Pre-sowing Tillage Research Articles

ВЛИЯНИЕ УРОВНЯ МИНЕРАЛЬНОГО ПИТАНИЯ НА ПРОДУКТИВНОСТЬ ЗЛАКОВО-БОБОВЫХ АГРОЦЕНОЗОВ В ЛЕСОСТЕПИ ПРЕДБАЙКАЛЬЯ

The article presents findings of the influence of different levels of mineral nutrition on plant growth and development, the impact of fertilizers on the botanical composition, on the productivity and forage benefits of cereal-bean agrocenoses in the forest-steppe zone of the Baikal region. The objects of research were mixed crops of oats with peas and millet with vetch, peas, and Austrian winter pea. Legumes are the main source of protein increase in feed. In the field, the most widespread, among legumes, were vetch, sowing peas, field peas (Austrian winter pea). As a result of phenological observations, it was found that the growth and development of plants depended on the biological characteristics of crops, weather conditions and directly on the mineral nutrition level. The millet reacted most effectively to the application of mineral fertilizers, starting from the exit phase into the tube. The introduction of mineral fertilizers in pre-sowing tillage contributed to an increase in the proportion of legume components in the total green mass yield and a decrease in cereals. The highest competition in agrocenoses of millet with legume components was vetch, its share in the mixture increased, compared to the unfertilized background, by 6 and 14.5%, depending on the background of fertilizers. It was found that, compared with the unfertilized background, mineral fertilizers increased the yield of green mass from 1.5 to 4.9 tons per hectare, the collection of dry matter from 0.4 to 2.0 tons per hectare and the collection of feed units from 0.3 to 1.3 tons per hectare. Digestible protein content in 1 unit increased with the introduction of nitrogen fertilizer (N45), depending on the type of components in the mixture, from 3.2 to 6.6 g, and with the introduction of complex mineral fertilizer (N45P30K30) from 2.5 to 9.6 g. All are millet-bean mixtures at all levels of mineral nutrition comply with zootechnical standards.

Justification of constructive technological scheme of multifunctional unit

It is developed a multifunctional soil processing unit with interchangeable working implements in the form of flat hoes to perform the subsoil tillage at 16…25 cm or cultivator hoes for carrying out pre-sowing tillage at 5…12 cm. Experimental studies of the unit have been carried out to study the effect on its traction resistance of the parameters of flat hoes, their location according to the scheme of “direct” and “reverse” wedge on the frame of unit, the optimal position of the middle plane-cutting paw relative to the side paws. The tillage unit was aggregated with the MTZ-82 tractor. The apex angle of flat hoes has been 95° and 110°, the width of their capture was 0.76 m. Processing of winter rye stubble was carried out with the use of tillage unit on heavy loamy sod-podzolic soil at its moisture content of 23.8% and hardness in the soil layer from 1.73 to 2.36 MPa. Processing of firm cultivated soil was carried out with the use of tillage unit on medium loamy sod-podzolic soil at its moisture content of 15.2% and hardness in the soil layer from 0.54 to 2.23 MPa. The traction resistance of flat hoes with a apex angle of 110°. Installation of flat hoes in the form of a “straight” wedge and the position of the middle flat hoes with the maximum displacement relative to the side flat hoes can reduce the pulling force of the tillage unit.

ANALYSIS OF COMBINED UNITS FOR PRE-SEED SOIL TREATMENT

Sowing of grain is carried out according to the best predecessors - grain and leguminous plants, tilled crops and perennial grasses. Depending on the predecessor, the type of tillage is selected. The imperfection of the working bodies of machines for the cultivation of soil is the main reason for the increase in the labor intensity of preparing the soil for sowing. The article reviewed and analyzed domestic producers of agricultural machinery and their products. A comparative analysis of modern combined units for pre-sowing tillage was performed.

