The description of a machine in the introduction to Section 1.1, which grouped a wedge together with an airplane, may be valid only at a certain level of conceptualization. But in a more formal sense, a machine is a device or mechanical contrivance consisting of two or more relatively constrained components which is energized by a power source to transmit and/or modify force and motion to accomplish some desired kind of work. In contrast, a tool is a human powered instrument or implement usually without parts that move relative to one another, like a hoe, a dibber, or the like, used to facilitate mechanical manual operations.
Classification by Field Operations
Field operations are tasks performed in the field at different phases of crop produc- tion. The major operations include land preparation, planting, weeding, and harvesting.
Based on these operations, the tools/machines used are classified into: land prepara- tion tools/machines; planting tools/machines; weeding/cultivation tools/machines; and harvesting tools/machines.
Hand-Tools for Land Preparation Hoes
Naturally, soil preparation is usually the first task in crop production, undertaken to achieve a variety of basic interrelated objectives such as seedbed preparation, weed
control, soil and water conservation, soil compaction amelioration, etc. In peasant agri- culture, soil or land preparation to achieve a combination of these objectives usually involves tilling with a hoe, and constitutes the most significant characteristic of the hand-tool (mechanization) technology.
Curiously, no manually operated machine for land preparation is commonly avail- able. The hoe is the most popular and most versatile tool used in developing coun- tries of the world, where peasant farmers account for close to 90 percent of the area under cultivation. The hoe is the tool used almost exclusively in land preparation of peasant agriculture, for combined primary and secondary tillage, and for land-forming operations such as ridging, bedding, mounding, bunding, ditching, etc. Hoes for land preparation come in different sizes, weights and peculiar shapes, having evolved over the years to suit widely varying crops and conditions of soil, farming culture, farmers’
physiques and temperaments. Described generally as long-handled implements with thin, flat blades set transversely, common technical features of hoes include long handles and heavy heads carrying the cutting blades or shares. Handles vary a great deal in length, shape and curvature. Blades also vary a great deal in shape, size and curvature, lead- ing to an intriguingly varied world of hoes, as illustrated by the small sample given in Fig. 1.2. Wide-bladed hoes are used for digging, ridging and mounding under normal soil conditions; narrow-bladed ones are used for hard soil conditions; while tined hoes, which are not very common, are used for stony conditions.
Machetes/Spades
Other hand tools used to complement the hoe in land preparation under peasant agriculture include machetes, axes, spades, forks, and rakes, which also vary in sizes and shapes, as illustrated in Fig. 1.2. Next to the hoe, the machete is one of the most important tools in peasant agriculture, where it is indispensable in land clearing and a host of other crop production operations.
Manual Planting Tools and Machines Hoes
The hand hoe of appropriate size and shape is the most versatile tool used by the peasant farmer in planting cereals, root crops and other crops. The farmer with the hand hoe can use his judgment and experience to place the seeds or planting materials at optimum depths and appropriate spacings within and between rows, and provide just the right firming pressure to achieve good yields. Hoes used for planting, while varying greatly according to diverse cultural preferences, usually are lighter and smaller than those for primary tillage or ridging, mounding, bedding or ditching operations, because less energy is demanded (see Table 1.1) and closer attention required.
Manual Planters
Unlike the case for land preparation, there are many hand-operated machines available for planting and sowing, often with improved results in terms of uniformity of plant spacing and row configuration. The manual planters may be as simple as dibbers, which are pointed instruments made of steel or wood tipped with steel, used to place seeds in the ground. Or they may be as sophisticated as the various types of jab planters or pushed
Figure 1.2. A Variety of Hand Tools for Land Preparation. A - Hoes; B - Machetes; C - Shovels, spades, forks and rakes.
or pulled seed drills with more complex seed metering devices. In this case, different metering mechanisms give rise to such planter types as seed-roller, fluted-roller, slide- roller and chain- and- sprocket driven seed drills/planters. Illustrations of some of the major types of manual planting tools and machines are given in Fig. 1.3.
It is important to state here that the more sophisticated pushed or pulled planters, which usually are equipped with seed coulters or other furrow openers, do require well- prepared seed beds, which a typical peasant farmer usually is not able to provide. In fact, a peasant farmer, whose only or major means of land preparation is the hand hoe, is not likely to prepare enough land area to make the ownership or use of the more sophisticated hand-operated planters economical. As a result, adoption of these pushed or pulled planters by peasant HTT farmers is very limited indeed.
Manual Weeding Tools and Machines Hoes
What is said about the hand hoe with respect to planting applies to weeding and cultivation. Generally speaking, in peasant agriculture, the heavy work of land prepara- tion using big hoes is handled by the men while subsequent field operations, especially weeding, are undertaken by women and children, using the smaller and lighter hand hoes that come in three major types: digging hoes, chopping hoes and pushing/pulling hoes.
Most peasant farmers own only the digging hoe type, which they use for different tillage operations, often with designs that are peculiar to certain traditional communities, such as the design called ikeagwu-agadi (literally meaning “exhaustion free for the aged”) by Igbo-speaking people of Nigeria, which is a very popular hoe (see Fig. 1.4) for weeding under all soil conditions, soil topography and cropping patterns.
