CHAPTER XXXI - Barley: Post-Harvest Operations

2 Post-Harvest Operations

2.1 Pre-harvest Operations

2.2 Harvesting

2.3 Transport

2.4 Threshing

2.5 Drying 

2.6 Cleaning

2.7 Storage

2.8 Gender participation and post harvest operationss

2. Post-Production Operations

2.1 Pre-harvest Operations

After physiological maturity, 10 or 15 days are required to harvest barley with combine in temperate dry lands. If this duration is exceeded, crop will get too dry and then cause shattering at harvest.

Harvesting time should be decided when barley stem becomes dry enough to be broken by hand easily in semi arid and arid areas. In humid regions seed moisture and hardness should be checked before deciding harvest by using teeth or using moisture meter.

In some areas rainfalls may force to postpone the harvest, but harvest before rainfall should be preferred, as seed after drying following rainfall may be discolored. In addition, delayed harvest can lead to yield losses. Klinner and Bigger (1972) found that yield loss of barley increased from 3.5% to 9.5 % as a result of delay in harvest date in the same location but loss increase was very low with wheat crop.

In humid or irrigated areas generally six-row and logging resistant varieties should be chosen. Akar et al. (1999) documented that lodging resistant barley cultivars gave 20 to 25% more yield than that of susceptible ones especially in excessive rainy seasons even in dray lands of Turkey (Figure 2.1). Yield and quality reducing economical diseases, pests and weeds should also be controlled either thorough use of resistant cultivars, agronomical procedures or pesticide use. In countries where malting industry is developed as in case of Turkey or malting barley export is common, the varieties should meet the quality requirements for malting.

Figure 2.1. Barley cultivars resistant and susceptible to lodging

In years or in areas where winter season is mild, barley grows and produces excessive canopy. If spring is rainy, the crop lodges, pests and diseases develop, grains can not mature and consequently the yield drops. The farmers whose crops are in the threat of lodging, cut the crop with machine or scythe for animal feeding. In the Marmara region of Turkey, farmers are hesitant to graze the crop by sheep due to damage caused by animals in rainy seasons. (Gökgöl, 1969).

Barley physiologically matures upon kernel moisture content drops to about 40 %. Harlan (1920) found that translocation to the kernels ceased at a moisture content of 42%. It can be harvested without loss of yield or quality after reaching about 35% kernel moisture but the grain can not be safely stored until the moisture content decreased to 14%, (Baldridge et al., 1985).

In Southeast part of Turkey, some of the agricultural enterprises (13.5 % of total surveyed) graze the barley crop when the vegetation is very low in the pasture areas. Some farmers (23 %) indicate that they graze barley crop early in spring to increase grain yield and 24.5 % of agricultural enterprises graze some portion of their barley acreages.

In North African countries (Algeria, Morocco and Tunisia), tall barley landraces and/or old varieties with long cycle phenology, have been grown. Broadcasting seed and offset disking the seed under in October/ November with 100 to 120 kg/ha seed rates are the practice of the farmers. Farmyard manure is used in livestock oriented farms. Generally, weed and disease control are not performed. Barley is grown as main crop in barley/weedy fallow or barley/cereal rotations. In Egypt, fallow/ barley/ pasture/ pasture cropping sequence was practiced in some areas. In those countries, barley is grown for double purpose: grazing during winter and after winter left for seed production if rainfall is sufficient (Anonymous, MEDRATE (EC-CIHEAM Co-operation project, 1998-2002) Regional Action Program ”Rain fed Agriculture” RAP-RAG Report of the Second Coordination Meeting, unpublished).

