**3. Results**

In the Northern region, CD and HE were selected as regional materials for agricultural use. These materials have been evaluated and used in some Asian countries as having high fertilizer effects (e.g. Austin et al., 2005, Matsui, 1997). However, in Ghana, these materials are considered as non-accessible resource because of lack of proper management technology, and psychologi‐ cal reasons (Coffie et al., 2005). In Ghana, it seems that gathering plant materials in the Northern region is more difficult than in the Ashanti region. Human and/or animal resource could be col‐

In the Ashanti region, PM and SD were selected. These materials are considered as having high agronomical potential especially in the Ashanti region. Commercial poultry farmers are generally concentrated in the Greater Accra and Ashanti regions hence almost 50% of poultry manure is produced in these two regions (Quarcoo, 1996). So poultry manure is par‐ ticularly accessible and available for rice production in the Ashanti region. SD is a byprod‐ uct material of lumbering industry which is popular in Ghana. Hence, its disposal has lately

This study therefore investigated the application effect of these selected organic materials on rice yield, and their proper processing methods for each organic matter application. The various processing (referred here as pre-treatment) include the following four treatments i.e. (i) ashing, (ii) charring, (iii) composting, and (iv) direct application. The effect of these four treatments on rice growth and yield were investigated. Organic materials have various forms, and each form has some advantages and disadvantages, as far as crop nutrition is concern. Therefore, this study investigated the best organic matter management option for rice production in Ghana, through the comparison of rice yield under four types pretreated i.e. ashed (ASH), charred (CH),

Ghana has several agro-ecological zones but these can be broadly categorized into forest and savannah. The experiments were conducted at the University of Development Studies (UDS; N 09°24'19", W 000°58'14") located in the Northern region which lies within the Guinea sav‐ annah agro-ecological zone, and at the CSIR - Soil Research Institute (SRI; N 06°45'18", W 001°35'30") which is in the Ashanti region and within the forest agro-ecological zone of the country. At UDS, the effect of rice straw (RS), cow dung (CD), and human excreta (HE) ap‐ plication on rice yield were investigated. At the CSIR-SRI, the effect of RS, poultry manure

Three types of organic materials that are potentially available were selected, for study site. Each of the organic material was applied to rice on the fields after pretreatment into ash (ASH), charr (CH), compost (CO), and untreated raw material (RW). The effect of Phosphate

composted (CO), or non-treated raw material (RW) organic materials application.

(PM), and saw dust (SD) application on rice production was evaluated.

lected in settlement ecosystem through some life style or system innovations.

become a major problem for the government and timber industry.

**2. Materials and methods**

**2.1. Research site**

34 Soil Fertility

**2.2. Treatments**

A 3-way analysis of variance (ANOVA) for rice grain yield under 36 treatments was con‐ ducted to verify the effect of organic matter application at each site, and to clarify the effect of interaction between three factors, i.e. type of organic material, pretreatment, and PR ap‐ plication. In this analysis, rice yield without organic matter application was excluded. The results of the 3-way ANOVA for rice grain yields did not show any significant difference between treatments and their interaction (Tables 1 and 2). Even though, all treatments were replicated three times, but it might not be enough to avoid specific variance of land condi‐ tion for elucidation of statistical difference.



economic benefit and transportation efficiency. Ash contributes in the enhancement of soil fertility with mineralization of organic matter, in elimination of bad organic substan‐ ces that may become plant growth inhibition factor, in supplement of Potassium and Sili‐

Improvement of Soil Fertility with Use of Indigenous Resources in Lowland Rice Systems

http://dx.doi.org/10.5772/53209

37

Charring has similar advantages and disadvantages as in ashing in the short-term but is ex‐ pected to show organic function compared with ashing. Recent studies reported that appli‐ cation of charred organic material could enhance crop production through increasing of soil organic matter, improvement of soil physical and biological properties (Glaser et al., 2002; Lehmann et al., 2003; Yeboah et al., 2009). And recently, the application of charred organic material has been focused as one of the important factor on the pedogenic process of Ama‐ zonian Dark Earth, that is known as tropical fertile soil with black colored surface (Naka‐

