Test for model specifications
Before estimating model parameters checking whether the stochastic production frontier is more appropriate than a conventional production function,
i.e. testing whether there exist technical inefficiency in the production process or not is important. In this test the null hypothesis is given as:
H0: g = δ0 = δ1 =...δ9 = 0, which states that inefficiency effects are absent from the frontier model, was rejected for the food crop farmers (Table 1).
Maximum likelihood estimates for parameters of the two estimated models are presented in Table 2. The result shows that farm size, labour, fertilizer and other agrochemicals and oxen are highly significant at 1 per cent level of probability while farm equipment is significant at 5 per cent of significance. Similarly, the study of (
Kidane and Ngeh, 2015;
Mango et al., 2015; Sherzod et al., 2018) explained that farm area and fertilizer; (
Sherzod et al., 2018;
Wollie, 2018) labour and (
Wollie, 2018) reported that ox are significant 1 per cent .
The estimated value for the γ for the food crop farmers was 0.669 and the values is significant at 1 per cent level of probability. These values indicate that technical inefficiency is highly significant in the food crop production activities in the study area. These results confirm the findings of (
Ajibefun et al. 2006;
Chiona et al. 2014;
Kidane and Ngeh, 2015;
Mango et al., 2015; Sherzod et al. 2018;
Wollie, 2018) that technical inefficiency is significant in the food crop production activities.
Technical efficiency estimates
The technical efficiency shows the ability of farmers to derive maximum output from the inputs used in food crop production. The technical efficiency estimates are presented and discussed subsequently (Table 3). The results show high variability in technical efficiency among the food crop farmers in the study area. The computed technical efficiency varies from 0.38 to 0.92 with a mean of 0.79. The result of mean efficiency is similar to the finding of (
Pradhan and Mukherjee, 2018). The variation in the level of the technical efficiencies in food crop production implies there is opportunity to improve the current level of technical efficiency by 21 per cent.
Impact of adaptation to climate change on technical efficiency
This section presents analysis of climate change adaptation strategies that influence technical efficiency in food crop production in the study area.
An inverse and statistically significant (at 1 per cent) relationship is found between crop diversification and technical inefficiency of food crop farmers (Table 4). This suggests that food crop farmers in study area who did not plant multiple type of crop experienced higher technical inefficiency. This is can be due to the reason that farmer engaged in multiple crop type is more efficient in allocating their resources like labour and land than his/her counterpart. Thus the adaptation of multiple crop type adaptation strategy would help the farmers to increase their level of technical efficiency.
The estimated coefficient for improved crop varieties is negative and significant at 5 per cent (Table 4). This implies an increase in use of improved crop varieties tends to increase technical efficiency. Policy and programmes regarding the development and provision of improved crop varieties would help the farmers in the study area to left up the level of technical efficiency.
An inverse and statistically significant relationship is found between technical inefficiency and adjusting planting dates of the respondents (Table 4). This implies an increase in adjusting planting dates tends to increase technical efficiency (or decrease technical inefficiency). Adjusting planting dates helps farmers to reduce the loss due to changing climate. Thus farmers capable to adjust their planting dates experienced higher technical efficiency. The availability of information on climate change can help the farmers to adjust the time of planting dates
i.e. increase the level of technical efficiency.
A negative and statistically significant relationship, at 10 per cent was found between irrigation practices and technical inefficiency in food crop production in the study area (Table 4). This implies that an increase in irrigation practices tends to increase technical efficiency. In the study area there is no functional irrigation technology. In the study area there is financial constraint that limits small scale famers to adopt irrigation technology. Government policy toward the development of irrigation schemes can help farmers in the study area to increase their level of technical efficiency.
The result shows that the coefficient for land fragmentation is positive and significant at 1 per cent level of probability (Table 4). For the positive significant coefficient, it implies that an increase in land fragmentation tends to increase the level of the technical inefficiency (
i.e. decrease technical efficiency). The finding shows that land fragmentation decrease level of technical efficiency in the study area. Land fragmentation is related to the use of time and other resource for agricultural production. In the study area farmers with more fragmented farm land are inefficient in using the agricultural resources. As policy intervention land consolidation farming can reduce the problem of land fragmentation and increase the level of technical efficiency.
Analysis of policy variables that affect technical inefficiency
The impact of selected climate change adaptation strategies (
i.e. improved crop varieties, adjusting planting dates, land fragmentation, irrigation practices) on mean technical efficiency of food crop farmers in the study area after simulation is presented in Table 5. These variables are determinants of technical efficiency that could be influenced by policy implementation to improve the technical efficiency. The simulation is done with an increase in the value of these selected variables at 5 per ent, 10 per cent and 20 per cent. The results of the simulations are presented in Table 5.
The results of simulation of policy variables show that the level of mean technical efficiency would increase with rising level of improved crop varieties, adjusting planting dates and irrigation practices (Table 5). An increase in the availability of improved crop varieties from 5 per cent through 20 per cent raised the mean technical efficiency from 77 per cent to 79 per cent (Table 5). Thus in the study area government can play a great roll to increase the level of technical efficiency of farmers. By institutional arrangement either government or the private sector can provide improved crop varieties, climate change resisting and those crop having short time harvest, to influence current level of technical efficiency.
Information on changing climate helps farmers to adjust planting dates of crops. With increase in information regarding the climate and farming experience farmers adjust the planting time. Thus, with increase in practices of adjusting the planting dates from 5 per cent through 20 per cent the mean technical efficiency raised from 79 per cent to 81 per cent.
Irrigation is one mechanism farmers practices in response to changing climate mainly rainfall. With increase in irrigation practices from 5 per cent through 20 per cent the mean technical efficiency raised from 79 per cent to 82 per cent. Training and facilitating the adoption of new technology regarding irrigation would increase the level of technical efficiency in the study area.
The climate change awareness as one policy variable shows that an increase in climate change awareness from 5 per cent through 20 per cent raised the mean technical efficiency from 80 per cent to 84. The dissemination of information concerning climate change helps farms to adjust time planting crops. Thus, concerned body, the government, private sector and NGOs can provide information of changing climate that would increase the level of technical efficiency of farmers in the study area.
Education as one policy variable shows that, an increase in level of education from 5 per cent through 20 per cent raised the mean technical efficiency from 80 to 83 per cent. Thus providing training and technology on irrigation by concerned body would increase the level of technical efficiency of farmers in the study area.
The results of the simulation of land fragmentation climate change adaptation variables show with increase in land fragmentation from 5 per cent through 20 per cent the mean technical efficiency declined from 72 per cent to 63 per cent. Thus to revert this value the government has to take some measures to reduce land fragmentation.