**10. Challenges to adoption of soil fertility enhacement practices**

Conservation agriculture and some of the practices that enhance the fertility of soil for crop production have been tested on-station by research in Ghana and most of them have been found to be proven. These practices are now at the on-farm testing stages by research and the Ministry of Food Agriculture in different parts of the country. Some of these practices are either new to the farmers such as conservation Agriculture, Agro-forestry and Alley cropping or they are the improved versions of farmers' practices such as crop rotation (alter‐ nating cereal and legumes), intercropping cereal and legumes, root crops with cereals and legumes, cover cropping. Despite the benefits demonstrated to farmers from the use of these technologies, adoption rate is very low. Some of the challenges militating against the adop‐ tion of these practices by farmers include:

### **10.1. Ownership of land**

were significantly (p< 0.05) higher than the initial N values but for P and K, there were no significant differences between the initial and after two years of intervention. The significant increases of percent N in the soil as a result of the various interventions also show how lim‐

The average cereal yields of farmers in Ghana are very low. There may be many causes to the low crop yields obtained by farmers in Ghana. These include the use of local crop variet‐ ies which are low yielding; poor management of the crop on the field (late weed removal, inadequate plant population, late harvesting) but paramount among these is low soil fertili‐ ty. This is because the same variety used by farmers without adequate supply of plant nu‐ trients have been found to yield lower than the same variety properly managed by research scientists including the provision of adequate quantities of nutrients especially nitrogen.

Table 10 shows some of the average yields of cereal crops by farmers in Ghana as against the yields obtained from properly managed fields with adequate supply of nutrients which leaves a very large yield gap of more than 40 %. Among the crops, sorghum has the largest yield gap of about 60 % with millet recording the lowest of about 30 %. Farmers in northern Ghana are of the view that sorghum does not require fertilizer for high yields and therefore do not apply fertilizer to the sorghum crop. On the other hand, the millet available are most‐ ly local varieties and do not respond to fertilizer. With the application of fertilizers and ade‐ quate management of the millet crop, the increase in yield was just 0. 5 tons/ha compared to

**9. Average farmer yields of some selected cereal crops Ghana**

the rest of the crops which had increases in yield of more than 1 ton/ha.

**Table 10.** National average yields (tons/ha) of some selected cereal crops in Ghana

**10. Challenges to adoption of soil fertility enhacement practices**

Conservation agriculture and some of the practices that enhance the fertility of soil for crop production have been tested on-station by research in Ghana and most of them have been found to be proven. These practices are now at the on-farm testing stages by research and

**Crop Average yields of farmers Achievable yields Yield gap Yield gap (%)** Maize 1.5 2.5 1.0 40 Rice - rainfed 1.8 3.5 1.7 49 Sorghum 1.2 3.0 1.8 60 Millet 1.0 1.5 0.5 33

ited nitrogen is in the savanna soils.

18 Soil Fertility

Source: Ministry of Food and Agriculture (MoFA)

Most of the farmers in Ghana do not own the land they farm on and they are therefore described as settler or migrant farmers if they come from other parts of the country and settle at that particular place. The amount of money to invest on such rented lands by these farmers will therefore depend on the length of time the land is rented for farming. A farmer with one year rent period will not be willing to invest so much on that land for farming compared to a farmer who is renting the land for over ten years. Secondly, the land owners may not even allow farmers to introduce long term investments on such short term rented lands. It will therefore be difficult for such farmers to adopt soil fertili‐ ty enhancing techniques such as Agro-forestry system or even the cultivation of tree crops since this will take a long time to yield benefits to the farmer. However, It was found that the system of land tenure in the forest or the transitional zones where the farmers are allowed to use a plot for several years for farming may not have difficulties in adopting no-till as part of soil fertility management practices. This, according to Ek‐ boir et al. (2002) if these farmers are allowed to use such lands for several years it will enable them to recoup the profits of their investments. Also, data collected on the farm‐ ers adopting any particular tillage system showed that farmers using their own lands adopted CA practices more easily than farmers on rented lands (Adjei et al. 2003).