It is well known that composted organic materials strongly contribute to crop production. Composting enhances the fertilizing capacity of an organic material. The C/N ratio of an or‐ ganic material decreases with composting, mineralization of the material also results in min‐ eral nutrient concentration. Organic matter decomposition and fermentation, can reduce disease and pestilence risk due to increase in temperature. However, it is also known that composting requires knowledge for keeping fermentation condition i.e. water contents man‐ agement. Composting is also laborious and the material is normally bulky requiring addi‐ tional labour to convey the material to the field and apply. Therefore it may be a difficult

Grain yield: (t ha-1); CON: Non-P application, BRP: Burkina Faso Phosphate Rock application, TSP: Triple Super Phos‐ phate application, WOM: without organic material, ASH: ashing, CH: charring, CO: composting, RW: raw material, Effectiveness of organic matter application: The rice grain yield at each plot / the rice grain yield at WOM under same

**Table 3.** Rice grain yield under organic and pretreated materials in Northern region

technical option for farmers due to some of these reasons.

ca (Anzai 1993).

mura et al., 2007)

P management condition.


### **3.1. Effect of indigenous organic resources application on rice yield in Northern region**

Rice yield under various organic material applications are indicated in Table 3. Least sig‐ nificant differences (LSD) at 5 % level are also shown in the Table. Statistical difference analysis, however, accord ANOVA priority to LSD. Mean value of rice grain yields un‐ der combined application of organic material, pretreatment, are indicated in Figure 1. The mean values were calculated by averaging of CON, BRP, and TSP for the three rep‐ lications. The rice yield in Northern region generally showed higher value (e.g. 2.51 t ha-1 at CO-HE mean value of CON, BRP, and TSP) compared with WOM (1.25 t ha-1 in means value of CON, BRP, and TSP).

CO and RW showed relatively higher value in RS treatments. It seemed that ASH and CH treatment for rice straw had lost more nutrients than the other organic materials. Meanwhile, RW-RS and CO-RS have physical beneficial effect on soil fertility such as mulching effect.

In the CD treatments, ASH and CH showed higher value in CON treatment, and CO and RW showed higher value in BRP treatment. CD contained highest P2O5 contents (1.72%) among three selected organic material. It maybe considered as the contribution of mineral‐ ized P from CD under combustion, that contributed to the increased rice grain yields.

The rice yields under HE application showed high value in CH and CO pretreatments. Espe‐ cially under CON treatment, CH showed 2.97 t ha-1 of grain yield and CO showed 2.93 t ha-1 of grain yield, respectively.

Generally, organic materials application increased rice grain yields compared with WOM. Organic materials application showed pronounced effect especially in CON treatment, i.e. in RS 3.96 times, in CD 4.21 times, in HE 4.46 times higher than WOM rice yield, respectively. On the other hand, there were not significant effects of organic material applications on rice yield under TSP treatment. The rice yield under TSP treatment ranged from 82 to 91% against rice yield on WOM.

Ashing has disadvantageous of nutrient loss and/or green-house gas production with dry combustion. Meanwhile when the material is ashed, there is significant reduction in both weight and volume. Labour and cost of transportation is greatly reduced resulting in economic benefit and transportation efficiency. Ash contributes in the enhancement of soil fertility with mineralization of organic matter, in elimination of bad organic substan‐ ces that may become plant growth inhibition factor, in supplement of Potassium and Sili‐ ca (Anzai 1993).

Charring has similar advantages and disadvantages as in ashing in the short-term but is ex‐ pected to show organic function compared with ashing. Recent studies reported that appli‐ cation of charred organic material could enhance crop production through increasing of soil organic matter, improvement of soil physical and biological properties (Glaser et al., 2002; Lehmann et al., 2003; Yeboah et al., 2009). And recently, the application of charred organic material has been focused as one of the important factor on the pedogenic process of Ama‐ zonian Dark Earth, that is known as tropical fertile soil with black colored surface (Naka‐ mura et al., 2007)

**Table 2.** 3-way ANOVA for rice grain yield in the Ashanti region

means value of CON, BRP, and TSP).

mulching effect.

36 Soil Fertility

of grain yield, respectively.

against rice yield on WOM.

