I . Summary

1. Introduction
People living in Mt. Kilimanjaro are called "Chagga". They run traditional agriculture that effectively utilizes limited resources and agricultural land in mountainous areas. It is characterized by crop and tree cultivation and livestock breeding around the house (Fernandes et al., 1984). Perennial crops such as bananas (staple food) and coffee (cash crop), and trees which provide firewood and fodder, are mixed. Livestock manure and feed residues are used as organic fertilizer and the crop residues are used as livestock feed. Chagga's traditional agriculture based on dynamics of diverse organic materials were certified as globally important agricultural heritage system (GIAHS) (FAO, 2011). However, in recent years, the function and structure of Chagga's traditional agriculture based on the cycling of organic materials between banana cultivation and livestock breeding, have changed due to shortage of agricultural land due to population increase, urbanization and market economy penetration, and there is concern that the sustainability of their traditional agriculture has been declined (Soini, 2005). The loss of sustainability of their traditional agriculture directly affects the livelihood and natural ecosystems on Mt. Kilimanjaro. Soil fertility is the factor that represents the carbon and nutrient status in the soil, in other words, the sustainability and the productivity of the land. Soil fertility in agricultural land is strongly affected by farmer's land management such as amount and type of fertilizer application, type of crop, intensity of tillage and mulching, and land management is the influential factor for soil fertility. In case of small-farmers such as Chagga people, land management depends on the individual farmers and is affected by household characteristics (e.g. family size, livelihood and land size), and surrounding socio-economic changes (e.g. population increase, market price change etc.) (Mowo et al., 2006). Therefore, this study will evaluate the influence of various changes surrounding Chagga on their land management and soil fertility of their traditional agriculture.
2. Materials and Methods
(1) Study site
The research village is a part of Kilema Kaskazini ward located on the southern slopes on Mt. Kilimanjaro in northeastern Tanzania (3° 16′ 56″ S, 37° 28′ 49″ E) (Fig. 1). The elevation is 1600 m a.s.l.. The rainy season is bimodal; the long rainy season is from March to May, and the short rainy season is from November to December. Annual rainfall at 1500 m a.s.l. on the southern slope is 1500-2000 mm and mean annual temperature is 19.0℃  (Hemp, 2006). The main soil type is classified as Andosols (Zeck et al., 2014). The number of population of the research village is 1343 and the number of households is 307 in total (Kilema Kaskazini village office, 2012). (2) Interview survey about the traditional agriculture and soil sampling Thirty one households were interviewed in from November to December of 2017 to get detail information about their traditional agriculture including yield and income from crops. Interview survey was conducted by face-to-face interview based on questionnaire sheet (Appendix 1) and note book to collect both qualitative and quantitative data with an interpreter. Next, to understand the relationship between land management and soil fertility, soil samples (0 − 15 cm) in each home garden were collected by using an auger from 31 households where interview survey conducted. All soil samples were air dried and sieved to pass 2mm in Soikoine university of agriculture and brought to Japan. Soil physico-chemical properties, such as soil carbon and soil nutrients will be analyzed at Kyoto university from April to June 2018. (3) Interview survey about the banana cultivation To identify the factor related to their selection of about 12 typical banana types for their home garden (Table 1) (Kubo et al., 2016), 12 households were interviewed in December of 2017. The interview was conducted by face-to-face interview based on a questionnaire sheet.
(4) Tasting test of bananas
To understand the relationship between the Chagga people and banana by quantitatively, the tasting test of bananas were conducted in December of 2017. Four typical type of bananas ( Mchare , Mnyenyele , Kisasa , Ndishi ) were taken from one home garden. Banana samples were peeled, washed with water and boiled for 20 minutes with a gas cooker. After that, banana samples were chopped in small pieces and used for taste test. The test was conducted for the sweetness, astringency, softness, and preference by tasting test sheet (Appendix 2) by 10 villagers. Mchare was adopted as a standard, and tasting test was conducted based on a relative evaluation.
