In this article recommendations about carrying out podkormok, podseva and resowing of winter grain crops are made. Besides, information on the care of crops of a winter rape is provided.
Recommendations on the care of crops of winter crops in
Review of weather climatic conditions autumn zimnegoperioda
Conditions of sowing and autumn vegetation of winter crops in 2008 were satisfactory. At the end of September and in October moistening top sloyov soils was sufficient for emergence of shoots and initial development, however further growth winter passed at shortage of moisture on all predecessors. Data of the APP UAAN Crimean institute on stocks of productive moisture under winter wheat on various predecessors are presented in the table:
Stocks of productive moisture under shoots of winter wheat
On October 27, 2008
The termination of vegetation of winter crops is noted on December 12th, for a decade after usual terms. Crops went to winter in a phase of the 3rd leaves – a kushcheniye, at a kustistost 1,6 – 2,1 stalks on one plant. Their condition was satisfactory and good.
For last period of rewintering the temperature mode was lowered. Average decade temperatures were lower usual on 5 – 6ºS. Such cold weather at the end of November – the beginning of January is observed each six years. The minimum air temperature went down to – 17ºS. The minimum temperature of the soil on depth of knot of a kushcheniye fell to – 7ºS at snow height to 2 see.
The critical temperature of a vymerzaniye by calculations makes: for normally developed crops of winter wheat – 15ºS, winter barley – – 12,5ºS. Beneficial effect on rewintering was rendered by the snow cover formed since the third decade of December on the middle of January. It protected the soil from a considerable vykholazhivaniye, despite small height – 1-2 see. The maximum depth of a promerzaniye of the soil made 35 cm that on 23 cm more mean annual indicator.
By results of the preliminary otrashchivaniye which has been carried out on January 9th, damages winter grain aren’t present, but rape damage is possible.
On a long-term forecast the average temperature of January is expected close to norm (norm – 1,5ºS), a precipitation is more than norm (norm of 32 mm).
Having sat down and having changed victims winter
Not to allow falling of a level of production of food and fodder grain it is necessary to watch a condition winter already today. Because in some regions of an autonomy during fall of temperature there was no snow cover and further deterioration of conditions of rewintering isn’t excluded, there is a probability of death or an izrezhennost of crops winter which it will be necessary podseyat or pereseyat.
There are some techniques of determination of viability of plants winter. Three are most widespread: an otrashchivaniye of crops in monoliths (the labor-consuming and long method, a damage rate define in 10-14 days and even more); the water method consists in an intensive otrashchivaniye of knot of a kushcheniye (roots and leaves are cut off, an otrashchivaniye carry out on light at temperature to 20ºS; the preliminary account carry out in 2-3 days and final for the 7th day of an otrashchivaniye); a method of biological control – the analysis of a cone of increase according to F.M.Kuperman.
The last the most exact and operative, but demands certain skills. It is that the plants selected by a technique are released from the soil, leaves; the kushcheniye knot (an increase cone) is cut by a razor edge lengthways and considered through a binocular magnifying glass (usual 6 – a 10-fold magnifying glass). At live plants an increase cone brightly white or pale green with a nacreous shade, tourist’s mountain; at insignificant damage of plants the basis of knot of a kushcheniye will have a dark shade. Such plants in the future will lag behind in growth. The lost plants differ yellow-brown or even brown coloring and turgor loss. The defeat zone, the high probability of death of plants, especially in the conditions of late and dry spring is more extensive.
The survival rate of crops winter after adverse wintering depends on conditions of spring vegetation and, especially, from time of its renewal. At early renewal of vegetation the progressive tense costs cool weather, increase of the sum of effective temperatures occurs gradually that gives the chance winter to take roots, raskustitsya and even weak, late poseyanny, "recover" and under further satisfactory weather conditions give a good harvest.
At late renewal of vegetation and increase of positive temperatures by the accelerated rates spring growth of the winter occurs in much worst conditions.
Defining the areas podseva or resowing winter, it is necessary to consider density and a phase of development of plants, time of renewal of vegetation and availability of moisture both in sowing, and in a meter layer of earth.
At early renewal of spring vegetation (Idekada of March) it is expedient podsevat only the most izrezhenny crops of winter wheat with density of 100-150 pieces/sq.m and winter barley – 100-120 pieces/sq.m.
At later renewal of vegetation (II-Iiidekad March) podsevayut izrezhenny crops of winter wheat by density of 200-220 pieces/sq.m and winter barley 180-200 of piece/sq.m. Winter barley clusters much better, than winter wheat therefore the smaller number of its plants on unit of area is allowed. The question podseva and resowing quite difficult also is higher the called figures defining density, rough. For decision-making it is necessary to survey each concrete field and to consider all complex of conditions: time of renewal of vegetation and density of standing, uniformity of distribution of live plants for crops squares, a phase of development of plants, a condition of a cone of increase and growth of secondary root system, stocks of productive moisture and a contamination.