Theoretical prerequisites for the bionic substantiation of spring soil leveler working bodies parameters

In the system of measures for pre-sowing tillage, special attention should be given to leveling the soil, ensuring an increase in the uniformity of seeding in depth, which has a significant impact on increasing yields. The main solution to this problem is to improve the design of aligners using a mechanical-bionic approach for the analytical description of the optimal forms and parameters of their working bodies. The design of the working body of the spring soil leveler is proposed, the cutting edges of the undercutting wings of which have ridges and hollows in the form of a logarithmic curve with a positive convexity of curvature inside the depressions, developed by the bionic prototype of the mole cricket (Gryllotalpa). Using the methods of agricultural mechanics, the theoretical dependence of the rational depth of the working bodies and the value of the tractive resistance of spring soil leveler on the travel speed, design parameters and physical-mechanical soil properties, which are proved by the results of experimental research on the south carbonated middle loamy black earth have been established. The experimental spring soil leveler provided the reduction of traction resistance by 7...8% (40...49 N) and had the best stability of motion in depth by an average of 1.5 times (± 0.5 cm) in comparison with the serial model of the working bodies of the leveler VPN-5.6 A.

Flexible element in the composition of the working bodies of the rotary soil-cultivating ripping-separating machine

Surface tillage for growing crops is carried out with the purpose of crushing its upper layer, grinding crop residues, destroying weeds and leveling the field surface. The purpose of the research is to determine the quality indicators of an experimental soil-cultivating rotor ripping-separating unit using a flexible working body in the form of a cable. Authors studied in field conditions the physicomechanical properties of the soil after autumn plowing, early spring harrowing and cultivation with lancet paws to a depth of 0,12 m. There was analyzed the structural-aggregate composition of the soil obtained after the passage of device, depending on the frequency of rotation of the rotor and the presence of a flexible element in the form of a cable. Studies have been carried out on an experimental soil-cultivating loosening and separating plant on a layer of soil, which, after processing, is stratified into two sublayers: the upper superseed, the lower layer in the seed embedding zone. In the lower soil layer there is a significant advantage of the working bodies with a flexible element in the form of a cable. Increasing the rotor speed from 1,1 to 2,3 s-1 contributes to an increase in the coefficient of soil structure in the lower layer by about 10 %, and in the upper layer by no more than 2,3 %. With the use of a flexible working body in the form of a cable in the composition of the working bodies of the experimental soil-cultivating rotary ripping-separating installation, the coefficient of structure is about 1,5 times higher than the working bodies without it, which provides more favorable conditions for embedding seeds in the soil. It was found that tillage using an experimental soil-cultivating rotary tillage-separating installation as part of the working bodies of which a flexible element in the form of a cable was applied allows us to improve the methods of pre-sowing tillage to improve its agrotechnical qualities.

The method for calculating the traction resistance of a flat disk

Scuffler with flat discs are widely used in areas, which are subject to wind erosion of soils, to cover moisture on the stubble fields. Flat discs do not wrap the layers they remove, but only loosen them, shifting them aside. It is preferable to use such scrapers during presowing tillage and on steam, since in this case there is less sputtering of the soil, and its lower (moist) layers are not carried to the surface. Therefore, many industrially manufactured scufflers are equipped with flat discs, and the task of constructing a mathematical model for the interaction of such discs with soil is topical. Many mathematical models of the disc-soil interaction, taking into account the distribution of soil reaction forces on the disk, have been proposed, but all these models were constructed assuming that the disk is moving in its plane. Therefore, they are not applicable to the disk of a lakeshield moving with a non-zero angle of attack in the soil. The purpose of this work is to construct a mathematical model that allows calculating the traction resistance of a disk moving with a given angle of attack. The basic assumptions made in the construction of this model: the speed of the translational movement of the disk and its depth are constant; friction in the disk bearing can be neglected; the soil pressure on the lateral surface of the disc and the force of the soil reactions per unit length of its blade can be replaced by their mean values. An explicit expression is obtained for the traction resistance of a disk of a scuffler moving with an angle of attack, depending on its relative depth, the angle of attack, and the empirical coefficients. The adequacy of the constructed mathematical model is confirmed by comparison with known experimental data. It makes it possible to significantly reduce the number of full-scale experiments on the study of the interaction of flat discs of a scuffler with the soil, replacing them with computational ones, and reasonably carry out power and strength calculations of such discs. In addition, it can be used to optimize the parameters of the flat discs of the scuffler.

