Quality of field work is the degree of compliance of quality parameters and timing of the actual performance of individual techniques with the requirements of standards or agrotechnical requirements. The quality of field work determines the yield of crops.
Quality of fieldwork depends on the technical condition of tillage and seeding units, proper adjustment, quality of previous tillage, soil conditions, timing of work and other conditions.
Violation of agrotechnical requirements for tillage leads to:
- deterioration of growth and development conditions of cultivated plants;
- lower yields;
- reducing the effectiveness of fertilizers and chemical plant protection products,
- reduction in the effectiveness of land reclamation,
- the possibility of the development of soil erosion,
- reduction of soil fertility.
As a consequence, there should be organized a permanent control over the quality of fieldwork, and in particular over the quality of performance of certain techniques of tillage.
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork (Русский Español)
- Problems of energy conservation and soil compaction
Navigation
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork (Русский Español)
- Problems of energy conservation and soil compaction
The quality of performance of a separate technique of tillage, sowing and others is determined by a set of indicators, which characterize the degree of suitability of the soil for optimal plant growth and performance of subsequent technological operations.
Evaluation can be done on a three- or five-point system: excellent, good, satisfactory, poor and very poor. Each technique is evaluated separately and the total score determines the quality of field work.
In production conditions the work is evaluated as good, if it is performed within the prescribed period of time in compliance with all agro-technical requirements. Satisfactory is the work performed on time, in compliance with the basic agronomic requirements, but some quality indicators may be slightly out of the allowable deviations, without having a significant impact on the yield.
Poor is the work performed with gross violations of deadlines or agrotechnical rules, resulting in a significant reduction in yields. In this case, the work is rejected and redone.
Assessment of the quality of the work can be carried out during their implementation, which allows you to identify and eliminate deficiencies in advance.
Evaluation of tillage quality
Discing
The main indicators for assessing the quality of discing include:
- time of work performance,
- the depth of loosening and its uniformity,
- degree of undercutting of weeds and cutting of perennial rhizomes of weeds,
- ridging of the soil,
- crumbling of the cultivated layer,
- absence of gaps and untilled strips.
In addition, the observance of straightness of movement, the depth of the breakdown furrow at the junction of the middle batteries, which should not be higher than the set depth of discing, is taken into account.
Timeliness of discing significantly affects the effectiveness of this technique. It is carried out immediately after harvesting cereals, not later than 1-2 days, in order not to allow the soil to dry out. Allowable deviation of loosening depth from the specified one is not more than 10%. The loosening depth is measured at the beginning of the machine’s work and in the course of performance. It is recommended to make at least 25 measurements on the area equal to the shift task of the machine, and calculate the average depth of loosening. The depth is determined with a ruler or metal rod with graduations as the distance from the surface of the uncultivated soil to the bottom of the furrow.
When measuring the depth of the cultivated field, it is necessary to reduce the obtained average value by an elevation coefficient of 10-15%. The elevation coefficient is the ratio of the average depth of the cultivated disced layer to the average depth of discing.
The degree of cutting of weeds is determined by counting the number of uncut plants on a square of 1 m2. Counting platforms are set along the diagonal of the field at the rate of one platform per 10 hectares of the field area.
The presence of gaps and untilled strips is determined visually during inspection of the field.
Plowing
Quality of plowing depends on the condition of the field at the time of plowing, size, configuration, soil moisture, technical condition of the machine and other conditions. Before plowing, the field must be free of straw, stones, coarse plant residues, and if necessary, the field must be leveled. The best quality of loosening and crumbling is achieved when tilling the soil in the state of physical ripeness; tilling dry soil leads to strong clumping and requires large energy costs.
Soils with different technological properties must be cultivated with different plough bodies. For plowing of cohesive sodded soils ploughs with helical bodies or frontal ploughs, which are equipped with helical working surfaces, are used. All types of plowing old plowed lands, with the exception of plowing the fallow land and steam, filling organic fertilizers, processed by plows with cylindroidal plow bodies with skimmers. In areas with insufficient moisture and soils subjected to wind erosion, plows with no-till bodies are used.
