Ankur Biswas

• Ph.D. (Agricultural Statistics)
• Senior Scientist at ICAR-Indian Agricultural Statistics Research Institute

In this study an attempt has been made to improve the sampling strategy incorporating spatial dependency at estimation stage considering usual spatial sampling like Simple Random Sampling (SRS) when the underlying population is finite and spatial in nature. Using the distances between spatial units an improved method of estimation, viz. Spatial Est...

Spectral discrimination of rice genotypes was investigated using canopy reflectance in the range of 350 to 2500 nm. The pre-processed reflectance spectra were statistically analysed using one-way analysis of variance (ANOVA) followed by classification and regression tree (CART) technique to find significantly sensitive wavelengths for discriminatio...

Ranked Set Sampling (RSS) is preferred to Simple Random Sampling (SRS) when measuring an observation is expensive or time-consuming, while ranking small subset of observations is relatively easy. Estimating the variance of RSS estimator has been found cumbersome under finite population. In this study, we propose two rescaling bootstrap variance est...

In sample surveys, the model calibration approach is an improvement over the usual calibration approach, where the concept of the calibration approach is generalized to obtain a model-assisted estimator using more complex models based on complete auxiliary information. In many surveys, the study and auxiliary variables vary across locations and the...

Agricultural statistics pertaining to crop area, yield, and production are indispensable for effective resource allocation and planning within the agricultural sector. Reliable and timely information on these statistics serve as vital inputs for policymakers and planners. The availability of reliable information on crop yield is an essential compon...

This is second volume of the training manual of the Centre for Advanced Faculty Training (CAFT) on “Modern Data Analytics Techniques for Agricultural Survey” during February 11 - March 03, 2025, under the aegis of the Education Division, ICAR, New Delhi. This offline training program is designed for scientists and teaching faculty from ICAR Institu...

This is trainning reference manual of Centre for Advanced Faculty Training (CAFT) on “Modern Data Analytics Techniques for Agricultural Survey” during February 11 - March 03, 2025, under the aegis of the Education Division, ICAR, New Delhi. This offline training program is designed for scientists and teaching faculty from ICAR Institutes and State...

Unlike the ordinary least square model, the geographically weighted regression model takes into account spatial non-stationarity and can capture the spatially varying relationship between several variables. Although a particular model should contain all pertinent covariates, too many insignificant covariates make the model unnecessarily complex. Th...

Post-harvest losses caused by insect pests, particularly the rice weevil, Sitophilus oryzae, pose a significant challenge in food storage facilities worldwide. To combat this pest, synthetic insecticides and fumigants are widely used. However, effective contact insecticides are scarce. Hence, the present study explored the alternatives by evaluatin...

In large-scale surveys, many practical challenges arise, including increased expenses for data collection, a growing need for statistics at a small-area level, decreasing response rates, and the need for timely estimates. In recent years, integrating data from multiple surveys has emerged as one of the most popular approaches for making inferences...

The General Crop Estimation Survey (GCES) scheme requires a large number of Crop Cutting Experiments (CCEs) to be conducted to get a reliable estimate below the district level. However, conducting a large number of CCEs imposes a financial burden on Govt. agencies. Additionally, large-scale surveys like GCES often result in many outlier observation...

Despite the Green Revolution's impact, many small-scale farmers continue cultivating landraces for their agronomic, culinary, and cultural values. This study, conducted in Odisha, focuses on region-specific on-farm conservation practices employed by farmers for landraces. Five focused group discussions were conducted in five villages, involving 15...

प्रायोगिक अभिकल्पनाओं का मूल सिद्धांत यह है कि उपचारों को प्रायोगिक इकाइयों पर पूरी तरह से यादृच्छिक रूप से वितरित किया जाना चाहिए। हालांकि, व्यावहारिक रूप में इकाइयों में अक्सर कोई संरचना होती है, जिससे ब्लॉकिंग की आवश्यकता प्रकट होती है। अनेक औद्योगिक प्रयोगों में कुछ कारक होते हैं जिनके स्तर अन्य से कठिनता से सेट किए जाते हैं। अगर इसके अतिरिक्त,...

In many agricultural, forestry, environmental, and ecological surveys, data are often spatial in nature and exhibit spatial nonstationarity. A well-known method for addressing spatial nonstationarity and capturing the spatially varying relationships between different variables is Geographic Weighted Regression (GWR). The calibration approach is one...

eLISS web portal and eLISS Data Collection App provides end-to-end Solution for major livestock products in India which is capable of sample selection, real time sample allocation, data collection from the field, field data supervision, real time survey monitoring, data cleaning, data analysis and generation of estimates of both number and producti...