Наукові основи точного механічного обробітку ґрунту і перспективи його впровадження в Україні

Precision mechanical tillage is a fundamentally new agricultural strategy of farming, which is based on the use of information technology and new technical means and involves the implementation of technological measures for the main and pre-sowing tillage, taking into account the spatial heterogeneity of the physical properties of the root-content layer as indicators of differentiation of field tillage. In the article were presented the main provisions and stages of the method of determining the soil spatial heterogeneity of the plot. It was characterized indicators of precision mechanical soil tillage and promising methods for measuring parameters for precision tillage, including technical and software. It was proposed the preliminary norms of the physical properties of the treated layer for substantiation of the intensity of the basic mechanical soil tillage. It was proposed the characteristic of the main stages of the transition to precision farming and the mechanisms that should ensure its effective functioning, it was calculated the expected economic efficiency of precision farming. In the article was analyzed the spatial heterogeneity of arable land of Ukraine in terms of basic physical characteristics (structure, bulk density and penetration resistance) in the crop layer and plow sole. Some general patterns of manifestation of the spatial heterogeneity of the investigated properties of the soil cover of the land plots and the crop in all natural zones of Ukraine are analyzed, it serving as the main argument for the transition from generalized zonal technologies to precision mechanical tillage. The baseline data for the technological substantiation of the development of precision tillage (according to the content of the blocks in the seed layer) was worked out. Prospects for the introduction of precision agriculture in Ukraine are considered, based on the successful experience of mastering precision farming systems. Key words: soil, precision tillage, spatial heterogeneity, physical properties.

Study of the process of soil strip tillage by vertical milling adapter

The substantiation of expediency of developing and determining optimal parameters of the implement for pre-sowing soil tillage by the Strip-till technology, was presented. The technical solution of the vertical milling adapter for strip tillage of soil, which is protected by an invention patent, was developed. The analytical study of the influence of vertical milling adapter on working medium indicates the achievement of high-quality soil crushing and stirring with the adjustable parameters of cultivation depending on the conditions of its performance and the assigned quality indicators. On the basis of regulative documents, the procedure of conducting laboratory and field studies was substantiated and the experimental plant with vertical milling adapters was developed. The factors, influencing the work of the experimental plant and the optimal indicators of quality of the technological process, were defined. We established the dependence of the parameters of tillage quality on the adapter parameters, according to which the maximum content 77.5 % of fractions with optimal diameter from 0.001 to 0.005 m and from 0.005 to 0.01 m in the cultivated layer is achieved at angular rotation velocity of the adapter disks 26.5 s –1 and velocity of translational motion 2.2 m/s; the optimal value of density 1.2 ... 1.25 g/cm 3 is achieved at angular velocity of rotation of adapter disks 14…16 s –1 at different values of velocity of translational motion; the maximum content of plant residues 79 % of optimum size from 0.005 to 0.03 m is achieved at angular velocity of rotation of adapter disks 26.5 s –1 and velocity of translational motion 1.2 m/s.

Оптимізація норми висіву насіння сої залежно від групи стиглості сорту для умов Центрального Лісостепу України