On fields with a thickness of fertile stand less than 20 cm plowing is carried out to a depth equal to the thickness of fertile stand, and the subsoil layer is simultaneously processed by ploughs to break the plow footing and the gradual increase in the thickness of fertile stand.
In production environments the quality of plowing is evaluated at the beginning of work and in the course of work.
The main indicators of the quality of plowing:
- plowing time;
- depth;
- uniformity;
- degree of crumbling of the soil;
- clumpiness;
- ridging;
- quality of piled ridge and breakage furrow;
- straightness of plowing;
- the degree of embedding of crop residues, fertilizers, weeds;
- absence of untilled strips.
Table. Agrotechnical requirements for plowing
| Deviation of average plowing depth from the specified depth, % | |
| Uniformity of plowing depth, % | |
| Soil crumbling (proportion of clumps larger than 5 cm in diameter), % | |
| Piled ridge height, cm | |
| Plowing depth under the piled ridge | |
| Embedding plant residues, weeds, fertilizers | |
| Plowing straightness (deviation from straightness per 100 m of run), cm | |
| The presence of raw strips, wedges and other errors |
Timeliness of plowing is determined by comparing the set agronomic term with the actual one. Thus, in the central regions of the Non-Black Soil zone plowing for winter cereals is carried out immediately after harvesting the preceding crop within 5 days, no later than 2-3 weeks before sowing. Deviation from the established agrotechnical term leads to soil drying, excessive clumping, and field weeding.
A plow equipped with interchangeable bodies with helical mouldboards should turn the layer by 140…180° at a plowing depth of 25 cm. Front and linear plows must provide a full turn of the layer by 180°.
Allowable deviation of plowing depth from the set – no more than 10%, should be uniform. An exception is made for the first two passes of the machine in the piled corral. According to other recommendations, deviations on flat areas are allowed not more than 15%, on uneven areas – not more than 10%. Micro-relief of the field surface is considered uneven if deviations exceed 15 cm. The depth of plowing is measured with a furrow gauge or ruler by measuring the distance from the surface of uncultivated soil to the bottom of the furrow. For evaluation 25 measurements on several passes of the plough along the diagonal of the field are carried out. The deviation of the actual plough working width from the constructive one should not be more than ±10%.
Breakout furrows and pile ridges should be straight and barely noticeable. Deviation from straightness should not exceed ±10 cm per 100 m of run. Depth of plowing under piled ridge – not less than half of the specified. Breakout furrows are plowed after the end of plowing.
Crumbling of the soil is defined as the ratio of the mass of clods smaller than 5 cm to the total mass of the soil sample, expressed as a percentage. The size of selected sample is 40x30x30 cm. Quality of layer crumbling is judged by clumpiness (C), i.e. the share of clumps more than 5 cm in diameter (100-C). The crumbling of the layer when plowing old arable soils with general purpose plows should be at least 75% (the content of fractions up to 5 cm in size).
The clumpiness is determined by a frame with an area of 1 m2, divided into squares of 1 cm2. Perform 8-10 overlaps along the diagonal of the field. The clumps more than 5 cm in diameter falling in the frame are measured in length and width and their area is determined. The clumpiness is estimated as the ratio of the total area of the clumps to the area of the frame as a percentage. Clumpiness, occupied by clumps larger than 10 cm, is allowed no more than 15% of the arable area.
The cohesion and ridging of plowing characterize the uniformity of the height of all ridges and the surface of the plowed field without depressions and elevations, the absence of staggering in individual passes of the machine. It is determined by a profiler or by a 10-meter long measuring cord, which is laid across the ridges so that it repeats the surface of the field. The ratio of the extension of the cord to its projection shows the ridgeiness coefficient. Ridgeiness when plowing in the fall in conditions of moisture and on sloping lands has a positive value. When plowing in dry areas, for winter crops and main plowing, on the contrary, ridges are flattened. Ridge height should not exceed 5 cm for plows with cylindrical bodies, 10 cm for screw bodies and 4 cm for front and linear plows.