3. Livelihood and traditional agriculture
(1) Results
a) Land usage The Chagga home garden is stretching the upper slopes of the Mt. Kilimanjaro (1200 − 1800 m a.s.l.). They cultivate mainly perennial crops such as banana ( Musa spp.) and coffee ( Coffea arabica ), annual crops such as maize, beans and taro, trees and grasses, and keep livestock such as cattle and goats in the home garden. Many of them have another land called ' kikamba ' in lowland area (900 − 1200 m a.s.l.) located 10 km far from their home, where they intensively cultivate maize, beans and sunflower with chemical fertilizer. The average home garden size was 0.30 ha with a range of 0.1 to 0.7 ha measured by GPS in 2017 for 31 households. This was about half of 0.56 ha that Soini reported in 2005. The decline in coffee prices in the global market and increase in pesticide price for coffee tree had an impact on their agriculture. In accordance with the interview pre-survey in 2015, 68% of total households of 145 households had stopped or reduced coffee cultivation. Instead of coffee, the area of cultivation of bananas, maize and fruit trees had been expanded. Some area in the home garden was diverted for only maize cultivation, since maize cultivation could not mix with banana and coffee cultivation for the necessity of sunlight. In my recent interview survey for 31 households in 2017, 58% of household have kept kikamba at lowland and the average size was 0.32 ha. This was also smaller than Soini's report in 2005. b) Crop yield from home garden and kikamba Table 2 presents crop yield from home garden and kikamba including banana, coffee, maize and beans from 31 households in 2017. Nineteen households continued coffee cultivation, 23 households kept kikamba , and 24 households got income from an off-farm job. The average yield of bananas during rainy season was 14 bunch ha -1 week -1 and it was twice of drying season. Consumption per capita of banana was about 660 kg yr ¹, which was much greater than that of an average of Tanzania (280 − 500 kg yr ¹ ). The banana yield was same as the household with coffee cultivation (11 bunch ha -1 week -1 ) and the households without coffee cultivation (10 bunch ha -1 week 1 ). On the other hand, the maize and beans yield from home garden of the household with coffee cultivation were 78% (180 kg ha -1 yr -1 ) and 73% (67 kg ha -1 yr -1 ) that of household without coffee cultivation (232 kg ha -1 yr -1 for maize and 92 kg ha -1 yr -1 for beans). The amount of personal consumption per capita of maize and beans of households with kikamba were 63 kg person -1 yr -1 and 16 kg person -1 yr -1 , respectively. On the other hand, households without kikamba , the consumption was 22 kg person ' ¹ yr ¹ for maize and 6 kg person -¹ yr ¹ for beans, respectively. c) Income from crop from home garden and kikamba Figure 2 presents income from each crop from home garden and kikamba of 31 households in 2017. Income from banana sales accounted for 60% on average of total income from all the crop grown in home garden and kikamba . In case of the households with coffee cultivation, income from coffee sales accounted for 29% on average (with a range of 4% to 100%) of total income all the crop grown in home garden and kikamba . The income of households with coffee cultivation from banana sales was 52% on average, while households without coffee cultivation accounted for 72% of all the crop grown in home garden and kikamba . In case of the households with kikamba , income from crop sales from kikamba accounted for 18% on average. Figure 3 presents the balance of income from kikamba (selling of maize and beans) and expenditure for kikamba (for transportation, labor, seed, fertilizer, and rent of tractor) of 23 households with kikamba . From this result, the expenditure was larger than income for 17 households. d) Frequency of appearance of banana, maize and rice for daily meal The interview survey was conducted about the daily meal (lunch and dinner) for 100 villagers in 2017. According to the interview survey, seven types of Chagaa's traditional meal made from banana were found, while maize was only one. Maize was often eaten as an Ugali which is staple food throughout Tanzania rather than traditional meal after introduced milling machines in this village 20 years ago. Figure 4 presents the frequency of appearance of banana, maize, and rice to the daily meal. From this result, banana accounted for 42%, maize was 44%, and rice was 14% of daily meal. e) Preference for staple food The interview survey was conducted about the preference for staple food including banana, maize, and rice for 90 villagers (48 villagers are male, 42 villagers are female) in 2017. Figure 5 presents the preference for staple food. From this result, banana was most preferred staple food (40%), followed by Maize (36%) and rice (24%). By gender, the ratio of male and female who liked bananas was almost same. On the other hand, the ratio of male who liked maize was twice than that of female. Rice was preferred by children, while banana and maize were preferred by adults.
(2) Discussion
In this study, the decline of home garden size per household has found due to increasing population. The traditional banana-coffee home garden was still continuing, but coffee cultivation itself had been decreasing due to the decline in coffee prices in the global market and increase in pesticide price. On the other hand, banana was still an important staple food for Chagga people, though the frequency of appearance of banana for the daily meal had decreased compared to the old days. The results also showed that banana became an important cash income source from crops for all households with or without coffee cultivation. This is probably because of the expansion of the banana market owing to the development of the transportation network and the expansion of consumption caused by the urban population increase. The stable consumption among the village and stable cash income from the market are considered as a motivation to keep growing banana in this area. Our results also showed that maize was becoming a staple food in this area. This is probably because of the exchanges with various regions due to the development of the transportation network, the changing eating habits and the introduction of machines. The kikamba size also has tended to decline. The results showed that kikamba has played an important role in producing maize and beans for self- consumption. However, it seemed difficult to get profit from kikamba . The households without kikamba are presumed the need to more cash income to buy maize and beans for their consumption. The increasing of demand for maize may resulted in increase of maize cultivation even in the home garden, and it would expand in the future due to the decreasing of kikamba size and high cost for maintaining kikamba.
