Verificación y reporte: proceso de validación y verificación externo como

“In describing farming systems and their characteristics, we start therefore with the

assumption that they did not come about by chance and that there is always a reason why farming in a specific case is carried out in one way rather than another

(Ruthenberg 1971, 7)”

Ruthenberg defines typical farming systems for the various stages of agrarian societies that were introduced by Boserup. Within each stage of these stages, peasants’ developed typical strategies that allowed for dealing with the challenges to tropical farming presented above. The following overview will introduce Ruthenberg’s (1971) view on important stages of tropical smallholder agriculture, i.e. the two shifting systems of shifting cultivation & semi-

permanent cultivation as well as the permanent cultivation systems permanent rain-fed cultivation. As the following chapter is based solely on Ruthenberg’s (1971) works, no further

citations will be given. The information presented here helps to understand the meaning behind the classification of the farming systems in the study sites. A reader with sufficient knowledge on the three above-mentioned farming systems may skip this chapter and continue at chapter 1.4.5.

According to Ruthenberg (1971, 62), peasants’ main goals of agricultural production are to 1) ensure a reliable food supply, 2) to produce tasty food. Therefore millet or maize are often preferred over crops such as manioc. A third goal is 3) to produce cash with one dominating cash crop, such as groundnuts or tobacco. These three goals drive the organization of crop production both in shifting systems and permanent systems, yet both systems differ strongly in regard to their main cropping principles. These will be presented below:

a) Shifting systems

The overview of tropical farming systems starts with shifting cultivation, which may be considered as the world’s pioneering farming system which initiates the conversion of forested land to cultivated land. In shifting cultivation, a few years of cultivation alternate with a lengthy fallow period – therefore, fields (and often also homesteads) have to be periodically relocated - they slowly ‘shift’ through a landscape of mostly natural vegetation. This system works almost without capital and is based on the balanced exploitation of soil nutrients during cultivation periods and soil nutrient regeneration during fallow periods (Ruthenberg 1971). Under sufficient land availability, i.e. where fallow periods are long enough to allow for the complete regeneration of soil fertility, this system allows for covering the basic food needs of peasants in a sustainable and labour-efficient way.

However, the system changes as soon as rising food needs of a growing population or increasing cash-cropping necessitate a gradual expansion of arable agriculture. This spatial expansion reduces the area of uncultivated land and ultimately forces households to replace long-term fallow by shorter fallow periods.

A cultivation system that typically follows on shifting cultivation under long-term fallow is semi-permanent cultivation. In this system, a cultivation period of a few years is usually followed by a fallow period of similar length. Homesteads are quasi-stationary, because the

shifting aspect of farming is reduced and most re-locations occur over longer time periods and short distances only. Still, it can still be considered as a shifting system.

The reduced fallow period is often insufficient for the regeneration of denser woody biomass. Therefore, the fallow vegetation in semi-permanent cultivation consists mostly of grasses and smaller bushes. It also results in a gradual soil nutrient exploitation and thus in lower yields/ha than in shifting cultivation systems (at least unless inorganic or organic fertilizer is applied, which is rare in semi-permanent systems). Stable semi-permanent cultivation is therefore found mainly in dry or humid savannas or in higher altitudes, where soil fertility is generally high and nutrient leaching a lesser problem. Only here do soils and climate allow for relatively stable yields under the short crop-fallow cycles of semi-permanent cultivation. In most other cases, ongoing soil degradation is a typical attribute of semi-permanent systems. They can therefore be seen as a rather transitional phase between shifting and permanent forms of cultivation, but not as a stable system (Ruthenberg 1971, 79). Many of the challenges that semi-permanent cultivators encounter are caused by their use of working routines that have been developed within shifting systems. Yet at the same time, these challenges also dramatically increase the likelihood of adoption of innovative technologies into farming with fallow periods. Semi-permanent cultivation may therefore be seen as a promising or even necessary step in the development of peasant societies.

