Large-scale land improvement by hydraulic engineering in the USSR has received a rank of an internal state policy major direction in 1966 after the decision of the CPSU Central Committee Plenums in May of 1966 and USSR «On land reclamation wide development for grain and other cultures high and steady yields achieving» Council of Ministers Decision on June, 16th, 1966.The reasons of the specified program acceptance in the USSR are considered, the meliorative construction and reconstruction of meliorative systems rates analysis for 1966-2004 is presented. The basic drawbacks, the problems encountered in land improvement and use of the reclaimed grounds are described in detail; the reasons of their occurrence and elimination ways, together with the land reclamation efficiency increase in Belarus ways are specified in the article. The nonprofessional conclusions criticism and recommendations on the drained agricultural grounds bogging is given. In opinion of the author, a key to the problems decision in the field of land improvement efficiency increase is in a high standard of farming on the basis of scientifically proved recommendations coordinated to the objects specific existing condition.

The text of 1892 year published book about the Polesye first mass drainage is presented. In 1873-1892 general-lieutenant Zhilinsky supervised over the expedition which fulfilled researches on Polesye of topographical, hydrometric and geological characteristics studying and has carried out the first mass drainage of this territory.The author characterizes the adverse conditions existed owing to the region significant marshiness prior to the drainage beginning in 19 century. Fulfilled by the expedition researches and the inspections results have shown, that Polesye drainage problem consist in new ways for the waters which are not holding in inflows of Pripyat natural channels drainforming by directing the surplus of water to the places where there is its lack, i.e. where it should be necessary to establish more correct waters distribution and movement in the area of Pripyat pool. The job executed by expedition results are summed up in the book; not only economic gains from Polesye bogs drainage (water drain) are described in detail, but also significant social and ecological population life conditions improvements are shown.

The article is devoted to the water current flows, speeds and depths definition way on crests of protections and inside the polder, based upon the water balance equations joint decision in polder, a chronological course of water levels in a high water, and the flow of waters flowing through all the elements of protections. Calculation of these characteristics (flows of water, speeds and depths) enables to determine the sites of a dam most dangerous in spite of polder washout and to fulfill its strengthening.The description of the streams flowing through the flooded older at passage of a spring high water dynamics is presented. The solution for water flows and speeds definition on crests of protective dams and spillways - slots in view of high water development character, polder design, and flowing over through the elements crests conditions is given. Water current through the longitudinal dam details, consisting in the fact that there is water inflow through its top part, and water outflow through the bottom for variable pressures on length and on a high water development time are considered in the solution. Underflooded and on some sites ununderflooded current can occur on each of these parts of a longitudinal dam. Dependences for conditions and current flows determining through the sites of a longitudinal dam are given. The dependences developed allow to calculate by means of the differential equations decision approximate ways the speeds dynamics on crests of spillways - slots and flooded dams taking into account the regime of a high water.

The problem of subsoil waters levels position optimization at drying-and-moistening meliorativesystems water regime regulation sites is considered for not leveled relief. The technique for the surface of ground settlement mark definition with respect to which subsoil waters levels maintenance in optimum limits reduces to a minimum an agricultural crops production shortage on the raised and lowered elements of a relief is developed. Character of a relief is taken into considered by means of the mark of a surface average weighted by the area deviation of the site from minimal. The simple approximated way of a settlement mark determining for a surface of ground is presented. Numerical experiment has shown, that surface of ground settlement mark depends on the character of a relief, does not depend on cultures grown up and can be accepted approximately identical for various cultures.

Researches analysis results for meliorative systems channels spending network transformation are presented. On the basis of the analysis sites it is proposed to divide all channel sections, being in unsatisfactory condition, into three types. Each of types is characterized by identical kinds of washout or silting deformations and identical types of channel forming process. As threshold limits, safe regarding the condition of channel deformations development in the open spending network, it is offered to accept the characteristic stages of deposits movement for each of three water-currents categories, grouped by the use and calculated flows passing hydraulic mode. According to the presented ordering base positions of actions appointmentf on channel and hydraulic regimes for water intaking rivers and spending channels management and concrete actions on their regulation are offered.

Calculated dependences for equilibrium quantitative estimation in a zone of drained grounds aeration are presented. The dependences developed allow to describe precisely enough equilibrium water content pattern diagram for the most of the reclaimed grounds, of Byelorussian territory. The offered form water content pattern diagram corresponds to the model of ground in the form of parallel capillaries with the radiuses changing according to Veibull distribution system. The optimum levels of subsoil waters on the reclaimed grounds design procedure is stated.

Herbivorous fishes cultivation possesses high economic and ecological efficiency at the decision of hydromeliorative systems ponds and channels overgrowing with water vegetation problem elimination. White amour, white and motley silver carp are potentially suitable for cultivation with such a purpose. Conditions necessary for these fishes normal ability to live description is presented in the article. Experience of herbivorous fishes use with a purpose of struggle against water vegetation in the hydromeliorative systems open channels, as important factor of their constant working capacity maintenance alongside with commodity fish production is analysed. Specific proposals regarding a necessary complex of research and developmental jobs carrying out for this problem solution in conditions of Belarus and its Polesye zone are stated in particular.

