Analysis of Determinants of Farm Size Productivity among Small- Holder Cassava Farmers in South East Agro Ecological Zone, Nigeria

Aims: To examine the socioeconomic characteristics of the farmers and determinants of farm size productivity among small-holder cassava farmers. Study design: Time series data. Place and Duration of study : The study was carried out in 2009 in the south-east agro ecological zone of Nigeria. April-June, 2009. Methodology : A multistage randomized sampling method was used in selecting four states – Abia, Akwa Ibom, Imo and Cross River and then 240 cassava farmers in the area of study. Structured questionnaire and interview schedule were used to elicit information from the respondents. Information sought bordered on the socioeconomic characteristics of the respondents and input use. Analysis of data was carried out using log-linear regression model and descriptive statistics such as tables, percentages and mean. Results: The results revealed that farm size was negative and significant at 1% and productivity of cassava increases with hired labour which is positively correlated with productivity at 1% level of probability. The coefficient of mode of occupation was positively correlated to productivity at 5%. It signifies that


INTRODUCTION
Cassava is a staple food for over 200 million people in sub Saharan Africa. It is the most important source of carbohydrate for human consumption in the tropics after rice and maize. It is an important food and cash crop in several tropical African countries, especially Nigeria where it plays a principal role in the food economy (Agwu, 2007). In most African countries cassava is becoming an important cash crop that has high potential for use as an industrial raw material to manufacture starch, flour etc. (Nweke et al., 2004). The use of cassava in confectionery industries recently in Nigeria is new and fast gaining ground. Cassava is an important food crop in south-eastern Nigeria. It contributes about 15% of the daily dietary energy intake of most Nigerians and supplies about 70% of the total calories intake of about 60% people in Nigeria (Ezulike et al., 2006).
Nigeria is the world's largest producer of cassava, with about 45.75 million metric tonnes and ranks 2 nd after yam in extent of production among the root and tuber crops of economic value in Nigeria (FAO, 2007). Planting of high yielding and improved varieties has resulted in higher cash from crop farm. According to Ajibefun and Aderinola (2004), small holder food producers face two major types of risks and uncertainties: yield (Output) and price uncertainties. The former has to do with the environment and the nature of agricultural production while the later is linked partly with seasonality of production and partly infrastructural facilities and government policies.
One of the important economic arguments in favour of the equitable distribution of farmland is that small farms are more productive (Masterson, 2007). The majority of studies of agricultural productivity in developing counties support the view that there is an inverse relationship between productivity and farm size (Berry and Cline, 1979;Barrett, 1996;Heltberg, 1998;Hazarika and Alwang, 2003;Masterson, 2007;Gul Unal, 2008;Okoye et al., 2007Okoye et al., , 2008aOkoye et al., 2008bOkoye 2009).
Land reform could contribute to improving both equity and efficiency in agriculture. One of the most common characteristics of the developing countries is the large share of agriculture in their economics. This feature produces the widely observed inverse size-yield relationship (IR) (Gul Unal, 2008).
Due to its policy implications for employment, efficiency, equity, and sustainability, IR has been one of the most important and hotly debated topics in agricultural economics for more than 40 years (Heltberg, 1998;Gul Unal, 2008). One critique leveled at the literature on the productivity-farm size relationship is that the measure used for land productivity, is inappropriate. Because it only compares total output to the size of the farm, ignoring other factors of production and input. Land productivity is said to be, at best, an incomplete measure of efficiency (Masterson, 2007). Therefore the objective of the study is to analyze the determinants of farm size productivity in south east agro ecological zone of Nigeria.

METHODOLOGY
The study area was the south east agro-ecological zone of Nigeria. The south east agro ecological zone comprises of nine states namely Abia, Akwa Ibom, Anambra, Bayelsa, Cross River, Ebonyi, Enugu, Imo and Rivers states.
A multistage randomized sampling technique was used in selecting 240 cassava farmers. In the first stage four states namely Abia, Akwa Ibom, Imo and Cross River States were randomly chosen. In the second stage, two agricultural zones were selected from each state giving a total of eight agricultural zones. In the third stage, 30 respondents (farmers) were randomly selected from each zone giving a total of 240 respondents.
Structured questionnaire and Interview schedule were used to elicit information from the respondents on labour, farm size, input use, output, capital and their socio-economic characteristics. Data were analyzed using descriptive statistics and the four functional forms of Regression model namely linear, exponential, Cobb-Douglas and log linear. The lead equation was selected based on certain econometric criteria.

Analytical Procedures
The four functional regression models-linear, Cobb-Douglas, Exponential and semi-log were the econometric models specified for explaining productivity in cassava production.

Socioeconomic Characteristics
The average statistics of the sampled cassava farmers are presented in Table 1. On the average, a typical cassava farmer in the zone is 49 years old, with 7 years of education, 24 years farming experience and average household size of 8 persons.
The average land owned by the farmer was two hectares, hired labour used in mandays was 182 and family labour utilized was 121 mandays. Cassava production in the zone is a female dominated occupation as about 61% of the farmers are females. About 68% of the farmers were visited by the extension agents during the year of this study, while 84% of the farmers belong to one cooperative organization or the other  Table 2 presents the results of the econometric analysis for cassava production in the zone. The semi-Log functional form was chosen as the best fit because of its high R 2 value and number of significant values in line with a priori expectations.

Econometrics Analysis
The productivity of cassava increases with hired labour which is positively correlated with productivity at 1% level of probability. This finding confirms an earlier work by Anyaegbunam et al. (2010). The study indicated that hired labour tends to be more productive than family labour because of the remuneration /wage involved. Most times hired labour may be under supervision by the farmer to make for efficient labour input and usage in the field The coefficients of farm size and age are significant and negative at 1% and 5% respectively. This implies that productivity decreases with increase in farm size. Okoye et al. (2009) found that there exists an inverse relationship between farm size and productivity. It is expected that age will have a positive relationship with productivity; since age is used as a proxy for experience but the reverse is the case in this study. The implication is that any increase in age will decrease farm size productivity by 2.30%. However, old age might be disadvantageous to agricultural production because most of the work is physically demanding (Ajibefun and Daramola, 2003;Ajibefun and Aderinola, 2004;Anyaegbunam et al., 2006Anyaegbunam et al., , 2008Okoye et al., 2009).
The coefficient of mode of occupation was positively correlated to productivity at 5%. It signifies that full time farmers are more productive than part time farmers. Productivity significantly increases with the use of fertilizer al 10%. This conforms to an apriori expectation that use of fertilizer increases output (Anyaegbunam et al., 2006)

CONCLUSION
Given the inverse relationship of farm size and productivity all factors related to farm size productivity such as hired labour, age, mode of operation and fertilize call for positive polices aimed at land reforms towards redistribution of land to make more land available to peasant and landless farmers in order to increase productivity and efficiency. Youths are therefore, encouraged to go into agriculture to bridge the encroaching generation gap in Agriculture.