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Organisation: International Rice Research Institute, Philippines (IRRI)
Author: Ray Lantin
Edited by AGSI/FAO: Danilo Mejia (Technical), Beverly Lewis (Language&Style), Carolin Bothe (HTML transfer)

CHAPTER X RICE: Post-harvest Operations

5.2 Major problems

5.3 Proposed improvements

5.4 How has the introduction of the improved technology affected income/responsibilities between genders?

5. Economic and social considerations

The straightforward method by which farmers can add value to the paddy is by drying it to a marketable moisture content. In most of the tropics the equivalent moisture content is 14 percent wet basis. When paddy is dripping wet as in the case when harvest time occurs during monsoon rain and a series of cloudy days will likely follow the rainy days, it is critical that the moisture content of the paddy be reduced to skin dry condition within 24 hours after harvest. An interim safe moisture content is 18 percent for a 2-week storage under dry and protected conditions or at most 20 percent for a few days storage with occasional stirring and aeration. The choice of how far down the moisture content should go depends on the urgency of reducing the moisture content of the bulk of the grain to a safe moisture level. A flash dryer will remedy the situation on an emergency basis. This moisture content will at least be a first aid in saving the paddy from deterioration and will give the farmer enough time to organise and implement a drying system or sundrying depending upon his resources. Under most circumstances however, the farmer will opt to sell the paddy at a low price to a trader or rice mill because the small holder is generally averse to risks. The alternative is government action to provide drying and storage facilities at strategic areas. This is what the grain agencies like BULOG in Indonesia and the NFA in the Philippines are doing to a limited extent. These government agencies also encourage the formation of farmers' co-operatives in rice milling with drying facilities.

For very small holders, the problem of saving the wet grain harvested during the monsoon rains needs to be solved. Even if there were a government facility for drying paddy, the small quantity and most often the cost of transporting the paddy becomes an additional financial burden which the marginal farmer will not likely take. An option is to aerate the small amount of paddy by piling it into small heaps to expose as much surface area of the grain to the atmosphere and prevent heating up of the bulk due to microbial action and grain respiration. This procedure will require frequent turning over of the grain. A meticulous farmer will even scoop out the thin upper layer of each heap to form another heap, which is drier than the grain beneath and at the bottom especially with an initially dripping wet grain. If available, a manually or pedal-operated blower or engine-powered blower used for field winnowing may be used to increase the aeration process. A household electric fan will also be useful and in fact being used by farmers. It is best to have the bottom of the heap to be resting on a fine mesh net on a platform with slatted floor to increase underneath aeration and to drain any gravity moisture from the grain heap. These are emergency measures for the small holder and will be impractical or will require much labour or space for a commercial scale operation. Nevertheless, in the absence of drying facilities the above procedure can be adopted as an emergency measure or first instance solution until favourable sundrying weather comes.

The rising cost and non-availability of labour due to increasing employment opportunities in industry in some developing countries, particularly in Asia, has increased the adoption of mechanisation of rice production and post-harvest operations. The small size of fields, however, limit the powered machines to pedestrian tractors and machinery which also determine the scale and method of operations in harvesting, threshing, in-field handling and field-to-road paddy and straw transport of paddy.

Unless major policy directions leading to more efficient field operations than in the small-sized fields are instituted, the field operations in harvesting and threshing will likely remain as it is for a long time although small-scale powered machines will increasingly be utilised. One of such policy directions is the land reformation and consolidation as has been done to some degree in Japan and in Taiwan, province of China. Due to increasing demand for small-scale machinery mainly for custom service operations by small village entrepreneurs, the local manufacturing industry has been progressing and gradually increasing the quality of farm machines as well making them more affordable than before. In most developing countries, the power unit, the small engine ranging from 5 to 10 kW, remains as an imported item and is a major high cost component of a machine. However, a given engine may be used for a variety of small machines ranging from land preparation, crop establishment and care, irrigation, harvesting, threshing, transport, drying, and perhaps, in-field hulling of paddy. An increased support in rice production and post-harvest machinery research and development as well as agricultural and industrial extension will eventually lead to minimised post-harvest losses and reduced costs. Improved timeliness and efficiency of operations resulting from appropriate machinery and its proper maintenance will redound to the benefit of the small holders.

