GENERAL CROP ESTIMATION SURVEY (GCES) R.P. Rathi NSSO (FOD) Agricultural Statistics Wing, CGO Complex, Block-II, NH-IV, Faridabad-121 001 1. INTRODUCTION In the context of primacy of Agriculture, timely and reliable statistics on crop production is of vital importance and significance. As the total production of crop is the product of the area under the crop and average yield per hectare, the Crop Production has two major components viz. Area sown and Average yield. The primary responsibility for collection of statistics on these two aspects rests with the State/UT Governments. Statistics of land use and area under crops are obtained as by-products of land revenue administration in respect of the land record States/UTs, commonly known as Temporarily Settled States. On the other hand, the Permanently Settled States, viz. Kerala, Orissa and West Bengal are reporting land utilization and area statistics based on sample surveys. At present, over 95 percent of foodgrains production is estimated on the basis of yield rates obtained from scientifically planned Crop Cutting Experiments conducted under the programme of General Crop Estimation Survey (GCES) carried out by the State/UT Governments. 2. OBJECTIVE The primary objective of General Crop Estimation Survey is to obtain fairly reliable estimates of average yield rates of principal food and non-food crops for each State and Union Territory and for such lower administrative unit as Block, District etc. which are important from the point of view of crop production. The estimates of yield rates thus arrived at, are generally adopted for the compilation of official estimates of crop production and used for the purposes of planning, policy formulation and implementation. 3. METHODOLOGY Under GCES, data on yield rates are collected through organizing and conducting crop cutting experiments by applying statistical techniques of random sampling. The crop cutting experiment consists of identification and marking of an experimental plot of a specified size and shape in a selected field on the principle of random sampling, harvesting and threshing the produce and recording the weight of the produce. For a part of the experimental produce or in some cases for the entire produce of experiment, further processing of the harvested produce is done for determining the percentage recovery of dry grains or the marketable produce. For paddy and cotton, the yield is expressed in terms of Rice and Lint respectively after applying the standard recovery ratio and ginning ratio. The size and shape of the experimental plot for various crops, in respect of different States are specified. The shapes of the cuts for various crops vary to some extent in different States. In most of the States and for many crops, the plots are either square of size 5 meters x 5 meters or rectangle of size 10 meters x 5 meters. In the State of U.P., the experimental plot is equilateral triangle of side 10 meters for most of the crops and in West Bengal, it is circle of radius 1.7145 meters approximately. For some crops, specially fruits and vegetables, it consists of either specific number of trees or number of rows of plants. Plants located at the 169
border will be included in the experimental plot if the stump of the plant is half inside the plot. Otherwise it is to be excluded. Each border plant should be examined accordingly. 4. COVERAGE OF SURVEY 4.1 General Crop Estimation Survey (GCES) is conducted in 20 land record States/UTs, 3 EARAS States and 6 other States / Uts as given below:- Details of GCES Coverage during 2008-09 States in which C E S was conducted Land Record States/Uts 1. Andhra Pradesh 2. Assam 3. Bihar 4.Chhattisgarh 5.Gujarat 6.Haryana 7.Himachal Pradesh 8.Jammu &Kashmir 9. Jharkhand 10. Karnataka 11. Madhya Pradesh 12. Maharashtra 13. Punjab 14.Rajasthan 15.Tamil Nadu 16.Uttar Pradesh 17.Delhi 18. Uttarakhand 19. Dadra & Nagar Haveli 20. Puducherry EARAS States 1.Kerala 2.Orissa 3.West Bengal Other States and Uts. 1.Andaman district of A & N Islands 2. Daman & Diu 3.Goa 4.Manipur 5.Meghalaya 6.Tripura States/Uts in which GCES was not conducted 1. Arunachal Pradesh 4. Mizoram 2. Chandigarh 5. Nagaland 3. Lakshadweep 6. Sikkim 170
4.2 During the agricultural year 2008-09, a total of 68 crops comprising 52 food and 16 non-food crops were covered under GCES in different States / UTs. The details of different categories of crops are given below:- Crops covered under GCES during 2008-09 S. No. Particulars No. of crops Food Crops 1 Cereals 7 2 Pulses & Beans 12 3 Small Millets 7 4 Condiments & SpiGCES 10 5 Fruits & Vegetables 16 6 Sugar (Sugarcane & Cocoa) 2 Total 54 Non Food Crops 1 Oil Seeds 11 2 Fibres 3 3 Drugs & Narcotics 2 Total 16 5. DESIGN OF SURVEY The sampling design generally adopted for the GCES during 2008-09 is that of Stratified Multi-Stage Random Sampling, with tehsils/taluks/revenue inspector circles/c.d Blocks/ anchals, etc. as Strata and revenue village within a Stratum as First Stage Unit of sampling, survey number / field within each selected village as sampling unit at the second stage and experimental plot of a specified shape and size as the ultimate unit of sampling. In each selected primary unit of sampling, two survey numbers/fields growing the experimental crop are selected for conducting crop cutting experiments. Generally, 80-120 experiments are conducted for a crop in a major district, where a district is considered as major for a given crop if the area under the crop in the district exceeds 80,000 hectares or lies between 40,000 and 80,000 hectares but exceeds the average area per district in the State. Otherwise, district is considered as minor for a given crop. Experiments in minor districts are so adjusted that the precision of the estimate is fairly high and the workload on the field staff is manageable. On an average, about 44 or 46 experiments are planned in a minor district. The number of experiments allotted to a district is distributed among the strata within the district roughly in proportion to the area under the crop in the stratum. In some States, the sampling design takes into account the stratification according to inputs viz. Irrigation and Seed variety for major crops. While the idea of evolving a general design for stratification needs examination, it is felt that there would be practical difficulties in attempting stratification according to variety mainly due to non-availability of required data in the present system of area statistics at different levels. 171
