The diversification in structural forms of agriculture such as Cropping pattern, live stock structure or agricultural enterprises explains the possibility or necessity to raise a variety of these forms which possess nearly an even proportion. Essentially, it is an indicator of multiplication of agricultural activities which obviously involve intense competition among various activities for space. The keener the competition the higher the magnitude of diversification, and lesser the competition, greater will be the trend towards specialization or monocultural farming, where emphasis is on one or two crops. Agricultural diversification is now almost a normal feature of stable agriculture and progressive farm management in most of the extensive agricultural parts of the world. In fact, this has been made possible by modern irrigation and the use of fertilizers, high yielding varieties, pesticides and mechanization technologies. Besides, there are other factors which force the cultivators to take to crop live stock or enterprise diversification. For complete comprehension of the geography of crops, live stock or agricultural enterprise of a region, the interpretation of their diversification is essential. In view of the importance of these attributes of agriculture, it is attempted here to measure and map the degree of crop diversification in Nellore District.

Nellore district the southern most coastal district of Andhra Pradesh lies between 13⁰ 30¹ and 15⁰ 6¹ of the Northern latitude and 70⁰ 5¹ and 15⁰ 6¹ of the Eastern longitude. It is bounded on the north by Prakasam district, on the east by Bay of Bengal, on the South by Chittor district and Thiruvallur district of Tamil Nadu and on the west by Veligonda hills which separate it from Cuddapah District. The principal rivers which drain the district are the Pennar River and other streams of occasional and torrential in character are Kandleru and Boggeru. The district spreads over an area of 13,07,000 hectares and accounts for 4.75 per cent of the total geographical area of the state. The Net area sown is reported as 3,33,451 hectares in the district .According to 2011 census the total population of the district accounts to 29.64 lakhs and the density of population is 227 Persons/sq.km.

The main Objective of the present study is to identify the crop diversifications in two time periods i.e. between the trienniums 1987-90 and 2012-15 in Nellore District. To bring out the changes in the diversifications in 25 years period.

In the present study, secondary data pertaining to General cropping pattern for two trienniums i.e., 1987-90 and 2012-15 have been collected from the Government records and reports from Chief planning officer, Hand book of Statistics, Agricultural office of Nellore District taking ‘Mandal’ as Unit. Simple statistical techniques such as percentages and averages have been used to analyse the data. To find out the crop diversification ranges, Gibbs-Martin diversification index method is applied and the changes in Crop diversification have been studied for 25 years period.

The district experienced relatively lower degree of diversification and it is decreased further during 25 years of period. An index value of 0.42 is observed during 1987-90 and 0.228 in 2012-15, which reveals the trend of crop specialisation rather than crop diversification in Nellore district. The Zero index of diversification is found in about 10 mandals during 1987-90 and 24 mandals in 2012-15. This also supports the tendency of crop specialisation Nellore especially with Paddy domination due to the availability of irrigation facilities and traditional background of Paddy cultivation right from the historical days in the district.