Excessive seed use can be considered as a kind of pre harvest loss. In some areas of developing countries, farmers tend to use higher seed rate as tradition or as compensation for winter kill of seedlings in harsh winter conditions. For instance in Turkey, particularly in dry land areas, the amount of seed planted is 30 to 60 % higher than recommended seed rate for barley. Farmers use higher rates to compensate the seedling kill by winter and losses resulting from improper seedbed and seeding method. A survey carried out in 3 main barley producing provinces in Turkey indicated that the seed rates changed from 160 to 362 kg/ha and averaged at 270 kg/ha (Balkan, 1981). Drought is a prevalent and constant threat on barley production in most of the developing countries. It seems that drought stress will be a more important stress in the future as a result of climate changes. The areas that can not be harvested due to drought are 5% of total barley acreage in southeast of Turkey and 34.6 % in Northern Syria (Somel et al., 1984). Crop rotation and soil productivity were reported as the main factors in the variability of barley acreage in the Southeast of Turkey. 39.7 % and 32.2 % of farmers declared rotation and productivity as the main reasons for the change in barley acreage, respectively. Only 5% of farmers declared barley price as he main factor in variability (Somel et al., 1987).

2.2 Harvesting

Depending on social economic situations such as plot size (acreage), altitude and slope, there are a lot of harvest methods in developing countries. Barley crops are harvested by hand tools such as sickle, scythe or just hand pulling, tractor mounted mower (Figure 2.2a) and combine. These methods are prevalent in mountainous areas where land is small and located on the sloping hills and harvesting machine can not access. Farmers on those areas are small scale, resource poor and mainly practicing animal husbandry. Hand pulling is generally employed in very dry years or areas with poor seed and straw yield and high price expectations. Hand harvest can also be adopted even in more humid seasons or flat fields when straw yield is very low, sometimes the hired combine machines cut the straw higher from the ground leaving majority of straw standing in the field. To obtain more straw, farmers, who produce whether livestock or not, harvest the crop near the ground by hand harvest tools as the barley straw is popular for animal feed and compost for mushroom production. The cost of the hand harvest changes from 35 to 60 EUROs per ha depending on demand and supply of labor of locations.

Most of the farmers (90 %) in Southeast of Turkey harvested the barley with combine, 10 % of farmers did harvest by hand. The percentage of hand harvest was 20.3 % in northern Syria. The harvest was made largely with the use of rented combines (94.4 %) and only 4.9 % of farmers used their own machines (Somel et al., 1984).

Combine is available in areas where the main agricultural activity is cereal production (Yurdakul et al., 1987). Combine harvest of barley crop is common in areas where topography is suitable, land size is large and farmers are relatively rich. Poor farmers in other areas generally raise livestock to sustain their lives. In developing countries combine harvesters are hired because most of the farmers can not afford to own combines. The loss in harvest with combines may be more prevalent in dry land areas where the harvest depends on the availability of combine harvester. In Turkey, barley is cropped in less acreage as compared to wheat. Therefore the combine harvesters come to the areas when wheat crops matured enough for harvest. Because the barley matures earlier than wheat, particularly in warm seasons, crops dry up extensively and become vulnerable to shattering loss and also bird damage at harvest. Following such years, barley harvested fields become as if planted due to emergence of shattered seed (Figure 2.2b).

Speed of combine at harvest is very important in terms of grain loss. Although the speed should be 4 to 6 km/h during harvest it was measured to be 7 - 8 or even 9 km/h in farmer condition (Demirci, 1982). This is because of high demand of combine owners to earn more by harvesting more fields in a given time.

The price of harvesting is set by open market conditions of different part of countries. 20 - 30 USDs is the cost of harvesting one ha of barley or wheat. According to extensive 4 year investigations on the amount of grain losses of barley and wheat crops associated with combine harvest in most of the provinces of Turkey indicated that the loss was reduced to 5.7 % and 4.5 % from 7.5 % during the study years by training of combine drivers. There were no differences between locally made and imported combine machines and combines with different ages. However, reduced loss was observed with drivers who were the owners of the combines as compared to hired drivers (Table 2.2.1)

2.3 Transport

The means of transportation of barley grains to market or to the granaries depend upon farm size, physical and geographical conditions, availability of transportation facilities.

Small size farmers prefer to sell their crop in village. In the southeast of Turkey 9 % of farmers sell the barley crop in village, 26.4 % sell to state agency (TMO) and 13.2 % sells to merchants in local markets. Generally the crops are transported to markets by tractors or trucks. The cost of transportation is about 1.900 TL/ton (1985-1986), (Yurdakul et al., 1987).

