Abstract production has increased because of the

AbstractRice is one of the most important sources ofcalorie and energy in human body. It plays an essential role in agrarianeconomy sectors of Bangladesh .

This study is an attempt tomeasure the growth and instability in area, production and yield of rice inBangladesh based on secondary data during the period 1972 to 2016 collectedfrom Bangladesh Bureau of Statistics.Different statistical tools have been used to perform the analysis. The analysisreveals that the area, production and yield of rice have increasedsignificantly. Though the production of rice has increased but it is notsufficient to meet the demand of the country. The analysis also reveals thatthe area, production and yield of rice are not stable during the study period.Therefore, researchers, policy makers and academicians should give properattention to develop new idea to increase the production of rice that fulfillsthe demand of the country.Keywords:Instability, Production, Area, Rice and Growth RateIntroductionThepopulation of Bangladesh is increasing rapidly. Rapid population growth, alongwith unplanned urbanization, causes the cultivable land area to be used fornon-agricultural purpose.

As a result, the cultivable area is reducedsignificantly (Akther et al., 2016). Rice is the main foodfor most of the people in Asia, almost half of world’s population live on rice(Bhuiyan, 1992). Al most 2.

4 billion people depends on rice and provides morethan 20% of their daily calorie intake (Lampe, 1995). The annual growth rate for riceconsumption in the Asia-Pacific Region over a period of 45 years (1950 to 1995)has kept pace with the demand, more through yield increase rather than areaexpansion (Papademetriou, 2000). Within 2030 our world population willincreased 8.27 billion and  we can ensureenough rice for the increasing population (Kubo and Purevdorj, 2004).With anincreasing population leading to an increase in demand, the main drivers whichdetermine rice production need to be identified (Milovanovic and Smutka, 2017).

Rice production has increased because of the use of modern technology and theprice of rice is increasing due to rising agriculture wage rates and declineavailability of cultivable land (Ahmed, 2004). Inrecent years the production of rice has increased in South Asian Countries butin other countries of the region yields have stagnated (Mutert and Fairhurst, 2002). Bangladesh has huge population ascompared to many others country and it occupies 8th position overthe world because of over population. With the increase of population ourcultivated land in decreasing day by day. About 75% country’spopulation is engaged in agricultural sector (BSGDMA, 2007).

Rice is oneof the dominant crops of the agrarian economy of Bangladesh and it reflected inthe high per capita rice consumption in this country (Shelley et al, 2016). In Bangladesh rice production most rain fed rice isfaced problem because of drought and Diurnal temperaturerange (Rahman etal., 2017).

Average yields per hectare and totalrice production increased significantly, leading to a substantial increase inthe supply of rice in the domestic market which resulted in significantreductions in rice prices and the average production cost of rice per acre interms of input use varied across the three rice crops as well as across thevarious stages of rice cultivation (Talukder and Chile,2014). Despite pressurefrom overpopulation, the country has reached self-sufficiency in riceproduction (Shelley et al., 2016). Production of rice has increased because ofthe development of high-yielding varieties and use of high level of fertilizerin last four decades (Prasadet al., 2016). Toachieve better economy and fulfill the demand of increased population, it isneeded to increase the production of rice. Rice production and area should beincreased and yield rate should be stable.

A good number of researches are donein this sector. However, these research works are not sufficient to improve thesector. Therefore, this study is investigated to know the change andinstability of rice production in Bangladesh.Materialsand Methods:Secondary sample data on area,production and yield of rice for the last 45 years from 1972 to 2016 have beencollected from different issues of Statistical Yearbook of Bangladesh Bureau ofStatistics (BBS). The whole period was divided into two periods to compare inarea, production and yield of rice. Period I starts from 1972 to 1993 andPeriod II from 1993 to 2016. To examine the nature of change, instability anddegree of relationship in area, production and yields of rice in Bangladesh,various descriptive statistical tools, such as mean, correlation co-efficientand coefficient of variation have been used.

The t-test, simple linearregression technique and semi log growth model have been used to analyze thedata. The data analyses have been performed by using SPSS software.RegressionAnalysis             To estimate the parameters, simplelinear regression models has been fitted to examine the change of production bythe change of area. The model can be expressed as:                                                     where, e ~N(0,), y is the production (in ton), xis the area (in acre),  is the intercept and  is the regression coefficient of the model.

Measureof Growth RateThe growth rates of area, production andyield of rice were workout by fitting a semi-log function of the type: ,where, y is the area (in acre) or production (in ton) oryield (ton/acre) and t is the time period (in year).Measurementof InstabilityAn index of instability in areainstability was computed for examining the nature and degree of instability inarea, production and yield of total rice in Bangladesh. The co-efficient ofVariation (CV) of rice was worked out for area, production and yield to measureof variability. However, simple CV does not explain properly the trendcomponent inherent in the time series data. Alternatively, the coefficient  of variation around the mean (C) rather than co-efficient ofvariation around the mean(CV) was suggested by Cuddy and Della(1978) as abetter measure of variability.Alinear trend  was fitted to theindices of area, production and yield for the study period and trendco-efficient ‘ was tested for significance. Whenever thetrend co-efficient was found significant, the index of instability wasconstructed as follows:where ,where  and s are the mean and standard deviation ofthe sample period.

