Crop harvesting: methods, timing and technique

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

All agricultural activity consists of a number of important stages. Harvesting, and especially grain harvesting, occupies the highest positions here. Let's take a closer look at the essence of this process: consider the timing, types of work, harvesting equipment and requirements for it, as well as much more that accompanies the harvest.

Crop harvesting - what is it?

Harvesting (in other words, reaping) grain is a combination of several operations:

• cutting an ear with or without a stem (the so-called combing);
• threshing;
• separation of grain from the threshing mass;
• cleaning grain from various impurities.

These works are performed in the indicated order, continuously or at some intervals in time. Grain harvesting is also related work:

• Sending the harvest from combines to the current or grain receiving point.
• Assembling and stackingstraw. Sometimes this product is simply crushed and scattered throughout the field.

Methods of harvesting grain

Grain harvesting is carried out in two ways, each of which is divided into several more:

• Combine:

  • single-phase;
  • two-phase.

• Industrial-flow (another name is non-combine):

  • ribbon;
  • sheaf;
  • three-phase.

Let's talk about each of them in more detail.

Harvesting grain with a combine

As we have already mentioned, wheat and other grain crops are harvested in two ways.

With a single-phase method, cleaning takes place according to the following algorithm:

1. The machine (most often it is the "Don", "Yenisey" harvester) cuts or combs spikelets with or without stems.
2. The harvested grain mass is threshed.
3. The combine extracts grain from the mass.
4. The grain is cleaned of all impurities and then loaded into the bunker.
5. Working with the non-grain part (straw and chaff): it is placed in a stacker or swath, after which it is crushed.
6. Straw is loaded into a trailer driven by a combine harvester, from where it is scattered across the field.

Another name for the method is direct combining. Use it for harvesting cereals of the following characteristics:

• lightly clogged;
• evenly ripening;
• sparse (density - 300 stems/1 m2);
• short (not taller than 50 cm).

Single-phase harvesting starts when the grain is fully ripe and its moisture content is not higher than 25%.

Two-phase or separate way. Work takes place according to the following scheme:

• Mowing stems with roller headers - the ripeness of the grain is waxy, and the humidity is 25-35%.
• Further, the stems are removed into 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 a harvesting machine such as windrowers is typical for the following type of grain:

• unevenly ripening;
• having a tendency to lodging and shedding;
• high-stemmed (more than 60 cm long);
• when density is less than 250 stems/m2;
• weedy crops.

Non-combine harvesting

Wheat and other grain crops are also harvested by industrial-flow methods:

• Tape. After mowing the stems, they are laid on special durable polyethylene tapes. Further, the filled polyethylene is pulled to the edge of the section, where the threshing of the mass filling it takes place. The products of this process are then transported to post-harvest processing, storage or further processing facilities.
• Sheaf. With this method, the stems are bevelled, after which they are formed into sheaves (cylindrical bales). Further, 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 processdelivered to warehouses or further processing facilities.
• Three-phase. Wheat harvesting takes place according to the following algorithm: mowing (or picking up the mass from the rolls), mass grinding procedure (sometimes the process does without it), 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 harvesters are involved in the work:

• Canvas-conveyor or drum pick-ups (SK-3U, PTP).
• Swath headers (ZHVN, ZHBA, ZHNS, ZHRB).
• Grain 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

Let's list the most important requirements for grain harvesting:

• Cleaning must be done quickly and efficiently, in ways that provide the best product quality.
• It is not allowed to leave gaps and flaws during the cleaning process.
• The cutting height of the stalk during harvesting depends entirely on the height of the grain stand. For a combine, this is a gap of 10-18 cm, for a windrower - 12-25 cm.
• The deviation of the actual cutting height from the set one should notbe more than 1 cm.
• Crop losses from the use of windrowers should not be more than 0.5% of the total mass.
• Crop losses when using a combine should not exceed the following shares: 2.5% - with the direct method of combining (where 1% is on the share of the harvester, and 1.5% is on the share of the thresher), 2% - when threshing and windrow pick-up (0.5% for pick-up and 1.5% for thresher).
• When cleaning the grain in the bunker, at least 95% of the immersed mass should come out with the direct method and at least 96% with the selection of windrows and threshing.
• Share of seed grain crushing - no more than 1%, feed and food - 2%, cereals and legumes - 3%.

Field preparation for work

For grain harvesting, the field needs to be properly prepared:

• Careful inspection and removal of all obstacles that interfere with the movement of equipment.
• Manual cutting of large obstacles that cannot be removed.
• Dividing the entire area into paddocks in such a way that each of them should be at least the daily productivity of one unit involved in cleaning equipment.
• The paddocks are areas of preferably rectangular shape, where the length is 6-12 times greater than the width for the tone movement of the technique and 3-5 times for the circular one.
• If the field area is more than 50 hectares, then plowing is done between the paddocks (width - two strokes of a five-plow arable unit) for fire safety.