An important difference between shifting cultivation and semi-permanent cultivation is that (with decreasing fallow periods) the similarity between peasant’s livelihood strategies slowly reduces. In shifting cultivation, households tend to apply very similar farming practices and cultivate just enough land to meet their basic food needs and generate some cash income. In semi-permanent cultivation, farm sizes vary considerably and there is a clearer social stratification into wealthier and poorer households. This situation becomes even more pronounced with rising land scarcity and under higher degrees of commercialization. Among others, it is farm-managerial abilities which determine how well a household deals with these changes. Differences in these abilities can be a main reason for social stratification and explain the wide variation in choice of crops, farming methods, field sizes and technology adoption.

Peasants whose farming systems have a pronounced shifting character try to adapt to the biophysical conditions of their specific environment. Ruthenberg (1971) identified three main approaches in peasant’s adaptation to natural site conditions: The first approach lies in the choice of land that is cultivated, and this trade-off decision goes beyond considerations of soil fertility. It includes aspects of labour needs for clearing, but also weed growth, pest occurrence or a plots distance to roads and water sources. Farmers may therefore choose to cultivate various less fertile but easily accessible plots near their homestead rather than a large tract of highly fertile but hard-to-clear land deep in the forests.

The second approach lies in the skillful combination of medium- and long-term fallow. While short-term fallows of 1-2 years are usually the result of unexpected labour-scarcity, longer fallow-periods of 2-5 (medium-term fallow) or 5-20 (long-term fallow) years represent answers to the problems of growing weed infestation and decreasing soil fertility that occur over the course of successive cultivation periods.

The third approach to adaptation lies in three interlinked principles of cultivation: Mixed

cropping, Phased Planting, Crop Rotations. These three principles can be encountered in all

forms of peasant cultivation, shifting as well as permanent. However, in shifting systems they are of highest variability. Mixed cropping refers to the simultaneous cultivation of two or more crops on same plot. In shifting systems, the choice of these crops is usually based on their adaptation to soil and surface conditions and rarely organized by a formalized principle. Usually, row cultivation is adopted only in later agricultural stages of higher permanence, i.e. when tree stumps and termite mounds have been removed from the fields and when plough- cultivation has been adopted (see next section on stationary farming). Advantages of mixed cropping lie in the reduction of yield risk from pests, the possibility to adapt cropping both to the soil conditions as well as the light and shade requirements of the planted crops, but also in the lengthening of the period of fresh food supply as well as more continuous soil cover due to different growth cycles of individual crops. Phased planting of different crop species results in a continuous sequence of growth and harvesting. It allows for the distribution of agricultural labour over a longer time period, a reduction of risk of crop failure due to weather or predation and the advantages listed under mixed cropping. Crop rotations, i.e. the replacement of one crop species with another in subsequent growing periods, does rarely occur in long-term fallow. Instead, one crop or a specific mixture is commonly cultivated for a few consecutive years. Only when cultivation periods last several years do peasants develop crop rotations (in order to deal with increasing weed & pest infestation and reduced soil fertility). In this case, important features of crop rotations are i) a division of fields into several smaller plots with different crops rather than a general rotation for the entire field and ii) a temporal sequence of crops, with crops requiring higher soil fertility (such as maize) being replaced over time with crops that are either not nutrient-demanding or that compete better against weeds and bushes (such as manioc).

Soil fertility management in Shifting Systems

The comparative advantage of shifting cultivation over any other peasant system lies in the “cost-free, effortless regeneration of soil productivity during the fallow period, especially

when the fallow consists of forest or bush vegetation” (Ruthenberg 1971, 31-32). As long as

fallow periods are of sufficient length to allow for the regeneration of soil fertility, shifting cultivation allows for the ecologically sustainable production of relatively high and stable yields even under the adverse climatic and soil conditions of the tropics.

