The New Encyclopaedia Britannica
Encyclopaedia Britannica, 1974 - Encyclopedias and dictionaries - 934 pages
 Propaedia: outline of knowledge and guide to the Britannica.--- Micropaedia: ready reference and index.--- Macropaedia: knowledge in depth.
Results 1-3 of 78
These are the structure of the agricultural ecosystem and the population densities
of the pests below which little economic damage will occur. Agricultural
ecosystems. If pest control depends on manipulation of pest populations, it
Agriculture. By the early 1970s agriculture produced less than 20 percent of the
national income and employed 35 ... the form of an increase in yields, made
possible by the greater use of fertilizers, other agricultural chemicals, and
Despite the small size and fragmentation, mechanization of agriculture has been
slowly progressing. ... the introduction of more efficient techniques of cultivation
and farm management to obtain a substantial increase in agricultural productivity.
What people are saying - Write a review
LibraryThing ReviewUser Review - keylawk - LibraryThing
This is the 198215th Edition, in two halves, with the Macropaedia and the Micropaedia. First published in 1768, the publisher is the oldest English-language encyclopedia still in print. Two Scottish ... Read full review