CHARACTERISTICS OF SELECTED SYSTEMS Robert E. McDowell and Peter E. H-ildebrand
The objective of this section is to direct attention to various levels of integration of crops and animals and portray the infrastructural dependence, within selected systems. Eleven systems are identified for Asia, Latin America, and Africa, and
each system is discussed in terms of some of the physical constraints of the region, e.g., climate, soils, elevation, crops and cropping systems, the role of animals, and the panel's assessment of the prospects for expansion of benefits derived from animals.
A standard format was used for ease in comparisons. The box identified as "Market," represents all off-farm activities and resources (except land); hence it includes products sold or labor going off the farm as well as purchased inputs and household items. The "household" is the core of the farm unit. in preparing the models of the systems, labor use, sources of human food, household income, animal feed, and the roles of animals. were the main focus. The solid arrows depictt strong flows or linkages (e.g., more than 20 percent of total income arises from the sales of crops, animals, or household-processed products). Broken arrows (- -)I are used when sales of crops or animals contributed less than 20 percent of household income, the interchange among functions was intermittent, or there was no routine pattern identifiable (Figure 2.3). Family labor applied
on the farm was identified, but off-farm employment or the amount of hired labor was not quantified except generally and is indicated by broken or solid arrows.
For most products there is a iir,,ci. relation to market. absent in cases where little is .old or when the household changes the characteristics of the product before sale (e.g., wool to yarn, milk to cheese, or manure to dung cakes) Household modification is shown by solid arrows from crop or animal products to household to market. Even though all crops require some processing, a distinction was made only when the
household modified or changed an already marketable product.
Fuel is extremely important on small farms. Gathering of wood or other materials often constitutes a significant expenditure of labor, or may represent an important source of income. in each system, the major fuel sources are identified.
The models presented are by no mans all-inclusive. Hundreds of models would be needed to characterize all small-farm systems. However, through am appreciation of the "interaction effects," the rationale of the "whole system" on small farms can be better understood and serve to explain why a single phase of technology, such a new variety of maize, may be rejected by small
farmers.
CROPS/ANIMAL SYSTE14S IN ASIA
Swidden System
The swidden system (Figure 2.3) is employed on 30 to 40 percent of all land in tropical Asia (H-arwood and Price 1976). It