Farmers in the forest and transition zones where share cropping arrangements exist between the settler or migrant farmer and land owners, they are encouraged to practice CA and other related practices because increase in the productivity of their crops will lead to an increase in their share of the harvest. Unlike in the north, lands are almost given out free to settler farmers and can also be seized back at anytime by land owners without any notice as there is no agreement signed between the farmers and their land owners. There are certain times land owners even seize back their lands when they find increases in crop yields of the settler farmers. In such situations, farmers in the northern Savanna zone will definitely be discour‐ aged from adopting any of these soil fertility improving practices since the land owners do not benefit from such increases and there is also no agreement signed between them to pro‐ tect the farmers from their lands being seized back.

#### **10.2. Difficulties in maintaining soil cover**

One of the three pillars CA is hinged on is the provision of adequate soil cover and it is one of the several ways of enhancing soil nitrogen. Unfortunately, it is very difficult to provide soil cover in the northern Savanna zone of Ghana because of rampant bush fires during the dry season. The northern part of the country also houses most of the country's livestock (goats, sheep and cattle). These animals either feed on the available crop residue left as a cover to the soil or the residues are removed and fed to them at home by the farmers. The removal of crop residue from the soil for livestock or the destruction by bush fires renders the soil bare. This exposes the soil to sunshine which is followed by erosion by the harmat‐ tan winds during the dry season and by running water at the beginning of the rainy season.

**10.3. Other uses of crop residues by farmers**

priving the soils of organic matter.

**10.4. Weed management**

Farmers in northern Ghana traditionally use crop residues as livestock feed, for housing, craft materials and as household energy source. Using crop residues as soil cover and organ‐ ic matter replacement is therefore foreign and conflicts with the uses that they are already familiar with for several years. The use of crop residues such as millet or sorghum stover as livestock feed in the Upper East region of Ghana where farmers produce crops alongside rearing of animals is very common. In the Upper East region in particular, due to high pop‐ ulation density in that part of the country, there is pressure on land use resulting into small farm lands. Despite the fact that common lands for livestock grazing is limited due to lack of land, farmers still rear livestock because of the high culture and economic value the natives place on livestock. Farm families keep livestock as investment and insurance against the risk of crop failure, for traction, for manure production and for milk and meat. These according to the farmers, make use of crop residue to feed livestock to take precedence over other uses. Animals are therefore allowed to feed on crop residues directly on the farm or the residues are carted home and fed to them. Some of the farmers are able to transport the manure from these crop residues consumed by the animals back to the fields others do not thereby de‐

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21

Of late, there have been increases in livestock numbers in the drier part of northern Ghana especially in the Upper East Region. The increase in the livestock industry in this region has also led to an increase for the demand for their feed and since they depend on crop residues for dry season feeding, residue for mulching the soil will be on the decrease. As a result of this intensification of livestock production, there is a fast developing market for crop resi‐ dues in these areas which further encourage the removal of these residues for sale to raise income for the family at the expense of maintaining the fertility of the soil. In the northern Savanna zone of Ghana where most farmers practice mixed farming, it is therefore left for the individual either to use the crop residue for mulch or use the residues as livestock feed. So far, experience has shown that most of the farmers go in for the earlier option where they use the residues to feed their livestock. Farmers however, still have several options of im‐ proving the fertility of their soils for high yields. These include selling some of the livestock to buy in-organic fertilizers, returning the residue in the form of manure to the farm or in some cases when the plot sizes are small, compost is produced and applied to the crops.

Experience has also shown that in areas where livestock numbers are low such as in the for‐ est and transition zones, the crop residues are not left as mulch but burnt as practiced in the traditional slash and burn system of farming. Apart from burning to control weeds in that system, it has also been found that burning helps to control pests and to reduce the popula‐ tion of rodents which tend to increase when crop residues are left on the field. Even though retention of crop residues is always advocated in CA, under situation of very high mulch

At first sight, spraying to kill the existing vegetation in the northern Savanna zone to plant a crop as in CA system appears like no other weed will ever germinate again. However, two

content, retention is not feasible and burning to reduce it seems to be a good option.

