Management practice adoption and productivity of commercial aquaculture farms in selected areas of Bangladesh

Adoption of scientific management practice is the pre-condition for increasing productivity in any farm business. This study estimates the level of scientific aquaculture management practice (SAMP) adoption, factor affecting adoption and its relation with productivity. Sixty aquaculture farms were selected from 3 upazilas of Mymensingh district of Bangladesh. Adoption level was measured by following Sengupta (1967) while Tobit regression was used to assess the determinants of adoption level. Polynomial regression was employed to show the relationship among farm size, adoption level and productivity. Result revealed that average SAMP adoption level was 54% where 53% farmers were medium adopter. Training, experience, education and extension service had significant positive effect on level of adoption. Productivity was significantly higher for those farmers who adopted more SAMP. Adoption level, productivity and profitability of small farmers were higher than that of large farmers. The study suggests farmers for adopting scientific management practices in order to increase the aquaculture productivity and profitability. Introduction Aquaculture has expanded tremendously in Bangladesh and achieved 5th position in the world accounting for 2.43% of the total global aquaculture production (MoF, 2016). This sector plays a significant role for reducing protein deficiency and malnutrition, generating employment and earnings foreign exchange. Aquaculture productivity needs to be increased to fulfill the excess demand of growing population. But productivity mainly depends on appropriate use of different inputs and management practices. Feed is the main input of fish production which captures about 70% of total production cost (Khan et. al. 2017, Alam et. al. 2012, Alam 2011). Fertilizer is applied to raise the phytoplankton in the pond. Good quality fingerling is another important input which moves-up the productivity of aquaculture. Farmers should be very cautious about the stocking density of fingerlings because over-populated ponds make aquaculture species susceptible to disease, less growth and death. Different water cleaning measures like removal of sediment, water exchange, salt and lime ensure good water quality which reduces harmful gas, disease prevalence and mortality rate. Culture system such as monoculture and polyculture also affects the aquaculture productivity. Farmers of developed countries follow the rules of scientific aquaculture management practices (SAMP) while farmers of developing countries are not capable to utilize all the management practices. Available information, access to information, necessary extension service and training are very important for adopting the SAMP. Furthermore, adoption of SAMP may be affected by different socioeconomic characteristics of the producers. There are few studies on technology and management practice adoption in the field of agriculture and aquaculture. Sreenivasa & Hiriyanna (2014) studied factors influencing adoption in non-traditional Seri culture with respect to mulberry and silkworm rearing technologies and found that education, farming experience and extension service significantly influenced the adoption of new technologies irrespective of holding size groups. Swathi et al. (2011) found that adoption behavior was high in harvesting, conditioning, sterilization, liming and feed management in scientific shrimp farms. Arora et al. (2009) observed stronger relation between adoption index and composite index of infrastructure which emphasized the need for improving infrastructure to increase adoption of agricultural technologies. Like these studies, Karunathilaka & Thayaparan (2016), Gedikoglu (2010),Singh et al. (2014) and Ndambiri et al. (2008) also dealt with adoption of improved technologies in different aspects of agriculture and aquaculture. But adoption level of SAMP and its relationship with productivity is almost absent in Bangladesh. Therefore, this study bears prime importance in assisting aquaculture farmers are regarding necessity of adopting SAMP in their operation. The specific objectives of the study are: (i) to estimate the level of SAMP adoption and identifying factors affecting adoption, (ii) to assess the relationship among adoption level, farm size and productivity in aquaculture farming. ARTICLE INFO Article history: Received: 27 February 2018 Accepted: 15 April 2018


Introduction
Aquaculture has expanded tremendously in Bangladesh and achieved 5th position in the world accounting for 2.43% of the total global aquaculture production (MoF, 2016).This sector plays a significant role for reducing protein deficiency and malnutrition, generating employment and earnings foreign exchange.Aquaculture productivity needs to be increased to fulfill the excess demand of growing population.But productivity mainly depends on appropriate use of different inputs and management practices.Feed is the main input of fish production which captures about 70% of total production cost (Khan et. al. 2017, Alam et. al. 2012, Alam 2011).Fertilizer is applied to raise the phytoplankton in the pond.Good quality fingerling is another important input which moves-up the productivity of aquaculture.Farmers should be very cautious about the stocking density of fingerlings because over-populated ponds make aquaculture species susceptible to disease, less growth and death.Different water cleaning measures like removal of sediment, water exchange, salt and lime ensure good water quality which reduces harmful gas, disease prevalence and mortality rate.Culture system such as monoculture and polyculture also affects the aquaculture productivity.Farmers of developed countries follow the rules of scientific aquaculture management practices (SAMP) while farmers of developing countries are not capable to utilize all the management practices.Available information, access to information, necessary extension service and training are very important for adopting the SAMP.Furthermore, adoption of SAMP may be affected by different socioeconomic characteristics of the producers.
There are few studies on technology and management practice adoption in the field of agriculture and aquaculture.Sreenivasa & Hiriyanna (2014) studied factors influencing adoption in non-traditional Seri culture with respect to mulberry and silkworm rearing technologies and found that education, farming experience and extension service significantly influenced the adoption of new technologies irrespective of holding size groups.Swathi et al. (2011) found that adoption behavior was high in harvesting, conditioning, sterilization, liming and feed management in scientific shrimp farms.Arora et al. (2009) observed stronger relation between adoption index and composite index of infrastructure which emphasized the need for improving infrastructure to increase adoption of agricultural technologies.Like these studies, Karunathilaka & Thayaparan (2016), Gedikoglu (2010), Singh et al. (2014) and Ndambiri et al. (2008) also dealt with adoption of improved technologies in different aspects of agriculture and aquaculture.But adoption level of SAMP and its relationship with productivity is almost absent in Bangladesh.Therefore, this study bears prime importance in assisting aquaculture farmers are regarding necessity of adopting SAMP in their operation.The specific objectives of the study are: (i) to estimate the level of SAMP adoption and identifying factors affecting adoption, (ii) to assess the relationship among adoption level, farm size and productivity in aquaculture farming.