2.4 Threshing

Threshing with “doven: Wooden threshing sled with flint blades, (Figure 2.4a)” which is driven by animals is not a common practice and particularly employed by small farmers in mountainous areas or in undeveloped areas of developing countries.

Figure 2.4a. Wooden threshing sled with flint blades

For this, a special location is prepared by hardening the soil surface, usually circle of 10-20 m. diameter for every year use. For threshing, the bunches of harvested barley is scattered around this hardened soil and the ‘doven' is pulled by an animal, mostly bulls or horse, over the scattered bunches around the circle. Usually pieces of a large stone of 20-40 kg is placed or even the thresher or his/her children gets on the ‘doven' to increase its weight so that the it creates sufficient pressure on the bunches. As the ‘doven' is pulled over the bunches, the flint blades cut the straw separating the grains from the heads. Then, the mixture of straw and grains is separated through winnowing using wooden pitchfork like shovels.

In more developed parts, engine powered or tractor driven threshing machines (Figure 2.4b) have replaced the old animal driven wooden threshing sleds, before modern combine harvesters came into use. These machines are still in use particularly in mountainous areas in Turkey and other developing countries.

Figure 2.4b. Threshing with a tractor driven threshing machine
(Vezirkopru, Samsun, Turkey)

In spite of lacking extensive survey data on the harvest losses during threshing with various equipments, a research in Turkey provided an estimation of such losses. It showed that the rate of broken grains of barley was between 1 - 5 % which is much more than that of wheat. Prior to harvesting with machines, batter and contra-batter of combine should be adjusted so that grains are not injured. Grain injury is worse than broken grains, since the broken grains can be separated during screening unlike the injured grains can not. The economic loss due to broken grains of barley amounted to 10 % of selling price of normal product (Tetik, 1982).

2.5 Drying

  As the other grains, barley must be dried before putting in granaries. For this purpose harvested crop is left in open and sunny place for drying near the granary in village conditions. It is aerated by inverting the heap with shovel and covered with a material during the night. Following this process the grains are transported in the granary. On the other hand, the crop harvested with other means (sickle etc.) than combine harvester are made bunches (Figure 2.5a) with their straw and left in he field as groups (called ‘yıgın' or “tokurcun”) ( Figure 2.5b) until the moisture content is reduced to low levels (12-14 %) to be taken for threshing.

Figure 2.5a. Bunches of barley left for drying after harvest

Figure 2.5b. Stacks of barley (yıgın) in field
(Vezirkopru, Samsun, Turkey

2.6 Cleaning

Cleaning barley grains is an important process for malt and feeding industries. During the cleaning process of malting barley product in Turkey, separated materials such as stones, earth, weed seeds and broken grains, and amounted to 10 % of total grains (A. Başgül, pers. comm.).

2.7 Storage

Generally barley is stored for a short period under shelter or in depots in order not to be affected by rainfall or other adverse climatic events. In Southeast Anatolia of Turkey 90 - 97.6 % of farmers store barley under shelter (roof shelter), 1.9 - 2.4 % leave the crop outside the closed areas (Yurdakul et al., 1987). Barley is stored either in bags (0- 3.8 % of farmers) or in gross (96.2 -100 %). In northern Syria 90.1 % of farmers keep the crops in closed areas in bags (71.5 % of farmers) or in gross outside (27.8) (Somel et al., 1987). Grains are stored in depots made by brick, cement, and wood or earth wells specially drilled. Storage types are described below.

2.7.1 Adobe depots:

Horizontal type adobe depots are used by rural people as their economic status permits only this type of depots. Some of these depots have ceiling made by tree or plant residue mixed with compacted soil. Outside and sometimes inside walls are filed with adobe. Floors are earth or cement covered by mud with cereal straw mix and white washed. In adobe depots, small amount of barley (5-10 tons) can be stored. Before the crop is put inside the depots, the floor is covered with straw, reed mat or in some cases with plastic cover. Adobe depots are known as unsuitable for storing barley grains.