The use of combines as a step towards mechanisation has had a forward linkage with post-harvest operations. The large volume of paddy being turned over to the processing plants in a short time has put pressure on the drying and storage facilities in Thailand, a major exporter of rice. Large capacity dryers are now being manufactured locally and have large demand, at least for the present. Because of lack of incentives for the farmer to dry paddy, the drying operation will continue to be an adjunct operation of rice milling and will take place at the rice mill site using mechanical dryers combined with mechanised sundrying whenever feasible because of its low cost especially due to free, albeit unreliable (during rainy season) heat energy. Sundrying with complementary mechanical drying will be a main drying operation to take advantage of the sun's free heat energy and the environmental friendly feature of the technology. Mechanised and precision-controlled sundrying (still a neglected area for technological innovations, though sundrying is widely used) in combination with artificial or forced-heated air-drying is a pertinent subject of research and development now and in the future.

The concept of increasing the income of small holders through value-adding in paddy or engaging in primary post-harvest operations at the farm level remains a question under the present system of low incentives or non-recognition of such added value either by design and necessity or by trade practices in most developing countries. The farmer will have larger margin of profit and therefore incentive if he dries paddy during the wet season. Only a few farmers will recognise and adopt this concept, as some sort of drying facilities will be needed. A government campaign and assistance will perhaps make more farmers adopt the value-adding concept rationalising that social benefits will accrue in terms of lessened post-harvest losses, better grain quality and self-sufficiency in the staple. Perhaps the more easily adopted technology is to make the production and field harvest and post-harvest operations of threshing, handling and transport more efficient through better infrastructures and this is also normally a government initiative and at best a community action.

5.1 General overview

Once the rice crop has produced the grains approaching the potential yield for the variety under a given cultural practice, soil and climatic conditions as well as a set of inputs and other factors in production, the actual amount of grain finally retrieved from the plant after all stages of processing does not normally match that yield. There are numerous ways by which that yield already in the plant could be lost and so does the opportunity for it to be of use as food or something else. This situation occurs because there are many steps to be taken in bringing that yield from the plant to the rice bowl. Each step in the production and processing entails a certain degree of reduction depending upon the technology used and the care given to prevent or minimise losses. The rice crop losses are reported as lumped as percentage of the yield per hectare.

The post-harvest operations begin at harvest and ends at the storage of the milled rice. The range of processes discussed here does not consider the costs and losses in delivery of the rice to wholesalers and retailers from the rice mill, in cooking, and finally in serving the rice food in the plate or bowl of the consumer.

The grain losses in the field may be incurred during pre-harvest period and at harvest time. Normally, the longer the harvested grain is left in the field, the higher the chances of incurring grain quality deterioration and spoilage due to weather, stackburning and delays in drying as well as physical loss due to rodents, pilferage, and other causes. Depending on whether the variety is shattering or non-shattering, field losses of the grain may be small or large even if the rice crop is still standing. Wind, rain and degree of maturity of the crop can have a large effect on the magnitude of such losses for a given variety.

5.2 Major problems

Harvesting and threshing are major problems in field operations while drying of the paddy is critical as a post-harvest operation. Since milling is an industrial process which can easily be controlled inside a building, the problems related to this process are determined by the quality of the paddy received by the mill. The critical factor is the drying of the paddy immediately after harvest. In some developing countries, drying of the surplus paddy for the market is not normally carried out by the small-scale farmers. Wet or freshly harvested paddy is sold directly to traders or to the rice mills and rice milling co-operatives. Somehow, the farmers avoid the risk of crop deterioration by disposing off the crop immediately. The problem of drying is passed on to the trader or rice mill owner but the farmer gets a low price for the undried paddy. The bottlenecks in post-harvest processing should be solved using the systems approach.

In harvesting and threshing the quality of the harvested crop, the degree of losses incurred and the efficiency of the operations and hence, overall costs are affected by factors related to the weather, variety of the rice, and the technology used. Harvesting and threshing during the monsoon season bring about problems of wet and lodged crop, high moisture grain which is susceptible to spoilage due to fungal and microbial invasion, difficulty in threshing, grain handling and transport regardless whether the methods are mechanical or manual, and the critical need for immediate drying of the paddy. It is obvious that one problem in a process stage affects the quality and efficiency of the next stage and mitigating measures at that stage are needed. This chain reaction continues up to the milling process until the semi-final product, milled rice is produced.