The Agricultural Research Data Book (ARDB) 2024, which is twenty seventh in the series, is an attempt to put together main components/indicators of such information and comprises of 180 tables which is organized for the purpose of convenience of the users into 10 sections. Agricultural research provides a vital input for planned growth and sustaina...

General Crop Estimation Surveys (GCES) based on Crop Cutting Experiments (CCEs) are conducted for estimation of crop yield following random sampling approach for almost all major crops. About 13 lakh CCEs are conducted every year which has now increased rapidly due to the Pradhan Mantri Fasal Bima Yojana (PMFBY) which is yield based insurance schem...

The study investigates the knowledge levels of custodian and non-custodian farmers in Odisha and Uttarakhand regarding landrace conservation and Farmers' Rights. Educational e-learning modules, were developed using ADDIE model and implemented to enhance farmers' understanding. The developed e-module were evaluated by a panel of experts comprising r...

Dual frame (DF) surveys are a special case of multiple frame (MF) surveys considering two frames covering the entire population. Dual frame surveys are applicable in those situations, where, one frame may cover the entire population but is very expensive to sample; so an alternate frame may be available that does not cover the entire population but...

The Himalayan region is a most fragile ecosystem globally. Trees make up around 90 % of the global biomass carbon pool and previous studies have shown that tree carbon balance cannot be easily assessed by conventional methods. Considering trees as a backbone of the forest ecosystem, present study assessed the heterogeneity in tree carbon density us...

In this study, a two auxiliary calibration estimator is proposed under two stage sampling design using a nonlinear constraint with the assumption of availability of population level auxiliaries at the cluster level and the size of the clusters were assumed unknown. The performance of the proposed estimator was evaluated through a simulation study....

A major goal of survey sampling is finite population inference. In recent years, large-scale survey programs have encountered many practical challenges which include higher data collection cost, increasing non-response rate, increasing demand for disaggregated level statistics and desire for timely estimates. Data integration is a new field of rese...

Bt cotton has played a great role in bollworm management since its approval for commercial cultivation in India. To ensure the longevity of Bt technology, structured refuge was advocated wherein, the non-Bt seeds were provided as separate pack along with Bt seeds. Poor compliance of refuge planting is considered as a major factor for resistance dev...

In survey sampling, auxiliary information is used to precisely estimate the finite population parameters. There are several approaches available in the literature that provide a practical method for incorporating auxiliary information during the estimation stage. In order to effectively utilize the auxiliary information, a geographically weighted r...

Operation Greens Programme of the Government of India focuses on post-harvest management of Tomato, Onion, and Potato (TOP) crops, value chain development, and value realization of farmers’ produce, which helps in enhancing livelihood security. The study conducted during 2022-2023 focused on factors determining the value realization of TOP crops un...

Two-phase sampling, also known as double sampling, can be a costeffective technique in large-scale surveys. By selecting a large sample, observing cheap auxiliary variables and properly incorporating the auxiliary variables into the second-phase sampling design, it can produce estimators with smaller variances than those based on a single-phase sam...

In India, cotton yield estimates are done using crop cutting experiments (CCEs) conducted within the framework of the general crop estimation surveys (GCES) methodology. In recent times, for obtaining reliable estimates at levels lower than the district, the number of CCEs has increased in comparison to the existing setup of GCES. This puts an addi...

In survey sampling, auxiliary information is often used to increase the efficiency of estimators of finite population parameters. The Calibration Approach is one of the popular techniques for such purposes. In this current study, product type calibration estimator of the finite population total has been proposed following well-known Calibration App...

The ratio in finite population is one of the most common statistics used in official statistics, demographic studies, agriculture and allied field of agriculture. In this paper, estimators of the ratio/proportion in finite population are developed by incorporating known auxiliary information under the calibration approach. The variance and the esti...

Population ratio is one of the most commonly used statistics in official statistics, agriculture and agricultural-related fields. When interest is in the estimation of ratio for rare but highly aggregated geographically distributed population, adaptive cluster sampling (ACS) design is usually used (Dryver and Chang 2007). Under ACS design, neighbou...

Information pertaining to agricultural research, education and related aspects available from different sources is scattered over various types of published and unpublished records. These scattered information are being compiled since 1995 in Agricultural Research Data Book (ARDB) through joint efforts of the ICAR-Indian Agricultural Statistics Res...

