The present study entitled “Study of Fertilizer Consumption Pattern in North Coastal Districts of Andhra Pradesh” has been attempted to identify the trends in fertilizer consumption. The reference period of study was from 1979-80 to 2003-2004 and the study was carried out for the North Coastal region of Andhra Pradesh comprising of Srikakulam, Vizianagaram, and Visakhapatnam districts.

Trends in fertilizer consumption, total cropped area, net irrigated area, rainfed area were identified by computing compound growth rates. Trends in Fertilizer consumption for these three North Coastal districts and Andhra Pradesh state as whole were studied. The determinants of fertilizer consumption were identified by multiple linear regression using non-price factors like total cropped area, rainfed area, net irrigated area and rainfall. An attempt had also been made to assess the rainfall pattern of these three North Coastal districts using cluster analysis.

The study revealed that the N, P, K and NPK total fertilizer consumptions marked a significant increasing trend for the North Coastal districts and state as a whole. Potash consumption recorded highest compound growth rate in all the districts. Almost all the three North Coastal districts exhibited positive trend but non-significant incase in total cropped area, net irrigated area and rainfed area. The rainfall pattern was identified for South-West and North-East monsoon periods using the cluster analysis and it revealed the most probable and representative pattern of rainfall in each district. It is also revealed that the total cropped area that determined fertilizer consumption mostly, followed by Rainfall among non-price factors that were included in the regression model.

The compound growth rates of Nitrogen, Phosphate, Potash and Total fertilizer consumption of Srikakulam district were 3.99, 8.19, 22.10 and 5.05 per cent respectively. Potash consumption was recorded the highest growth rate over the years in the Srikakulam district. It was revealed the change in consumption levels over the years. The compound growth rates of Nitrogen, Phosphate, Potash and Total fertilizer of Vizianagaram district were 5.80, 6.65, 20.38 and 6.31 per cent respectively. The compound growth rates of Visakhapatnam district were 6.45, 4.44, 18.05 and 6.59 per cent respectively. The compound growth rates of Nitrogen, Phosphate, Potash and Total fertilizer for entire Andhra Pradesh state were 5.05, 6.06, 6.46 and 5.45 per cent respectively.

The cluster analysis revealed the season wise rainfall pattern for twenty five years of rainfall data for the all the three districts. The average rainfall for the most probable clusters was obtained. The rainfall pattern in Srikakulam district was identified by cluster analysis and thecluster-1 with 0.44 probability referred as most probable pattern of rainfall during the South-West monsoon and the cluster-1 with 0.56 probability referred as most probable pattern of rainfall during North-East monsoon. In Vizianagaram district the cluster-2 with 0.48 probability referred as most probable pattern of rainfall during South-West monsoon and the cluster-2 with 0.44 probability referred as most probable pattern of rainfall pattern during North-East monsoon. In Visakhapatnam district the cluster-1 with 0.68 probability referred as most probable and representative pattern of rainfall during South-West monsoon and the cluster-2 with 0.44 probability referred as most probable pattern of rainfall during North-East monsoon.

Out of the four independent variables viz., total cropped area, net irrigated area, rainfed area and rainfall that were included in the regression model, in most of the cases for all the three districts only the total cropped area turned out to be significantly affecting the fertilizer consumption. However, in Vizianagaram district the rainfall turned out to be significant in determining the Nitrogen consumption during sub period-2 and the total fertilizer consumption during subperiod-2.

The time series data on production of crops often exhibits a discontinuity in the year to year variations. These disturbances are mainly due to the impact of technological innovations in the crop. Under this situation, the conventional time trend models fail to provide an appropriate model for forecasting, as these models are based on the assumption of uniformity in the year to year variations. Similar is the case with measurement of growth. The growth rates obtained from the data that exhibits a discontinuity often present illusionary picture of the data. The study was therefore planned to explore the applicability of Spline models in forecasting the food grain production, as ‘discontinuity’ in the year to year variation is the fundamental assumption in these models. An attempt was also made to measure the growth rate with due consideration of discontinuity in the data. The study was confined to the three regions of A.P as well as state of A.P as a whole and was based on 40 years of production data covering the years 1966-2005.Three categories of crop production namely total food grains, total oilseeds and total pulses were considered in the study and forecasting models as well as growth rate were obtained.

Spline Models were found to be relatively efficient than the conventional trend fitting models in forecasting of crop production.

The Growth analysis revealed that the  production data of crops exhibited a considerable increase in the production level, over the years in all the regions and the state. Total pulses production have emerged as the most promising crop with regard to the increase in the production in the recent years. In general, the growth of production in total food grains and oilseeds   during the recent years was found to be exhibiting a stagnancy, indicating the need to evolve development measures in these crop categories.