Soybean is a crop plastic to such characteristic as plant allocation on the area. Numerous studies of different varieties demonstrate this fact. That is why optimal density of soybean plants must be determined by experimentally research for each separate variety. The research aim is to establish optimal seeding rates of soybean varieties of early-ripening and fast-ripening groups. The experiment was founded in the conditions ofprivate farm “Pryorillya” Novi Sanzhary district, Poltava oblast. The farm is situated in the central forest steppe of Ukraine. This part of our country has temperate-continental climate. The research object is soybean varieties Terek, Vilshanka, Kuban and Luna. The fields of our experiment were sown by winter wheat last year. The soil is deep chernozem soil, with little humus and average humus content. The technology of soybean cultivation in the experiment was characterized by the following stages: decortication of stubble remains was donein the second decade of July, ploughingto the depth of 22-24 cm was done in the second decade of September. In spring when soil became physically mature closing of moisture was conducted. Before sowing soybean there was possibility of doing two cultivations depending on weeds growth. Pre-sowing tillage of experimented plots of land was made in the second decade of May: cultivation to the depth of 10-12 cm including harrowing to the depth of 6-8cm. Soybean was sown by drilling method with row-spacing of 15cm in the second decade of May. The depth of seed covering was 4 cm,seeding rate for each variant was applied according to the experiment scheme. Seeding material was treated with rhizotorphinbefore sowing. Weed was controlled by one pre-sowing and two post-sowing harrowing by light, spike-tooth harrow.Pre-sowing harrowing was used in five days after crop sowing. The first pre-sowing harrowing was done in the period when rows marked and the second pre-sowing harrowing was done while coming two true leaves of soybean plants. All other technological operations concerning crop cultivation for all variants of the experiment were done similarly. According to the research results during 2013-2015 yearsamong fast-ripening varieties variety Vilshanka formed the highest yield. Yield of variety Vilshanka varied from 2.26 to 2.46 t/ha. Productivity of variety Terek in 2013-2015 years was at the level of 1.91-2.34 t/ha. Depending on density of plants on sown area yield of variety Terek was the greatest ( 2.25 t/ha) on the variant with seeding rate of 900 thousand/ha. Maximal yield of variety Vilshanka of 2.43t/ha was gained on the variant with seeding rate of 900 thousand/ha. During 2013-2015 years variety Kuban produced the highest yield among early ripening varieties. Yield of variety Kuban varied from 2.28-2.64 t/ha. Variety Luna formed yield at the level of 2.26-2.44 t/ha during the same period. Depending on density of plants on sown area variety Kuban produced the greatest yield of soybean (2.57 t/ha) on the variant with seeding rate of800 thousand/ha. Seeding rate of 800 thousand/ha influenced on productivity of variety Luna in the best way. Yield of variety Luna was 2.41t/ha. Conclusions and perspectives of further researches. Impact of variety qualities and seeding rates on the level of soybeanyield has been established. Influence of weather conditions on formation of yield of soybean varieties of different ripeness group has been analyzed. It has been determined that during three research years the most favourable weather conditions for yield formation were in 2015. Early-ripening varieties produced higher yield among the groups of variety ripeness. The seeding rate of 900 thousand/ha affected yield formation of varieties of fast-ripening group in the best way. For varieties of early-ripening group optimal conditions for gaining high yield were created in agrophytocenosis with seeding rate of 800 thousand/ha. On average during three research years variety Kuban produced the highest yield at the levelof 2.57 t/ha.According to duration of vegetation periodvariety Kuban belongs to early-ripening group. Variety Vilshanka formed the highest yield at the level of 2.43 t/ha among fast-ripening varieties. Thus, it has been defined that for optimization of conditions of soybean growth and development nutrition area must be corrected according to the group of variety ripeness. That is whystudy of impact of soybean plant density for new varieties is a perspective of further research.

Spatial heterogeneity of physical properties of the soils in Ukraine

Aim. To investigate structural composition (lumpiness), bulk density and penetration resistance in soils of Polissia, Forest-Steppe and Steppe. Methods. The experimental plots were allocated on the fi elds in a regular network. The measurements performed before harvesting testifi ed to an equilibrium condition of soil physi- cal properties. The data ware processed by the geostatistical method. Results. The key parameters of spatial heterogeneity (variation factors, histograms, autocorrelation function, variogrammes, 2-D and 3-D diagrams, etc.) were received. The heterogeneity of physical properties, revealed in all soils, is characterized by moderate and increased values. As a result the investigated fi elds were divided into three agrotechnological groups by qualitative parameters of their physical properties. Conclusions. The recommendations on pre-sowing or basic tillage of various intensity – without tillage (if parameters are close to the requirements of the sown culture), with moderate tillage of zone type (if parameters are close to modal values) and with tillage of the enhanced intensity (if parameters are unsatisfactory and more intensive pre-sowing tillage is required) were formulated for each group.