During moldboard plowing all weeds, stubble and crop residues, fertilizers, turf must be plowed. At plowing depth of 22-30 cm, plant mass should be incorporated to the depth of 10-15 cm with traditional plows and to the depth of 12-15 cm with front and linear plows. Depth of planting is determined by cutting the soil 40 cm wide (or the width of the plow) across the ridges to the depth of plowing.
Shallow plowing should ensure that 40-50% of stubble and crop residues are retained on the surface of the field. It is not allowed to crumble the soil into particles smaller than 1 mm.
One of the walls of the cut is made plumb, by which the upper and lower boundaries of the ploughed turf or plant residues are determined. According to the obtained data, a profile of a cross section with indication of the location of embedded turf is built.
In production conditions, the quality of embedded plant residues is determined visually by evaluating the amount of un-embedded stubble, turf per 100 m2 or 1 ha, which should not be more than 5.
The depth of plowing of field edges and headlands must correspond to the depth of plowing of the main area. Skipping between adjacent machine passes, unplowed wedges, plowing along the slope, except for overwatered lands are not allowed.
Flat-cutting
The quality of flat-cutting is evaluated according to the following indicators:
- term,
- working depth,
- uniformity,
- degree of soil crumbling,
- keeping of stubble on the surface of the field,
- adherence to joint overlaps in adjacent machine passes,
- ridging of the surface,
- straightness of tillage.
Table. Agrotechnical requirements for flat-cutting of the soil
| Deviation of the average depth of tillage from the set depth, % | ||
| Soil crumbling (fraction of clumps 3-5 cm in diameter at shallow tillage and 3-10 cm at deep tillage), % | ||
| Stubble retention rate (for one pass of the flat cutter), % | ||
| Height of ridges formed by ripper tines, cm | ||
| Width of furrows formed by ripper tines, cm | ||
| Trimming weeds | ||
| Overlap of adjacent unit passes, cm | ||
Timeliness of work, selection of implements and depth of flat-cutting are determined taking into account zonal features, soil type and moisture, biological characteristics of the crop, erosion risk, organizational and production conditions.
Loosening the soil is carried out in optimal periods: shallow – by flat-cut cultivators, such as КПШ-9, КПШ-11 at the depth of 8-16 cm and deep – by flat-cut deep tillers, such as КПГ-2-150, КПГ-250, ПГ-3-100 at 25-27 cm. The proportion of clods characterizing the degree of loosening of 3-5 cm for shallow and 3-10 cm for deep tillage should be the predominant part in the cultivated layer at the optimum moisture content of the soil.
Tillage depth should correspond to the specified one and be uniform. The permissible deviation of the average working depth from the specified one must not exceed ±1-2 cm for shallow tillage, and not more than ±2-3 cm for deep tillage. The working depth is determined across the entire working width of the machine with a metal rod with graduations. Measurements are taken not nearer than 30 cm from the track of the flat-cut unit. For objective evaluation 25-30 measurements along the field diagonal, on the area equal to the shift task, as a rule, 10 hectares are carried out.
The degree of stubble preservation on the surface during shallow tillage must be 85-90%, during deep tillage – at least 80-85%. To account for intact stubble on the surface of the soil are plotted area length of 10 m and a width equal to the width of the unit, on which measured the width of all the furrows left by each working tool plow. All measurements are summed up and the width of the tracks of the flat-cut unit is defined, expressing it as a percentage of the total length (10 m).
