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Mechanized Farming for Slopeland Orchards in Japan
Masahiro Miyazaki
Shikoku National Agricultural Experiment Station
1-3-1, Senyu, Zentsuji, Kagawa 765, Japan, 1998-10-01

Abstract

In Japan, most of the farm work in slopeland orchards in the past has been carried out manually, since there has been no suitable machinery. However nowadays there is a severe problem of aging farmers and a shortage of young successors, especially for citrus orchards on steep hillsides. For this reason, the staff of the Shikoku National Agricultural Experiment Station have developed a mechanized farming system for slopeland citrus orchards. This involves the construction of farm paths, and the use of machines which the operator walks behind, such as an air-blast sprayer, a raised bed transporter and a hand-held shallow cultivator. This new mechanized system has reduced the total work hours by more than 30%, while farmers' incomes have increased because of the improved quality of the citrus fruit.

Abstracts in Other Languages: 中文(1098), 日本語(1171), 한국어(1167)

Introduction

As in most Asian countries, the area of arable land in Japan is very limited. For this reason, upland areas have been cultivated since ancient times. After World War II, orchards replaced the traditional upland crops of potato or mulberry trees in southwest Japan. Orchards of Satsuma mandarin, the most popular citrus variety in Japan, became particularly common. Since slopeland orchards are well-drained, well exposed to sunshine and well ventilated, farmers could grow sweet citrus fruits.

However, the mechanization of such orchards lagged behind lowland Japan because the steep gradients and high-density planting made the use of machinery difficult, and sometimes even dangerous. As a result, farmers had to tend their orchards by hand, spending long hours stooped over their trees. Statistics showed that the yearly labor demand for citrus crops per hectare was four times higher than for rice production using a riding tractor, a tillage implement, a rice transplanter and a headfeeding combine.

Moreover, farming in Japan is facing a growing problem of a shortage of efficient farmers, as the average age of farmers grows and the number of young recruits falls. Japan also has higher production costs than most countries overseas, which makes domestically produced agricultural products more expensive than imported ones. Finally, consumers in recent years have shown a marked preference for high-quality foods.

To help farmers solve these problems, the Shikoku National Agricultural Experiment Station is carrying out research on the mechanization of steep slopeland orchards, and has tested additional new technology developed by farmers themselves.

Construction of Farm Path System

The mechanization of slopeland orchards with steep gradients depends on the construction of paths for agricultural machinery. The construction of wide farm roads or paths to allow the passage of large machines is not desirable on steep slopelands. The construction costs are high and there is a danger of landslides. Furthermore, the total yield from the orchard falls because so many trees have been cut to make space for machinery. Instead, a new farm path system was developed for small machines.

It includes two kinds of path, a work path which is one meter wide, and a connection road with a width of more than 1.3 m. The connection road acts as a backbone, while work paths are attached laterally to the backbone. To make sure that machines can travel safely along the paths, the gradient of the connection road should be less than 27%. The path should have a turning circle where the machine can turn round, with a diameter of 2 m ( Fig. 1(1129)).

The farm paths also function as hillside ditches, intercepting run-off water. It is important to pave them, to prevent erosion and to allow machines to travel smoothly. We have developed a low-cost cement aggregate pavement, using soil from the orchard itself rather than gravel and sand brought in from outside. The cement is mixed with a coagulent powder and water, and hardens into a smooth, durable paving. Such a pavement is easy to construct, and the total cost is comparatively low.

Construction and surfacing of a farm path is carried out as follows:

  • The path is dug out using a small back hoe.
  • Cement is mixed together with the coagulant and spread over the soil surface.
  • It is mixed together with the soil, using a rotary-tiller.
  • Water is sprinkled onto the mixture, using a power sprayer.
  • A rotary-tiller is used to mix all the ingredients thoroughly together, and smooth down the surface.

The ratio of soil, cement, and coagulant in pavement materials is 100:13:0.3, respectively. The pavement depth is 7 - 10 cm.

It is also important to install a water supply system. Usually a water storage tank is constructed at the lower end of the connection road, to collect runoff water which runs down the farm paths. The water is used for irrigation, or for mixing pesticide sprays. In order to protect the side slope of the work path from erosion, the soil surface is stabilized vegetatively. Pelleted grass seed is planted on the slope and sprayed with soil coagulant. This gives effective protection while the grass grows over the soil surface.