At the high standard of farming (crops winter since autumn on carefully cut soil and lack of weed vegetation) are admissible having sat down izrezhenny winter for several reasons: time is won, moisture in the soil is saved and expenses of work and means decrease.
On the fields sowed with violation of an agrotechnology, non-uniformly izrezhenny, littered, cultivation on depth of seal of seeds is carried out and having changed. Having changed it is better to carry out early summer (summer barley, oats) or winter two-handles.
It is considered that at superearly crops (February) winter barley of the two-handle yields a harvest at level of summer barley and even above, at later crops (March) is more preferable to sow summer barley of the zoned grades.
Izrezhennye crops winter podsevayut across sowing ryadok on small speed of movement of the unit norm of seeding of 2-3 million vskhozhy seeds on hectare. It is better to use mnogoseyalochny hitches with tractors on caterpillar to a course.
When resowing it is necessary to carry out high-quality cultivation on depth to 6-7 cm and crops by full norm of seeding – 4-4,5 million vskhozhy seeds on depth of seal of 5-6 cm with an obligatory prikatyvaniye annulate shporovymi skating rinks.
If for the organizational and economic reasons in time not pereseyali, the soil is carefully prepared under crops of later summer cultures or a field taken away under autumn sowing and processed as early steam.
On fields winter, not subjects podsevu and to resowing, it is necessary to create favorable conditions for growth and development of plants.
Carrying out podkormok
Growth of crops is limited by a lack of nitrogen more often. Plants contain more atoms of this element, than another, received of the soil. In this regard nitrogen is the most important component of a mineral food of plants in comparison with others macro – and the microcells which shortcoming also negatively affects growth of plants and their stability to adverse weather conditions and diseases.
The long-term researches which have been carried out on fields of the APP UAAN Crimean institute on studying of doses, ratios, ways and terms of introduction of mineral fertilizers, showed that the increase in doses of phosphoric and potash fertilizers didn’t render appreciable influence on crop size years with a various vlagoobespechennost. On the contrary, a superfluous nitric food at a good vlagoobespechennost caused strong growth of winter grain crops, their intensive kushcheniye that led to a zagushcheniye of crops, a fast siccation of the soil, defeat by mushroom diseases and drowning.
Scientists of institute defined that for winter grain crops an optimum dose of fertilizers on busy pairs and not steam predecessors is kg/hectare N45R40. Potash fertilizers didn’t promote increase of a crop winter because of high security of soils of the Crimea with this element.
Concerning nitrogen it is established that the winter grain consume nitrogen continuously since the vegetation beginning before its termination and after renewal – to dairy ripeness, with small delay in a kolosheniye. Its maximum absorption is observed during the period from an exit phase in a tube to dairy ripeness of grain.
Now cause alarm low stocks of moisture both in arable, and in a meter layer of earth, especially on not steam predecessors. In these conditions the special approach to a choice of terms, norms and ways podkormok winter is necessary each kg of fertilizers gave the maximum increase of a crop and paid back costs of cost of fertilizers and their introduction.
Top dressing of the winter gives an essential increase of a crop even at introduction of full norm of fertilizers under the main processing of the soil or under preseeding cultivation. On the average the increase of a crop makes 2-4 c/hectares. In the absence of the main application of fertilizers, top dressing winter in a dose of 30 kg ñ.ó./hectare give higher increase of a crop – to 5-7 c/hectares.
It is not recommended in the conditions of a waterless valley at low stocks of moisture in the soil to increase norm of introduction of nitrogen more, than 30 kg ñ.ó./hectare, and at low stocks of mobile phosphorus (less than 1,5 mg/100 of g of the soil) any dose of nitric fertilizers doesn’t give effect. In any case it is necessary to remember that introduction nitric podkormok less than 30 kg ñ.ó./hectare doesn’t pay back costs of their introduction.
According to researches of many scientific institutions which have been carried out in various soil and climatic regions of Ukraine, optimum term of carrying out podkormok is spring renewal of vegetation winter. These top dressing give the greatest effect at early terms of renewal of vegetation when process of a nitrification is suppressed because of low temperature in a korneobitayemy layer of earth and low rates of its warming up. At late renewal of spring vegetation there is a fast warming up of the soil, processes of a nitrification go more actively that in a bigger measure promotes transfer by soil microorganisms of organic substance in mineral, available to a food of plants a form. In this case, at the main introduction of mineral fertilizers by full norm, top dressing of the winter are less effective.
