All agricultural activity consists of a number of important stages. Harvesting, and especially grain harvesting, occupies the highest positions here. Let’s carefully understand the essence of this process: we will consider the terms, types of work, harvesting equipment and requirements for it, as well as many other things that accompany the harvest.
Harvesting crops - what is it?
Harvesting (in other words, harvesting) of cereals is a combination of several operations:
- cutting an ear with or without a stem (so-called combing);
- threshing the crop;
- the selection of grain from the mass of threshing;
- cleaning grain from various impurities.
These works are performed in the indicated order, continuously or at certain intervals in time. Grain harvesting is also related work:
- Departure of the harvest from the combines to the current or grain collection point.
- Assembly and storing of straw. Sometimes this product is simply crushed and scattered throughout the field.
Grain Harvesting Methods
Harvesting grain is carried out in two ways, each of which inside itself is divided into several more:
- Harvester:
- Industrial-flow (another name - non-combine):
Let's talk about each of them in more detail.
Combine harvesting
As we have already mentioned, harvesting wheat, as well as other grain crops, takes place in two ways.
With a single-phase method, cleaning takes place according to the following algorithm:
- The machine (most often it is a Don, Yenisei combine) cuts or combes the spikelets with or without stems.
- The collected grain mass is threshed.
- From the mass of the harvester allocates grain.
- Grain is cleaned of all impurities and then loaded into the hopper.
- Work with the non-cereal part (straw and genital): it is stacked in a stacker or roll, and then crushed.
- The straw is loaded into a trailer driven by a combine, from where it is scattered throughout the field.
Another method name is direct combining. Use it for harvesting grain following characteristics:
- slightly clogged;
- evenly ripening;
- sparse (density - 300 stems / 1 m 2 );
- undersized (not higher than 50 cm).
Single-phase harvesting begins when the grain is fully ripe and its moisture content is not higher than 25%.
Two-phase or separate method. The work takes place according to the following scheme:
- Mowing the stalks with roll reapers - the ripeness of the grain is waxy, and the humidity is 25-35%.
- Further, the stems are harvested in rolls, where they dry out for some time. During this period, due to the nutrients contained in the stems, the grain has time to ripen.
The use of this method and such a harvesting machine as roller reapers is typical for the following type of grain:
- unevenly ripening;
- having a tendency to lodging and shedding;
- high stem (more than 60 cm in length);
- with a density of less than 250 stems / m 2;
- clogged crops.
Non-Combine Cleaning
Harvesting wheat and other crops is also carried out by industrial-flow methods:
- Tape . After mowing the stems, they are laid on special durable polyethylene tape. Next, the filled polyethylene is pulled to the edge of the site where the threshing mass is thrashing. Then the products of this process are transported to the points of post-harvest processing, as well as storage or further processing.
- Sheaf . With this method, the stems are mowed, after which they are formed into sheaves (cylindrical bales). Then these bales are tied with twine, after which they are sent to processing points. Here, the crop passes through threshing, then the products of this process are delivered to warehouses or to further processing points.
- Three phase . Wheat harvesting is carried out according to the following algorithm: mowing (or selection of mass from rolls), mass grinding procedure (sometimes the process can be dispensed with), transportation to processing points, drying, delivery to warehouses, threshing and further transportation of grain and straw to processing sites or storage.
Harvesting Equipment
Typically, the following sweepers are involved:
- Cloth-conveyor or drum sorters (SK-3U, PTP).
- Roll headers (ZhVN, ZhBA, ZhNS, ZhRB).
- Combine harvesters (Don, Yenisei, Niva-Effect, Vector).
The following equipment is used for grain processing:
- receiving units;
- grain cleaning machines ;
- grain loaders with throwers;
- grain dryers;
- grain cleaning and drying complexes.
Agrotechnical conditions for grain harvesting
We list the most important requirements for grain harvesting:
- Cleaning should take place quickly and efficiently, in precisely such ways that would ensure the best indicators of product quality.
- During the cleaning process it is not allowed to leave passes and blemishes.
- The height of the cut stem when harvesting is completely dependent on the height of the stand. For the harvester, this is a span of 10-18 cm, for a roller header - 12-25 cm.
- The deviation of the actual cutting height from the set should not be more than 1 cm.
- Losses from the use of roll reapers should not exceed 0.5% of the total mass.
- Crop losses when using the harvester should not exceed the following shares: 2.5% - with the direct method of combining (where 1% - on the share of the header, and 1.5% - on the share of the thresher), 2% - when threshing and selecting rolls (0 , 5% is the share of the pick-up, and 1.5% is the share of the thresher).
- When cleaning grain in the hopper, at least 95% of the submerged mass should come out with the direct method and at least 96% with the selection of rolls and threshing.
- The share of crushing of seed grain is not higher than 1%, feed and food - 2%, cereals and legumes - 3%.
Field preparation for work
To harvest the grain field, you need to properly prepare:
- A thorough inspection and removal of all obstacles that impede the progress of the equipment.
- Manual mowing of large obstacles that are not possible to remove.
- Breakdown of the entire site into corrals in such a way that each of them in size should be at least the daily output of one unit involved in cleaning equipment.