This farm path system not only permits the use of small machines, but also improves light conditions in the lower and inner tree canopy, and promotes soil conservation in orchards.

Development of Small Machines

Because farm paths in slopeland orchards are steep and narrow, ordinary farm machinery cannot be used. Instead, we designed specialized machines with the following basic specifications.

  • They use crawler treads, rather than wheels.
  • The operator does not ride on the machine, but walks behind it.
  • The machine has a very small turning circle.

Mechanization of Pest and Disease Control

In fruit production, chemical sprays are necessary for pest and disease control. In Shikoku, they need to be applied about ten times each year. At present, power sprayers with long hoses are widely used, but they have a high labor demand. Farmers need some kind of sprayer with a lower labor demand and higher efficiency.

In response to this need, we designed an air-blast sprayer. The operator walks behind the sprayer along a farm path. The sprayer is equipped with an axial fan, and emits a fine, dense mist of chemical particles which can reach trees up to 15 m away. The operator can direct the spray precisely onto the target by controlling the direction of a fan drum, that can be adjusted freely between 35 degrees upward and 20 degrees downward. The turbulent air disturbed by the fan drum shakes the leaves of trees, so that chemical spray adheres to both sides of the leaves ( Fig. 2(1011)).

One row of trees is sprayed at a time, as the machine moves along the work path. Once the row is finished, the machine turns around at the turning point and travels back down the same path to spray the trees on the other side. Since the machine needs only a single operator, farmers can spray their trees any time pesticide is needed without having to seek outside assistance.

The sprayer has a tank for liquid pesticides with a capacity of 300 liters. It can apply pesticide at a rate of 3000 to 5000 liters per hectare, with a working efficiency of 0.15 ha/hour. This represents a reduction in working hours of about 35%, compared to conventional knapsack sprayers.

Mechanized Transportation

A transporter with crawler treads can be used to carry heavy loads such as harvested fruit, fertilizer and manure. With a good network of farm paths, such a transporter can make a big improvement in the efficiency and comfort of farm work.

The transporter we developed has an adjustable elevated bed. Its loading capacity is 10 containers (a 200 kg load). By raising the bed, the labor of loading harvested fruit from the transporter to a truck can be reduced. In addition, the raised bed can be a platform for the farmer when carrying out operations in the tree canopy, such as pruning, thinning and harvesting ( Fig. 3(1124)). This transporter makes a particularly marked reduction in the labor needed for transporting fruit during harvesting, so that the output of harvested fruit per worker can be increased. Tests showed a 37% reduction in the working hours needed for harvesting.

Mechanized Fertilizer Applications

The application of fertilizer three times each year (in spring, summer and autumn) does not require many working hours in fruit production, but the work of carrying and spreading fertilizer over an orchard is rather hard.

We developed a fertilizer unit mounted on the bed of the transporter. The capacity of the hopper is about 100 L. Granular or pellet type fertilizer fed through an auger attached to the bottom of the hopper is led to a discharge pipe, and blown out with air from a centrifugal fan. Mounting and unmounting the unit on the bed of the transporter is easy, because of the transporter's hydraulic lifting system ( Fig. 4(1022)).

Fertilizer can be applied in a band up to 4.6 m wide, at a rate of 14-25 kg per minute. At this rate, the operator can apply fertilizer to 0.4 ha per hour.

Mechanized Weed Control

Mowing weeds in orchards on steep hillsides is hard work, and has to be done four times a year. We developed three different kinds of portable machine for removing weeds. One is a hand-held shallow cultivator, one is a cutter with a small mounted engine, and the third is a small rotary mower.

Shallow Cultivator

The hand-held shallow cultivator has a rotary drum fitted with a number of V-shaped claws, which can remove weeds without damaging the tree roots ( Fig. 5(1098)). This machine is also suitable for mixing fertilizer and residues into the soil after fertilizer has been applied. It gives a 50% reduction in the labor needed for weed control.

Mounted Cutter

The cutter has a long handle supported by a shoulder belt, with a cutting blade on the end. The handle is attached by a flexible shaft to a power unit mounted on two wheels ( Fig. 7(1156)). The power unit is pulled along the work path by the operator. Since it is mounted on two small wheels, it is lighter and more comfortable than knapsakc type cutter carried on the back of the operator.

