Distribution of Agroforestry Species in the Southeast Nigeria

This study investigated indigenous agroforestry species combinations and location pattern in Southeast Nigeria. Primary data were obtained by means of interview schedule from 400 farmers drawn by multistage random sampling technique from the zone. Data obtained were analyzed with descriptive statistical tools. General observation was also made on local agroforestry patterns. The study identified twenty-five (25) tree and shrub species as common woody components of agroforestry practice in the zone. It was also revealed that more species were located in homegardens than in farm fields. The ratio of species located in homegardens to that in farm fields was 7:4. Fruit and vegetable yielding trees and shrubs were found in homegardens while timber, stakes, fuel and economic trees were located in farm fields. Other identified species were located in both compounds and farmer’s fields mostly for boundary maintenance. Root and tuber crops were the dorminant arable crop components of the local agroforestry practice, for instance yam (71.5%), cocoyam (69.5%) and cassava (56.5%). Other important components included leafy vegetables (68.5%) and cowpea (58.5%). Rice production is least associated with the practice (4.5%) in the zone. It was recommended that extension intervention in the zone should emphasize introduction of cereals and legumes in their local agroforestry practice.


Introduction
Although agroforestry is an age-old approach to land use and an old practice in many African and Asian countries, it has been defined in modern times as a dynamic, ecologically based natural resources management system that through the integration of trees in farmland and range land, diversifies and sustains production for increased social, economic and environmental benefits for land users at all levels ( ICRAF, 1997).The ruling objective for agroforestry, therefore, is to increase the human-ecological carrying capacity of rural areas, with the priority of improving food production systems.It has the potential to provide rural households with food, fodder, fuelwood and other products.At the same time, agroforestry can help ensure the sustained productivity of the natural resource base by enhancing soil fertility, controlling erosion and improving the micro-climate of crop land and grazing lands.Nwokeabia (2002) observed that because of values associated with certain tree species, farmers have always left them standing while preparing the sites for arable agriculture.Some of these trees and shrubs provide a multiple of edible products, medicines, protective and soil improvement functions, fodder and wood for rural and household implements, food processing raw materials and export products.In a study on indigenous agroforestry practices among farmers in Southeast Nigeria, Umeh (2008) stated that various forms of agroforestry practices exist in the zone.These include homestead garden, trees on crop land, improved fallow, multistory crop combinations and sylvopasture.A positive relationship was identified to exist between indigenous-based agroforestry practices and income of farmers in Southeast Nigeria (Umeh, 2009).In a related study in Philipines, Brown (2003) observed that a farmer's adoption of agroforestry technology depends on the following criteria: food (supplying immediate household needs), income (providing cash to service other needs), future (providing savings for long-term needs), building (providing wood materials for construction of new houses) and erosion (activities that minimize soil loss).
Agroforestry design strives to maximize positive interactions between trees and other elements (crops and animals) and minimize negative interactions.This is achieved through appropriate species selection, spacing, and management practices (Elevitch and Wilkinson, 2000).Careful advanced planning is, therefore, important to maximize benefits of agro forestry practices.For a better understanding of agroforestry design in Southeast Nigeria and the potentials for optimal realization of benefits of the system it is imperative to investigate the agroforestry species and patterns of combination among farmers in the zone.
The main objective of this study is to investigate agroforestry species and pattern of location among farmers in Southeast Nigeria.

Methodology
The area of study is South east zone of Nigeria.Southeast Nigeria is made up of five states, namely: Anambra, Abia, Ebonyi, Enugu and Imo States.
The people are mainly of Igbo tribe of Nigeria.The traditional economic activities of the people of the area is farming, which is often complemented with other non-farm activities.A multistage random sampling technique was adopted for the study.In the first stage, three states, Ebonyi, Enugu, and Imo were randomly selected from the five states.Then four local government areas from each of the three states were randomly drawn to give a total of twelve local government areas.Three communities were further drawn randomly from each of the selected Local Government Areas.Finally, twelve farmers were drawn by means of systematic sampling from each of the communities to give a total of four hundred and thirty respondents.However, only four hundred (400) well-completed and returned copies of interview schedule were used for analysis.Trained enumerators were used to administer the interview schedule on the farmers.The obtained data for the study were subjected to simple statistical tools such as percentages and frequency distribution.General observation was made on local agroforestry patterns.

Results
The data were analyzed to identify tree and shrub species common in agroforestry systems in the area of study based on location.Arable crop components of local agroforestry practices were also determined in the study.

<Table 1>
Table 1 presents some of the identified tree and shrub species found grown in combination with arable crops in the area of study.
Analysis of data in the table indicated that yam production was most common arable crop component of agroforestry practice in the study area (71.5%).Cocoyam production is ranked next to yam as the dominant crop combination of agroforestry systems in the area (69.5%).Other major arable crops that form components of the practice include cassava (56.5%), cowpea(58.5%),andleafy vegetables (68.5%).Rice production was identified as the arable crop least associated with agroforestry practice.This result implies that tuber and vegetable crops formed components of agroforestry practices in the study while cereals were less associated with practice in the area.The tuber crops and leafy vegetables are carefully selected for integration with trees in order to optimize the production and positive effects of agroforestry and to minimize negative competitive effects.

Conclusion
The practice of integrating wood perennial crops with arable crop production is a common practice among the farmers of Southeast Nigeria.More diverse species of trees and shrubs were found in home gardens where they provide shade to man and livestock, among other services.Income generating species, such as timber and fuelwood providers were found in association with arable crops in farm fields while food producing woody species, fruits and nuts were identified with home gardens.

Recommendation
Based on the findings, it is recommended that interventions through introduction of improved woody species for agroforestry purposes in the zone should recognize the local people's agroforestry needs and patterns of distribution in home gardens and farms.

Table 1 .
Percentage Distribution of Some Common Tree and Shrub Species based on Location

Table 2 .
Percentage Distribution on Arable Crop Components of Agro forestry