6. ORGANISATION OF SURVEY Assignment relating to planning of survey, training of field staff, organization of field work and tabulation of data is the responsibility of the State Agricultural Statistics Authority (SASA) in each State/UT. The SASA in the State is either the Director of the Bureau of Economics and Statistics or the Director of Agriculture or the Director of Land Record depending on the administrative arrangements in each State/UT. The primary field work of the survey is generally entrusted to the staff of the State Department of Revenue, Agriculture, Community Development or Statistics, exclusively or as a part of their normal duties. In the six States viz, Assam, Kerala, Meghalaya, Orissa and West Bengal and in the UT of Puducherry, the primary work was done during 2008-09 by trained whole time staff of the Department of Statistics. 7. SAMPLE SIZE OF SURVEY The number of experiments planned over the last 10 years shows an overall rising trend, indicating the overwhelming response to the approach for adoption of objective sampling techniques of crop cutting experiments in greater magnitude from year to year for estimation of yield rates in the country. The significant rise in no. of experiments in GCES from 2004-05 onwards is due to inclusion of experiments required for the purpose of National Agriculture Insurance Scheme. During the year 2008-09, a total of 8,91,757 experiments were planned under GCES at all India level. 8. TRAINING OF PRIMARY WORKERS A programme for imparting training to primary workers engaged in the conduct of crop cutting experiments under the GCES is held in each State at the beginning of each season/year. Usually Department of Agriculture of various States arranges such training programmes and normally training camps are organised in each district. All the Revenue Inspectors, Tehsildars, BDOs, Extension Officers and such officials attend the training camps and discussions are held for the conduct of crop cutting experiments. The State Governments prescribes one booklet generally known as "Procedure for the Estimation of Crop- Production on Random Sampling method in the State". It gives in detail the procedure of selection of two independent survey/sub-survey numbers on major crops both food and non-food crops as also all necessary steps to be taken by the primary worker at different stages in the conduct of crop-cutting experiment. The book-lets are supplied to the workers and all the details are discussed during the training camps. The training is imparted on the following main points:- i) Selection of villages: For all crops put together in most of the States, a common sample of village is chosen at the beginning of the agricultural year by simple random sampling without replacement either from the list of TRS villages in the stratum in the States where the TRS is in operation or from the list of villages constituting the stratum in States where TRS is not in operation. Also a set of additional villages is chosen in a similar fashion from each stratum. In certain States, the selection of villages is done season-wise and crop-wise. ii) Selection of survey numbers: Normally in each State, SASA prescribes one booklet known as "procedure for the estimation of crop production on Random Sampling Method in the State". It gives the procedure of selection of survey numbers on major crops both food and non-food. It also mentions the steps to be taken by the primary worker at different stages of the conduct of crop cutting experiment. In every village, two survey numbers are required to be 172
selected for conducting the crop cutting experiments. For the selection of two survey numbers, the first essential requirement is the frame. Thus, a frame of survey number should be made available or be prepared. iii) Selection of the fields: After selection of two survey/sub-survey nos., the primary worker has to physically locate the survey number with the help of patwari, village map etc. If the selected survey number contains only one patch with the specified crop, the same is selected. If it contains more than one patch growing the crop for which the experiment is to be done, the one nearest to south-west corner is selected. 9. SUPERVISION Supervision of field work is an essential part of any large-scale sample survey for ensuring quality of data collected. A threefold approach is adopted in the States for supervision of crop cutting experiments planned under GCES. This includes Supervision by the statistical staff of State Agricultural Statistics Authorities (SASA), Supervision by the Departmental staff i.e. by the supervisory officers of the Departments whose workers are responsible for the conduct of crop cutting experiments in the field and Supervision by the Technical personnel of the NSSO (FOD). 10. PROCESSING & RELEASE OF RESULTS OF SURVEY After collecting data from field, the data is processed at various levels as per the State practices in different States/UTs. The result of the survey in terms of yield estimates at various levels is made available to the Ministry of Agriculture for computing national level production estimates. 173