**3.1. Effect of indigenous organic resources application on rice yield in Northern region**

Rice yield under various organic material applications are indicated in Table 3. Least sig‐ nificant differences (LSD) at 5 % level are also shown in the Table. Statistical difference analysis, however, accord ANOVA priority to LSD. Mean value of rice grain yields un‐ der combined application of organic material, pretreatment, are indicated in Figure 1. The mean values were calculated by averaging of CON, BRP, and TSP for the three rep‐ lications. The rice yield in Northern region generally showed higher value (e.g. 2.51 t ha-1 at CO-HE mean value of CON, BRP, and TSP) compared with WOM (1.25 t ha-1 in

CO and RW showed relatively higher value in RS treatments. It seemed that ASH and CH treatment for rice straw had lost more nutrients than the other organic materials. Meanwhile, RW-RS and CO-RS have physical beneficial effect on soil fertility such as

In the CD treatments, ASH and CH showed higher value in CON treatment, and CO and RW showed higher value in BRP treatment. CD contained highest P2O5 contents (1.72%) among three selected organic material. It maybe considered as the contribution of mineral‐

The rice yields under HE application showed high value in CH and CO pretreatments. Espe‐ cially under CON treatment, CH showed 2.97 t ha-1 of grain yield and CO showed 2.93 t ha-1

Generally, organic materials application increased rice grain yields compared with WOM. Organic materials application showed pronounced effect especially in CON treatment, i.e. in RS 3.96 times, in CD 4.21 times, in HE 4.46 times higher than WOM rice yield, respectively. On the other hand, there were not significant effects of organic material applications on rice yield under TSP treatment. The rice yield under TSP treatment ranged from 82 to 91%

Ashing has disadvantageous of nutrient loss and/or green-house gas production with dry combustion. Meanwhile when the material is ashed, there is significant reduction in both weight and volume. Labour and cost of transportation is greatly reduced resulting in

ized P from CD under combustion, that contributed to the increased rice grain yields.

It is well known that composted organic materials strongly contribute to crop production. Composting enhances the fertilizing capacity of an organic material. The C/N ratio of an or‐ ganic material decreases with composting, mineralization of the material also results in min‐ eral nutrient concentration. Organic matter decomposition and fermentation, can reduce disease and pestilence risk due to increase in temperature. However, it is also known that composting requires knowledge for keeping fermentation condition i.e. water contents man‐ agement. Composting is also laborious and the material is normally bulky requiring addi‐ tional labour to convey the material to the field and apply. Therefore it may be a difficult technical option for farmers due to some of these reasons.


Grain yield: (t ha-1); CON: Non-P application, BRP: Burkina Faso Phosphate Rock application, TSP: Triple Super Phos‐ phate application, WOM: without organic material, ASH: ashing, CH: charring, CO: composting, RW: raw material,

Effectiveness of organic matter application: The rice grain yield at each plot / the rice grain yield at WOM under same P management condition.

**Table 3.** Rice grain yield under organic and pretreated materials in Northern region

Grain yield: (t ha-1); CON: Non-P application, BRP: Burkina Faso Phosphate Rock application, TSP: Triple Super Phos‐ phate application, WOM: without organic material, ASH: ashing, CH: charring, CO: composting, RW: raw material, Effectiveness of organic matter application: The rice grain yield at each plot / the rice grain yield at WOM under same

Improvement of Soil Fertility with Use of Indigenous Resources in Lowland Rice Systems

http://dx.doi.org/10.5772/53209

39

**Figure 2.** Effect of organic matter application on rice grain yield in Ashanti region. Means values of CON, BRP, and TSP treatment are indicated. WOM: without organic matter, RS: rice straw, PM: poultry manure, SD: saw dust ASH: ashing,

**Table 4.** Rice grain yield under organic and pretreated materials in Ashanti region

P management condition.

CH: charring, CO: composting, RW: raw material

**Figure 1.** Effect of organic matter application on rice grain yield in Northern region. Mean values of CON, BRP, and TSP treatment are indicated. WOM: without organic matter, RS: rice straw, CD: cow dung, HE: human excreta, ASH: ash‐ ing, CH: charring, CO: composting, RW: raw material

#### **3.2. Effect of indigenous organic resources application on rice yield in Ashanti region**

Rice yields under various organic materials applications in Ashanti region are shown in Table 4 and Figure 2. The significant difference by 3-way ANOVA was not found as the same as Northern region. The cultivar used in Ashanti region (Sikamo) was different from Northern region (GR18), so rice yields could not be simply compared between the two research sites.