By implication, the chopping hoes, used to chop the weeds and soil, though suitable under hard or friable soil conditions and all conditions of soil topography and cropping pattern, are much less popular. Still less popular are the pushing/pulling hoes, used to cut weeds under the soil surface but suitable only under friable soil conditions. Some examples of weeding hoes are given in Fig. 1.4.
Rotary Hoes and Wheeled Cultivators
Human-powered rotary hoes for weeding do exist but are mainly used for row cropped paddy rice or upland crops in friable soils. Also, many designs of human-powered wheeled cultivators, with different kinds of weeding shares (tines, hoes, etc.) are avail- able but are suitable only for row crops in friable soils. Some examples of rotary hoes and wheeled cultivators are given in Fig. 1.4. Naturally, use or ownership of these more sophisticated human-powered weeders is very much restricted, thereby severely lim- iting their impact on the activities of peasant or small-holder farmers of the tropical world.
Slashers
For completeness, human-powered slashers, most commonly in the form of machetes or cutlasses, should be mentioned as important human-powered weeding tools used by peasant farmers. Slashers are used to cut down above-ground parts of weeds and are especially useful in controlling weeds in plantations or perennial crops.
Figure 1.3. Some Examples of Manual Planting Machines. A - Hand-pushed centrifugal grain/fertilizer broadcaster; B - Hand-pushed rotary injection planter; C - Hand-pushed seed drill
D - A variety of jab planter.
Figure 1.4. Some Examples of Weeding Tools and Machines. A - Weeding hoes (Ikeagwu-agadi); B - Improved weeding hand hoe; C - Hand-pushed rice weeder; D -
Wheeled hand-pushed weeder; E - Hand-pushed ridge-profile weeder.
Manual Harvesting Tools and Machines
From discussions thus far, it is evident that tools and machines for field operations used by peasant farmers have retained their pristine forms and sizes as developed by their ancestors centuries ago. This is particularly true of harvesting operations for which the hoe, various diggers, machetes and knives, sickles and scythes, persist as the major tools available to peasant farmers of the developing countries of the world. A few man- ual harvesting machines have been developed here and there, but they cannot compete favorably with the manual harvesting tools in terms of cost and efficiency.
Hoes
If the hoe is thought ubiquitous in peasant agriculture, well so it is. It is the principal tool used by small holder farmers to harvest root and tuber crops (yams, cocoyams, potatoes, corn, cassava, etc.) as well as all crops that develop underground, such as groundnuts. Of course, the type of hoe used depends on the crop, the topography (flat, beds, ridges or mounds) and the soil type or condition (hard or friable, plastic or muddy).
Happily, in most cases, a suitable hoe is always available.
Diggers and Lifters
A variety of simple tools consisting of long-handles with sharpened or speared digging tips made wholly of wood, wooden with steel tips, or made wholly of steel, form a second group of tools known as diggers, which are used to harvest root and tuber crops, especially yams. Often they are used together with hoes to deal with roots and tubers that develop at considerable depths in the ground. Sometimes, shovels and forks, where available, are used in place of wooden diggers. There are also a number of designs of hand tools called lifters, used for root crops, especially cassava, as illustrated in Fig 1.5.
Machetes and Knives
For harvesting cereals (millet, corn, rice, sorghum) peasant farmers use various types of machetes or knives developed over the centuries to cut the plant stalk or grain heads, in a once-over operation or selectively, with the special advantage that shattering losses are minimized. Another advantage is that inclusion of unnecessary vegetation is drastically reduced, making for lower transport costs and safer storage. The main disadvantage is the inherently high labor requirements, which can be considerably higher than those for sickles, especially for heavy crops. Special knives have been developed for some crops, such as sugar cane and oil-palm.
Sickles
A sickle is a peculiarly shaped knife, very popular in the harvesting of cereals, con- sisting of a curved metal blade with a sharpened edge and a wooden handle fitted on to a shank known as the tang. The length of the blade and its curvature, as well as the shape of the handle and its angle of attachment, varies a good deal from one culture to the other, as illustrated in the sample presented in Fig. 1.5. Typical specifications of a sickle also are shown.
Scythes
A scythe is a variant of a sickle, composed of a long, curving blade with a sharp edge, made fast at one end to a long, bent shaft with a handle forming a unit called the snath.
Figure 1.5. Some Examples of Harvesting Tools other than Hoes and Machetes. A - Different traditional sickle shapes; B - Some Nigerian sickles; C - Various harvesting hooks; D - Scythe
handles; E - Different scythe blades; F - Sickle dimensions; G - Cassava lifter.
The curved lengths of scythes vary quite considerably, with the shorter bladed ones being more suitable for difficult terrains such as hill slopes. The lengths and curvatures of the snaths also vary a good deal as they are designed to permit users of various statures to operate with both hands and outstretched arms. Specifications for scythes are similar to those for sickles. Samples of scythe blades and snaths are shown in Fig. 1.5.
