Postagrogenic Evolution

Eurasian Soil Science - The succession of natural vegetation on the former arable soils triggers the processes of postagrogenic restoration of soil ecological functions specific of a particular...     

Changes in the Carbon Stocks,Microbial and Enzyme Activities of Retic Albic Podzol in Southern Taiga during Postagrogenic Evolution

Eurasian Soil Science - Soil organic matter largely controls the ecosystem functions of soil and is a source of energy and a nutrient substrate for the soil microbial community as well. The...