In the RS treatment, the mean rice yield values for CON, BRP, TSP rice yields showed higher value than WOM, but RW-RS showed relatively lower values than the other treat‐ ments. The RW-RS was the best harvested RS treatment in Northern region, so there were different effectiveness trend of RS treatment between Northern and Ashanti region. Northern region is located in Guinea-Savannah zone, and has little annual precipitation. Soils were kept under upland condition over a long time. Ashanti region is in the Equa‐ torial Forest zone that has higher rainfall and that lowland rice can be cultivated under submerged condition throughout the year. Probably the difference of RW-RS effect on rice yield between the two sites was attributed to difference of organic matter decompo‐ sition rate caused by variation in water conditions.

Improvement of Soil Fertility with Use of Indigenous Resources in Lowland Rice Systems http://dx.doi.org/10.5772/53209 39


Grain yield: (t ha-1); CON: Non-P application, BRP: Burkina Faso Phosphate Rock application, TSP: Triple Super Phos‐ phate application, WOM: without organic material, ASH: ashing, CH: charring, CO: composting, RW: raw material,

Effectiveness of organic matter application: The rice grain yield at each plot / the rice grain yield at WOM under same P management condition.

**Table 4.** Rice grain yield under organic and pretreated materials in Ashanti region

0.0

two research sites.

ASH

sition rate caused by variation in water conditions.

ing, CH: charring, CO: composting, RW: raw material

CH

CO

RW

ASH

WOM RS CD HE

**Figure 1.** Effect of organic matter application on rice grain yield in Northern region. Mean values of CON, BRP, and TSP treatment are indicated. WOM: without organic matter, RS: rice straw, CD: cow dung, HE: human excreta, ASH: ash‐

Rice yields under various organic materials applications in Ashanti region are shown in Table 4 and Figure 2. The significant difference by 3-way ANOVA was not found as the same as Northern region. The cultivar used in Ashanti region (Sikamo) was different from Northern region (GR18), so rice yields could not be simply compared between the

In the RS treatment, the mean rice yield values for CON, BRP, TSP rice yields showed higher value than WOM, but RW-RS showed relatively lower values than the other treat‐ ments. The RW-RS was the best harvested RS treatment in Northern region, so there were different effectiveness trend of RS treatment between Northern and Ashanti region. Northern region is located in Guinea-Savannah zone, and has little annual precipitation. Soils were kept under upland condition over a long time. Ashanti region is in the Equa‐ torial Forest zone that has higher rainfall and that lowland rice can be cultivated under submerged condition throughout the year. Probably the difference of RW-RS effect on rice yield between the two sites was attributed to difference of organic matter decompo‐

**3.2. Effect of indigenous organic resources application on rice yield in Ashanti region**

CH

CO

RW

ASH

CH

CO

RW

1.0

2.0

3.0

Rice grain yield

(t ha-1)

38 Soil Fertility

4.0

5.0

6.0

7.0

8.0

**Figure 2.** Effect of organic matter application on rice grain yield in Ashanti region. Means values of CON, BRP, and TSP treatment are indicated. WOM: without organic matter, RS: rice straw, PM: poultry manure, SD: saw dust ASH: ashing, CH: charring, CO: composting, RW: raw material

The application of poultry manure resulted in higher yield except ASH and CH under CON treatment. However, ASH-PM showed low yield (5.20 t ha-1) under CON treatment, but showed high yield under BPR and TSP treatments (6.83 and 7.20 t ha-1), respectively.

**4. Conclusions and recommendations**

**fed lowland rice cultivation in Savannah zone**

nificantly.

on rice yield.

Rice grain yields generally increased with the application of the various organic matters. Grain yields under organic matter application showed approximately 1.5 to 1.6 times higher than those of WOM in Northern region, and 1.1 to 1.2 times higher than WOM in Ashanti region. However in some case e.g. RW-SD, did not show any positive effect of application on rice yield, and so the proper pretreatment for each organic resources need to be selected.

