The effectiveness of demand forecasting as a management tool depends on the availability of data on crop area and output, produce prices, crop response to fertilizer application, fertilizer consumption, area under high yielding varieties, etc. Those engaged in fertilizer distribution should remain in touch with departments and agencies concerned with credit extension, seed distribution, crop prices and subsidies. Availability of data enlarges the range of choice for the policymaker and the fertilizer distributor in selecting the most appropriate method from among several alternatives. Annex XVIII is a list of data needed for demand forecasting and market development and the likely sources from which they can be collected.
The area under different crops for each season and fertilizer consumption by crop are vital pieces of information for measuring the effect of cropping patterns on fertilizer consumption. However, such data is difficult to collect from thousands of farms. Sample surveys are a reliable and economical substitute for direct data collection in order to ascertain cropping changes in response to produce prices, input prices, seasonal conditions and other environmental factors. The sample should be a cross section of farmers representing different crop management levels, sizes of land holdings and agro-climatic conditions.