Harvesting Hooks
The cereal or grass harvesting tool called the reaping hook was developed as a sort of hybrid or cross between the sickle and the scythe. Reaping or harvesting hooks, like sickles and scythes, come in varying sizes and traditional shapes as illustrated in Fig. 1.5. They have short handles and very sharp blades, so that a user crouches to cut the free standing crop without supporting or holding it. Preference for the harvesting hooks appears to be a cultural trait.
Economics of Human-Powered Tools/Machines for Field Operations
The discussions so far have shown that human-powered tools/machines for field operations are quite limited, consisting essentially of hoes, machetes, knives, hooks and diggers, virtually preserved in their pristine shapes and sizes by the peasant farmers who inherited them from their great ancestors of many centuries ago. The overriding characteristics of these implements are their relatively low energy demand, low labor productivity, low technology, low output and inherently high laboriousness and tedium, all of which have direct and indirect relevance to the economics of hand-tool technology (HTT), over and above the purely capital cost considerations.
The low-technology characteristic is important because it implies that these imple- ments can be, and generally, are fabricated by the farmers themselves, as well as by local artisans and blacksmiths, so that their supply is largely in response to their demand. Al- though local manufacture in itself is a good thing and should be encouraged for various economic reasons, it must be noted that, given the intrinsically low-volume, the lack of formal scientific basis, and the absence of quality control in the production process, the products generally are of low quality.
In addition to artisans and blacksmiths, some urban-based companies in some devel- oping countries manufacture the hand tools of interest, as shown in Table 1.6. But such companies often have to contend with many local problems, such as: lack of the right kind of steel locally; inimical or non-conducive manufacturing environment; poor technologi- cal support institutions, infrastructure and superstructure; stiff or unfair competition with directly imported alternative goods; and unrealistic excises and sometimes discouraging duties on imported raw materials. Additionally, the companies face the serious problem of low or uncertain volume of sales arising from the fact that their customers, the peasant farmers, who are usually among the poorest of the poor in their country, have limited capacity to invest in new implements, even when the implements they use are too old and or worn out and require replacement. As a result of these severe local problems, the few existing companies lack the requisite incentives to invest in the improvement of the products or expansion of their operations, all with predictable consequences. This means that needs for most of these implements are usually satisfied by importation from the developed countries, such as Austria, Belgium, Germany, Spain, the United Kingdom, and the United States.
Table 1.6. Some Formal Companies in Some Developing Countries that Manufacture Some Human Powered Implements for Production Field Operations
H M R W S R F M P S S G P C
Country Company K H H T K Y H L L
Brazil Azotupy Ind. Met. Ltd ∗ ∗
Bangladesh Zahed Metal Ind. ∗
Cameroon Tropic ∗ ∗ ∗ ∗ ∗
Chile Famae ∗ ∗
China China Imp/Exp Corp ∗
India Kumaon Nursery ∗ ∗
Kumar Ind. ∗ ∗ ∗ ∗ ∗
Yantra Vidyalaya ∗ ∗ ∗
Bharat Ind. Corp ∗ Cossul & Co. Ret. Ltd ∗
Kenya Datini Mercantile Ltd ∗ ∗
Oyani Rural Centre ∗
Malawi Chillington Agric Ltd ∗ ∗ ∗
Nepal Agric.Tools Fac. Ltd ∗ ∗ ∗ ∗
Niger A.F.M.A. ∗
Nigeria Crocodile Match. Ltd ∗ ∗
W.Nig. Tech Ibadan ∗
Zartech, Ibadan ∗
Peru Fahena S.A ∗ ∗ ∗
Herramieutas S.A ∗ ∗ ∗ ∗ ∗ ∗ ∗
Herrandina ∗ ∗
Phillipines Agric. Mech. Dev. Pro ∗
Sri Lanka Kanthi Ind. ∗
Agric. Impl. Factory ∗ Tanzania Sarvudaya Kandy ∗
Ubongo Farm Imp/ ∗ ∗
Zana Za Kilimo Ltd ∗ ∗
Uganda Chillington Tool Ltd ∗
Zimbabwe Bulawayo Steel Prod. ∗
Garba Ind. (Pvt) Ltd ∗ ∗
Temper Tools” Ltd ∗ ∗ ∗ ∗
Tool making Eng’g.
Note: H - hoes; M/K - machetes/knives; RH - rotary hoes; WH - wheeled hoes; S - spades/shovels; R - rakes; F - forks; MT - mattocks; P - picks/axes; SK - sickles; SY - scythes; GH - grass hooks; PL - jab/roller planters; CL - cassava lifters.
It is clear that there are many factors that combine with capital cost considerations to make the economics of hand-tool technology in developing countries quite intrigu- ing. With small and usually irregularly shaped plots planted with a mixture of crops, a cropping system that tolerates the feasible use only of primitive hand-tools that may be old and worn out, leading to poorly cleared land, poorly tilled soils and poor plant- ing in irregularly formed rows, the outcome is inevitably a poor harvest. Under these circumstances, with low cost advantage and low productivity, the economics of peasant agriculture using HTT, exhibits the vicious cycle of poverty-begetting-poverty.