The same problems appear to be magnified for small holders because of scarce resources to do mitigating measures like quick drying or transport to the market of wet paddy. They have lesser capability to absorb losses than the big landholders or commercial rice producers. They are forced to sell the paddy at very low price which may be the best thing to do under the circumstances to prevent greater losses, if not total loss.

5.3 Proposed improvements

The sale of the paddy, the final product from the farm, is the major if not only means by which the farmer, especially the small holder, can benefit from rice production. Straw, the only other by-product of rice production in the farm but has not been fully tapped by most farmers, except in places where it has market value as animal feed or thatch.

An increase in sales proceeds of means increased income. This increase in income can be achieved through increased quantity and improved quality of the product. Increased quantity is achieved through enhanced productivity of the cropping system and increased amount of production through improved production technologies as well as reduction of losses in the field. Improved quality of the paddy can be achieved essentially though variety selection in terms of eating quality, improved crop care (irrigation, pest and weed control), optimum harvesting time, and improved post-harvest processing. Field processing activities, including harvesting, threshing, cleaning and handling are more for retaining that quality or preventing grain deterioration rather than improving it.

Unfortunately, the small holder usually participates in the post-harvest processing stage only at harvesting, threshing and handling which may still be considered as the tail end of the farm production system because the product is considered as raw material and no value has been added so far. The concern is more of sustaining the quantity and the quality of the crop as produced, that is to add value and prevent the paddy from deteriorating.

The small holder does not have the capability or resources and the incentive (in many places) to do any further processing. Attempts by government extension services to promote drying at the farm level of paddy for sale have not been successful because the economic benefits for the farmers are not significant in terms of labour inputs and capital costs involved as well as the affordability to wait for higher prices of paddy. Any incentive from the paddy trading industry in terms of value or price increase given to the farmer to dry the paddy is usually very low, so that the farmer is forced to sell the wet paddy at a low price or else the paddy will deteriorate and will have zero or near zero value. The small holder family only dries the paddy retained at the household for immediate family consumption and for food and cash security at least until the next harvest.

After the field post-harvest procedures and activities have been optimised, such that production has been maximised, losses have been minimised, and the excellent quality of paddy have been attained, a possibility of the small holder increasing the cash income is an increased efficiency of the traders and millers of the traded rice in their operations and passing on part of the savings in costs to the small holder through better paddy prices. This is at best theoretical, as the traders and millers will likely keep the windfall from such efficiencies rather than share it with the producers or they are more likely to share such efficiencies to consumers. Only increased competition, increased market demand for rice or reducing supply by lowering production (indeed a counter-productive method) with no government intervention by importation of rice will increase the price of paddy.

Rice processing and trading co-operatives among farmers have been successful in many places in assuring farmers a fair price for their paddy and enabling them to get benefits from the processed and traded rice by virtue of their share of ownership of the processing facilities and the business. This strategy has been promoted by governments but is beset by problems of lack of management skills and capital investment costs. While there are success cases, there are also failures of attempts to organise and sustain rice processing co-operatives.

Perhaps an effective strategy is to empower the farmers to process the paddy (at least partly) in the farm by hulling it and trading the brown rice for further processing by the rice milling co-operatives or the private commercial mills. Brown rice can have a separate path leading to a niche market among the health-conscious consumers is developed countries. This alternative will entail not only innovative approaches to the technology but also changes in the pattern of field production, trading, storage and consumption of rice.

The reduction of field losses in harvesting and threshing can increase the profits of the small holder. Shifting from the manual to the proven efficient mechanical method of harvesting will greatly reduce harvest losses. The fast rate of harvesting and threshing enables a timely removal of the grain from the field which may be critical during the monsoon season. Drying the crop by the small holder aimed at increasing value of the paddy has not been a popular activity because of the low returns from the drying process. However, very wet paddy resulting from a rainy harvesting and threshing episode, will command a low price unless it is dried properly. In such a case the margin of profit may be high as the choice could be between a total loss or no profit and reduced profit due additional expenses in drying. Small portable axial-flow threshers which have been originally designed by IRRI are now being manufactured and distributed locally in many developing countries. Pedal-operated threshers have been accepted in the terraced fields in the highlands because of their portability and affordable costs, especially if made locally.