- Corrals are areas of preferably rectangular shape, where the length is 6-12 times longer than the width for the tonal movement of equipment and 3-5 times longer for the circular.
- If the field area is more than 50 hectares, then plowing is made between the pens (width - two moves of the five-plow arable unit) for fire safety purposes.
Technology movement
The direction of movement of the aggregates should completely coincide with the direction of plowing - this greatly speeds up the process. When harvesting with felled reapers, it is taken into account that the directions of the reapers should not conflict with the wind rose - their coincidence with the direction of the prevailing wind currents is necessary. Harvesting laden bread is carried out at an angle to lodging or across it.
Separate cleaning is the application of the following traffic patterns:
- tone clockwise;
- rut counterclockwise;
- shuttle;
- circular.
With direct combining, the machine moves in two main ways:
- Tone with loopless one-way movements and tone with a closed loop.
- Circular with various turns: reverse, at an angle of 45 degrees.
When breaking the site into corrals, the following types of swaths are determined:
- angular;
- longitudinal;
- slopes;
- discharge line.
Grain harvest
When does harvesting begin? Work takes place in the last summer month. At the end of August they usually end.
Yields are affected by weather conditions both during ripening and during harvesting. Torrential rains can greatly complicate the process, as well as strong winds - they lead to a stump. However, in our time, specialists of the agricultural complex are available technologies that allow you to collect all the grain from the fields, regardless of environmental conditions.
The standard time for grain maturation from dairy to wax ripeness is 3-5 weeks. You need to have time to collect these already fully-fledged ears in a few weeks. In addition to harvesting equipment, by the beginning of the harvest, the necessary number of dump trucks for loading grain should also be ready - sometimes they even rent additional equipment from state enterprises.
Harvesting grain is only an intermediate stage of harvesting. Behind it comes the more important - the preservation of grain. Its post-harvest ripening ends only when it reaches the highest quality indicators. There are two important conditions for this:
- grain moisture should be lower than set so that the quality does not begin to deteriorate;
- storage temperature should not exceed 15 degrees;
To speed up the drying, ventilation using dry warm air is used. The whole process as a whole lasts about 2 months.
Corn picking
Harvesting corn is not only collecting ears, but also leafy mass. Harvesting corn for grain today is carried out by specialized Khersonets machines.
Not all maize is harvested by a machine method - only non-growing and early ripening varieties with small leaves and dense stems, with erect cobs with well-separated wrappers. Harvesting is carried out in two directions:
- Only collecting ears (without threshing) . Separate special mechanisms are used to cut the stem, detach the fetus, chop the “leg”, clean the head, and also dry and thresher the grains.
- Simultaneous harvest and threshing . For cutting plants, threshing grains and grinding leafy stalk, more universal devices are used, for example, a header for harvesting corn for grain or a converted combine. Sometimes corn with this method is harvested with an ordinary grain reaper, and is cleaned and dried in a hospital.
Harvesting of corn begins when it reaches wax ripeness. Cleaning lasts 10-15 days. Ears of corn, which go to the seeds, are selected at the very beginning of full maturity. If the moisture content of the grain does not exceed 30%, then harvesting can be combined with threshing.
Post-harvest corn processing is divided into two directions:
- drying and processing of threshed seed;
- drying and processing of both peeled and unpeeled ears.
Pea harvest
When collecting peas, it is important to correctly determine the beginning of the harvesting harvest. An early start threatens to stop the influx of nutrients, and a late start threatens crackling of the pods and loss of fruit. Harvesting equipment can be used in dry and hot weather, when peas ripen quickly and simultaneously.
If the weather is unstable, the air temperature is low, the crop matures unevenly, and there is also a high clogging of the site with herbs, then a separate harvest is necessary. This requires ripening of the fruits in the rolls in the absence of rain - for their best drying out.
The optimal beginning of harvesting strada is the presence of at least 80% ripe pods on the bush. At this time, the peas should have a characteristic yellow color and be easily separated from the mother bush. Harvesting usually lasts no more than 4 days, and ripening - 5. Wet peas are harvested only in rainy weather. At the moment of dew, it is better to refuse to harvest - this reduces the humidity of the beans.
For picking peas for grain, single-drum combine harvesters will be the most optimal. Their speed should not exceed 6 km / h.
Crop shortage prevention
Crop yields are not enough to collect the planned volumes of raw materials - it is still necessary to properly process and preserve them. To do this, do the following:
- Control of the height of the cut of the stem and the correct installation of pitched boards at the rolls.
- Control over the accurate unloading of combines - preventing this process on the go, if the trucks do not properly approach the unloading auger.
- Thorough processing of grain - unpeeled, it is not suitable for storage.
- Application of technologies to reduce grain moisture - thermal drying, active ventilation.
- Mandatory crop disinfection.
- Storage of raw materials only in specialized granaries.
- Systematic verification of the suitability of seed material.
- Timely pest control.
Harvesting crops is a complex and responsible process, consisting of several stages, different for different types of crops. At each of its stages, it is necessary to choose the most suitable scheme of actions, which depends on the characteristics of the crop.