**Enhancing Soil Fertility for Cereal Crop Production Through Biological Practices and the Integration of Organic and In-Organic Fertilizers in Northern Savanna Zone of Ghana**

James M. Kombiok, Samuel Saaka J. Buah and Jean M. Sogbedji

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/53414

**1. Introduction**

In Ghana, it has been estimated that 60 % of the population makes their living from subsis‐ tence farming with an average of 27% living in extreme poverty (MoFA, 2002). This is be‐ cause the most dominant economic activity of the area is agriculture and once agriculture is not well developed, one of the effects is poverty. As observed by many, one of the character‐ istics of underdeveloped agriculture is the dominance of subsistence farming in these re‐ gions (MoFA, 2002, RELC 2004). The slow economic growth and high poverty level prevailing in Northern Ghana (Upper East, Upper West and the Brong-Ahafo regions) is therefore directly linked to the underdeveloped agricultural sector of the area.

The most affected area in the country is Northern Ghana as it is estimated that up to 80% of the population in this part of the country is poor (Ekekpi and Kombiok, 2008). The many agricultural interventions to transform the small scale farming system and reduce poverty in northern Ghana have largely failed due to several problems such erratic rainfall and poor soils. Further analysis of the northern Ghana agricultural sector problems indicates that poor soils result in low crop yields which are negatively affecting the development of Agri‐ culture (RELC, 2005).

It is therefore not surprising that low soil fertility has always been mentioned by farmers as one of the constraints affecting cereal production in Northern Ghana (RELC, 2005). This is confirmed by the fact that low grain yields of cereals attributed to poor soils for the past dec‐

© 2012 Kombiok et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 Kombiok et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

ade has been ranked first among the constraints collated from all the districts of northern Ghana at the various regional planning sessions.

**3. Land rotation or shifting cultivation**

population of the country.

**cover crop**

pea are used.

It is a crop production system based on rotation of cultivated period on a given piece of land. The cultivated period is always shorter than the fallow period because the system is characterized by the use of very little or no external soil fertility improving inputs. The soil fertility is therefore recovered by a natural process which is often very slow. The length of fallow period is determined by land availability but can last between 10 and 20 years after which the vegetation is cut back to allow another cycle of farming activities(EPA, 2011). This is no longer practiced because of the scarcity of arable land as a result of high growth in

Enhancing Soil Fertility for Cereal Crop Production Through Biological Practices and the Integration of Organic...

http://dx.doi.org/10.5772/53414

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**4. Cover cropping and improved short-season fallow with leguminous**

down or killed by weedicides so that the seasonal crops can be planted in the mulch.

The practice of planting certain crops to cover the cultivated area of fallow land thereby pro‐ viding protection for the purpose of reducing erosion by rain drop splash and surface runoff and weed growth is referred to as cover cropping. Where necessary, cover crops are cut

Improved short fallow is the planting of leguminous cover crops consciously with the objec‐ tive of protecting the soil surface and fixing nitrogen as part of the crop fallow. The system is practiced where land is limited and farmers rely on little or no external soil enhancing ma‐ terials to improve the soil fertility status. Examples of cover crops*: Mucuna pruriens, Dolicus lablab Canavalia ensiformis.* Sometimes edible cover crops such as the creeping types of cow‐

Improved fallow systems using e.g. *Mucuna puriens* are promoted by different projects in Ghana. So far, the system seems to be adopted only by some farmers in certain areas (Quan‐ sah et al., 1998). Benefits observed by the farmers may vary and include increased soil mois‐ ture, weed suppression and residual yield effects on maize. Leguminous fallows have been used in northern Ghana to accumulate N from biological N fixation (BNF), smother weeds, and improve soil physical properties (Fosu et al., 2004). Leguminous cover crop systems ap‐ parently were more extensively tested than tree fallow systems in the country. Demand for arable land in many parts of the country has increased in recent years in response to increas‐ ing human population. This situation is gradually moving the emphasis from resting fallow to continuous and intensive cropping. However, some farmers in southern Ghana can still fallow their lands up to two years or two seasons. Leguminous cover crops such as *Callopo‐ gonium, Dolichos, Mucuna* and *Cannavalia* species are the main cover crops used during this short fallow. In the north, farm lands to undergo short term fallow of about two years were planted to either *Mucuna* or *Callopogonium* and left for these number of years. In the third year the residue was either ploughed in or if it was dry, the crop was planted directly into the mulch. This system was found to increase maize yields in both on-station and on-farm trials (Kombiok et al, 1995) as seen in Table 1. The highest mean yield of maize was obtained

The low soil fertility in this part of the country is therefore blamed on the bush fires which usually occur annually during the dry season commencing from October to April the following year (SARI, 1995). This situation renders the soil bare exposing it to both wind and water erosion in the dry and rainy seasons respectively thereby depleting the macro-nutrients such as Nitrogen, Phosphorus and Potassium (NPK) and organic matter from the soil.

Initially, farmers used to replenish the soil with its nutrients by practicing shifting cultiva‐ tion or land rotation. However, with the increase in population which has put pressure on land use, this practice is not being sustained and this therefore calls for other measures to maintain soil fertility for sustainable crop production in the savanna zone of Ghana.

The purpose of this chapter is therefore to expose to Agricultural science teachers/trainers, scientists and farmers:

