RU2236116C1 - Method for suppression of weed plants in coniferous seedling nursery - Google Patents

Abstract

FIELD: agriculture and forestry.

SUBSTANCE: method involves treating sown plants with substances for suppressing growth of weeds, such as aqueous draw of coniferous needle litter; mulching with saw dust and coniferous needle litter; spraying with above aqueous draw once two weeks until seedlings reach standard size.

EFFECT: reduced contamination of coniferous seedling nursery with weeds, reduced intensity of manual labor for seedling care and improved growing conditions for seedlings.

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Description

The invention relates to agriculture, and in particular to methods of weed control in forest nurseries.

A known method of weed control in crops of cultivated plants, including the physical destruction of weeds (manual) weeding and (mechanized) cultivation. During the growing season, coniferous plants from seeds and rhizomes located in the arable layer of the nursery soil sprout and quickly develop herbaceous plants from the group of segetal and ruderal species, i.e. weeds. In the process of evolution, they adapted to the mandatory periodic disturbance of the soil during its processing in agrophytocenosis. Possessing faster growth than seedlings, weeds quickly occupy a dominant position in the crop and go to the upper tier. Seedlings, however, remain in the lower tier, where, lacking in solar radiation, moisture and nutrients (as a result of competition with weeds), they slow down growth and development.

Therefore, at present, to eliminate competition between cultivated and weed species in crop production, mechanical methods of weed control are widely used. In forest nurseries at the beginning of the growing season, when seedlings of tree species are still small, sowing is done manually at least once every 2-3 weeks. In this case, only the active part of the populations of weed species (i.e., only vegetative individuals) is removed from the sowing. But since the process of emergence of seedlings in weeds is stretched in time, and the “seed bank” is large, crops are overgrown again and require weeding.

As the seedlings grow, cultivators (KPP-1.5; KPP-1.5 and others) are used to destroy weeds and loosen the soil in the inter-row space at the crops. In the lines themselves, weed removal is still carried out manually / Novoseltseva A.I., Smirnov N.A. Directory of forest nurseries. - M: Forest. industry, 1983.- S. 68-69 /.

The disadvantage of the analogue is that the destruction of weeds by weeding is an expensive and time-consuming process. Mechanical cultivation leads to partial damage to seedlings, and periodic disturbance of soil compilation during cultivation even stimulates the appearance of new seedlings of weed plants on sowing / Markov M.V. Population plant biology. Kazan: Publishing house of Kazan University, 1986.- P.38-39, 42-44 /.

The prototype of the proposed method is a method of weed control on coniferous crops, which consists in spraying the seed tapes with solutions of substances that inhibit the growth of weeds, namely herbicides of selective action (velpar, simazin, goal, propazin, fusilade, etc.), as a result of which more death occurs parts of weeds and a decrease in vitality in the remaining. On pine crops, the Velpar herbicide is recognized as the most effective and safe (for crops), which can be used at any time after emergence. In spruce and larch crops, the most effective and safe (for seedlings) is the autumn use of goal, which can also be used in pine crops / Use of herbicides and arboricides in forest cultivation: Handbook. Shutov I.V., Belkov V.P., Martynov A.N. and others - M .: Agropromizdat, 1989.- S. 22, 34, 57-61 /.

The disadvantages of the prototype are the incomplete destruction of weeds and their involuntary “selection” for resistance to safe doses of chemicals, technical difficulties in ensuring targeted spraying of seed tapes and withstanding given doses of pesticide (working fluid flow rates) when using tractor sprayers, partial damage to seedlings, toxicity and prolonged decontamination of herbicides, environmental pollution and other negative consequences of the environmental plan.

Herbicides kill the treated weeds, but not all (both in quantity and in species composition). Therefore, in order to prevent strong growth of weeds resistant to this drug and preserving the vitality of weeds unstable to this pesticide, it is recommended to periodically remove the latter from sowing by weeding. If this is not done, the surviving weeds form offspring that are not susceptible to the previously used herbicide. In this case, non-susceptible species grow rapidly, compete even more with seedlings for light, moisture, nutrients and reduce the productivity of cultivated plants.

