Indian Official Statistics: Part VII (c)

Agricultural Statistics
1. Crop Production Statistics
  1. v. Currently, for most food crops and some of the cash crops, the estimation of yield rate is done with the help of crop-cutting experiments. The estimate is build up by actually harvesting, threshing and weighing the crop growing in small areas (called ‘cuts’) selected amongst the fields. A stratified multistage random sampling method is used for the preference, with tehsils (each containing 100 to 300 villages) as strata, a village as the primary unit, a field growing the particular crop as the secondary unit and a cut within the field as the ultimate sampling unit.
  2. vi. For each crop, generally two to ten villages are chosen at random from each stratum; in each village, two fields growing the crop are selected; and in each field a cut of prescribed size is marked out for conducting the crop-cutting experiment. The size of the cut to be made varies from 1/500 th of a hectare (20m X 10m) in the case of cotton. But the commonest cut-size is (10m X 5m) of a hectare.
  3. vii. The methods which used in Kerala, Orissa and West Bengal are slightly different. In West Bengal, for example, the area under a police station is taken as the stratum and the sampling unit is a square grid of area 2.25 acres. For the survey on area under crops, sampling grids are chosen at random from all the police stations at the rate of one per ½ square mile and all the plots falling wholly or partly in the grid are enumerated. For the yield survey, grids are randomly selected from each stratum and in each selected grid generally one cut is taken at random for each and every crop. The cut is circular area composed of three concentric circles of radii 2’, 4’ and 5’7” for all crops excluding potato, arhar and sugarcane, in which case the cut is a square area of side 15’.
  4. viii. In each stratum, a simple arithmetic mean of yield per cut is obtained. The yield from a mixed sown cut is divided by the corresponding eye-estimate of the proportion of area under the given crop; these figures for all such cuts and the yields of cuts sown solely with the given crop are added up to obtain the average of each strata. The district average is found by weighting each stratum average by the proportion of the net area sown in each of the strata. The State average in its turn, is obtained by weighting each district average by the proportion of the total net area that falls under the crop.
  5. ix. For non-forecast and plantation crops, the available estimates are ad hoc estimates as distinct from those available for forecast crops. The estimates of area and production of tea, coffee and rubber used to be based on special returns received by the DES from the State Governments. However, in the absence of the necessary data from the State Governments, all-India figures of area and production of coffee and rubber, as available from the Coffee Board and the Rubber Board, respectively, are being used from 1965-66 and 1066-67, respectively. Data regarding tea also are being extracted from the information received from the Tea Board.
  6. x. As regards minor crops, for State with a primary reporting agency estimates of area are made in the basis of complete enumeration, but for other States the area estimates are extremely unreliable. The available yield estimates are everywhere impressionistic and unreliable. Recently, sampling methods are being used for some of the crops, especially for those falling under fruits and vegetables and spices and condiments.
  7. xi. The two most important DES publications in area and yield of crops are the following:
    1. Estimates of Area and Production of Principal Crops in India (annual). This gives estimates of area, production and average yield per hectare for the principal crops (both forecast and non-forecast) along with data on rainfall. The estimates of area and yield for the current year as also some previous years are given State-wise, except for coffee and rubber, for which only all-India estimates are available. The rainfall data are published for each of the 29 rainfall divisions of the country. As regards food grains, separate estimates of area and production of kharif and rabi food grains are available for all-India and the major States. The figures of rice are given separately for autumn rice and winter rice.
    2. Agricultural Situation in India (monthly). This gives the first as well as the subsequent forecasts of area and production of forecast crops. The revised estimates also appear in the publication. Similar, estimates for plantation crops are also given. (In addition, it contains data of agricultural prices, viz. Farm procurement prices, wholesale process and retail prices.)

Other publications on agriculture are:

Indian Agriculture in Brief (DES, annual). This gives a snapshot picture of whole agricultural economy. State-wise figures are given for some important items like land utilisation, area, production and yield rate and livestock population.
Bulletin in Food Statistics (DES, annual). This presents an integrated picture of the production, procurement, export and import, distribution, market arrivals and prices of food grains.
Tea Statistics (annual), published by the Tea Board. [Another annual publication named Tea Digest has been started by Tea Board since 1991.]
Coffee Statistics (annual), published by the Coffee Board.
Indian Rubber Statistics (annual) and Rubber Statistical News (monthly), both published by the Rubber Board.
xii. One should mention here that a set of estimates of yield is prepared every year by the Agricultural Statistics Wing of the NSSO. These are based on yield rates estimated from a sub-sample of official crop cuts, whose yields are harvested, threshed and weighed under the supervision of the NSSO. For area, the official figures are utilised.
xiii. The current system of estimation of area and yield of crops leaves scope for improvement in more than one respect:
1. A uniform method of estimation should be followed in all the States. For yield forecast, alternative methods based on metrological factors and using a multiple regression model may be considered for adoption.
2. Statistics of yields separately for irrigated areas and non-irrigated areas are still not available in most States. Area and yield data for improved agricultural practices (like use of pesticides, fertiliser and HYVs) are also not collected separately. This position calls for a change.
3. The method of crop-cutting experiments for the estimation of yield rate has not yet been extended to commercial crops and minor crops in most States. This should be done to improve the quality of such data.
4. A set of statistics that needs to be built up is that of land utilisation according to land use potentialities.
5. xiv. We shall briefly consider other types of agricultural statistics, viz. livestock statistics, fishery statistics and forestry statistics.

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Vaibhav Miglani, an aspirant of knowledge in statistics is currently pursuing his "B.Sc(H) in Statistics" from "Ramanujan College, University of Delhi". He wants to become one of the greatest minds in the field of statistics.