Wykorzystanie biostymulatora Nano-Gro i międzyplonu ścierniskowego jako czynnika fitosanitarnego w monokulturowej uprawie pszenicy ozimej

Summary One-factorial field experiment was conducted in 2010–2013. The aim of the study was to evaluate the usefulness of Nano-Gro biostimulant and stubble catch crop in reducing the occurrence of stem base diseases of winter wheat growing in continuous crop under traditional or reduced post-harvest and pre-sowing tillage and the influence of these factors on wheat productivity. The significantly higher infection of stems and roots of winter wheat growing in continuous crop as well as the decrease in grain yield by 12.3% were observed in relation to crop rotation. In plowing system the seed-dressing with Nano-Gro biostimulant and the combined use of that product with the annual plowing down stubble catch crop of white mustard significantly reduced the infection of stem base respectively by 28.7 and 21.9% compared with monoculture without regenerative practices. After tillage simplification stem base diseases reduction (by 17.5%) were found only after plowing down biomass of cat ch crop. The degree of the root system infection generally did not depend on tillage and regenerative practices but there was significant correlation between grain yield and index of root infection.

Effect of cover crops on emergence and growth of carrot (Daucus carota L.) in no-plow and traditional tillage

<p>The aim of the experiment was to determine the influence of cover crop biomass incorporated into the soil at different times and using different treatments on carrot emergence and growth. 7 species of cover crops were included in the study: <em>Secale cereale</em>, <em>Avena sativa</em>, <em>Vicia sativa</em>, <em>Sinapis alba</em>, <em>Phacelia tanacetifolia</em>, <em>Fagopyrum esculentum</em>, and <em>Helianthus annuus</em>. </p><p>Number of emerged carrot plants significantly depended on the cover crop used and on the method of pre-winter and spring pre-sowing tillage. Carrot emerged best after a rye or oats cover crop. Regardless of the cover crop species used, the largest number of carrots emerged in cultivation on ridges. In other variants of no-plow tillage, number of seedlings was significantly lower and did not differ from that under traditional plow tillage. The highest leaf rosettes were formed by carrot growing after a rye or oats cover crop. The highest rosettes were produced by carrots in the treatments where tillage was limited to the use of a tillage implement in spring and the lowest ones after pre-winter plowing. The effect of tillage on the emergence and height of carrot leaves largely depended on weather conditions in the successive years of the study. The largest number of leaves was found in carrots grown after a buckwheat cover crop and in cultivation without cover crop, while the smallest one after phacelia and white mustard. Carrots produced the largest number of leaves after a sunflower cover crop and the use of a tillage implement in spring, while the number of leaves was lowest when the mustard biomass was incorporated into the soil in spring. The use of cover crops significantly increased the mass of leaves produced by carrot as compared to the cultivation without cover crop. The largest mass of leaves was produced by carrots grown after the phacelia and mustard cover crops. Conventional plow tillage and pre-winter tillage using a stubble cultivator promoted an increase in the mass of carrot leaves.</p>

Effect of presowing tillage on hydrophysical properties of soil and winter wheat yield under irrigated conditions in southern Kazakhstan

Presowing tillage when growing winter wheat under irrigation conditions must be done in relation to the weather conditions. Under favorable conditions, presowing cultivation to a depth of 8–10 cm is recommended. This promotes optimal soil density and maximum yield of winter wheat (up to 48.9 centners/ha). In dry years, the given presowing tillage methods didn’t have a substantial effect.

Энергоресурсосберегающие технологии и техника для обработки почвы и посева в засушливых условиях

The paper presents results of research on the effective ways and means for tillage and seeding in the cultivation of crops in drought weather conditions. In order to improve the treatment quality, moisture-accumulating capacity and water saving of the soil in cropping technology with minimum tillage, including its final (finish) preparation for sowing with lower power consumption, we proposed new tillage methods. The first method involves post-harvest surface moisture-challenging loosening the stubble to a depth of 3-5 cm, the main non-recourse autumn moisture-absorbing loosening to a depth of 20-30 cm, deep moisture-accumulating Diesel hoeing to a depth of 40-65 cm, the spring surface moisture-closing loosening to a depth of 4-5 cm and moisture-mulching pre-sowing tillage to a depth of 4-5 cm with a seal seed bed and combing the weeds in the stage of “white thread”. The second method comprises the moisture-accumulating phase, which is performed in the autumn, when in the soil a vertical slit with a controllable pitch was made by spade working units and placing them in a staggered manner. Then we perform a second spring moisture-saving phase by solid surface loosening and mulching with rotary tools with working units to a depth of seeding. So that to implement the proposed methods the authors developed a set of tillage and seeding equipment (69 types of devices, 30 types of working units, 35 types of plug-in modules). Their production was mastered. The developed machines provide higher yields by 5 kg per hectare, reduce energy and labor costs up to 50%, have a competitive advantage over domestic and foreign counterparts.