Materials and Methods
The study was based on the primary data collected from 60 aquaculture farms located in 3 major aquaculture producing upazilas (Trishal, Fulpur and Tarakanda) of Mymensingh district of Bangladesh.Pangas and tilapia were dominating species which contributes more than 40% of total aquaculture production in the study area.Therefore, pangas farm was chosen with mono and polyculture system.The farms were selected by using stratified random sampling technique from the lists provided by Upazila Fisheries Officer (UFO) and data were collected following face to face interview with pretested questionnaire in 2015.Fifteen aquaculture management practices were considered as presented in Table 1.These management practices were coded as '1' for the response "who use less than the recommended dose", '2' for "who use more than recommended dose" and '3' for "who use same as recommended dose".Some management practices like weed control, dyke rising, species combination (surface, mid and bottom), feeding as per body weight, water quality test and maintain record book were coded as'1' for the positive response and '0' for the negative response.Again, the adoption quotient/level was classified as high adopters (66.67% to 100%), medium adopters (33.34% to 66.66 %) low adopters (up to 33.33 %) and nonadopters (0).
In addition, Tobit model was used to identify the factors affecting adoption level of SAMP.Hence adoption level ranged from 27.77 to 88.89 therefore, Tobit model was a better choice for this data set.The empirical Tobit regression model was as follows:

Results and Discussion
Socio-economic characteristics of farmers Farmers' adoption of SAMP was highly influenced by socio-economic status which changes over time (Olaoye et al. 2016).Study found that the mean age of farmers was 38 years while their level of education was 8 years (Table 2).In addition, experience in aquaculture farming found on an average 3.52 years.Alam, (2011) found the similar mean education and age of pangas farmers in Bangladesh but mean experience of farmers was much higher than the study.Average family size found 4.97 which is greater than national average (BBS, 2016).Although dependent members was more in the large family, but they worked as family labor in aquaculture ponds and thus reduce labor cost as well as enhance productivity.

Profitability of aquaculture
Profitability analysis shows the financial situation of aquaculture farms whether farming is economically feasible or not.Result found that per hectare total cost of aquaculture was Tk. 2250358.Feed was the single largest cost item which consisted about 77.77% of total cost while Khan (2012) and Alam (2011) found that feed occupied 71% and 70% respectively.Although feed was the main input for aquaculture but its cost is increasing year by year due to rising price of different raw materials.Labor was the second highest cost that captured 11.05% of total production cost.This input was essential for maintaining all SAMPs.Fingerling captured 5.29% of total cost.Per hectare productivity of aquaculture was found about 33642 kg and this finding is consistent with the studies of Khan et al. (2017), Alam (2011), Ali et al. (2013) and Ali & Haque (2011).Result showed that net return or profit from per hectare of pond area was about Tk 886522 and the BCR was1.39.It implies that farmers can earn profit Tk.0.39 by investing Tk. 1 which indicates aquaculture was a profitable business in the study area.Ajiboye et al. (2011) and Thompson & Mafimisebi (2014) found the identical result in their analyses.

Level of management practice adoption
Adoption level for an individual farmer was computed from the adoption scores gained by the farmer.Result reveals that 23.33% farmers were high adopter while 53.33% were medium adopter.Result also showed that average adoption level is 54% which lied in the medium level (33.34% to 66.66%).Percentage of high adopted farms was low because of less adoption of different scientific management practices.Among these practices, farmers were struggling to follow timely feed application because most of the farmers were not always able to afford the cost of the feed.This situation arisen due to change in feed price.This result consistent with the study of Gawde et al. (2006).Sakiband Afrad (2014), Njankoua et al. (2012), Bucciarelli et al. (2010), Kashem (2005), Tziraki et al. (2000) and Hussain et al. (1994) got similar result for education and training.Besides, positive and significant coefficient of extension services implies that the farmers those had better communication with extension services providers were higher adopter.Especially, extension agent, technician and resource person provided necessary suggestions on different management practices and those services enhanced aquaculture productivity.Ragasa et al. (2013) and Perey (2016) identified the positive relation between adoption level and extension services.Experience of aquaculture farmers also had positive significant effect on adoption level.Generally, experienced farmer have vast knowledge about the management practices due to learning by doing.Distance from farm to residence had negatively significant effect on adoption level implied that the higher distance, the lower the adoption.If the farm is situated in distant places, it becomes difficult to manage.Normally, farmers apply feed in the pond two times in a day.When it is far from home, it was difficult for them to provide feed timely.Moreover, they cannot apply medicines in their pond at the time of disease prevalence.Hailu et al. (2014) found the identical result on the effect of distance on adoption level.