Improvement of Soil Fertility with Use of Indigenous Resources in Lowland Rice Systems

http://dx.doi.org/10.5772/53209

41

**4.1. Suggestion for indigenous organic material application in Northern region, for rain-**

The best promising organic material for agricultural use in Northern region is rice straw (RS). CO-RS and RW-RS treatment showed high positive effect on rice yield in the Northern region trial. It seems adequate amount of mineral plant nutrients were supplied due to de‐ composition of RS and that soil physical and biological properties were enhanced. On the other hand, CH-RS and ASH-RS also showed positive effect on rice yield, however, it should be considered that charring needs input of labor and capital, and that ashing will im‐ pact the environmental negatively. Moreover, ashing process can reduce effectiveness of soil

CD application showed high yield in all pretreated plots. It is well known that CD appli‐ cation is effective for rice production. In the Northern region, however, it is far from rec‐ ommended materials because of difficulty in material gathering. Most of CD in this region was produced by cattle grazing, that means farmer needs to collect CD scattered through‐ out savannah forest. This study indicated that CD has similar effect on rice yield com‐ pared with other organic materials. The use of CD in rice cultivation can be as popular as RS due to both availability and accessibility. While RS is readily available in the rice fields extra labour is require to search and collect CD. However, after using CD as fuel CH-CD and ASH-CD can be used in rice production since these materials increased rice yield sig‐

Rice yields average of HE application was almost same as those of CD. Improvement of crop productivity has been reported by many existing studies. However it also has been men‐ tioned that HE usage has difficulty to diffuse for farmers because of hygienic risk and psy‐ chological avoidance. These obstacles can be resolved by either combustion process such as CH and ASH, or composting process. CO-HE indicated highest yield among four pretreat‐

According to the results from Northern region trial, authors suggest that CD and/or HE composting based on RS usage should be well examined as the effective and affordable technical options for farmers. HE composting still have the difficulty of gathering, but technology introduction on collecting and separating urine and feces, such as Eco-San toi‐ let, will open the way for proper management of HE, especially in Northern region. More‐ over CD and HE composting based RS can be expected to increase RP application effect

physical and biological properties observed under CO and RW application.

ment in HE treatments, the yield was almost twice higher than WOM.

Under the SD application, RW-SD produced a lower value compared with other SD application. RW-SD under all three P treatments showed a similar yield as WOM (Effectiveness against WOM: 1.05 at CON, 0.95 at BRP, 0.98 at TSP). Only the RW-SD did not show the positive effect of organic matter application on rice yield. The RW-SD in Ashanti region was direct application of woody material for submerged condition. So, decomposition rate and plant nutrient release rate seemed to be extremely slow, and thus causing nitrogen starvation for the treatment.

#### **3.3. The combination effect of various organic materials and phosphate rock application**

The agronomic efficiencies to TSP under various organic matter applications are shown in Table 5. Agronomic efficiency was calculated from the difference in grain yield (t ha-1) of PR to those of TSP treatment. This efficiency can be considered as the indicator of BRP being a possible alternative to TSP. According to FAO (2004), BPR direct application showed 97% of agronomic efficiency in lowland rice cultivation.

Under this study and within the Northern region in Ghana, the agronomic efficiency of BPR direct application against TSP was relatively lower in WOM, RW-RS, ASH-HE (54, 66, 62%, respectively). Treatments of ASH-RS, RW-CD, CO-CD, CH-HE, CO-HE showed efficiency of over 120%, suggested that combined application of PR and organic materials was effective in PR application. It is well known that organic matter application is one of the effective techniques to solubilize PR. This may be so due to PR dissolution in organic acids produced by microorganisms, through decomposition of easily decomposable organic substances.

On the other hand, within the Ashanti region, only CO-SD showed a lower value (71%). The other treatments including WOM gave similar trend with higher values that ranged from 84% to 118%. This result shows that agronomic efficiency did not increased by organic mat‐ ter application. These results do not only indicated that BPR can be use directly as alterna‐ tive fertilizer, but also indicated that there are not clear positive effects of organic matter application on PR agronomic efficiency enhancement.


RS: rice straw, CD: cow dung, HE: human excreta, PM: poultry manure, SD: saw dust, WOM: without organic material, ASH: ashing, CH: charring, CO: composting, RW: raw material directly applied

**Table 5.** Effect of various organic material application on changes of agronomic efficiency (%) in BPR direct application against TSP application