Most of the cover crops being promoted as materials for soil fertility improvement are not edible and so farmers are not very enthusiastic in adopting them for use. Most farmers therefore choose grain legumes among the range of soil fertility management practices due to the immediate provision of food (Chikowo et al., 2004; Adjei-Nsiah et al., 2007; Kerr et al., 2007; Ojiem et al., 2007). It has however been found that practices such as green manures and agro-forestry legumes even though do not provide immediate benefits, they are more efficient in providing nitrogen and mulch for subsequent crops (Giller and Cadisch, 1995). Experience has shown that farmers in the northern part of Ghana do not regard cover crops as part of their traditional crops and therefore cover crops have no significance in monetary terms to them. This explains why farmers are not adopting cover crops such as *Callopogoni‐ um* and *Mucuna* for soil fertility improvement even though results have shown that these cover crops give adequate cover to the soil and increase soil nutrients for high crop yields. It is difficult for farmers to replace crops they are used to with new crops especially when the new crops cannot give immediate economic returns to them.

Farmers in northern Ghana practice mixed-cropping which mostly involves cereals/legumes and cereal/cereal and this situation does not favour the inclusion of *Mucuna* and *Callopogoni‐ um* because of the climbing nature of these cover crops. Intercropping these cover crops with cereals can easily smoother the main crops and these cannot also be easily used as short sea‐ son fallows since each of them needs more than six months to develop and cover the soil for optimum benefits. Work done by Loos et al. (2001) showed that *Mucuna* planted too early would result in competition for nutrients with the associated crop but planting it late also reduces its chance to properly establish. Knowing when to plant *Mucuna* is therefore very important if weed suppression and high quantity of N (150 N kg/ha) are to be achieved from the cover crop. Yield loss estimated at 30 % has also been recorded from fields of *Mucuna* intercropped with maize due to competition for nutrients, light and space.

Reports from farmers in the forest and transition zones also indicate that planting crops in no-till system is time consuming and laborious since it is by using a dibbler or a cutlass to create holes for placing the seeds. Farmers further complained that germination of seeds was negatively affected when these were planted in high amounts of soil cover. In such sit‐ uations, the reduction of the soil surface mulch by partial burning becomes necessary to en‐ hance germination which gives the farmer additional work. Other difficulties involved in planting crops under thick mulch include hidden tree stumps which could wound farmers in the process or dangerous reptiles like snakes hiding in the mulch to bite farmers during planting or weed control by hand. The introduction of jab planters reduced the time used in planting crops in the mulch but it was also dependent on the experience of the farmers.

## **10.3. Other uses of crop residues by farmers**

dry season. The northern part of the country also houses most of the country's livestock (goats, sheep and cattle). These animals either feed on the available crop residue left as a cover to the soil or the residues are removed and fed to them at home by the farmers. The removal of crop residue from the soil for livestock or the destruction by bush fires renders the soil bare. This exposes the soil to sunshine which is followed by erosion by the harmat‐ tan winds during the dry season and by running water at the beginning of the rainy season.

Most of the cover crops being promoted as materials for soil fertility improvement are not edible and so farmers are not very enthusiastic in adopting them for use. Most farmers therefore choose grain legumes among the range of soil fertility management practices due to the immediate provision of food (Chikowo et al., 2004; Adjei-Nsiah et al., 2007; Kerr et al., 2007; Ojiem et al., 2007). It has however been found that practices such as green manures and agro-forestry legumes even though do not provide immediate benefits, they are more efficient in providing nitrogen and mulch for subsequent crops (Giller and Cadisch, 1995). Experience has shown that farmers in the northern part of Ghana do not regard cover crops as part of their traditional crops and therefore cover crops have no significance in monetary terms to them. This explains why farmers are not adopting cover crops such as *Callopogoni‐ um* and *Mucuna* for soil fertility improvement even though results have shown that these cover crops give adequate cover to the soil and increase soil nutrients for high crop yields. It is difficult for farmers to replace crops they are used to with new crops especially when the