So,the index of instability ( is the multiplication coefficient ofvariation to the square root of unexplained variation by the trend equation y=.Result and DiscussionChange in Area, Production and Yield of RiceAs the number of people increased agricultural area of rice hasbeen increased. As a result the production of rice has been increased. Thecultivable area, production and yield of rice have increased 1.06, 1.78 and1.

89 times respectively during the last 45 years. The average production ofrice is 26561.10 metric tons in period II, while it was 14034 metric tons inperiod I. The change between these two periods is highly significant (P<0.

01). Though, the production has increased significantly but it cannot meetthe current demand of the country. From the analysis it is evident that thereis a significant changed in area, production and yield of rice in Bangladesh(Table 1).Table1: Changein area, production and yield of rice in Bangladesh   Mean Value t-value p-value Field of measurement Period-I Period-II     Area 25170.84 26598.23 -4.261 0.00 Production 14034.

45 26561.10 -8.786 0.

00 Yield 0.55560 0.9902 -9.

84 0.00  Correlation AnalysisFrom the correlation analysis it is observed that the productionof rice is strongly positively correlated (r =.884) with its area for wholeperiod. The relationship between production and area of rice is also highlysignificant which implies that the increment of area strongly affects theproduction of rice to increase. Similarly the area and production of rice forthe period I and period II are also significantly correlated (Table 2).Table2.Relationshipbetween area and production of Rice in Bangladesh Criteria              Value of Correlation co-efficient (r) p-value   Area V Production   Whole-Period  0.884 0.

01 Period-I  0.673 0.01 Period-II  0.953 0.01  Regression AnalysisThe simple linear regression models were fitted for estimating theresponse of production of rice due to the change of their respective area. TheResults show that the estimated coefficients of production on area aresignificant during the whole period, Period I, and Period II. It implies thatthe production of rice has increased by 5.28, 2.

15 and 4.33 times during thewhole period, Period I and Period II due one unit increase in arearespectively. So an increasing trend is found in rice production with theincrease in its area (Table 3). Table3.

Testingdependency of production on area of Rice  Measurement Period Constant value Regression coefficient t-value p-value whole period -116244.49 5.28 12.43 0.

00 Period I -40068.837 2.15 4.

07 0.01 Period II -88671.335 4.33 14.37 0.00  Growthrate of area, production and yield of RiceGrowth rate provides acceptable good measures of variation in pastand it future change. The exponential model is used to measure growth rate.

Since the cultivable area of rice is increased, the production is alsoincreased. It is found that the growth rate of area, production and yield ofrice are positive and significant during the whole period, period I and periodII respectively. It is observed that the production of rice is increased 2.

7%,3.5% and 2.6% during the period I, period II and Whole period respectively. Thegrowth rate of production is higher in period II than any other period.Similarly growth rate of yield is higher in period II than the whole period.

So, a remarkable growth rate of area, production and yield of rice have beenobserved during the study period (Table 4). Table 4: Growth rate ofarea, production and yield of Rice Field of Measurement Measurement  period Growth Rate (%) p-value   Whole period 0.3 0.00 Area Period I 0.3 0.001   Period II 0.

7 0.00   Whole period 2.9 0.00 Production Period I 2.7 0.00   Period II 3.5 0.

00   Whole period 2.6 0.00 Yield Period I 2.4 0.00   Period II 2.8 0.

00  Instability in area, production andyield of RiceFluctuation in area and production are correlated as larger areagives higher production if all other inputs remain constant. But instability ofyield may be due to weather condition, natural calamities like floods,droughts, cyclone etc. and technical changes.

So variation of agriculturalproduction always exists in Bangladesh. Our analysis supports this claim. Theproduction and yield of rice showed highest degree of instability during wholeperiod. The area of rice also showed remarkable variation during the wholeperiod. The area, production and yield of rice showed the significantfluctuation during study period (Table 5).Table 5: Instability in area, productionand yield of rice in Bangladesh Field of Measurements Measurement  Statistics Whole period Period I Period II     Area     CV 5.1% 3.2% 5.

1% R-Square 0.649 0.436 0.814 p-value 0.00 0.

00 0.00 D-W 0.57 1.031 0.993 CV around trend line 3% 2.4% 2.2%     Production     CV 38.7% 18.

1% 23.4% R-Square 0.936 0.

953 0.968 p-value 0.00 0.00 0.00 D-W 0.218 1.95 0.898 CV around trend line 9.

8% 3.9% 4.1%     Yield     CV 33.9% 16.4% 18.9% R-Square 0.96 0.

937 0.975 p-value 0.00 0.

00 0.00 D-W 0.25 1.156 0.886 CV around trend line 6.8% 4.1% 2.9%  Conclusion:Rice is the most important food inBangladesh.

The findings reveal that overall production of rice in Bangladeshis satisfactory as the average area, production and yield have increased. It isobserved that the production and yield has increased for period I and periodII.  The growth rate of area andproduction are also increased. Therefore, it is concluded that cultivable areais important factor to increase the production of rice. If we fail to increasecultivate land, the production will suffer most.

But area is limited. So, it isbetter to consider other factors which affect the production. The productionmay be depends on quality of seeds, new technology, quality of fertilizer etc.So this research may be helpful for the stakeholders and policy makers toovercome food problems in Bangladesh. AcknowledgementWe like to thanks the Bangladesh Bureauof Statistics to provide us their collected data.