Relationship between farm size and adoption level
Local polynomial regression showed that farm size and adoption level was inversely related.i.e. adoption level decrease with increase in farm size (Figure 1).More labor and capital was needed to maintain the large farm.
But credit constraint was one of the main problems for large aquaculture farm for maintaining the appropriate input application.As discussed earlier, feed was the main input and occupied two third of the total production cost, therefore large farmer couldn't apply appropriate amount of feed during culture period.On the other hand, more labor was need for application of input and other management of farm, especially for security purpose.But large farmers were not able to adopt in scientific way due to scarcity of labor.This result was consistent with Andrei (2011), Ureta et al. (2006) and Just & Zilberman, (1983).

Relationship between farm size and productivity
The relationship between farm size and land productivity has been widely debated and several reasons and explanations for the inverse relationship had been put forward and tested.Imperfect factor market was the main issue for the debate.Local polynomial regression in Figure 2 revealed the inverse relationship between farm size and productivity.The probable reason might be the small farmers can easily supervise their farms.They got a relative advantage of using more family labor that reduce the monitoring and supervision costs of hired labor with respect to the large farms (Thapa, 2007).In addition, large farms were overusing fertilizer, pesticides, etc. which led to the degradation of their natural resource that causes less productivity (Sial et al.,  2012).In developing countries, this inverse relation was found by Desiere (2016), Gaurav & Mishra (2014), Bhalla & Roy (1988), Feder (1985) and Fan & Chan-Kang (2003).Nevertheless, Sadhu & Singh (1996) found positive relation between farm size and productivity.

Relationship between adoption level and productivity
There is no doubt that management practices was linked to the productivity.A lot of technologies has been introduced by research institutes under the Government of Bangladesh and other related organizations which concerned with innovations.Theory tells that innovative management practices affect the productivity in the aquaculture sector.Local polynomial regression depicts a positive relationship between adoption level and productivity implying that productivity was significantly higher for those farmers who adopted SAMP (Figure 3).Ahmed (2015) found similar result in the case of maize production.Gray & Shadbegian (1998), Thapa (2007), Belay et al. (2014), Moreno and Surinach (2014), Asfaw & Shiferaw (2010) also found that productivity of high adopters were greater than that of less adopter.A summary of the results depicted in Table 6.It reveals that productivity, total return and profit of high adopter farmers were higher than others.Farm size of high adopters was small and was more productive and profitable.In addition, BCR was found more in case of high adopter compared to others.Overall, the result indicated that SAMP has enhanced the productivity and profitability in aquaculture.Ansah (2014), Adeshinwa & Bolorunduro (2007) and Thompson & Mafimisci (2014) found that adoption level, farm size and productivity were affected by each other.

Conclusion and policy recommendation
Adoption of SAMP is essential for increasing the productivity of any farm business.This study tried to estimates the level of adoption of scientific aquaculture management practices, factors affecting adoption and its relation with farm size and productivity.For this purpose, 60 aquaculture farms were selected from Mymensingh district of Bangladesh.Aquaculture farming was found profitable in the study area.In terms of adoption, average adoption level of SAMP was about 54% while 53% farmers were medium adopter.Training, experience, education and extension service had significant positive effect on adoption level while farm distance from home and age of the aquaculture fish farmers had negative effect.Adoption level and farm size were inversely associated implying that small farmers were relatively higher adopter compared to larger ones.High adoption level was positively related with productivity and profitability of aquaculture farming.In order to enhance the aquaculture productivity, farmers are suggested to adopt scientific management practices.Department of Fisheries (DoF), Bangladesh Fisheries Research Institute (BFRI) and other related organizations can prepare and distribute leaflet on SAMP and production system.In addition, training on scientific aquaculture production system and extension services needs to expand all over the country.
services (dummy; 1= if extension service has received and 0= otherwise) and e = error term.Furthermore, polynomial regression model was employed to show the relationship between farm size, productivity and adoption level.Theoretical polynomial regression smoothing model can be describe as: Consider a set of scatter plot data {(x 1 , y 1 ), . . .,(x n , y n )} from the model for some unknown mean and variance functions m(•) and σ 2 (•), and symmetric errors with E( ) = 0 and Var( ) = 1.The goal is to estimate m(x 0 ) = E[Y |X = x 0 ], making no assumption about the functional form of m (•).

Figure 1 .
Figure 1.Relationship between farm size and adoption level

Figure 2 .
Figure 2. Relationship between farm size and productivity

Figure 3 .
Figure 3. Relationship between adoption level and productivity