Crop growth models play a major role in sustaining the world-wide food security. These models are used to simulate crop growth during the growing season, and the final crop yield at the end of the growing season, given the farmers’ management practices. At a more strategic level, these crop growth models play an important role to decision makers to take timely decisions regarding food import and/or export strategies. The simulation accuracy of crop growth models relies on the quality of the input data.

Describes the organization, objectives and results of the aerial survey programme of the Kenyan Rangeland Ecological Monitoring Unit from 1976 to 1979, with particular reference to the methodology used, animal population estimates, esp. herbivores, and reliability of aerial survey data in terms of aerial, ground & remote sensing counts.

Examines decision making models formulated to guide the allocation of funds between alternative lines of research, issues emerging from the survey to the formation of ILCA's research policy, and various theories that account for the direction that research has taken in different contexts and reviews the past allocation of resources to livestock research in 10 African countries; includes proposal for further work.

Looks at the allocation of resources to livestock research in Africa. Assesses the role of agricultural research and its value to national governments. Investigates the appropriate criteria to use for decision making by comparing three kinds of decision-making models. Presents conclusions for policy-making.

This document is divided in eight chapters. The first chapter reviews rangelands and rangeland development in Ethiopia. The second chapter is an introduction to the Borana Plateau with ref. to natural resources and pastoral society. It reviews secondary information on geology and sociology, as well as original information on climate, soils, wildlife, plant ecology and water resources for the central Borana Plateau. Chapter three deals with vegetation dynamics and resource use.