For example, on a 10 m long plot the total width of the damaged stubble strips is 1.5 m, then the degree of stubble conservation is equal to:
Roots of weeds during flat-cutting should be cut at the depth of the working bodies stroke, and the cultivated surface should be leveled. Ridges at the junction of ripper tines should be no higher than 5 cm, and the width of furrows in the places of tine legs passes – no more than 15 cm.
Gaps between adjacent machine passes, as well as gaps and unprocessed strips, wedges are not allowed. Turning strips are also processed to the specified depth.
Quality evaluation of pre-sowing tillage
The soil prepared for sowing (planting) must meet the following requirements: be fine lumpy, well loosened to the depth of sowing seeds, have compacted seed bed, weed vegetation is completely absent.
The clumpiness, i.e. the share of clods 3 cm in diameter and more must not be more than 15-20% in humid areas and 10% in arid ones. Clod sizes larger than 10 cm2 in the sowing layer are not allowed.
Quality of pre-sowing soil preparation is usually evaluated as a whole, rather than individual techniques, immediately before sowing.
Quality indicators of seedbed preparation include:
- timing of processing,
- tillage depth,
- uniformity of tillage,
- clumpiness,
- crumbling of the soil,
- degree of weed cutting,
- absence of uncultivated turning strips, wedges.
Table. Agrotechnical requirements for pre-sowing tillage
| Deviation of the average machining depth from the set depth, % | |
| Uniformity of soil tillage by depth, % | |
| Clumpiness (fraction of clumps larger than 3 cm in diameter), % | |
| Ridge height, cm | |
| Soil surface | |
| Trimming weeds | |
| The presence of raw strips, wedges and other errors |
Pre-sowing tillage is carried out before sowing or on the day of sowing.
An important indicator of pre-sowing tillage is thorough loosening of the soil to the depth of seeding and leveling of the surface. For this purpose, pre-sowing cultivation across or at an angle to the direction of plowing is used. Repeated tillage is carried out across the previous for better crumbling and leveling, on sloping lands – across the slope or along the horizontal relief.
The depth of loosened layer is determined with a metal ruler or a rod with graduations. For objective estimation carry out 25-30 measurements along the field diagonal and calculate the average value. The uniformity of the depth is determined by the deviation of the average processing depth from the specified one or by calculating the coefficient of field leveling.
Clumpiness and ridging are evaluated in the same way as for plowing.
The degree of weed undercutting is determined by overlapping a 1 m2 frame along the diagonal of the field and counting the uncut weeds. 10-15 counts are made per area, uncut plants are not allowed.
After finishing tillage of the field, cultivate turning strips, edges of fields. Untilled areas, ridges, depressions are not allowed.
The surface of the field cultivated by anti-erosion system must be windproof with at least 60% of the crop residues retained.
Evaluating the quality of sowing
Quality indicators of sowing (planting) include:
- sowing time,
- rates of seeding,
- established sowing depth,
- spacing of joints between rows,
- straightness of rows,
- absence of unseeded places.
Table. Agrotechnical requirements for sowing
| Deviation of the average sowing depth from the specified one, % | for small-seeded crops and grasses ±5 |
| Uniformity of seed embedment depth, % | |
| Seed rate deviation from the specified, % | |
| Deviation of the width of docked row spacing, cm | on adjacent aggregates ±4 |
| Row straightness (deviation from straightness per 100 m of run), cm |
Sowing (planting) should be carried out at the optimum time for the crop, taking into account its biological characteristics. Early crops are sown at the soil temperature of 4-6 ° C at the depth of the seed, late crops – 10-12 ° C.
Sowing should be carried out evenly with the set seeding rate. Deviations from the specified seeding rate should be no more than 4%. Uniformity of sowing of seeds by each seeding unit is determined by the number of seeds sown, for example, for a certain number of rotations of the seeder wheel. The seeds must be evenly distributed in the row at a given depth in a compacted bed and covered with loose soil. The deviation of the average sowing depth for cereals should be not more than ±1 cm, for fine seeds – not more than ±0,05 cm. Seeds on the surface are not allowed.