4. The Chagga people and banana cultivation
(1) Results
a) Factors related to the selection for banana cultivation The interview survey was conducted about the characteristics of each banana, frequency of cultivation, market demand, personal preference about 12 banana types for 12 households in 2017 to identify the factors related to the selection for banana cultivation. Based on the interview survey, Mchare was the most traditional type of banana for cooking around this area. The Mchare was more suitable to cultivate in this area and easy to get new banana trees. It was used for almost all traditional meals of Chagga. The Kisasa introduced 20 years ago in this area, is strong against pests, growing fast and strong for wind with the low height. The Mnyenyele is the best banana for the Chagga people, however the cultivation is much more difficult than other types. The Ndishi also is the most traditional type of banana around this area for making local brew called mbege. The mbege is drunk frequently on a daily basis and is provided for celebrations and funerals traditionally by the Chagga people. Based on the interview survey, Mchare was the most cultivated type, followed by Kisasa and Ndishi. The Kisukari, Matoke and Mnyenyele were cultivated in small amounts, while other types were very few. The Mchare and Kisasa are the largest types to be shipped to the market, followed by Matoke, Ndishi, Mnyenyele and Kisukari. The Kisasa have a large demand from urban areas as a fruit. Market price is highest for Mnyenyele , followed by Mchare, Matoke and Kisasa . Almost all villagers preferred Mnyenyele the most, followed by Mchare and Matoke . The Kisasa did not prefer much in this village. b) Characteristics of taste of Mchare , Mnyenyele , Kisasa and Ndishi Table 2 presents the characteristics of taste of Mchare, Mnyenyele, Kisasa and Ndishi . The sweetness did not differ greatly in Mchare and Mnyenyele , while Kisasa was little sweeter than Mchare . On the other hand, Ndishi was much less sweeter than that of other 3 types. The astringency did not differ greatly in Mchare and Kisasa , and Mnyenyele had a bit less astringent than Mchare . On the other hand, Ndishi had a much astringency. The softness did not differ greatly in Mchare and Mnyenyele , while Kisasa was little softer and Ndishi was much softer than that of Mchare. The Mchare and Mnyenyele did not show a big difference in sweetness, astringency and softness. However, Mnyenyele was estimated for as the most preferred, Mchare and Kisasa were the second most preferred, and Ndishi was the last for the total evaluation.
(2) Discussion
The results showed that the selection of banana type for cultivation is made based on ease of cultivation, market demand, characteristics of each banana and personal preference. The Mchare has been selected for the cultivation due to the easy for cultivation, the stable demand from the market and the good taste with any traditional meals. The Kisasa has been preferred to cultivate more in recent years due to the strong resistant to disease, growing fast, increasing market demand and the normal taste. The Mnyenyele is the type of banana which was most preferred by villagers, trading at high prices in the market. Although cultivation of Mnyenyele is quite difficult, it is considered that the cultivation will continue in the future even small amount. The Ndishi has been selected for the cultivation due to the easy for cultivation, the resistant to disease, the good characteristics for making brew and stable demand for traditional usage. The Chagga people has maintained several types of banana and developed own banana culture based on both their own experience and current situation. 5. Conclusion In this study, factors related to the policy decision on traditional agriculture and banana cultivation in Mt. Kilimanjaro were evaluated by recording observations, conducting interviews and performing on-site trials. The results showed that land management of Chagga's traditional agriculture was directly related to the households conditions such as farm size, yield of crops, character of each crops, domestic economy, family size and personal taste, and the socio-economic conditions such as population increase, market price, market demand and development of transportation network and technology. The traditional agricultural style centered on banana-coffee cultivation and livestock breeding based on the organic materials cycling seems to be changing with decline of coffee cultivation due to decreased coffee prices in the global market and increased pesticide price. On the other hand, the banana cultivation is considered to continue due to stable consumption among the village and stable cash income from the market. The results of this research also showed how the Chagga people understand each type of banana deeply. They have selected banana type for cultivation based on ease of cultivation, market demand, characteristics of each bananas and personal preference. However, the demand for maize for daily food was increasing more and more in the study site. The increasing of demand for maize may resulted in increase of maize cultivation even in the home garden, and it would expand in the future due to the decreasing of kikamba size. Expansion of maize cultivation in the home garden is directly related to the declining of banana-coffee cultivation. As a result, there is a concern that the traditional agriculture system based on cycling of organic resources between banana cultivation and livestock breeding will be changed in the future.
