<P> Some sources of agricultural productivity are: </P> <Ul> <Li> Mechanization </Li> <Li> High yield varieties, which were the basis of the Green revolution </Li> <Li> Fertilizers: Primary plant nutrients: nitrogen, phosphorus and potassium and secondary nutrients such as sulfur, zinc, copper, manganese, calcium, magnesium and molybdenum on deficient soil </Li> <Li> Education in management and entrepreneurial techniques to decrease fixed and variable costs and optimise manpower </Li> <Li> Liming of acid soils to raise pH and to provide calcium and magnesium </Li> <Li> Irrigation </Li> <Li> Herbicides </Li> <Li> Genetic engineering </Li> <Li> Pesticides </Li> <Li> Increased plant density </Li> <Li> Animal feed made more digestible by processing </Li> <Li> Keeping animals indoors in cold weather </Li> </Ul> <Li> High yield varieties, which were the basis of the Green revolution </Li> <Li> Fertilizers: Primary plant nutrients: nitrogen, phosphorus and potassium and secondary nutrients such as sulfur, zinc, copper, manganese, calcium, magnesium and molybdenum on deficient soil </Li>

Who evolved the method of measurement of agricultural efficiency