The sowing depth is determined by opening 2-3 rows from the front and rear coulters of seed drills, not following the tractor’s trail. To do this, first level the surface and measure the distance from the soil surface to the sown seeds. For an objective assessment at least 20 measurements are carried out along the diagonal of the field and several passes of the seeder.
For more accurate determination of the sowing depth use a cylinder with notches every 10 mm, in which the flaps are inserted. The cylinder is dipped into the row deeper than the seeds are sown, taken out and dissected by the sliders in 10 mm layers of soil. The seeds are separated from the soil on sieves and are counted according to their depth.
Straightness of the rows during sowing is estimated visually or by measuring the distance from the row to the straight line. The deviation should be no more than ± 10 cm per 100 m of the race, that is, the row must fit into a rectangle of 100×0,2 m.
Permissible deviation of docking row spacing at adjacent seed drills should not be more than ±2 cm, and the width of docking row spacing in two adjacent aggregate passes should not deviate from the specified width of the row spacing more than ±5 cm.
Turning strips, must be sown with the same seeding rate as in the whole field. Unseeded and double-seeded places are not allowed.
Evaluating the quality of crop care work
The quality of inter-row cultivation is evaluated according to the following indicators:
- tillage time,
- depth,
- uniformity,
- degree of crumbling of the soil,
- degree of weed cutting,
- absence of damage to crops.
The soil in the inter-row area must be tilled to depth, not allowing damage to the root system of the crop, with the observance of the protective zone in the rows.
The soil in the cultivated zone should be loosened, fine lumpy, leveled, except for crops requiring hilling. All weeds in the area of the cultivator working tools passage must be trimmed. Mineral fertilizers applied as top dressing – shall be embedded in the soil to a specified depth.
When hilling, wet soil must be covered to the stems of the plant. Damage to cultivated plants during the performance of tillage is not allowed. The quality control of care measures shall be carried out both at the beginning of work and during its implementation.
Productivity
The productivity of arable and other machines is the amount of work of a given quality done by them in the time interval T. Productivity is divided into theoretical (calculated) and actual productivity.
Theoretical productivity W is calculated by the formula:
W = 0.1BvT,
where B – design width of machine (plough), m; v – theoretical speed of machine, km/h.
Actual performance is always less than theoretical because of deviations of working width B, the actual speed vp and net working time Tp from the calculated values.
The working width of the machine may differ from the design one due to incorrect connection of machines to the tractor, erroneous adjustment of working tools, inaccurate machine operation, overlapping of the working width of individual machines included in the machine, poor technical condition and defects of the machines. The working speed of the machine differs from the theoretical one due to slipping of the undercarriage and poor technical condition of the tractor. Time during which the unit directly performs useful work (plowing, harrowing, etc.) differs from the calculated one, because part of the working time is spent on transfers, turns, stops for regulation, repair, cleaning and filling machines and on other organizational activities.
Therefore, the actual productivity is determined by taking into account the correction factor K by the formula
Wf = 0,1BvTK,
where K = BpvpTp / (BvT)
The organization of the units seek to ensure that the actual performance sought to the theoretical. To do this, they maximize the use of the design width of the working width, operate at higher speeds and optimally realize the time of the shift, also organize two- and three-shift units, especially in busy periods. Timely measures for maintenance of machines, compliance with the frequency of cleaning operations, lubrication, checking the condition of individual assemblies, working bodies, transmissions and their preventive adjustments are also of great importance.
To improve the maintenance of machines, group work of arable units is used.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Agricultural and Reclamation Machines. Klenin N.I., Sakun V.A. – M.: Kolos, 1994. – 751 p.: ill. – (Textbook and textbooks for higher education institutions).
Agricultural machinery. Khalansky V.M., Gorbachiev I.V. – Moscow: KolosS, 2004. – 624 p.: ill. – (Textbook and textbooks for higher education institutions).