Long-term fallow as the main means of managing soil fertility is commonly supplemented by one or many of the following practices: i) using domestic waste to fertilize plots near the homestead, ii) establishment of garden plots on old animal kraals or homestead sites, iii) mixing of green vegetation with soil, iv) using ash of burned vegetation as fertilizer or, very rarely, v) the application of inorganic fertilizer.

The transition from shifting towards semi-permanent cultivation presents a major challenge to farm management. Fallow periods are now of insufficient length to restore soil fertility completely. However, no adequate alternative fertilization techniques have been developed yet. Therefore, “semi-permanent land-use systems often represent nothing more than

degraded forms of previously balanced systems of shifting cultivation (Ruthenberg 1971, 67)”.

the holding to a nearby, fertile plot, ii) fertilization of fields with animal manure by livestock- rearing peasants. To minimize the labour-needs of this task, peasants tend to avoid the manual spreading of manure on their fields but rather shift their kraal’s location, thus creating a sequence of fertilized plots within an otherwise un-manured field, iii) green manuring, i.e. the incorporation of cut fallow vegetation and weeds into soil by manual labour and, where cash and markets are more easily and reliably accessible, iv) via inorganic fertilization. In general, this system’s ability to provide food in the long-run depends on either i) highly fertile soils that even over long time periods manage to compensate for reduced fallow periods or ii) the ability to restore soil fertility even under grassy fallow. A more common phenomenon, however, is the iii) stabilization of yields at low average levels.

Labour use and seasonality of labour-demand in Shifting Systems

Labour requirements, both total and seasonal, differ strongly between shifting cultivation and semi-permanent cultivation. In shifting cultivation, time spent on farming typically accounts for less than half of a household’s working time. The most labour-demanding tasks are field clearing, harvesting and food processing. Due to long distances between fields and homesteads, crop transport can also be a time-consuming task, especially in case of root crop cultivation such as manioc. Weeding becomes a bigger task only under longer cultivation periods, because grass growth is suppressed by both fallow vegetation and clearing by fire. Land preparation and planting are less arduous tasks than in other systems, because hoe-based soil cultivation usually becomes the rule only in semi-permanent cultivation. The exception to this is shifting cultivation in the dry savannas. Here, longer cropping periods of up to ten years (which are sometimes interrupted by short-fallow periods of one to two year) necessitate the use of intensive hoe-cultivation practices. This will for example be the case in study site Cusseque, Angola.

A typical characteristic of shifting cultivation is labour division, which exists in three distinct forms: i) division by gender, ii) division by plots (e.g. men taking care of heavier work while women focus on grassy plots) and iii) division by crops, with men usually focussing on cash crops and women on subsistence crops.

Shifting cultivation usually relies upon hand-tools as major implements and avoids the use of domestic animals for cultivation. Reasons for this include limited grazing possibilities in dense forests, the high labour needs of animal husbandry and the fact that the tree-stumps left in shifting cultivation fields are an obstacle for effective plough-cultivation. Removing tree- stumps from fields whose location is regularly shifting would be very labour-consuming and also reduce the growth of the desired fallow vegetation. Another important reason for the low importance of draught animals is the low seasonality of labour-demand: clearing, harvesting and processing, the three central tasks of shifting cultivation, can be done in a relatively leisurely manner and over a longer time period. The speed and strength of oxen-drawn ploughs are not yet needed to cope with growing seasonal labour-needs (such as occur in semi-permanent cultivation).

Contrary to shifting cultivation, the most time-demanding tasks of semi-permanent cultivators are hoe cultivation and weeding. They are more fatiguing than the main tasks of shifting cultivation and need to be carried out in a timely manner within the growing season. In

general, peasants in semi-permanent cultivation spend more time on their fields than in shifting cultivation, because of rising labour-needs per unit of output produced as well as because of the additional labour required by cash cropping.