The treatment of crops with solutions of some herbicides by a mechanized method requires directed spraying on the sowing lines, which leads to an uneven distribution of the herbicide over the area. The uneven distribution of pesticide over the area also contributes to the lack of automatic synchronization of the flow rate of the working solution with the speed of the unit. Therefore, in some areas it is possible to overestimate the dose of the herbicide, and in others it is underestimation. When deviating from a predetermined dose, damage to cultivated plants or failure to obtain the desired silvicultural and economic effect occurs. When treating crops with herbicides, it is possible (and in the case of their frequent use and in excessive doses - certainly occurs) damage or growth retardation of seedlings, manifestation of phytotoxicity of the soil (i.e. accumulation of pesticides in it). Herbicides introduced into the soil have a toxic effect on the microflora of the soil, enhance the mineralization of humus, and increase the content of nitrogen compounds, which under certain conditions can lead to burn seedlings.

Herbicides used in forest nurseries are pesticides with a certain degree of toxicity for both humans and other representatives of the animal world. Consequently, the destruction of weeds on coniferous crops through the use of herbicides is dangerous due to excessive pollution of the environment and requires special measures and strict adherence to the rules ensuring the sanitary safety of those working with them / Use of herbicides and arboricides in forest cultivation: Handbook. Shutov I.V., Belkov V.P., Martynov A.N. and others. - M .: Agropromizdat, 1989. - P. 57-61, 65-69, 125-126, 131-144, 157-167 /.

In addition, it is known that weeds harm cultivated plants when they are in the dominant tier. If they do not overtake seedlings in growth, then their competitiveness is sharply reduced, since most species belong to explants. In a small amount and being sown in the second tier with respect to seedlings, they not only do not harm, but even become useful, shading the surface of the soil, thereby reducing its temperature at noon. Accumulating nutrient elements in the form of organic matter, grassy weeds (ending the life cycle) return them, when the aboveground part is decomposed, to the nursery soil, thereby reducing the loss of nutrients from leaching by moisture from spring snowmelt, rain and watering. It follows that the complete destruction of grassy vegetation in crops by using chemical weed control agents (including by mechanical means) interrupts the natural cycle of nutrients in agrophytocenosis and does not make sense from a phytocenotic and, in general, from an environmental point of view view.

An object of the invention is to create conditions that prevent mass germination and rapid growth of weeds in coniferous crops and the emergence of herbicide resistant weeds, eliminating the need for directed spraying and strict dosing of the flow rate of the working solution, the use of complex technical solutions to ensure synchronization of the flow rate of the solution and speed aggregate movements, absence of damage and death of cultivated plants, invertebrate animals and beneficial microorganisms soil mobility, elimination of the danger of environmental pollution by pesticides, safe working conditions for workers working on crops, as well as the restoration (to a certain extent) of the biophilic elements circulation, energy flows and natural trophic connections lost during the cultivation of planting material during the creation of agrophytocenosis in the nursery.

The problem is solved in a method of suppressing weeds on coniferous crops, including treating crops with substances that suppress weed growth, where according to the invention, the crops are treated with water infusion of softwood litter, and then mulching with sawdust and softwood decay are carried out, and then the crop is sprayed with the above infusion once every two weeks until the seedlings reach standard sizes.

In the proposed method, in contrast to the prototype, the suppression of growth processes and a decrease in competitiveness in weedy herbaceous plants and, conversely, its increase in woody plants is achieved through the use of not environmentally hazardous pesticides, but only natural substances and materials (i.e., infusion from litter of needles for spraying, sawdust and litter of needles for mulching), which are part of coniferous stands.

Spraying crops with water infusion from needles, unlike the prototype, does not require an exact dosage of the solution, and when treated with infusion, even with very high doses and more frequent treatments, environmentally hazardous substances do not accumulate in the soil for both flora and fauna, t .e. phytotoxicity is not manifested, and microorganisms even increase vital activity. Therefore, the need to synchronize the speed of movement of the unit and the amount of sprayed solution, as well as directed treatment of plants on crops is no longer necessary. From this it follows that the development of new complex technical systems for processing crops using the proposed method is not required.