Rotary Mower

The rotary mower has a centrifugal blade made of plastics cord. The mower is manipulated over the ground using only one hand, just like using a mop ( Fig. 8(1118)). The operator can cut weeds under trees without bending his back.

Mechanization of Other Farm Practices

We have also developed other types of machinery mounted on the transporter, such as a manure spreader unit and a chipper to cut branches and leaves into small pieces suitable for composting. We are now investigating the performance of these models in field tests. We are also testing an electronic clipper developed in France, driven by a light battery pack belted around the waist, which reduces the working hours needed for pruning. A knapsack-type low-volume herbicide sprayer powered by a battery, is giving promising results. With a working capacity of 3L/ha, it further improves the comfort and convenience of orchard care.

Mounted Cutter

The cutter has a long handle supported by a shoulder belt, with a cutting blade on the end. The handle is attached by a flexible shaft to a power unit mounted on two wheels ( Fig. 6(1051)). The power unit is pulled along the work path by the operator. Since it is mounted on two small wheels, it is lighter and more comfortable than a knapsack type cutter carried on the back of the operator.

Rotary Mower

The rotary mower has a centrifugal blade made of plastic cord. The mower is manipulated over the ground using only one hand, in the same way as using a mop to clean a floor ( Fig. 7(1156)). The operator can cut weeds under trees without bending his back.

Mechanization of Other Farm Practices

We have also developed other types of machinery mounted on the transporter, such as a manure spreader unit, and a chipper to cut branches and leaves into small pieces suitable for composting. We are now investigating the performance of these models in field tests. We are also testing an electronic clipper developed in France, driven by a light battery pack belted around the waist, which reduces the working hours needed for pruning. A knapsack-type low-volume herbicide sprayer powered by a battery is giving promising results. With a working capacity of 30 L/ha, it further improves the comfort and convenience of orchard care.

Benefits of Mechanized Farming System

We have tested the benefits of the new system by comparing it with the conventional system in working orchards. These tests showed that the new mechanized system reduced working hours by more than 30%, and also made the work much lighter ( Fig. 8(1118)). Farmers' incomes have increased under the system because of improved fruit quality ( Fig. 9(1123)).

  • A fruit grower who introduced this new system indicated three main advantages.
  • He was able to expand the scale of his farm operations.
  • He could produce high-quality fruit because of his intensive care of the trees.
  • Workers were released from much of the hard manual labor of maintaining a slopeland orchard.

Conclusion

In steep slopeland orchards, small machines are an effective way of reducing the labor demand and making work easier. Small machines, however, show less efficiency than large machines on which operators ride, such as the trucks and air-blast sprayers that are widely used in flatland orchards. Therefore, it is very important to make a systematic plan, and lay out paths and facilities efficiently. Water storage tanks or irrigation pipes in orchards can improve the efficiency of pesticide sprayers by providing water as required. The labor needed to keep down weeds in orchards will be greatly reduced if farm paths are paved. A good network of farm paths connected to public roads also facilitates the transportation of harvested fruit and the delivery of fertilizer.

In developing machines for slopeland orchards, it is necessary to consider the quality or yield of fruits, soil conservation, and labor costs. For this reason, research on mechanization should be carried out in close cooperation with farmers, administrators, and machine manufacturers.

The slopeland orchards of Japan are being abandoned by young people because of the hard work of fruit production and the relatively low income. Mechanization is one of the key technologies for overcoming this problem.

References

  • Japanese Society of Agricultural Machinery. 1996. Introduction to Japanese Agricultural Machinery (III), pp. 60-82.
  • Miyazaki, M., K. Kawasaki and M. Daikoku. 1986. Running performance and adaptability of 6-wheel-drive transport vehicle on sloping land. Bulletin of the Shikoku National Agricultural Experiment Station 47: 54-77. (In Japanese with English abstract).
  • Miyazaki, M. 1996. Machines for hillside tangerine orchards. Farming Mechanization 2947: 4-8. (In Japanese).
  • Miyazaki, M. 1997. Working hood type sprayer. Journal of the Japanese Society of Agricultural Machinery 59,1: 137-138. (In Japanese).
  • Miyazaki, M. 1997. Development and prospects of mechanization in citrus orchards located on steep hillsides. Journal of Agricultural Science 52,5: 206-210. (In Japanese).
  • Takatsuji, T. 1997. Labor saving production system of high-quality citrus fruits on steep sloping land. Journal of Agricultural Science 52,2: 57-62. (In Japanese).
  • Yamamoto, H. 1996. The Use of Mulches for Sustainable Agriculture in Slopeland Areas. II. Shikoku, Japan. Food and Fertilizer Technology Center for the Asian and Pacific Region, Taipei, Taiwan ROC. Extension Bulletin No. 426, pp. 5-8.

