fertilizers and machinery. Only in this way can agriculture be made to give a 
definite contribution to the national economy. However, fulfilment of all 
needs will only be possible provided modern methods of research are used as a 
sound foundation. 
At the same time, the development of industry should provide the population 
with money to buy the products of their developing agriculture, and in addition 
absorb that part of the population inevitably displaced from the land. Apart 
from the most undeveloped types of subsistence farming, food and all other 
agricultural products must be bought. Only if the farmers will receive in the 
near future a sufficiently high price for the food which they produce, can 
agriculture be developed in a sound way. Even then, the international funds 
being made available will be urgently needed, since they must provide the large 
amounts of money needed to start this uplift. This money must provide for 
research as well as for the construction of works for soil conservation, irrigation 
and drainage, and possibly also for the first gifts of chemical fertilizers to start 
the increase of production on soils which have almost always been depleted 
by past methods of farming. 
Soil survey, land use survey, land classification survey, soil erosion survey and 
soil conservation survey are all urgently needed to give a sound foundation 
for this development. They are urgently needed for various aspects such as: 
1. the general inventory of the soil resources of a country to find the best way 
for their development, 2. to indicate the priority of their development with 
regard to related projects, including those in the industrial sphere, and to the 
social and economic needs of the country, 3. to put the development projects 
on a sound basis which prevents the investments for development being put 
in the wrong place at the wrong time and in the wrong way, 4. to make it 
possible for the farmers who are going to be settled on these projects to attain a 
higher standard of living and a more economic production. Only if these 
conditions are fulfilled will the farmers be able to contribute continuously to 
the food production and the general economic development of their country. 
These needs put a heavy burden on the soil surveyor who must provide the 
basic data and who must cooperate with his colleagues in agronomy, soil con 
servation and plant breeding for the evaluation of his data for practical agricul 
ture. Furthermore, this task must proceed with sufficient speed in order that 
the execution of development projects is not hampered by a lack of data. The 
aerial photograph is therefore an essential tool in improving the efficiency of 
these surveys. Only by making an intelligent use of this tool in connection with 
the necessary field work can the development of a country be achieved in such 
a way that rural development will have maximum benefit from the data 
provided by modern science, in the shortest possible time. 
A particular part of the agricultural domain is the forestry branch. Especially 
for the tropical regions we may expect a considerable increase in the value of 
the forest in the future. To demonstrate the justification of this statement I will 
quote some data obtained from a recently published report of the FAO.