2.7.2 Cement or pile depots:

The horizontal cement/pile depots are partly suitable for storing barley. These are used by some governmental institutions and farmers who produce relatively more amount of barley than small producers and merchants (Figure 2.7.2a,b). Cement and pile depots have cement floors and brick or stone walls covered with straw mixed with mud. Lime is applied on wall surfaces and roofs are covered with stainless undulated pane or tile.  They do not have any aeration mechanism. Windows on opposite walls are situated near the roofs to provide aeration. Barley grain is handled generally by labor.

2.7.3 Wooden depots:

Wooden depots store barley in a good condition for long time and are usable for many years. Wooden depots constructed during Çorum- Çankırı Rural Development Project (FAO) are still functional in Turkey (Figure 2.7.3). They get moisture inside from the top at very low rate or with difficulty, but the walls provide good aeration resulting in cool product in the granary.  The wooden granaries are constructed on elevated, easily aerated and southern parts of the farm buildings. One of the important drawbacks of the wooden depots is rodent damage to the crop and wood material. To protect the woods from damage caused by rodents, metal panes with slippery and dented corners are placed inside the wooden granaries. These stores are ideal for barley storage in developing countries if adequate measures are taken to prevent entry of rodents and rain. The second drawback of wooden granaries is the cost. Only rich farmers can afford to install wooden depots.

2.7.4 Vertical wooden depots:

In addition to horizontal ones, these types of storages can also be seen in rural areas. They are constructed under large spaces in houses such as balcony or veranda of double floor village houses. They have top and bottom openings where barley grain circulation can be made (Figure 2.7.4).

Figure 2.7.2a, b. Horizontal cement/pile depot

Figure 2.7.3.  Horizontal wooden depot

Figure 2.7.4. Vertical wooden depot

2.7.5 The vertical earth well depots:

They are built in farm buildings and disinfected by lime or heat in areas where the wood materials are expensive and inaccessible. They are in various types. Although the farmers in rural areas generally sell the product immediately after harvest some part of grains are stored for the next season's seed and animal feed. Acting as the rules of free market, the farmers having very large land and no debt either sell the product

or keep it in earth horizontal depots until sell off. On the other hand, farmers who have insufficient acreage of land and insufficient economic power to construct granaries, dig earth wells to store the grains in areas where the direction is northern and water table is below 5-6 m. If well granaries are constructed so that water entrance from the bottom and sides is prevented, they are suitable for safely storing of dry and clean product after harvest for a long period. Some farmers place the cereal straw in the bottom of the well before placement of grains. After removal of the grains the straw is burnt prior to storage of next load of grains.To some extend, this practice removes the moisture of the well and helps to disinfect the pests and fungi in the well. Before the grain is put inside, new cereal straw is spread on the bottom of the well at 20-30 cm thickness. Then, some amount of grain is put and side walls of the well is covered with cereal straw at the same height as the grain load. Then the grain is put again and side walls are covered with straw. The well is filled up this way and the top of the well is covered tightly with a mixture of various materials (cereal straw+ fine soil+ mud +stone etc.). In order to check the stored grains in the well, an iron rod is pushed into the grains along the well and in the next day it is checked by hand whether it is warmed or not. If the rod is warmed, it is understood that the product in the well has a storage problem. There are different kinds of applications of the storage method in various countries.

According to Donahaye et al. (1995) fifty tons of locally grown barley were stored in an underground pit hermetically sealed inside a polyethylene liner at Kibbutz Lahav. Gas measurements and observations showed that a satisfactory hermetic seal was obtained within the liner after seven weeks of storage (1.0-32 per cent O₂). However, the efficiency of the seal was reduced by the gnawing activity of rodents which damaged the liner, and this appears to be a limiting factor for this type of storage. Changes in moisture content and in germination power were minimal during the storage period. Marked seasonal temperature changes were only recorded at the periphery of the grain bulk, while at the center the temperature remained stable. Barley grains which was removed after 15 months of storage, during nine of which the liner was sealed, was clean, of natural brightness and color, of low moisture content, and uninfected.

2.7.6 Modern Silos:

A lot of feed and malt companies store their raw material to be processed during the year in big silos made of concrete (Figure 2.7.6a) or steel (2.7.6b) immediately after barley harvest in Turkey. In addition to these, Soil Product Office (TMO), a governmental organization and monopoly on cereal long term storage in Turkey, stores the barley in big silos by modern methods across the country. Its storage capacity is almost 5 million tons and 10 to 50 % of this capacity has been allocated for long term barley storage during the last thirty years (B. Baran, 2003, per. com.)