Sawdust, coniferous litter and the infusion of it are non-aggressive and harmless to humans. Therefore, their use makes weed control in coniferous crops safe in every way. Mulching with sawdust in combination with litter of needles in the sowing for coniferous seeds creates not only a more favorable microclimate (illumination, temperature, soil and air humidity), but also some others characteristic of natural forest phytocenoses, conditions for which for a long time seed adaptation occurred in the process of evolution and was fixed in the genotype. Decomposing, sawdust and litter enrich the soil with organic matter and nutrients, at the same time have an allelopathic effect on seeds, seedlings and young weed plants. However, at the open location of the nursery, due to the high level of illumination, temperature, and turbulent moisture transfer at high wind speeds, the mulching layer quickly dries up and the process of decomposition of organic matter (sawdust + needles fall off) stops, the allelopathic effect of biologically active compounds on weed seeds weakens, and then stops until new wetting with precipitation or irrigation water. To ensure the necessary level of allelopathic effect on populations of weed herbaceous plants and its strengthening, immediately after sowing seeds of cultivated plants, crops are processed by spraying the surface of the soil with a water extract from the litter of the same species. During the growing season after mulching, the seeding treatment is repeated several times. Due to this treatment and mulching, mass germination of weed seeds is prevented, and the emergence of shoots of herbaceous plants significantly slows down their growth and development. Mulching with sawdust in combination with coniferous litter and processing of crops with a water extract from dead needles do not have a negative effect on seed germination and seedling growth. The use of herbicides to suppress weeds in coniferous crops in nurseries does not have a similar effect.

After the seedlings are closed, the shading of the soil created by them also inhibits the germination of weed seeds, and weeds that have lagged in growth have low vitality and cannot compete with the cultivated tree species.

The difference and originality of the proposed method, compared with the prototype, lies in the fact that the method is based on phytocenotic principles and involves the transformation of the ecological situation on coniferous crops (in the arable land) in the direction of greater compliance with the conditions that are characteristic of natural forest plant communities. An almost unattainable goal is the maximum complete destruction of weeds to exclude their competition with seedlings on crops due to the use of herbicides, in the proposed method it is replaced by a more realistic goal - reducing the number and competitiveness of weeds while partially retaining them on crops to enhance the circulation of biophilic chemical elements while increasing biological stability of the agrophytocenosis system. In forest plant communities under the canopy of the stand and in adjacent areas, grassy vegetation is almost completely absent or exclusively forest species are found in the actively vegetative state, while segetal and ruderal species are not found. This is due to both low illumination and the release of biologically active compounds (ALS) by woody plants into the environment. There is numerous evidence that a large proportion of ALS is in the litter, consisting of needles (leaves), part of the bark, small branches and twigs of woody plants / see 1. Grodzinsky A.M. Allelopathy of plants and soil fatigue: Izb. tr / Editorial: Romanenko V.D. (ed.) and others; USSR Academy of Sciences. Center. rep. Nerd. garden. - Kiev: Science. Dumka, 1991 .-- 432 p .; 2. Kolesnichenko MV Century Biochemical mutual influence of woody plants. - M .: Forest. industry, 1968. - 150 p.

UAS secreted by litter inhibits germination, delays the emergence of seedlings, and inhibits the growth and development of individuals of species that are not characteristic of this phytocenosis, i.e. in the process of evolution did not acquire biological properties that provide them with the opportunity to grow together with dominants. The species dominating in the forest community, along with the microclimate, form a specific allelopathic background, thereby providing the offspring (seeds, seedlings and young undergrowth of dominants) with a “comfortable” ecological niche in biogeocenosis.

The method is implemented as follows: after sowing coniferous seeds, seed tapes are sprayed with a working solution, which is an aqueous extract from the litter of needles at the rate of 0.5 l of solution per 1.0 sq. M of sowing (500 l / ha). Immediately after spraying, the sowing is covered with a 0.5-1.0 cm layer of mulch from fresh sawdust and 0.5-1.5 cm with a layer of litter (forest litter from stands). Mulching with sawdust and litter not only prevents the germination of weeds, but also creates favorable conditions for the conservation of soil moisture, preventing the rapid blowing of sawdust from sowing tapes. To maintain the allelopathic background, spraying the sowing with water infusion of pine litter is carried out during the entire vegetation every 2 weeks, i.e. with an interval of 12-15 days. If there are a small number of weed plants on the sowing that have reached the upper tier in relation to the seedlings, it is advisable to carry out manual weeding. The liquid is prepared by insisting 1 part of pine litter in 6 parts of water for 24 hours. Before use, the solution is filtered to remove mechanical impurities that may clog the sprayer.