In Myanmar, the system of mechanical threshing has increased in popularity among farmers because of the significant benefits derived from their use. From observations in the adoption of mechanical technologies such as mechanical threshers in developing countries, the custom operation by a local entrepreneur who buys the machine such as a thresher, appear to be a popular and fast process. Custom services in threshing and cleaning of paddy benefit the farmer because of the faster output and cheaper rates. The system spares the farmer the investment and operational costs of the machine and may not be viable from the ownership consideration. The utilisation of the rice husk as domestic cooking fuel has increased in popularity in Myanmar perhaps because of the aggressive manufacturing and marketing by a local fabricator of a Vietnam-designed rice husk stove which has been modified by IRRI.

5.4 How has the introduction of the improved technology affected income/responsibilities between genders?

In most small rice farms in developing countries, women play a major role not only in production but also in post-production operations. In many countries, women are involved in or do most of the manual harvesting, threshing, winnowing, handling and sundrying drying. The men do the hauling and operate any powered machine if it is used while the women act as helpers.

In general, postproduction technology development and transfer programmes have been carried out on the assumption that the technology is either sex-neutral or that men are the main users and decision-makers. This assumption is often incorrect because women and other household members have quite different technology needs than men because of their different knowledge, experiences and skills, physique, stamina, etc.

Women workers are usually the first ones to be affected by a new technology introduced to improve processing. A powered machine will immediately displace women or relegate them into lesser tasks as helpers as the men take over the machine, be it a power tiller-mounted harvester or an engine-operated thresher. A pedal-operated thresher, however, fits the physique of women and is therefore accepted as a labour-saving device where mostly women do traditional harvesting and threshing.

Sundrying of paddy for household consumption is also a traditional task of women. Men do assist in the handling of the bags or containers. Since mechanical or forced heated air-drying is usually done by rice traders and millers, women are not much affected by such technology.

Most rural women in developing countries are traditionally responsible for pounding rice using the mortar and pestle or the beam hammer/pounder (dheki). Where the steel huller mills have been introduced, these traditional methods fade away. In most cases the substitution has been beneficial to the women because of the great relief from the arduous work or otherwise, because their family income has contracted. Sometimes, the change has given them the opportunity to explore other means of income generation, a luxury they could ill afford because their time is being used up by the major family obligation of milling rice which is just one of their several domestic tasks. At the worst perhaps, the displacement of women from their income generation of hand-pounding of rice for sale in the community (a marginal micro-enterprise at that), is temporary as some well-to-do community consumers would still prefer the pounded rather than the milled rice during the transition stage. With a small rice mill, such as IRRI micro-mill modified from a Chinese design, a women's group in the Philippines was able to increase income and obtain the bran for animal feed. The milling micro-enterprise was easily patronised by the villagers who were spared the time and effort to go to the far commercial rice mill to have their paddy milled. In effect, the introduction of the technology on a pilot basis has given economic and social benefits.

In a rural appraisal on the roles of the different household members in the postproduction of rice and other crops in Isabela and Quirino provinces in the Philippines, the following activities of women were observed (Paris and Duff, 1989):

Harvesting. Performing this task varied according to the culture and economic need of the family. In one village, men dominated harvesting because they were considered fast workers and could stand tougher jobs (exposure to sun or rain for long periods while at work). In another village of another province, harvesting was dominated by women and children (8-14 years old) because they were available or left behind during the harvest period as the men folk did the land preparation immediately after harvesting their own fields or worked as hired labour. In some cases, men looked for harvesting/threshing jobs in neighbouring villages where payment was in the form of in-kind share of the harvest which was larger than wage or contract work paid for in cash.

Threshing. Mechanical threshers were adopted because of their efficiency, less grain loss and immediate recovery of the threshed grain within the day compared with hand threshing which must be closely supervised by the farmer-owner to control losses and technical pilferage (not threshing thoroughly to give more yield to gleaners who are relatives of the threshing labourers). Mechanical threshing was dominated by the crewmen of the hired thresher. They performed the feeding of the harvested rice, bagging the threshed grain, sewing the bags and stacking them at the threshing site. Other men did the in-field and field-to-road transport as well as loading on the transport vehicle, consisting of animal-drawn sled or cart or motorised tricycles, trailers pulled by small tractors, jeepneys, pick-up trucks and lorries which were usually hired by the buyer of the harvested paddy. Depending upon the distance, the transport job was paid for separately from harvesting.