In India, Food and Agriculture Organization of the United Nations (FAO) was implementing a project “Strengthening Agriculture Market Information System (AMIS) in India using Innovative Methods and Digital Technology” and supporting the efforts of the Ministry of Agriculture and Farmers Welfare, Govt. of India. This project identified the potential...

It is a hybrid spatial model that combines the strengths of two widely used regression models, MARS (Multivariate Adaptive Regression Splines) and GWR (Geographically Weighted Regression), to provide an effective approach for predicting a response variable at unknown locations. The MARS model is used in the first step of the development of a hybrid...

The calibration approach is a popular technique for incorporating auxiliary information for estimation of population parameters in survey sampling. In general, the Calibration Approach assumes the availability of population-level auxiliary information. On the contrary, in large scale surveys, it is often the case that population-level data on auxil...

The developed package can be used to generate a spatial population for different levels of relationships among the dependent and auxiliary variables, along with spatially varying model parameters. A spatial layout is designed as a [0,k-1]x[0,k-1] square region on which observations are collected at (k x k) lattice points with a unit distance betwee...

The elliptical model is a generalization of Multivariate normal distribution. In this study aquifer data (Jones 1989) was fitted using the spatial t model. Cross-validation and trace criteria are used to determine the degrees of freedom of spatial t.

Large scale surveys, for example, household surveys, are the most important components in every national statistics system. These types of large-scale surveys are the primary and sometimes unique source of data for measuring many of the variables relating to Sustainable Development Goals (SDG) indicators. The problem of missing observations is very...

McIntyre (1952) introduced Ranked Set Sampling (RSS) to advance upon Simple Random Sampling (SRS) for circumstances where any preliminary ranking of sampled units is possible for variable of interest using visual inspection or some other means without physically measuring the units. Further, the RSS was classified into three sampling protocols name...

Adaptive cluster sampling (ACS) technique is usually used for estimation of the abundance of an exclusive, clustered biological population. Commonly, neighbouring units are added to the sample if it satisfies a predetermined criterion. Use of auxiliary information to increase the precision of estimators is a very general practice. This paper deals...

Sample survey is a cost effective mean to collect reliable information about a finite population. There are various sampling methodologies, among them two-phase sampling is generally used for estimating population mean or total under the two different situations. First, when the information of the auxiliary variable is not readily available and the...

In a Dual Frame (DF) surveys, set of two frames is used instead of a traditional single frame of sampling units from the target population. Dual frame surveys are applicable in those situations where one frame covers the entire population but very expensive to sample; so an alternate frame may be available that does not cover the entire population...

रेशम ऊंचे दाम किंतु कम मात्रा का एक उत्पाद है जो विश्व के कुल वस्त्र उत्पादन का मात्र 0.2 फ़ीसदी है। रेशम उत्पादन एक श्रम आधारित उच्च आय देने वाला उद्योग है अर्थात इसके उत्पाद के अधिक मूल्य मिलते हैं, अत: इसे देश के आर्थिक विकास में एक अहम साधन समझा जाता है। विकासशील देशों में रोज़गार सृजन हेतु खासतौर से ग्रामीण क्षेत्र में तथा विदेशी मुद्रा कमाने...

In this study, an attempt was made to develop bootstrap variance estimation procedure for Spatial Estimator (SE) of finite population mean in presence of missing observations under Simple Random Sampling Without Replacement. The Proportional Spatial Bootstrap (PSB) method has been proposed considering spatial relationship between sampling units. Un...

Timely and accurate estimates of crop areas are critical for enhancing agriculture management and ensuring national food security. This study aims to combine remote-sensing data and survey data to improve the accuracy of crop area estimates and decrease the cost of crop surveys at district level. In this study an estimate of mango area was obtained...

When survey data shows spatial non-stationarity then geographically weighted regression (GWR) approach explains the data more effectively than standard global regression model. In this article, two outlier robust geographically weighted regression (RGWR) estimators have been proposed to estimate the finite population total under spatial non- statio...

Ranked Set Sampling (RSS) is preferred over Simple Random Sampling (SRS) when measuring an observation is expensive or time consuming, but can be easily ranked at a negligible cost. Biswas et al. (2015) proposed a Spatial Estimator (SE) of population mean under RSS through prediction approach incorporating spatial dependency among sampling units of...

Projections of environmental change are motivating greater emphasis on future constraints to agricultural production.The pace of population, climate and environmental change has compelled the crop community to consider those stresses that are likely to result in significant yield declines. Crop improvement efforts have benefited greatly from advanc...