Big losses of nitrogen are observed and at very early podkormkax, long before renewal of spring vegetation, and also on deeply chilled soil and on snow cover: the chilled soil doesn’t pass moisture of thawed snow or a rain, and dissolved tuki will be flown down in the lowered sites of a microrelief and to concentrate there, and on the raised sites of a field of loss will be minimum or are brought to naught. Carrying out podkormok winter in early terms a carbamide is especially inadmissible. Ammonia losses from a carbamide brought superficially, are observed earlier, than urea manages to get to the soil. At early carrying out podkormok and ammoniac saltpeter can disappear in the form of ammonia, but it doesn’t alkalinize the soil as a carbamide.
Progressive tense the main way of application of fertilizers in top dressing was continuous – razbrosny. Spreaders RUM-0,5, 1-RMG-4, because of imperfection of a design, couldn’t distribute evenly across the field necessary norm of fertilizers that reduced efficiency of their action.
As showed APP UAAN Crimean institute researches, fertilizers are most effectively used at carrying out podkormok winter crops by grain seeders of the SZ-3,6 type. At the same dose, but at application of fertilizers by grain seeders, productivity of the winter raised at the expense of uniform distribution of fertilizers and their seal on depth 5-6 see. Researches showed that the winter were less damaged at the longitudinal direction of seeders to crops. Because of big resistance of a soshnik among crops, he "goes" to row-spacings, excepting damage of plants and destroying thus 30-40 % of wintering weeds.
It is necessary to feed up, first of all, those crops which are placed on busy pairs and not steam predecessors, seed-growing, and also underdeveloped, but not the izrezhenny.
Considering high cost of fertilizers, fuel and other material resources, expediency of carrying out podkormok the winter is defined by economic calculation.
Care of crops of a winter rape
Before leaving in winter crops of a rape should have: density of standing of plants of 60-80 pieces/sq.m, placement of a point of growth from a surface no more than 3 see. A root neck – the most sensitive part of a rape. Well developed plants with diameter of a root neck of 6-8 mm are capable to maintain frosts to-18 – 19°S, and at snow cover – 2-6 cm – to-25 – 30°S. Insufficiently developed plants (crops of late terms with quantity of the real leaves less than 5 pieces) practically perish at temperature-10 – 12°S.
Weather conditions of this winter and financial crisis in the country set thinking on expediency of carrying out spring actions on the care of crops of a winter rape.
It is not necessary to carry out top dressing in January as the brought nitrogen won’t be used by plants. Optimum term of top dressing of a winter rape comes at achievement of steady daily average air temperature at level +5oS and above. Usually is a February-March. Plants during this period have white young backs that is the basic priznakomnachala vegetations.
At this time a condition of plants of a winter rape define as follows: green plants dig out on depth of 10-15 cm and if the main root isn’t damaged, even at damage of lateral roots, such plants consider normal, "live" and if easily razmochalivaetsya – plants consider the main root as victims.
Estimate a condition of a winter rape after rewintering on the following parameters:
· at density of standing of "live" plants more than 40 pieces/sq.m crops are considered as the good;
· at uniform distribution and existence on 1 sq.m 20-40 plants – satisfactory;
· in the presence of less than 20 plants on 1m2 crops are considered as the weak.
However, solving a question of resowing of weak crops, it is necessary to remember the high regenerative ability of a rape allowing almost completely to compensate damages by frosts.
It is impossible podsevat weak crops of a winter rape summer.
Under a winter rape nitric fertilizers are brought in early terms of vegetation by results of a preliminary estimate of a condition of plants after rewintering. From shoots till the end of flowering the rape consumes 96-98 % of nitrogen. The maximum need for nutrients, and especially in nitric, is noted in the spring. With one centner of seeds of a rape from the soil 3,6-3,9 kg of nitrogen are taken out, and taking into account straw the actual requirement makes 4,8-5,3 kg/c of nitrogen.
For exact definition of amount of brought nitrogen on 1 hectare the calculation method, proceeding from gross requirement is used. Its general dose pays off for a planned crop and is taken out by a rape for all vegetation. Subtracting nitrogen containing in the soil and in sheet weight from the general necessary dose, we receive the amount of nitrogen necessary in the form of top dressing in the spring. Definition of the content of nitrogen in sheet weight to be carried out as follows: the sheet weight ² is cut off, weighed and pays off with 1 m in centners on hectare. On the average 1 centner of green material contains 0,5 kg of nitrogen.
Example:
Thus, it is necessary to bring 60 kg of nitrogen on 1 hectare. Introduction should is carried out once, razbrosny way.
L.Radchenko, the deputy director on nauchnojrabote.
K.Zhenchenko, N. Saenko, S. Tomashov, senior research associates of laboratory of agriculture, Crimean IAPP UAAN.
T.Kozlova, chief agrometeostantsiiklepinino.