For these reasons, the relatively rigid division of labour common to shifting cultivation is replaced by a more flexible system, where for example men are becoming increasingly involved in field work (such as weeding or harvesting). Furthermore, the subdivision of the fields into individual plots for each family member is abandoned in favour of a more centrally organized use of land and labour.

Seasonality of labour-demand becomes very pronounced in semi-permanent cultivation, especially as long as no draught animals are introduced to the system for helping with ploughing and weeding. This seasonality typically contributes to the rising importance of cattle husbandry in semi-permanent cultivation. It also begins to serve as insurance for crop losses or sickness, which become more common in semi-permanent cultivation due to reduced and more erratic yield levels. Ultimately this development may result in a rising social function of cattle, e.g. as a bride price or a status symbol. Cattle also becomes an important provider of meat and milk. Due to these reasons, large cattle herds are characteristic for later stages of semi-permanent systems, while in shifting cultivation livestock plays only a little or no role at all.

Evolution towards permanent farming systems

A typical evolutionary pathway of (rain-fed) tropical peasant farming systems leads from shifting and semi-permanent cultivation to permanent farming (Ruthenberg 1971, 98). This trend signifies an intensification of labour use, which aims at increasing land productivity. Ruthenberg identifies two main reasons which induce intensification: The first is necessity, a push-factor, and it is typical for those areas where population pressure forces smallholders to abandon fallowing and find alternative soil fertility management practices. While traditional systems become increasingly unable to provide for the basic food needs of smallholders, they become more likely to try out and develop new, more labour-intensive production methods. The second reason is the existence of pull-factor for intensification. As peasants seem to prefer living close to markets, water sources and neighbours, they tend to move into already relatively densely populated areas. Here, they are again forced to adopt systems of shorter fallows or even permanent cultivation systems. In fact, the benefits of living here seem to outweigh the additional labour needs that arise when adopting more intensified systems. Another advantage of adopting a more sedentary lifestyle lies in the easier dissemination and adoption of technological innovations. It can also cause increasing investments into infrastructure, such as fences, anti-soil erosion terraces or the replacement of grass or clay huts with solid houses and tin roofs. Rising permanency may thus present the foundation for an intensification process that would not be possible under fallowing systems.

b) Permanent cultivation systems

Systems of permanent cultivation are characterized by cultivation periods which are either not at all or only for a short time interrupted by a fallow period. The most common permanent cultivation systems of the tropics are irrigation farming and perennial cropping, which represent rather late stages in the intensification process. In this dissertation, the focus lies on the stage of permanent rain-fed cultivation, which is rarely a stable farming system, but rather represents a possibly negative end-point of the intensification process. As will be shown in chapter 1.6.2-1.6.3, study site Mashare and possibly also Seronga are in danger of following this development.

Generally, systems with permanent rain-fed arable farming develop out of shifting systems via the continual expansion of arable farming at the expense of fallow. They are typically characterized by i) a permanent division of arable land and grassland within the same holding, ii) a clear demarcation of fields and iii) a dominance of annual and biannual crops. Although trends towards these characteristics may already be discovered in shifting systems, they dominate only under permanent systems.

The following overview will focus on permanent rain-fed cultivation in the African savannas, i.e. areas matching the biophysical environment of the Okavango catchment. Here, permanent cultivation has usually developed due to two different goals of peasants. First, it is used to cover the basic food needs of a slowly increasing population. This is often achieved by developing sophisticated methods of manuring. Due to the high labour needs of these methods, holdings are usually small and yield per invested labour hour low. Second, it is employed to generate additional income by increasing the share of cash cropping. In this case, the adoption of sophisticated manuring techniques is less common and soil mining widespread (at least until all available land had been put into production).

However, there is a third way of how rain-fed permanent cultivation has developed. In India, this happened especially in areas where soils are naturally poor and where no irrigation is adopted, so that after centuries of cropping the yields stabilized at very low levels. This describes a Malthusian trap and areas characterized by these farming systems this are known as famine areas. Most traditional types of permanent rain-fed agriculture in the tropics can