STRATIFICATION


The process of dividing an area or population into relatively
homogeneouv subgroups in order to increase sampling efficiency.



STRIP CROPPING

The growing of two or more crops simultaneously in distinct strips
of several rcs with each strip capable of independent
cultivation.



SUB-AREA

A subdivision of a TARGET AREA within which common physical,
biological and socioeconomic factors prevail.



SUBSISTENCE FARMER


A farmer producing food
having, in consequence,
production or consumption.


primarily for farm family needs and
a low capacity to purchase inputs for


SUBSYSTEM

A SYSTEM which is part of a larger system.



SUPERIMPOSE- TRIALS

Relatively simple RFSEARCHER-MANAGED TRIALS applied across a range
of farmer-nanaged conditions. The experiments are usually
composed .f a small set of tre-atments that evaluate the
performance of alternative COMPONENT TECHNOLOGY for a CROPPING or
LIVESTOCK SYSTbM. Ihe treatments are superimposed, generally
without REPLICATION. on similar trial fields.



SUPPORT SERVICES

Systei-s that influence the appropriateness of a new technology,
e.g. roar's, transportation, markets, available credit,
irrigation, and sources of supply for seed, herbicides and
fertilizer.


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