Kring Sveriges kuster hamnar tång och sjögräs (även kallad släke) som ruttnar, sprider dålig lukt och som läcker närsalter tillbaka till havet vilket kan bidra till en ökad lokal övergödning. Ett område som är särskilt drabbat av stora mängder släke är sydöstra Sverige inklusive landskapen Skåne, Blekinge, Öland och Gotland. Släke har tidigare använts inom jordbruket som gödningsmedel på grund av dess näringsrika innehåll men med införandet av konstgödslet har användningen av släke minskat. Denna studie sammanställer data från rapporter kring Sveriges sydöstra kust för att kartlägga hur kadmiumhalterna kan variera beroende på plats och tid. Dessutom utförs beräkningar för att bedöma om släke eventuellt skulle kunna integreras i dagens jordbruk. Resultaten visade att 22 av 104 insamlade värden av kadmiumhalter överstiger gränsen för biogödsel och avlopsslam på 2 mg Cd /Kg TS samt att det finns lokala skillnader angående kadmiumhalter. Beräkningarna visade att släke kan troligen ersätta fastgödslet som används idag på grund av liknande näringsinnehåll. Tillgången till släke begränsar däremot hur väl släke kan ersätta mineralgödslet och fastgödslen. Dessutom överstiger kadmiumtillförseln till åkrarna den tillåtna gränsen på 0,75 g/ha. Slutsatsen blir därmed att släke inte bör användas ensamt för att bidra med näring till matgrödor på grund av dess höga kadmiuminnehåll. Istället kan det användas till icke matgrödor eller möjligtvis kombinera mineralgödsel med släke för att hålla kadmiumhalterna i styr, samtidigt som eutrofieringen i Östersjön förmildras. / Around the coasts of Sweden there is a distribution of macroalgae that rots which causes it to smell bad and it also leaks nutrition back to the ocean which causes a growth in local eutrophication. Especially the southern eastern part of Sweden is affected by this, including the landscapes Skåne, Blekinge, Öland and Gotland. These macroalgaes have previously been used within agriculture as fertilizer because of its high nutritional content but the introduction of inorganic fertilizers has decreased the use of macroalgaes. This study compiles the data from reports gathered on the southeastern coasts of Sweden to map out how the concentrations of cadmium can vary depending on position and time. Furthermore, calculations were made regarding the potential replacement of macroalgae with different types of manure by comparing the amount of nutrients that each fertilizer contains. The results showed that 22 of 104 collected values of cadmium concentrations exceeded the limit of 2 mg Cd/Kg TS and that there are local variations when it comes to cadmium content in macroalgaes. Calculations showed that the macroalgae can probably replace the manure from cow and pig, mainly because of its similarities in nutrient contents. The limiting factor to how well the inorganic fertilizer can be replaced is the amount of macro algae on the coasts - there are small amounts. The infusion of cadmium however is too large and exceeds the limit of 0,75 grams per acre. The conclusion is therefore that macroalgae should not be used alone for food crops as the cadmium levels are too high. It can instead be used for non-food crops or combine the macroalgae with inorganic fertilizers to keep the cadmium levels low while also mitigating the eutrophication of the Baltic sea.

Climate change and weather phenomena like the El Niño-La Niña Southern Oscillation aremaking agriculture increasingly vulnerable in the Global South. In Malawi, where morethan 90% of the agriculture is rain-fed, food insecurity is becoming an annual problem. Inthe past, governmental policies have focused on improving maize production, which has ledinto mono-culture and a dependency on this crop resulting in acceleration of food insecurity.To fight hunger, non-governmental organisations and international donors are now focusingon promoting cassava due to its low-input requirements and drought resistance. Althoughcassava is marketed as somewhat of ’a new discovery’ in Malawi, the root crop has beencultivated in the country for nearly as long as maize. This thesis explores the historicalecology of cassava in Malawi and its involvement in historical food crises, where it wasused as a famine crop. Nowadays, cassava is mostly promoted as a cash crop but variousconstraints are still in the way of cassava production and processing which will be examinedin this thesis. Furthermore, the thesis explores the eects of agricultural policies on cassavaand the ways in which non-governmental organisations are promoting cassava. It will alsobe shown that the perception of cassava is not unison in Malawi and that the promotionof cassava should be adapted to the specific local situations. Additionally, based on thehistorical and current experience of cassava cultivation in Malawi, the possible eectsof an increased cassava cultivation and processing on food security will be discussed, inparticular based on the three dimensions of food security: food availability, food access andfood use.