Farmers in northern Ghana practice mixed-cropping which mostly involves cereals/legumes and cereal/cereal and this situation does not favour the inclusion of *Mucuna* and *Callopogoni‐ um* because of the climbing nature of these cover crops. Intercropping these cover crops with cereals can easily smoother the main crops and these cannot also be easily used as short sea‐ son fallows since each of them needs more than six months to develop and cover the soil for optimum benefits. Work done by Loos et al. (2001) showed that *Mucuna* planted too early would result in competition for nutrients with the associated crop but planting it late also reduces its chance to properly establish. Knowing when to plant *Mucuna* is therefore very important if weed suppression and high quantity of N (150 N kg/ha) are to be achieved from the cover crop. Yield loss estimated at 30 % has also been recorded from fields of *Mucuna*

Reports from farmers in the forest and transition zones also indicate that planting crops in no-till system is time consuming and laborious since it is by using a dibbler or a cutlass to create holes for placing the seeds. Farmers further complained that germination of seeds was negatively affected when these were planted in high amounts of soil cover. In such sit‐ uations, the reduction of the soil surface mulch by partial burning becomes necessary to en‐ hance germination which gives the farmer additional work. Other difficulties involved in planting crops under thick mulch include hidden tree stumps which could wound farmers in the process or dangerous reptiles like snakes hiding in the mulch to bite farmers during planting or weed control by hand. The introduction of jab planters reduced the time used in planting crops in the mulch but it was also dependent on the experience of the farmers.

new crops cannot give immediate economic returns to them.

20 Soil Fertility

intercropped with maize due to competition for nutrients, light and space.

Farmers in northern Ghana traditionally use crop residues as livestock feed, for housing, craft materials and as household energy source. Using crop residues as soil cover and organ‐ ic matter replacement is therefore foreign and conflicts with the uses that they are already familiar with for several years. The use of crop residues such as millet or sorghum stover as livestock feed in the Upper East region of Ghana where farmers produce crops alongside rearing of animals is very common. In the Upper East region in particular, due to high pop‐ ulation density in that part of the country, there is pressure on land use resulting into small farm lands. Despite the fact that common lands for livestock grazing is limited due to lack of land, farmers still rear livestock because of the high culture and economic value the natives place on livestock. Farm families keep livestock as investment and insurance against the risk of crop failure, for traction, for manure production and for milk and meat. These according to the farmers, make use of crop residue to feed livestock to take precedence over other uses. Animals are therefore allowed to feed on crop residues directly on the farm or the residues are carted home and fed to them. Some of the farmers are able to transport the manure from these crop residues consumed by the animals back to the fields others do not thereby de‐ priving the soils of organic matter.

Of late, there have been increases in livestock numbers in the drier part of northern Ghana especially in the Upper East Region. The increase in the livestock industry in this region has also led to an increase for the demand for their feed and since they depend on crop residues for dry season feeding, residue for mulching the soil will be on the decrease. As a result of this intensification of livestock production, there is a fast developing market for crop resi‐ dues in these areas which further encourage the removal of these residues for sale to raise income for the family at the expense of maintaining the fertility of the soil. In the northern Savanna zone of Ghana where most farmers practice mixed farming, it is therefore left for the individual either to use the crop residue for mulch or use the residues as livestock feed. So far, experience has shown that most of the farmers go in for the earlier option where they use the residues to feed their livestock. Farmers however, still have several options of im‐ proving the fertility of their soils for high yields. These include selling some of the livestock to buy in-organic fertilizers, returning the residue in the form of manure to the farm or in some cases when the plot sizes are small, compost is produced and applied to the crops.