Acknowledgments
We thank Professor M. Kilasara, and staff of Sokoine University of Agriculture for support in Tanzania. This work was supported by grants from the Global Leadership Training Programme in Africa (GLTP) of University of United Nation in Japan. 1. 2. 3. 4. 5. 6. 7. 8. Fernandes, E.C.M., O'Kting'ati, A., Maghembe, J., 1984. The Chagga homegardens: a multistoried agroforestry cropping system on Mt. Kilimanjaro (Northern Tanzania). Agroforestry Systems. 2, 73–86. Globally Important Agricultural Heritage Systems (GIAHS). http://www.fao.org/giahs/en/ Soini, E., 2005. Land use change patterns and livelihood dynamics on the slopes of Mt. Kilimanjaro, Tanzania. Agricultural Systems. 85, 306–323. Soini, E., 2005. Changing livelihoods on the slopes of Mt. Kilimanjaro, Tanzania: Challenges and opportunities in the Chagga homegarden system. Agroforestry Systems. 64, 157–167. Mowo J. G., Janssen G. H., Oenema O., German L. A., Mrema J. P., ShemdoeSoil R. S., 2006. Soil fertility evaluation and management by smallholder Soil fertility evaluation and management by smallholder, Agriculture, Ecosystems and Environment, 116, 47–59. Hemp A., 2006. The banana forests of Kilimanjaro: biodiversity and conservation of the Chagga homegardens, Biodiversity and Conservation, 15, 1193–1217. Zech, M., 2006. Evidence for Late Pleistocene climate changes from buried soils on the southern slopes of Mt. Kilimanjaro, Tanzania. Palaeogeography, Palaeoclimatology, Palaeoecology. 242, 303–312. Kubo R. and Kilasara M., 2016. Brewing technique of mbege , a banana beer produced in northeastern Tanzania, Beverages, 21.
Fig. 1. Map of the study site on Mt. Kilimanjaro in Tanzania. Figure 2. Income from selling bananas, coffee, maize and beans in home garden, and maize(K) and beans(K) Figure 3. Financial balance of income from kikamba and expenditure for kikamba (n=23) Figure 4. Frequency of appearance of banana, maize and rice to daily meal (n=100)
Appendix 2. Tasting test sheet Tasting Test Name: A
B lc
Ranking Standard (   ) / A (   ) / B (   ) / C (   )
I'd like to contribute to improving livelihood in Africa and SDGs as a researcher of soil and agriculture. I'm interested in the activity by the United Nation because their practices are all for improving the whole world. First of all, I'd like to appreciate the kindness and understanding of all villagers in my study site for my education and research. They have helped and encouraged me so much. Without them, I believe that I could not continue my research in Africa. Secondly, I realized that local people know well about their land. Therefore, it is important to trust them. Though, it depends on the situation. At last, all practices including daily life and research activity in Africa need much more time to achieve than we predict. Because facilities, transportation…etc (I spent whole a day to find out one plus driver in village!!) were not substantial, we needed to devise ways and means. It is sometimes very difficult being in a limited environment and stressful, but it made me improved and a tougher researcher. I could improve my adaptation capacity after I faced to many challenges, from small challenges (how to make a fire by firewood) to big challenges (how to make an effective interview for villagers). Incidentally, in Tanzania, since the president changed in 2015, various things have changed a lot. Everything has been much more strict, complicate and expensive for foreigners. I learned through my own experience that even researcher had suffered from such kind of changes which were brought by internal political and economic issues. Through this research, I am more interested in the traditional agriculture in Africa than before. Though I only have an experience in Tanzania, there are so many types and methods of traditional agriculture in the world, especially in Africa. As SDGs showed, the necessity of building sustainable agriculture is growing worldwide regardless of developed countries or developing countries. Since small-scale agriculture including traditional agriculture and family agriculture plays a critical role in sustainable agriculture, therefore further understanding of the function and ability of small-scale agriculture operated in various areas is required. I fell the holistic understanding of the relationship between the livelihood and their agriculture will become much more important in the future. Therefore, I'd like to continue to research about the traditional agriculture from the point of view of soil, agriculture and social science. Finally, I would like to feedback to them what I studied and learned in Africa to contribute improving their livelihood and environment. Through this research and life experiences in Africa, I really realized that I could not live alone and my research would be achieved only with the cooperation of the local people. All experiences including both success and challenges in Africa must be food for your future.