Examples of specific implementation of the method are as follows: in the nursery of the educational-experimental forestry "Vyazovskoye" SSAU im. N.I.Vavilova on the sowing of common pine studied the effect of mulching with the litter of a number of tree species in combination with the spraying of sowing tapes with water infusions of these litter on the growth of weeds. The experiment was carried out according to the scheme of the Latin square (5 × 5) with options:

1 - without mulching (control);

2 - mulching with litter of common pine;

3 - mulching with litter of oak oak;

4 - mulching with litter of aspen;

5 - mulching with sawdust.

When counting and observing on crops in 1 year, the presence of 11 species was noted, and for 2 years - 10 species of weed vegetation. Moreover, during the entire period of cultivation, some species were present on accounting plots for only a short period of time and were absent after crops (weeding). In order to obtain reliable information, coefficients of community of weed species according to Jacquard were determined. The values of the coefficients showed that in 1 year of cultivation in the plots of the 1st (control) and 2nd varieties, 66.7% of the species recorded in the experiment were present. At the same level, a commonality of species was noted between 1 and 5 variants.

For 2 years of cultivation, the coefficient of commonality of species between the 1st and 2nd variants decreased to 55.6%, and between 1 and 5 it increased to 90%. Therefore, of all the species, only those were selected for analysis, whose individuals were represented on the crops during the entire duration of the seedling cultivation: annual-backed shiritsa (Amaranthus retroflexus L.), chicken millet (Echinochloa crusgalli (L.) Beauv), white gauze ( Chenopodium album L.); biennials - gray hiccups (Berteroa incana (L.) DC) and perennials - colorful motley (Coronilla varia L.), lettuce (Tatar molokan) (Lactuca tatarica (L.) C.A. Mey).

The greatest effect on the inhibition of weed growth was found in option 2 with mulch from sawdust and litter of common pine and spraying of the sow with water infusion from litter of the same breed. The use of only sawdust and coatings from litter of other breeds with spraying of the sowing with the corresponding infusions took place, but was less effective. The proposed method significantly reduced the number of weeds compared to the control on the crops of 1 year of growing seedlings by 6.4 times (including annual 6.6 times, two-year - 9.0 times and perennials - 5.8 times) , their average height is 1.2-4.0 times, and the total biomass in absolutely dry state is 5.8 times or more. In the crops of the second year of growing seedlings, the number of weeds decreased by 11.5 times (including annuals by 24.5 times, two-year-olds by 17.0 times and perennial by 8.0 times), their average height was 2.0 -6.3 times, and the total biomass in a completely dry state by 8.2 or more times. At the same time, juvenile (one- and biennial) weeds were more strongly oppressed, compared with perennial (see table).

It was established that this method of weed control not only does not adversely affect the seed germination and growth of common pine seedlings, but also contributes to an increase in their biometric parameters and the yield of standard planting material in comparison with the control variant.

Using the invention will achieve the following results.

1. To reduce the weediness of coniferous crops by 6.4-11.5 times, the height of weeds 1.2-6.3 times and their biomass (in the absolute dry state) not less than 5.8-8.2 times , which reduces the complexity of growing planting material of seedlings of ordinary pine, by reducing the number and volume of work with manual care. The costs of manual labor (in man-days) for caring for crops are reduced by 2.1 times, i.e. no less than with weed control by herbicides / cm. The use of herbicides and arboricides in forest growing: Handbook. Shutov I.V., Belkov V.P., Martynov A.N. and others. - M .: Agropromizdat, 1989. - S.71-72 /, and the work of mechanisms (tractor and machine shift) - 1.3 times.

2. Improve seedling growth conditions, increase the yield of standard coniferous planting material from 1 ha by at least 30% (by the example of ordinary pine by 37.2%), which is slightly higher than when using herbicides / cm. The use of herbicides ..... P.71 /.

3. Eliminate the technological and technical difficulties associated with the need to strictly dose the flow rate of the working solution when spraying crops to prevent damage to seedlings, phytotoxicity of the soil, etc.

4. The process of growing seedlings to make completely environmentally friendly for the environment in general and for nursery workers in particular.

5. To increase the use of biophilic chemical elements in the process of their circulation and the stability of the flows of substances and energy, as well as trophic bonds in the artificial system of agrobiogeocenosis of the nursery.

Claims (1)

A method of suppressing weeds on coniferous crops, comprising treating crops with substances that inhibit weed growth, characterized in that the crops are treated with water infusion of softwood litter, then mulching with sawdust and softwood decay, and then the crop is sprayed with the above infusion once every two weeks before seedlings reach standard sizes.