Experience has also shown that in areas where livestock numbers are low such as in the for‐ est and transition zones, the crop residues are not left as mulch but burnt as practiced in the traditional slash and burn system of farming. Apart from burning to control weeds in that system, it has also been found that burning helps to control pests and to reduce the popula‐ tion of rodents which tend to increase when crop residues are left on the field. Even though retention of crop residues is always advocated in CA, under situation of very high mulch content, retention is not feasible and burning to reduce it seems to be a good option.

#### **10.4. Weed management**

At first sight, spraying to kill the existing vegetation in the northern Savanna zone to plant a crop as in CA system appears like no other weed will ever germinate again. However, two weeks after planting the crop, one finds a huge mass and diversity of weeds vigorously springing up thereby making the first weeding after planting very difficult and laborious since this is done by hand. At times the high infestation of weeds in such a system is due to bad selection of weedicide, low doses of the chemical and poor spraying techniques.

time needed. Chemical fertilizers which are needed to generate biomass at the beginning of CA practice in the Savanna zone have their depots located in the regional capitals of the country making it almost impossible for most of the farmers who are in rural areas. One of the difficulties involved in the implementation CA and other technologies designed to en‐

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

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

23

The Food Crops Development Project (financed by the African Development Bank) imple‐ mented mostly in the forest and transition zones saw the supply of inputs to project clients by some major agro-input companies. According to Boahen et al., (2007) farmers use the project as collateral to gain access to the inputs for crop production. In that system the Project sent a request to the shop to provide a certain quantity of inputs, for which the farm‐ er pays later into a bank account created for this purpose. The Inputs and tools supplied to the farmers in this system ranged from pesticides and fertilizer to equipment and tools like knapsack sprayers, cutlasses and hoes. The above indicates that the implementation of any soil fertility enhancing technologies in Ghana by donors through projects is always success‐

This calls for sustainability to be built into every project implemented to make sure that the farmers own and operate the system even after the project. Some of the suggestions given to

Urging the farmers to form co-operatives where they can be registered and linked to finan‐ cial institutions such that even after the project, the farmers can get financial assistance from

Secondly, training of farmers on both the process and the content of the project will be very

The donors or project implementers should always look for their local partners and work with them. This will enable the activities of the project to continue through the efforts of the

Farmers in the north of Ghana have expressed their gratitude for the introduction of CA and other related technologies as labour is scarce and some of these practices are ways of reduc‐ ing labour costs for crop production. Technologies such as no-till and direct seeding are practices demonstrated to the farmers of the north which are devoid of tilling the land either by hand hoe or tractors. Even though the introduction of these technologies are appropriate, the equipments and tools to go with these practices are not yet available for sale in Ghana except those used for the demonstrations. The planting of the crops in the mulch without these tools remains a challenge to the adoption of these technologies as farmers spend more time to get the seeds planted using dibblers and cutlasses. Implements like knife-rollers, rip‐ pers and no-till seeders are needed to facilitate planting in CA which are yet to be made available in the country. According to the farmers, planting is easier with dibblers or cutlass‐ es when the soil is bare but becomes more difficult if there is a high surface mulch as in CA

Currently in Ghana, the most common practice available for medium- and large-scale farm‐ ers is the tractor-mounted disc plough and harrow which are imported and sold to either

hance crop yields may be lack of accessibility to inputs such as weedicides.

ful but the systems breaks down immediately the project ends.

important for the visibility of the project after it has been concluded.

introduce sustainability into such projects include:

local partners after the duration of the project.

and the crop is to be planted in rows.

such Institutions

Rio (1992) estimated over 45 % as the annual yield loss of crops due to weed infestation in heavily infested fields. Other effects include waste of human energy in controlling weeds. It has been found that reducing tillage intensity alone as described in CA without adequately covering the soil as practiced by most farmers is one way of promoting weed infestation on their fields. In the situation whereby crops are planted haphazardly leaving some gaps, weeds quickly infest and occupy these areas making their control very difficult as this re‐ quires weeding several times by hand hoe.