The Calibration Approach proposed by Deville and Särndal (1992) is a popular technique to efficiently use auxiliary information in survey sampling. In this study, calibration estimators of the finite population total have been developed under two stage sampling design along with variance of the estimator and the corresponding estimator of variance....

Multiple frames are preferably used when a satisfactory sampling frame, covering the whole population in question, is unavailable or even if such a frame is available it may not be economically advantageous to use that frame for survey because of high cost of sampling per unit. In this paper, we dealt with the problem of variance estimation of the...

Pulses are a major constitutent along with rice or wheat in the Indian diet of the middle and lower class. Slight reduction in the production results in drastic increase in the price of pulses due to the deficit unfulfillment in the short duration as India is the only largest and important producer along with the major consumer. Survey is done in t...

Agricultural Research Data Book (ARDB) is an important Indian Council of Agricultural Research (ICAR) publication which provides valuable information in the form of comprehensive compendium regularly on annual basis. This publication is widely used as a reference book for data on various aspects of agriculture and its allied sector. The ARDB is a r...

Horticultural crops unlike field crops are perennial in nature, not having distinct phenology. It is difficult to discriminate horticultural crops using temporal multispectral data. Major limitation of multispectral data is lesser number of bands and mixed pixels which may not be able to discriminate fruit crops but the hyperspectral data has the a...

This ARDB 2018 is twenty first edition in the series. It is divided into 10 sections for the purpose of convenience of the users. It provides information on natural resources, agricultural inputs, animal husbandry, dairying, fisheries, horticulture, production, productivity, agricultural engineering, export, import, place of India in world agricult...

Auxiliary information is often used to improve the precision of estimators of finite population total. Calibration approach is widely used for making efficient use of auxiliary information in survey estimation. We proposed the regression type estimators of the population total using the calibration approach under the assumption that the population...

Hartley (1962) suggested the use of more than one sampling frame to draw samples from the desired population under study. Many earlier studies have established the fact that the use of more than one frame is cost effective to achieve same level of precision. In this paper, we use ranked set sampling (RSS) to draw independent samples from each frame...

Estimation of major crop yield rates at the district level using calibration estimation technique is reported here when auxiliary information is available at the unit level only for the selected villages within each district and when the sampling design under consideration is two-stage equal probability without replacement. An estimator was develop...

On the basis of a gaps analysis, a methodology has been developed to estimate crop area and crop yield in mixed and continuous cropping scenarios. In this regard, several alternatives have been considered, depending upon the information available in the agricultural statistical system. The different methods for the area apportionment of a crop mixt...

This technical report provides findings of field tests conducted in selected districts/study area in three countries i.e. Indonesia, Rwanda and Jamaica on the basis of methodology developed by the team at ICAR-IASRI on estimation of crop area, yield and production under mixed and continuous cropping. Different methods of determination of crop area...

The Data Book has been compiled through the joint efforts of the ICAR-Indian Agricultural Statistics Research Institute (IASRI) and Indian Council of Agricultural Research (ICAR). This edition contains the latest information / data as available in the country at the end of June 2016. The first edition of the Data Book, which had the information up...

Regression type estimators of the population total were developed using the calibration approach under the assumption that the population level auxiliary information is available at primary stage unit level under two stage sampling design. The variance and the estimator of the variance of the proposed estimators were also developed. Theoretical res...

This technical report focuses on methodologies used for estimation of a crop area and crop yield under mixed and continuous cropping. It provides a review of the literature on methodologies used for estimation of crop area and crop yield in developed and developing countries. The report begins with descriptions of relevant concepts and definitions...

Ranked Set Sampling (RSS) is preferred over Simple Random Sampling (SRS), when measuring an observation is expensive or time consuming, but can be easily ranked at a negligible cost. While working with spatial population, classical statistical methods fail to capture the dependency present in the underlying data. In this article, an attempt was mad...

This technical report provides the gap analysis in the context of mixed and continuous cropping with regard to crop area and yield estimation. Based on gap analysis, an appropriate methodology is developed for carrying out estimation of crop area and crop yield in the mixed and continuous cropping scenario. Various concepts and definitions of surve...

When measuring an observation is expensive, but ranking a small subset of observations is relatively easy, ranked set sampling (RSS) can be used to increase the precision of the estimators. Estimating the variance in case of RSS has been found to be cumbersome in the context of finite population. Therefore, in this paper, we propose two different v...