1.2. Agrotechnical requirements.

The surface treatment of the soil — one of the most important agrotechnical actions of receiving big crops of crops. Its primal problems — to loosen the high layer of the soil on depth of crops of seeds, to level the surface of the field, to provide a melkokomkovaty structure of a sowing layer, to create the condensed bed at a depth of seal of seeds, to destroy shoots of weeds, to close up the introduced mineral fertilizers, to keep moisture in sowing and arable layers, to improve microbiological activity and the food mode of the soil, to create conditions for productive work of farm vehicles on crops, care of crops and harvesting.

Methods of the surface treatment of the soil change depending on soil climatic conditions, a land relief, the developing weather conditions, features of the grown-up cultures, system of fertilizers, character of a contamination of fields, presence of wreckers, diseases and many other conditions of concrete economy. There fore the rational flow diagram of this operation has to be based on evidence-based system of agriculture of each economy and its main link — systems of crop rotations. The surface treatment is differentiated depending on a species of the cultivated plants. Increase in the standard of farming, introduction in practice of high performance herbicides allow to minimize its receptions. On the basis of explained the choice of technological processes regulate the procedure sheet on cultivation of crops depending on soil climatic conditions and a condition of the field before processing.

For ensuring the required quality of the surface treatment with tillage machines it is necessary to know and to strictly keep agrotechnical requirements. The chief agronomist of economy establishes the terms and duration of carrying out processing of the soil necessary the combined machines and units according to agrotechnical terms, the developed weather conditions and the sizes of fields. If the obrakbotka consists of several receptions, then it is desirable not to lacerate them in vremekn.

Now destruction no more than 10-15% of an eddish for one pass of the car when processing on depth to 16 cm and no more than 15-20% is considered admissible when loosening on depth to 30 cm. Processing of the soil has to be carried out to the established agrotechnical terms at optimum humidity. Permissible variations of average depth of loosening from set should not exceed ± 1 cm when processing on depth to 16 cm and ± 2 cm with a depth up to 30 cm, and should not exceed fluctuations of depth on width of capture the 4-5th. On joints of passes and between paws of tools rollers no more than 5 SI high, and in places of passing of racks - furrows by width checking no more than 15 cm and no more than 8 cm in depth are allowed. Roots of weed plants and a fruit drop need to be cut completely at a depth of the course of actions. Flaws on a joint of interfacing passes of the tool are not allowed. Flaws or admissions are not allowed. As flaws most often appear as a result of negligent driving of the tractor, judge them by the form traces of actions of cars and tools. Traces have to be pryamolineynykm.

The ends of the site process also accurately, as well as the main site on which diversity in any index of a kachestkv should not be looked through (for example to a glybistost, a surface grebnistost, seal of a weed rastiktelnost and a dung). Most often diversity of these indexes — result of work at different speeds, and also negligent driving of the unit and the poor a sostoyakniya of actions of cars and tools (blunt edges, a rusty working poverkhknost).

At any processing it is desirable to receive lumps of the soil of 1 in Size... 10 mm are also undesirable — particles less than 0,25 mm. These indexes depend on a type of processing and properties of the soil. They are hard-hitting, but are desirable.

Actions at the end of the processed site of the field should be switched on and off on one line; a permissible deviation — no more than ±0,5 m.

To each type of processing of the soil are shown specific a trebovakniya. It is not allowed that bezotvalny tools for loosening of soils subject to a wind erosion destroyed more than 10% of an eddish for one pass at shallow loosening and more than 25% — at deep and that at the same time the soil разруша¬лась to particles less than 1 mm.

In the high loose coating of the soil, lumps more than 3 cm should not sokderzhatsya, the grebnistost of a surface of an arable land has to be no more than 3... 4 cm.

Estimating quality of operation of tillage machines, consider a sokblyudeniye of all agrotechnical requirements, remembering that the main thing from them - fight against weeds.

Cultivators for continuous processing of the soil have to process the soil on depth not less than 8 cm. The deviation of average depth from the given is allowed by ±3 cm. In the top processed layer of earth there should not be lumps more than 10 cm by the naikbolshy size. The surface of the field after pass by a disk harrow has to be conjoint, and depth the razvalnykh of furrows and height the svalnykh of crests - no more than depth of processing. Weed plants have to be cut not less than for 97%.

2. Initial parameters Input datas are given in tab. 8.1: B — width of capture of a cultivator, m; a — depth of processing, cm; bo — the design width of a rykhlitelny paw, mm; α — the angle of entry of a paw into the soil, a hail.; θ — a corner between the planes limiting area of deformation of the soil, a hail.; lo — a paw sock departure concerning a rack, mm; f — a soil friction coefficient about a paw.