value, such as Afrara and Iroko. Many shrubs and herbaceous crops are associated with the plantation, of which a variety of Yams seems to be the most important, planted as single tubers where the soil is considered to be especially rich. Also: Cassava, exploiting openings in the canopy, perhaps around an outcrop of rocks or where a Cocoa tree has died; Pineapples which appear to be used as boundaries; Alligator Pepper; Chillies; and remarkably, Piper guinensis, which is a fine substitute for what Europeans call pepper, Piper nigra, one of the most valuable spices in world trade, and the reason why the West African coast between Lome and the Niger Delta was once called the Grain Coast.
Although cashew is widely grown, it is not grown in association with Cocoa. Nonetheless there is a mixed plantation of predominantly Cashew and Mango trees which has been successfully established on the steep and rocky soil of Imo Hill overlooking the school. The farmer has also started to establish 'Bush Mango' trees, Irvingia gabonensis, the fruit of which is of high value and used for making Ogbono Soup.
One might say that agroforestry is a necessity rather than an option if the agricultural and environmental problems faced by farmers in the LEM ecozone are to be solved. Improved varieties of crop species and the liberalisation of fertiliser marketing are essential, but their benefits will only be felt if they are applied to healthy soil. And given the demands that are being and will continue to be made of them, the soils of Southern Nigeria can only be maintained and improved through raising Biomass and by practising sustainable agriculture, which is, in the tropics, agroforestry. The ramifications of agroforestry farming are an improvement in hydrological conditions and a reduction of the pressure on the surviving forests.
13.2.3 FACTORS WHICH DISCOURAGE THE INTRODUCTION OF AGROFORESTRY
There is a lot of talk about agroforestry being the solution to all the problems of tropical agriculture, but it must be accepted that although when rural population densities reach a critical level agroforestry practices often arise as a necessity, there are a number of factors which tend to mitigate against agroforestry, particularly against what might be called formalised or text-book agroforestry techniques (such as alley cropping) recommended by academic proponents of agroforestry.
Alley Cropping: the cultivation of arable crops between hedgerows of soil restorative or maintenance shrubs or trees
The three factors which mitigate against agroforestry are land-tenure, poor access to fertiliser and the limitations of human energy.
Land Tenure
For a start, land tenure appears to affect the adoption or otherwise of agroforestry techniques. The conventional wisdom being that farmers who do not own their own land will not be encouraged to grow perennial crops which do not produce marketable harvest in the short term.
There is indeed some truth in this statement. Nonetheless there is sufficient evidence to suggest that it is not the whole truth so that proponents or otherwise of