Discussion

Several participants were interested in the cost of the farm mechanization program in Shikoku. It was pointed out that although this machinery can reduce labor costs by 30%, if labor costs are low this represents only a small amount of money. In such a situation, it may not be cost effective to buy machinery.

Mr. Miyazaki agreed, but pointed out that in Japan, low prices of around US$0.3/kg are paid for citrus used for processing, while the price for fresh fruit is at least five times this amount. Since machinery gives improved growing conditions and enables farmers to care for their trees intensively, the quality of fruit produced in a mechanized system is high, and so are the prices for the fruit produced.

Japan's consumers are not increasing their consumption of fruit, now about 40 kg per person per year, and they do not want to buy poor-quality fruit. Mechanized farming is helping farmers in this situation.

Mr. Miyazaki was asked whether communal use of machinery could lower the investment cost. He answered that in relation to labor costs, prices of the slopeland orchard machinery used in Japan are relatively low (US$ 16,000 for an airblast sprayer, US$ 6000 for a raised bed transporter, US$ 600 for a shallow cultivator, and US$ 600 for a handheld rotary mower). The total cost of a full set of machinery is about US$30,000. The government provides a subsidy which covers 50% of this cost. The machinery was developed for individual rather than communal use. It is difficult to transport machinery from one farm to another. Also, small machines of this kind are very slow, so a farmer may take some time to complete his work, even though his orchard may be small. Another advantage of farmers owning their own machinery is that they can use it when they need it, without having to wait for other users. Some farm practices should be carried out within a short time. Spraying, for example, often has to be done within two days to prevent a major pest outbreak.

Mr. Miyazaki was also asked how farmers covered the cost of construction work in their orchards. He explained that farmers themselves construct the work paths, side slopes and storage tanks. The prefectural government pays about half of the construction costs, and also helps farmers to plan the layout. The cost to the farmer is fairly low, which is why the system is being widely adopted by citrus producers in the area.

Index of Images

Figure 1 Layout of Farm Path System

Figure 1 Layout of Farm Path System

Figure 2 Air-Blast Sprayer Driven by an Operator on Foot.

Figure 2 Air-Blast Sprayer Driven by an Operator on Foot.

Size: Length: 2.06 m, Width: 0.96 m, Height: 1.41 m, Weight: 510 kg, Spray capacity: 13-27 L/min,

Air flow rate: 180 m 3/min).

Figure 3 Raised Bed Transporter

Figure 3 Raised Bed Transporter

(Size:Length:2.1m,Width:1.0m,Height:1.1m,Weight:510kg,Loadingcapacity:500kg,Liftingheight:1.1m)Figure 4 Fertilizer Unit Mounted on Transporter

Figure 4 Fertilizer Unit Mounted on Transporter

(Size:Length:1.9m,Width:0.9m,Height:1.4m,Weight:335kg,Dischargecapacity:14-25kg/min)Figure 5 Hand-Held Shallow Cultivator

Figure 5 Hand-Held Shallow Cultivator

(Size:Length:1.1m,Width:0.5m,Height:0.3m,Weight:12kg,

Depthofcut:1-3cm,widthofcut:36cm)

Figure 6 Mounted Cutter

Figure 6 Mounted Cutter

(Size:Length:3.7mWidth:0.4m,Height:0.3m,Weight:9.9kg)

Figure 7 Rotary Mower

Figure 7 Rotary Mower

(Size:Length:2.2m,Width:0.4m,Height:0.8m,Weight:8.0kg,Cuttingwidth:30cm)Figure 8 Working Hours Needed for Conventional and New Mechanized Systems

Figure 8 Working Hours Needed for Conventional and New Mechanized SystemsFigure 9 Changes in Farmers' Incomes

Figure 9 Changes in Farmers' Incomes

(Incomeratio:Incomein1993isregardedas100%)

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