and plant varieties, and productivity. Clearly, there is no universally best technology for agriculture, as all agricultural techniques must be adjusted to local soil, climatic conditions, and factor endowments. However, a society must clearly innovate in both major aspects of the mechanical package and biological package of agricultural technology in order to effect a viable technological variation. 9 Thus, the optimal levels of capital-labor substitutability, as well as plant variety-chemical fertilizer complementarity, have to be employed and kept in place. The productivity effects of such technological input in LDC agriculture cannot be overemphasized.
Agrarian production in most LDCs commonly displays certain peculiar and crucial features. The most important of these features with regard to technology, is the seasonal nature of operations: the busy seasons of planting and harvesting when labor needs are high, and the slack gestation periods when the producer would really need none or only a very small workforce for maintenance of the farms. 10 To effect technological variation, there is the need for simultaneous application of mechanical and biological packages. Establishing and using the products of Agricultural Research Centers, and creating rural capital such as roads and irrigation systems will enhance varied technology.
LDC governments must adopt more aggressive postures in regard to introducing new inputs and new techniques, and must use Extension Services to spread the transfer of these new techniques to the farmers. Rural dwellers in the LDCs learn from their neighbors - and technology travels more rapidly when neighboring agricultural entrepreneurs in a country have equitable assess to varied technological facilities. The key to success in overcoming the major scientific and engineering constraints facing the LDCs' agriculture also involves rural education, which would help increase the channels of contact and encourage people to abandon archaic tenure methods in favor of varied technology.
These are common-sense specifications, but they get at the heart of the failure of the agricultural sector in LDCs. Perhaps it is because such "common sense" is obvious, and not based on any sophisticated computer simulatory modules, that they are not effectively and seriously applied. Implementing these straightforward practical policies will go a long way toward improving agricultural productivity in the LDCs.