Effect of different pre-sowing tillage on quantity and quality of parsnip (Pastinaca sativa L.) root yield in ridge cultivation

Parsnip is a very valuable vegetable due to its nutritional value and dietetic quality. It is moreover herbal raw material abundant in active substances. The yield quality of vegetables greatly depends on thorough pre-sowing soil tillage. The present study aimed at evaluating the influence of different presowing soil tillage (medium-deep ploughing, cultivating) and plant growing methods, flat or ridge cultivation, on the yield of parsnip and some biometric traits of its roots. The field experiment was carried out in 1999, 2000 and 2002 on lessive soil with the granulometric composition corresponding to medium silty loam. The parsnip cultivar 'Półdługi Biały' was the experimental plant species. The cultivation of parsnip on ridges had a significant influence on increased total yield of roots and decreased yield of small roots, as compared to flat cultivation. A significant increase in unit weight of the root and its diameter in the top part was also recorded in the latter type of cultivation. Spring pre-sowing tillage had no significant effect on parsnip yields. An increasing trend was observed only for total and marketable root yield in the ploughed plots. When parsnip is grown on lessive soil (which has an unstable structure), plants cultivated on ridges after spring pre-sowing plough are the most beneficial treatment combination.

Growth and Yielding of Onion Under Conservation Tillage

Growth and Yielding of Onion Under Conservation Tillage A field experiment with conservation tillage was set up to study the effect of using cover crops: spring rye (Secale cereale) and vetch (Vicia sativa), and various methods of soil preparation prior to sowing: no-tillage, rotary disk ploughing in the spring, and pre-winter disk ploughing, on the growth and yielding of onion cv. Wolska as compared with conventional cultivation methods. Sprouting of onion plants was best on those plots where spring rye mulch had been mixed with the soil during pre-winter disk ploughing. Mixing the soil with the biomass of vetch by disk ploughing in the spring reduced the extent of sprouting. Growth of onion plants was best following traditional soil cultivation. On those plots, onion plants were the tallest and produced the most leaves. The soil conservation factor employed by taking advantage of the mulching effect of intercrop plants of spring rye and vetch was found to reduce the total and marketable yields of onion in comparison with traditional cultivation. The most beneficial pre-sowing tillage method for onion was traditional tillage consisting in pre-winter ploughing and soil preparation treatments in the spring, without the presence of a mulching crop. Among the soil mulching plants under comparison, a more beneficial effect on onion yields was produced by the spring rye. As far as conservation tillage is concerned, the best effects were obtained following spring tillage in which rye mulch was mixed with the soil by disk ploughing.

The Effect of Different Soil and Plant Cultivation Methods on Yield and Chemical Composition of Scorzonera Roots

The Effect of Different Soil and Plant Cultivation Methods on Yield and Chemical Composition of Scorzonera Roots In 1997-2000, field experiments were carried out on a grey-brown podzolic soil. The experimental plant was scorzonera (Scorzonera hispanica L.) cv. Einjährige Riesen. The aim of the experiments was to assess the yields of scorzonera roots in different soil and plant cultivation systems: ridge and flat cultivation, reduced soil tillage prior to sowing (shallow tillage), and the application of cover crops (Sinapis alba L., Vicia sativa L., Phacelia tanacetifolia B., Avena sativa L.) in conservation tillage and no-tillage systems. Reduced spring tillage did not have a negative effect on the yields of scorzonera roots. Cultivation of plants on ridges had a positive effect on the total and marketable yields of roots in comparison with flat soil cultivation. Mulching with cover crops had a significant influence on the increase in the marketable yield of roots. No-tillage cultivation did not have a negative effect on the total and marketable yields of roots. Reduction in spring tillage prior to sowing, soil mulching, and no-tillage cultivation had no negative effects on the inulin content of scorzonera roots. Among the investigated cover crops, Sinapis alba L. was the most beneficial plant for increasing the inulin content of roots. Cultivation of plants on ridges and flat soil, and reduction in spring pre-sowing tillage did not have a significant effect on the protein content of roots. Irrespective of the soil cultivation methods, a significantly higher protein content was found in the roots harvested from the plots mulched with Vicia sativa L. The various plant cultivation conditions exerted a considerable influence on nutrient uptake. Roots of the plants cultivated on ridges contained higher amounts of P, K, and Ca. Soil mulching created better conditions for nutrient absorption. A significant effect of Sinapis alba L. in increasing the P and K content of roots was also observed.