Authors have set as the purpose as much as possible to unify the objects designing methodology on the basis of flat depressions typification at meliorative systems on the reclaimed mineral grounds in conditions of limnetic-glacial landscapes reconstruction and restoration. On the basis of the information analysis of on soil, geomorphological and hydro-geological conditions of flat depressions formation in low limnetic-glacial landscapes on the reclaimed mineral grounds the principles of its typification are offered, dominant signs for each type of flat depressions are established. Proposed flat depressions typification has multilevel structure and includes the following descriptions: for landscape areas, types of the grounds, meliorative objects, land tenure optimization fields, flat depressions. Each level has the specific information content which can be presented in the form of the verbal or numerical characteristic and coded.

The question of boggy territories grounds properties parameters determining ways improvement has got an urgency now. The dependences establishing connection between physical properties specific parameters and grounds structure that allows to reduce the quantity of parameters directly determined in laboratory conditions and to determine it by calculations are presented in the article. The results obtained are intended for the grounds properties determining in engineering-and-geological researches for meliorative and water economy construction. Its application provides the substantiated and economic engineering decisions acceptance at designing stage.

The technique of peat soils structure density estimation is offered for various ash content at dynamic loading action. Peat and the mineral residual with already known physicomechanical characteristics is discriminated in the soil structure when considering its structure. In field conditions the estimation of energy expenses for ground compression by machines and mechanisms is based on an assumption, that chemical energy of fuel will be transformed in mechanical energy. It is proposed to predict the density of ground structure on the basis of a ground compression power intensities ratio in field and laboratory conditions determining results.

Value of influence of variability of weather conditions on fluctuations of a crop of agricultural crops is certain. The analysis of available publications and results according to influence of factors on productivity of agricultural crops is resulted. Methods of forecasts of the productivity, applied in republic now are described. It is necessary to develop stage-by-stage model of the account of influence of factors which would add kinds of forecasts applied in republic for specification of applied methods of forecasts. In clause laws of influence of meteorological conditions on process of growth and development of plants are described. That duration of the vegetative period is characteristic for years with a high grain yield is specified. Duration of phases grain depends not only on accumulation of the sums of temperatures, but from the whole complex of factors.

The method of creation of diploid winter rye variety “Turquoise” based on the display of heterosis effect at a free intervarietal pollination and cover in one population of a vast majority of varieties and hybrids from the different ecological-geographic groups is described in the article. A short characteristic of the main economic-valuable attributes of a new variety is reported here.

Land improvement promotes the agricultural production stability, increase of other intensification factors application efficiency. Subsoil waters level control allows to create optimum conditions for the plants growth and development, as a result the agricultural crops productivity increase reaches 30%. Calculations show, that profit from agricultural production achieved on the drained grounds, in view of annual expenses for necessary meliorative actions makes 7 million c.u. at profitability about 16%.

Researches of forage agrocoenosis productivity on post-peat soil complexes of the Belarus Polesie have allowed to select the most perspective forage crops, which have well proved in complex water-physical and temperature conditions. The economic and power estimation of efficiency of their cultivation was determined. On the basis of the selected crops were molded and selected perspective and productive crop rotations, making system of meadow and field forage production on the naturaltechnogenic soil complexes formed on a place of degraded turbaries of the Polesie. The economic and power estimation of their efficiency was determined.

Data on peat soils drainage and agricultural use influence on long-term grasses аgrochemical properties and productivity are cited. Influence of mineral fertilizers application and herbages short-term flooding on their efficiency increase up to 31,9 % of absolutely dry substance is revealed in 3-cut use comparing to the control. Organic substance mineralization intensity increase is noted at herbage summer flooding after 1 and 2 crops hay for 3 days.

Data on cereal herbages resistance to overwetting on the reclaimed sites are presented. Researches were spent on sod-podsol gley (gleying continuous from depth of 20-30 cm) and sod-podsol gley-like sandy soils with spring stagnation of water. On sites with flooding duration more than two weeks (sod-podsol gley ground) the sowed species density for five years has decreased in 1,6-2,3 times, and on sites with flooding duration less than two weeks (sod-podsol gley-like ground) - in 1,3-2,3 times. Rootstock grasses - painted grass, brome beardless and tall bent grass, had appeared the steadiest species. They have been better adapted to spring overwetting and by fifth year of life occupied the leading position (40,5-78,9 % on weight) in herbages. Timothy grass was one of less steady species. By third year of a life its participation in herbages decreased in 2,5-4,0 times.

Data on clover-cereal mixed grass crops on inundated peat soils research results are presented in the article. The best cereal components and its optimum mixing ratio with meadow clover for this valuable long-term bean culture wider promotion on peat soils are determined.The role of separate mixed grass crops components in meadow clover productive longevity and its coenotic value in a herbage is shown. The most productive mixed grass crops are proposed.