Technology movement

The direction of movement of the aggregates must be completelycoincide with the direction of plowing - this greatly speeds up the process. When harvesting with felling headers, it is taken into account that the directions of movement of the harvesters should not conflict with the wind rose - they must coincide with the direction of the prevailing wind currents. Harvesting of laid bread is carried out at an angle to the laying down or across it.

Separate cleaning is the use of the following movement patterns of equipment:

• tone clockwise;
• going counterclockwise;
• shuttle;
• circular.

In direct combining, the machine moves in two main ways:

1. Tone with loopless one-way movements and tone with closed loop.
2. Circular with various turns: reverse, at an angle of 45 degrees.

When dividing the plot into paddocks, the following types of swaths are determined:

• corner;
• longitudinal;
• cuts;
• discharge line.

Grain Harvest

When does the grain harvest start? Works are carried out in the last summer month. They usually end at the end of August.

Yields are affected by weather conditions both at ripening and at harvest time. Heavy rains can greatly complicate the process, as well as strong winds - they lead to a plow. However, in our time, the specialists of the agricultural complex have access to technologies that allow them to harvest all the grain from the fields, regardless of environmental conditions.

Standard grain maturation time from milky to waxyripeness - 3-5 weeks. It is necessary to have time to collect these already fully poured ears in a few weeks. In addition to harvesting equipment, the necessary number of dump trucks for loading grain should be ready by the beginning of the harvest - sometimes they even rent additional equipment from state-owned enterprises.

Grain harvesting is only an intermediate stage of harvesting. It is followed by a more important one - the preservation of grain. Its post-harvest ripening ends only when it reaches the highest quality indicators. There are two important conditions for this:

• bean moisture should be below the set value so that the quality does not start to deteriorate;
• Storage temperature should not exceed 15 degrees;

Dry warm air ventilation is used to speed up drying. The whole process as a whole takes about 2 months.

Corn picking

Corn harvesting is not only the harvesting of the cobs, but also the harvesting of the stalk. Harvesting of corn for grain today is carried out by specialized machines "Khersonets".

Not all corn is harvested by machine - only non-lodging and early-ripening varieties with small leaves and dense stems, having erect cobs with well-separated wrappers. Harvesting is carried out in two directions:

• Cobs only (no threshing). Separate special mechanisms are used for cutting the stem, separating the fruit, chopping the "leg", cleaning the head, as well as drying and threshing the grains.
• Simultaneous harvest and threshing. For cutting plants, threshing grains and chopping leafy mass, more versatile devices are used, for example, a header for harvesting corn for grain or a converted combine. Sometimes corn with this method is harvested with a conventional grain harvester, and cleaned and dried at the hospital.

Corn picking starts when it reaches waxy ripeness. Cleaning lasts 10-15 days. Cobs with grains that go to seeds are selected at the very beginning of full maturity. If the grain moisture content does not exceed 30%, then harvesting can be combined with threshing.

Post-harvest processing of corn is divided into two directions:

• drying and processing of ground seed;
• drying and processing both shelled and unshelled cobs.

Collecting peas

When picking peas, it is important to correctly determine the beginning of the harvesting campaign. An early start threatens to stop the flow of nutrients, and a late one - crackling pods and falling fruits. Grain harvesting equipment can be used in dry and hot weather, when peas ripen quickly and at the same time.

If the weather is unstable, the air temperatures are low, the crop ripens unevenly, and there is a high infestation of the plot with herbs, then separate harvesting is necessary. This requires the ripening of fruits in windrows in the absence of rain - for their best drying.

The optimal start of the harvesting campaign is the presence of at least 80% of ripe pods on the bush. At this time, the peas should havecharacteristic yellow color and easy to separate 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 time of dew, it is better to refuse harvesting - this reduces the moisture content of the beans.

For harvesting peas for grain, single-drum combine harvesters will be the most optimal. Their speed must not exceed 6 km/h.

Prevent crop shortages

The yield of grain crops is not enough to collect the planned volumes of raw materials - it still needs to be properly processed and stored. To do this, do the following:

1. Checking the cutting height of the stem and the correct installation of pitched boards near the windrows.
2. Monitoring the accurate unloading of combine harvesters - preventing this process on the go, if the dump trucks approach the unloading auger incorrectly.
3. Careful processing of grain - uncleaned, it is not suitable for storage.
4. Using technologies to reduce grain moisture - thermal drying, active ventilation.
5. Compulsory crop disinfection.
6. Storage of raw materials only in specialized granaries.
7. Systematic testing for the suitability of seed material.
8. Timely pest control.

Crop harvesting is a complex and responsible process, consisting of several stages, different for different types of crops. At each stage, it is necessary to choose the most appropriate scheme of actions, which depends on the characteristics of the crop.