Technical, Economical and Ecological Estimation of Up-To-Date Combined Soil Tillage, Fertilising and Sowing Machines

Comparative studies have been carried out to estimate the possibilities, purposefulness and efficiency of combine soil tollage, fertilising and sowing machines and units for field crops used on peasant farms under the Baltic conditions. It is found out that most widely used machines and units are aggregates combining pre-sowing tillage of soil (combined cultivators, or revolving power harrow), mineral fertiliser application (pneumatic distributors) and grain sowing (pneumatic, or mechanical sowing machines). As to the agrotechnical terms, the ploughing-sowing aggregates may have limited application. The most suitable are tractor-mounted machines. For combined aggregates preference should be given to more powerful tractors having frontally mounted equipment as well. In contrast to single-operational machines, the use of combined aggregates removes the weather risk, improves the quality of work, raises their efficiency, reduces the consumption of energy and fuel (accordingly, the amount of harmful exhaust gases) and cuts the total costs by 10-18 %. For agrotechnical, energetic, economical and ecological considerations the up-to-date combined aggregates of soil tillage; fertiliser application and sowing are efficient and should be widely introduced on the farms of Latvia.

On-farm seed priming to accelerate germination in rainfed, dry-seeded rice

Demand for rice is increasing in West Africa, but farmers in upland rice areas face the twin constraints of drought and competition with weeds. Fast germination, establishment, and vigorous early growth of seedlings are essential to produce reasonable yields, particularly where presowing tillage and seedbed preparation are minimal.

Weeding method and pre-sowing tillage effects on weed growth and pearl millet yield in a sandy soil of the West African Sahelian zone

Weed control for the West African Sahel rainfed crops is done mainly manually, resulting in high labor requirements. Because of the seasonality of rainfed farming, weed control is often late and incomplete, resulting in considerable losses in crop yield. We examined the case of weed control in continuously cultivated pearl millet ( Pennisetum glaucum (l.) R. Br.) on a sandy soil. During 3 years we evaluated the effects of pre-sowing ridging and combinations of hand and mechanical weeding powered by donkeys on: seasonal weed growth (separating within-row and between-row weeds), pearl millet yield, and labor requirements for weeding. Four weeding methods resulted in levels of weed control decreasing in the order: full field hand weeding (W f); between-row weeding by animal traction plus additional within-row hand weeding (W a + h); between-row weeding by animal traction (W a); and no weeding (W 0). Weeding method was the single most important factor that affected weed growth and, hence crop yields. Depending on the year, average weed dry matter at harvest ranged from 140 to 270 kg ha −1 for method W f to 3000 to 3520 kg ha −1 for method W 0. Correspondingly, the highest millet yields ranging from 279 to 1012 kg ha −1 were obtained with W f with a total weeding labor requirement of 70.1 h ha −1. The W a + h method required 51.8 h ha −1 and resulted in yields, depending on the year, that were 78 to 100% of the W f method. The W a method resulted in unchecked within-row weed growth that exceeded those in weedy check plots, and reduced crop yield to 28 to 34% of W f. Finally, unchecked weeds reduced yield to 2 to 10% of W f. Pre-sowing tillage reduced seasonal weed growth, increased crop yields, and was particularly effective in reducing the amount of crop weeds for the W a weed control method. The continuous growing of millet did not change the amount of seasonal weed dry matter during the experiment.