Gleaning. Women and children, usually the relatives of the hired labour for the threshing operation, tried to recover grains from the straw or threshing yard. Landless and marginal farmers sometimes did gleaning to augment family income. Each gleaner could recover about 25 kg of paddy in a day.

Hauling. Men usually dominated this job, which required strength and stamina. Women assisted in lifting the bag onto the shoulder or head of the men.

Drying. When sundrying the grain, men did the hauling, loading and unloading on the drying floor while the women and children took turns in spreading, stirring and watching over the grains to be dried. They also assisted the men in bagging and loading of the grains at the end of the drying period.

Storing. Most of the grains were sold immediately to the buyer. Only about 800 to 1500 kg were stored per farm household per season. Storage could be in bulk or in sacks in one corner of the house, in bamboo baskets or wooden boxes. Sometimes the grain was stored in a warehouse which could be a separate shed or an extension of the house with galvanised sheet roofing and wooden or concrete walls and floors.

Marketing. In one village, farmers sold their paddy in buying stations located outside the village from where they could obtain cash payments and loans and farm inputs. In another far-away village, buyers pick up the grains using big trucks to ensure payment from farmers who obtained loans or advanced payments from them. Both the father and the mother decided on the volume and price of the grain to be marketed but the mother usually managed and kept the proceeds after marketing.

The above observations in the post-harvest operations for rice may vary from country to country, depending upon the culture. However, in most developing countries in Asia, women do share a major portion of the labour inputs in such operations.

In the northern mountain provinces or Lao PDR where exchange of labour is still practised, especially in subsistence level farming in the slash and burn cultivation of rice, the whole handling job from harvesting to storage is done without any cash payments - only food and drinks and return labour. Women usually perform the hauling and piling of the harvested stalks to the threshing site, and the cleaning or winnowing operation. Some women participate in the actual threshing operation itself, which is predominated by men.

Custom threshing operation by engine-powered threshers is becoming popular in extensive lowland rice areas near urban centres.

In Bhutan, women haul the harvested stalks to the house and if the grain shatters due to over maturity or varietal characteristic, losses are incurred at various actions such as in lifting, carrying and laying down the harvested bundle.

In the Philippines, women had greater than 50 percent involvement in post-harvest activities, mainly in sundrying and marketing. Women were significant participants in the disposal of output, specifically in marketing decisions such as where and when to sell and what selling price. Women contributed 17 percent and 26 percent of the family labour used in harvesting of wet and dry season rice, respectively. They contributed 16 percent and 19 percent in total post-harvest activities.

Few alternative employment opportunities or rural industries existed to absorb the displaced labour at the time the machines were introduced. Caution should be exercised in introducing any labour-displacing technology such as mechanical harvesters in a labour-surplus, low-wage environment.

Decisions on which type of rice mill is to be used for milling the family grain are often made by women, especially when they are involved in backyard swine production. While increasing milling recovery of such rice mills, the reduced bran-rice mixture and brokens decreases the value of the by-product as animal feed, an important feed in backyard swine production in the Philippines.

Any intervention, which eliminates the Engleberg type rice mill or improve it to increase the milling recovery, will bring about socio-economic problems and choice of any other alternatives. Using other feed ingredients such as crop residues to reduce the rice bran requirements is a potential solution to the problem.

The decline in demand for female labour adversely affects the category of rural women at risk- those belonging to landless householders or without sufficient land to support their families. This situation aggravated further when the female is head of a household with children. With the introduction of small power threshers in the early 1980s, the time spent by women in harvesting and threshing decreased from 8 h/ha in 1975 to 3 h/ha in 1980. On the other hand, use of portable threshers decreased turn-around time for rice production and enabled farmers to grow two crops of direct seeded rice in a year.

In Bangladesh, rural women are responsible for most post-harvest operations, particularly processing which is a carried out near or on their homesteads. Rural electrification stimulated the rapid spread of small, inexpensive, electrically-driven mechanical rice mills in the early 1970s. By 1979, about 23-26 percent of total rice production was machine-milled and labour productivity was substantially higher (5.6 t/man-day) for machine milling compared to the manually operated dheki mill (0.2 t/man-day).

The improved mills have benefited farm families by reducing the participation of female household labour in this arduous task and by lowering the cost of hired labour. The mills also increased milled rice output and reduced processing losses. It was estimated that household labour for husking declined from 58 percent to 55 percent and hired labour from 32 percent to 16 percent.


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