Peculiarities of plantation forestry on dried peat-steppes of the Forest-Steppe of Ukraine and its impact on soil

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Panfyly research station of the NSC «Institute of agriculture of the NAAS»

Peculiarities of plantation forestry on dried peat-steppes of the Forest-Steppe of Ukraine and its impact on soil

Panfily

Abstract

afforestation peat bog woody soil

Goal. To determine the most adapted wood breeds for plantation afforestation of different function in the conditions of drained peatlands of the Forest-Steppe. To study the peculiarities of growth and development of newly created forest crops in specific conditions of organogenic soils. To determine the influence of afforestation on the change of water-physical properties of drained organogenic soils. Methods. General scientific (hypotheses, inductions and deductions, analogies, generalizations) and special (field, laboratory, mathematical, statistical, computational) - for research and their generalization. Results. The best indicators of productivity in these conditions were shown by tree and bush willows, black poplar, sticky alder, and hybrids of Euro - American poplars. The optimal length of unrooted cuttings for the creation of energy plantations was 25 cm. For afforestation of black alder on drained organogenic soils, it is advisable to create forest crops with seedlings 1.0 - 1.2 m high according to the scheme 3.0x1.0 m, which ensures survival at the level of 98%. Over the last 52 years, the density of peat in the upper layer (0 - 30 cm) in the forest stand has not changed (the difference is 3%), while in the lower layers it has increased by 18 - 20%, but the soil density remains low (average 0.250 g/cm3) and high total moisture content (345%). The decrease in soil mineralization in forest stands compared to hayfields indicates a slowdown in the decomposition of peat organic matter under the forest, which is important for the preservation of peatlands. After the cycle of plantation afforestation, re-agricultural use of lands with improved water-physical properties of the soil is possible. Conclusions. The creation of forest plantations on drained organogenic soils is quite possible and expedient. With the use of different species composition and changes in planting density, you can create plantations of tree crops for different purposes. The highest indicators of productivity in these conditions had tree and bush willows, black poplar, alder sticky and hybrids of Euro-American poplars.

Key words: tree plantations, survival, growth, potash fertilizer, biological activity, water-physical properties.

Main part

One of the main tasks of drainage reclamation was and remains the expansion of areas for agricultural production. Today, the most appropriate is the use of these lands as a fodder base for livestock with a priority for growing perennial grasses. However, the weak economic condition of rural communities that have drained peatlands does not allow for productive use of these lands with a significant reduction in livestock, and to carry out timely repairs and modernization of the drainage network. This leads to overgrowing of weeds, unproductive loss of organic matter of peat, increasing the risk of fires.

On the other hand, there are powerful farms that use drained peatlands and appropriate technical and financial resources and can sow high-yielding and profitable row crops using chemicals. This, in turn, accelerates the mineralization of peat, often leads to wind erosion, increases the level of pollution of groundwater and, consequently, other reservoirs. Therefore, the introduction of technologies that minimize the impact on the environment and bring anthropogenically developed area to natural ecosystems is relevant for management of drained organogenic soils, which have already significantly changed their condition due to land reclamation.

In this regard, one of the possible ways to improve the situation is to grow tree plantations for various purposes, primarily for the rapid production of wood. It should be noted that research on afforestation in drained peatlands was conducted mainly on upland swamps (Karelia, the Baltic States, Belarus), and they concerned the creation of forests on newly drained lands. Studies of the peculiarities of afforestation in the old arable carbonate peatlands of the Forest-Steppe of Ukraine were carried out in a limited volume, moreover, without sufficient scientific substantiation. However, the specific conditions of drained peatlands, namely: relatively high groundwater levels, specific water-physical and agrochemical soil conditions, high competition with natural vegetation, slightly different temperatures and reduced growing season, require special selection of crops [1 - 7].

A significant advantage of plantation afforestation on organogenic soils is earlier maturity, compared with similar plantations on rich mineral, naturally drained soils of land [8]. This is best in line with the idea of creating tree plantations, as in accordance with DSTu 2980-95 «Forest crops. Terms and definitions «[9], plantation forest crops are forest crops with accelerated plant growth, created to reduce the time of growing special forest products of high quality. The main purpose of forest plantations is to obtain the maximum number of products per unit area.

As potentially fertile, but excessively moist, peat bogs belong to the subtree trophotopes - C. Prior to drainage, woody vegetation was represented mainly by small forests of alder and birch, in the second tier dominated by shrub species of willows, buckthorn, rarely hazel. The degree of coverage of the territory reached 40% [10]. After drainage, the hygrotopes changed to wet - 4 and wet - 3, and soil fertility, due to mineralization of organic matter and long-term agricultural use, increased to dibrovnyh conditions - D.

Such conditions are optimal for growing plantations of fast-growing species, namely poplar, willow, black alder.

The purpose of research. Install the most suitable wood species for plantation afforestation for various purposes in the conditions of drained peatlands of the Forest-Steppe. Investigate the features of growth and development of newly created forest crops in specific conditions of organogenic soils. To study the influence of tree plantations on the main water-physical properties of the drained peat bog. Assess the possibilities of further agricultural use of lands after the cycle of plantation afforestation.

Materials and methods of research. Research on forest management of drained peatlands was conducted by the Panphilic Research Station of the NSC «Institute of Agriculture NAAS» in 2005-2011. In the following years, research was conducted on the species composition of trees and shrubs, the optimal agricultural techniques for creating plantations were determined, and the effect of potash fertilizers on forest crops was studied.

The soil of the experimental plots is characterized by the following indicators: carbonate soil (37 - 49%), water pH 7.3 - 7.8, depth of peat 3 - 4 m, decomposition of peat in the arable layer 65 - 70%, bulk density 0.375 - 0.435 g / cm3, ash content 39 - 57%, gross nitrogen content 1.57 - 1.89%, phosphorus 0.45 - 0.76%, potassium 0.09 - 0.12%.

The intensity of CO2 release was determined by the method of B, I, Shtatnov, and the cellulose-destroying activity of the microflora by the method of applications. Water-physical characteristics of the soil were determined by generally accepted methods in agronomy. Statistical processing was carried out according to the «Methods of field experience (with the basics of statistical processing of research results)» edited by BA Armored.

Research results. The main factor that determines the ability of wood species to grow and develop on drained lands is their biological adaptation to conditions of excessive humidity, when the groundwater level even in the summer months is 60-120 cm (Table 1), and in the cold season fluctuates within 10-45 cm from the soil surface. It is also important to take into account the specifics of carbonate peatlands, namely the alkaline reaction of the soil solution (pH> 7.0), and the lack of one of the main nutrients - potassium.

Groundwater level, cm from the soil surface, cm