Farmers generally produce multiple crops while selectively adopting modern technologies to meet various needs. The main aim of this study is, therefore, to identify the range of socio-economic factors influencing the adoption of modern agricultural technology in multiple food crops and the corresponding impacts on productivity and food availability at the farm-level in South-eastern Nigeria. In this study, three major food crops (i.e., rice, yam and cassava) and two elements of modern technologies (i.e., HYV seeds and inorganic fertilizers) are considered. The hypotheses of the study are that inverse farm size – technology adoption, size – productivity, size- profitability and size – food availability relationships exist in Nigerian agriculture. The research is based on an in-depth farm-survey of 400 farmers from two states (251 from Ebonyi and 149 from Anambra states) of South-eastern Nigeria. Data has also been derived from surveys and interviews of ADP Program Managers and NGOs. A range of qualitative and quantitative methods including inferential statistics, bivariate probit model and regression analysis were used in order to achieve the specific objectives and test hypotheses. The results show that sample respondents are dominated by small scale farmers (81% of total) owning land less than 1 ha. The average farm size is small estimated at 1.27 ha. Farmers grow multiple crops instead of a single crop, i.e., 68% of the surveyed farmers grew at least two food crops. The level of modern technology adoption is low and mixed and farmers selectively adopt components of technologies as expected and use far less than recommended dose of fertilizers in crops. Only 29% of farmers adopted both HYV seeds and fertilizers as a package. The study clearly demonstrates that inverse farm size – technology adoption, farm size – productivity, and farm size – food availability relationships exist in agriculture in this region of Nigeria; but not inverse farm size – profitability. The bivariate probit model diagnostic reveals that the decision to adopt modern technologies are significantly correlated, implying that univariate analysis of such decisions are biased, thereby, justifying use of the bivariate approach. Overall, the most dominant determinants are the positive influence of farming experience and the negative influence of remoteness of extension services on modern technology adoption. The per capita per day level of mean food produced is 12322.74 calories from one ha of land and food available for consumption is 4693.34 calories which is higher than the daily requirement of 2000 calories. Yam is produced mainly for sale while cassava is produced for consumption. Regression analysis shows that farm size and share of cassava in the total crop portfolio significantly increases food availability. A host of constraints are affecting Nigerian agriculture, which includes lack of extension agents, credit facilities, farm inputs, irrigation, and value addition and corruption, lack of support for ADP staff and ineffective government policies. Policy implications include investment in extension credit services and other infrastructure (e.g., irrigation, ADP staff), training of small farmers in business skills, promotion of modern technology, as a package as well as special projects targeted for cassava (e.g., Cassava Plus project) in order to boost modern technology adoption in food crops, as well as improving productivity, profitability and food availability at the farm-level in Nigeria.

Ce travail aborde l’enjeu du vivrier marchand dans la lutte contre la pauvreté des ménages dans l’espace rural du département de la Mvila. L’agriculture vivrière est encore pratiquée par plus de 80% de la population active dans les villages de la Mvila. Pendant longtemps, les cultures vivrières sont exclusivement autoconsommées dans la cellule familiale. Aujourd’hui, s’il est vrai qu’une grande partie de leur production est encore destinée à cette fin, quelques ménages font progressivement du vivrier marchand une réelle ressource économique. L’augmentation de la commercialisation vivrière est souvent une réponse à la baisse du pouvoir d’achat de nombreux ménages agricoles ou à la croissance de la population urbaine non agricole. Cependant, indépendamment des motivations qui guident le choix du vivrier marchand, il semble souvent une opportunité financière qui peut contribuer à l’amélioration des conditions de vie dans les villages. Depuis 1960, l’État multiplie des tentatives visant à réduire les stéréotypes qui associent exclusivement l’agriculture vivrière à l’autoconsommation. Après la crise agricole de la fin des années 1980, la relance de la promotion du vivrier marchand s’intensifie. Pour atteindre cet objectif, il s’ensuit la légalisation des GIC et le financement de divers programmes de subventionnement et d’accompagnement des producteurs. Pourtant, dans les villages du département de la Mvila, la commercialisation vivrière évolue timidement. Et pour beaucoup de ménages, le vivrier marchand reste une source de revenus accessoire. Par conséquent, de façon générale, la contribution de cette activité à la réduction de la pauvreté rurale est encore insuffisante. De nombreuses raisons permettent de comprendre l’insuffisance des résultats de cette stratégie gouvernementale de lutte contre la pauvreté rurale. Il s’agit par exemple de la dépendance paysanne à la cacaoculture ou de la baisse des dynamiques des ménages ruraux autour de la commercialisation vivrière. Cette situation est aussi entretenue par l’absence de modernisation des appareils productifs et commerciaux des cultures vivrières. Un environnement qui entraîne une baisse des volumes, augmente les risques et diminue la rentabilité économique de cette activité. Et, malgré l’évidence de quelques dynamiques des organisations paysannes, l’ampleur des défis actuels restreint beaucoup la faisabilité des initiatives de lutte contre la pauvreté des ménages ruraux avec le vivrier marchand. / This research examines the role of food-producing trade in fighting against poverty in the rural households of Mvila division in Cameroon. Subsistence agriculture appears to be the principal production activity in the target villages 80% of the active population interviewed is involved in such activities. For a long time, self-consumption has been the main orientation of crop production. However, food-producing trade has gained a lot of economic importance these last years. By so doing farmers find alternative income source after cocoa price has dropped while the urban population, not involved in agriculture, has significantly increased. Regardless of the motivations behind the choice of farmers, food-producing trade leads to income diversification and financial power aiming at improving the living conditions of rural people. Since 1960, the central government of Cameroon has been trying to change believes that restrict food crop production to self-consumption in the households. The crucial economic crisis associated with agricultural export products led to Food-producing trade intensification. This objective has been accompanied by Common Group Initiative (CGI) encouragement and other financing subsidy bodies in the rural areas. It is however worthy noticing that, the villages of Mvila division are far to emerge in income generating activities as many households are still timid in adopting food-producing trade. Therefore, the contribution of such activities to poverty reduction is still insufficient. This kind of contradiction can be justified by several factors, including farmer dependence on cocoa farming or farmer fatigue on agriculture and marketing in general. This situation is also sustained by the lack of modernization of the productive and commercial food crop equipments. That global environment leads to decrease of agricultural production volumes and economic return while the risks increase in rural areas. Although some farmer organizations obtain good results, the scale of the current challenges greatly restricts the feasibility of rural households' poverty alleviation initiatives.