In Turkey, barley grain is also stored as heap in open areas and in closed vertical and horizontal depots and the tops of the heaps are leveled (Esin, 1990).  They are as follows:

2.7.6.1 Modern open heap depot units:

There are two types of this storage systems; oval and circular, respectively. The former is loaded with transposable machines while the latter is loaded with constant ones. In Turkey, capacity of oval units changes from 2.5 tones to 5 tones whereas that of circular units starts from 10 tones (Figure 2.7.6.1).

Figure 2.7.6a. Concrete depot

Figure 2.7.6b. Steel depot

Figure 2.7.6.1.Circular heap depot

2.7.6.2 Polyethylene and earth covered heaps:

The system invented by old Anatolian civilizations was developed by TMO and commonly used by the governmental organization throughout Turkey when especially its modern storage capacity is not enough to store enormous amount of barley and wheat and some food legumes grains. It is the first model of hermetic storage system in the world and has been used by TMO during the last sixteen years. Selecting of sandy soils and 5 to 10 % of sloppy zones are two important prerequisites to safely store barley and wheat grains for short and long term storage. Two layers PVC are set on the soil and barley grains are filled in the PVC then grains are covered by PVC over liners and the heaps created with 2 m height are re-covered with 5 to 10 cm soil layer (Figure 2.7.6.2 a,b,c). Long term yield losses in this hermetic storage system in TMO conditions are 0.5 to 1% throughout Turkey (B. Baran, 2003, pers. com.).

Figure 2.7.6.2a. Diagram of an earth covered heap

b

c

Figure 2.7.6.2b,c. Earth and polythene covered heaps

2.7.6.3 Oilcloth covered heaps:

This storage system is completely the same polyethylene and earth covered heaps excluding coverage material. In this type of storage, oil clothed material is used instead of PVC (Figure, 2.7.6.3 ). 

Figure 2.7.6.3. Vertical cross section of heap with oilcloth surrounded by earth pad

2.7.6.4 Low stone walls covered PVC:

This is another sound example for hermetic storage method. In this system; floor is cemented with low walls made of stone or brick. Then polyethylene is laid on the floor and barley grains are filled and then covered with PVC. Varnava et al. (1995) examined the method under Mediterranean conditions with small modifications. A large (75 x 25m) concrete platform with low walls was filled with barley and covered with a PVC over liner and a polyethylene under liner. The barley formed a pile of 4,018 tones with a peak of 7 m high and was stored for 34 months under hermetic seal. Periodic monitoring was carried out to determine temperature fluctuations, inter granular gas composition, insect infestation, and grain quality parameters. Ambient temperatures were shown to create temperature gradients in the upper layers, and moisture migration occurred towards the peak of the grain bulk. However, the resulting spoilage by moulds was limited to 0.22% weight loss on an annual basis. An additional 0.12% loss due to insect damage, and spillage resulted in an annual storage loss of 0.34%. Possible solutions to this problem were discussed. The platform successfully protected the grain against insect, bird, and rodent attack and provided safe storage during the rainy season. At the end of storage, the PVC over liner which had been used continuously since 1988 remained with low gas-permeability, retained its mechanical characteristics and was suitable for reuse.

2.8 Gender participation and post harvest operationss

The operations during and after harvest requires more labor than the pre harvest procedures. The gender participation operations seem to depend on the level of overall development and mechanization. In very rural areas the harvest and post harvest operations are based on the working of all family members, man and women, in most cases including the children as well. This is because the harvest is done by hand using physical instruments such as sickle, scythe, hand pulling or tractor mounted mower and requires a lot of labor. The families can not afford hiring labor and therefore all members participate in harvest. Similarly, threshing is also based on participation of both females and males. In such areas females participate by actively doing the harvest job or threshing as well as preparing the food for the members in the field. However, in more developed areas where operations are more mechanized the involvement of women is decreased. The operators of the harvest machines, threshers or combiners are mostly males and in most cases women may participate in supply of food in the field.

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