The outcomes almost half of a century investigations emphasize a double role, which diagnostics and parametrization of oxygenous state play in relation to soil medium and advantage of this state to water regime. The correct saturation of soils by oxygen prevents their morphological and chemical degradation and also stabilizes conditions for evolution of soil-forming processes. The possibility of continuous receipt of oxygen providing needs of soil medium creates optimal conditions for vegetation developing here and metabolism of the vegetation considerably influences soils formation and development. The boundary parameters for optimal saturation of soils with oxygen cause their humidification surplus of which promotes development of reduction processes, soil degradation and exerts the toxic attack for plants, but a shortage of moisture disturbs progress of biochemical processes in soils and vegetation of plants. In this connection the importance of land reclamation for creation of an optimal water regime satisfying simultaneously ecological and agricultural production requirements is increased. The quantitative approach to an assessment of a waterand-air regime of soils on the basis of their morphological characters is also the basis for parametrization of technical decisions applied in designing drainage systems. It is possible to use determination of the soil anoximy caused by gleyzation process in hydraulic solutions and analyses of the closed drainage network.The important outcome of introduced investigations is the indicating of an especial role of ferrocompounds in creation of oxygen regime of soils. The oxygen-iron compounds are some kind of an oxygen accumulator in soil, and the technological stabilization of oxygen regime of soil medium owes not only create favorable agro-ecological conditions, but also counteract an removal of reduced iron from soil structure.

The given distributions eroded soils on the agricultural grounds of Byelorussia on materials of large-scale soil inspection are cited. Generalizations and the analysis of change of properties and pa-rameters of fertility soils under influence of processes of erosion are made. It is shown, that washout results in deterioration physical properties soils the least moisture capacity, a range of an active moisture, density of addition, density of a firm phase of ground, general porosity is reduced, the maximal hygroscopicity and humidity of destruction of plants is increased. Agrochemical parameters eroded soils are determined by properties tillage horizons. Washed off ground essentially differ from non-eroded first of all the reduced stocks and the contents humus and nitrogen, that most of all worsens their fertility and negatively influences efficiency cultivated on these soils agricultural crops. At the same time on improvement agrochemical parameters of fertility in the greater degree, than on other properties eroded soils, it is possible to influence application of organic and mineral fertilizers. Decrease in washed off soils number microorganisms, contents humus and nitrogen causes their lower biological activity in comparison with non-eroded soils.

The agricultural fields of irrigation (AFI) influence on natural waters quality long-term researches results are presented. Ammonium, phosphates, chlorides and organic substances increased content that is caused by cattle-breeding drains overflow is stated in it. It is shown, that for additional cleaning AFI returnable waters bioengineering constructions can be used. Only for 5 years the bioengineering constructions have prevented the phosphates 8,6 tons and almost three times more ammonium dump into a water intake.

With a purpose of peat fires localization and liquidation efficiency increase the bore of deep suppression is developed, which provides the water (fire suppressing composition) direct delivery into a ground to the depth up to 1m.The design of a bore for the fires deep suppression on peat swamps without use of water external sources is presented, and the tests results are presented in the article, too. Mounting the tank on the water source or use the several bores simultaneously will essentially increase the efficiency of peat fires localization and liquidation in depth up to 1 m.

One of haymakings and pastures restoring problem decision ways is undersowing the granulated grasses seeds without embedding it into root mat. For granulation seeds of grasses investigation authors have chosen peat as the basic component and investigated the characteristics of peat granules.On the basis of the researches fulfilled the theoretical substantiation of peat granule strength under static loading action with the purpose of giving to dry granules the properties necessary for its safety in the undersow moment, and also at transportation and storage. Results of the experiments on studying the granules dynamic strength and seeds germinability in granules with various additives are presented in the article.

The researches have enabled us to establish that fertilizing the pastures promotes herbages botanical structure improvement, its contamination reduction and valuable grasses participation increase. The mineral fertilizers introduced in optimum norms and ratio considerably improve the quality of a pasturable forage by increasing productivity.In determining the norms and ratio of mineral fertilizers for annual superficial introduction on cultural pastures it is necessary to consider type of a habitat, soils features, its supply with basic feeding elements, herbage character, its economic use and planned crop.Phosphoric and potash fertilizers play the important role in cultural pastures efficiency and longevity and high-quality herbage preservation increase. However its action reveals differently on different types of soils, and increases of a crop from these fertilizers application can change in significant limits, first of all, depending on soils provision with accessible for plants forms of phosphorus and potassium. At cultural pastures long use and bean components relative content decrease in structure of a herbage alongside with phosphorus and potassium deficiency it is necessary to bring nitrogen. Nitric fertilizers introduction on pastures in dozes below optimum reduces the content of not sowed species in a herbage and allows to increase its use duration.

The technique of Belarus meadow vegetation and meadows condition estimation, which includes the questions of information gathering and analysis, inspection network designing, field jobs carrying out technology, long-term grasses fields mapping, haymakings and pastures, and complex estimation of herbages. The index scale of the herbage complex estimation, having four groups of quality, allows to establish visually a degree of needs in improvement. Results of meadows condition estimation not only allow to characterize a degree of root mat broken state and a grassy cover thinned condition, but also to determine a complex of the actions promoting herbages renewing and meadow grounds efficiency increase.