Low crop yields are often explained by unfavourable rainfall conditions, the natural poverty of the soil in terms of nutrients and the low use of fertilisers. In order to find appropriate solutions for the sustainable management of soil fertility, a study was carried out on the Fertility Maintenance Trial (FTM), an experimental system established in 1960 in central western Burkina Faso, where organic and/or mineral fertilisation regimes combined with crop rotations have been tested. The approach of this study consisted of a synthesis of existing agronomic data from 2011-2019 on the three (03) crop rotations. Soil samples were taken from a depth of 0-20 cm for physico-chemical analysis. We also measured yields on the cotton and sorghum plots during the 2018 and 2019 seasons. The results show that yield variability can be attributed not only to fertilisation, but also to crop rotations and the annual rainfall recorded over the period. The sorghum-cotton and sorghum-cowpea rotations produced the highest average sorghum yields, at 547 kg.ha-1 and 642 kg.ha-1 respectively. Sorghum monoculture recorded the lowest sorghum production. Chemical analyses revealed higher phosphorus use in the sorghum-cowpea rotation compared with the other rotations. The study of cropping system efficiency also revealed the role of legumes in crop rotations in maintaining and preserving soil fertility. In addition, we recommend integrated soil fertility management (organic and mineral fertilisation, crop rotations, etc.) for sustainable management of productive capital on cotton farms in Burkina Faso.

The diagnosis of fertility is a prerequisite for the formulation of balanced and site-specific fertilizer recommendations. To do this, omission trials were set up on 60 plots in the Sourou Valley. The trials were divided into Hydromorphic tropical eutrophic ferruginous brown soils and Vertic tropical eutrophic ferruginous brown soils. Each trial included 06 treatments: 0N-0P-0K, 0N-30P-40K, 120N-0P-40K, 120N-30P-0K, 120N-30P-40K and 120N-30P-40K + 2.5 t.ha-1 of organic matter. Grain and straw yields, soil chemical characteristics and plant nitrogen, phosphorus and potassium exports were determined. The results showed that Vertic tropical eutrophic ferruginous brown soils are slightly richer in carbon, nitrogen and phosphorus than into Hydromorphic tropical eutrophic ferruginous brown soils. Indeed, the initial nitrogen, phosphorus and potassium contents calculated from the exports were respectively 71.20 kg.ha-1, 30.02 kg.ha-1 and 187.19 kg.ha-1 for the Vertic tropical eutrophic ferruginous brown soils, against 52.47 kg.ha-1, 19.10 kg.ha-1 and 159.62 kg.ha-1 for the into Hydromorphic tropical eutrophic ferruginous brown soils. Furthermore, the results showed that nitrogen and phosphorus are the two limiting nutrients for rice production on these two soil types. The internal N use efficiency was 80.59 kg grain.kg-1 N on into Hydromorphic tropical eutrophic ferruginous brown soils and 60.09 kg grain.kg-1 N for Vertic tropical eutrophic ferruginous brown soils. The results of this diagnostic will be used as a basis for the formulation of balanced and site-specific fertilizer recommendations.

Understanding farmers soil fertility management practices allow to conduct efficiently agricultural development programs and appropriate researches. This study was conducted in western Burkina Faso, in the Hauts-Bassins and Boucle du Mouhoun regions. The objective is to determine agricultural production systems and farmers soil fertility management practices on corn farms. The analysis of diversity was carried out by surveys in the form of individual interviews administrated to 100 maize productors. Ultimately, depending on production systems, farming practices and geographic position, three types of maize farms have been identified: scrubland fields which represent 81% of maize farms and which have the lowest yields (1784 ± 640 kg / ha); the village fields representing 12% with a yield of 2250 ± 899 kg / ha and finally the shebang fields representing 7% with a yield of 2529 ± 787 kg / ha. Among the cultural operations, plowing and weeding are carried out by harnessing. Regarding organic fertilization, 43.7% of farmers use compost made from various domestic substrates. The fertilization regimes in the scrubland fields, village fields and shebang fields were respectively 12, 6 and 4. The fertilization regime of 150 kg / ha of NPK + 50 kg / ha of urea corresponding to the dose recommended on cotton is the most common. The high number of fertilization regimes negatively influenced the yields in the bush fields. Thus, the yield by type of field was strongly correlated with farmers organo-mineral fertilization practices (r> 0.60). The intakes of the doses of NPK are fractionated unlike those of urea. The main source of fertilizer supply for farmers (67.8%) is cooperative credit.

Burkina Faso's agricultural systems are space-intensive and are characterized by their low productivity. In the past, a shifting cultivation system with fallow was practiced by farmers. With demographic pressure and the migratory phenomenon, this traditional system of regeneration and management of soil fertility has almost disappeared. The search for manure formulas adapted to the main crops of the East was the object of our study. To this end, a participatory evaluation using the matrix scoring method made it possible to establish the value of these combinations of manures. The study covered thirty (30) fields in leached tropical ferruginous soils with a sandy clay texture (Kotchari, Pentinga). The participatory evaluation by producers made it possible to assess the probability of acceptance of several manure formulas by them. This probability of accepting the manure options generally reflects the performance of a combination of manures and the producers' preference for this manure. For the producer, yield, economic reproducibility, accessibility to inputs and valuation of labor constitute criteria for the adoption or rejection of a manure formula. The cultural weight of speculation is also a criterion for adopting a fertilizer formula. It emerges from this participatory evaluation: the relevance of the organo-phosphate manure formulas (5t / ha fo + 50Kg / ha Urea 5t / ha; fo + 200Kg / ha BP + 50Kg / ha Urea and 5t / ha fo + 200Kg / ha BP + 50Kg / ha Urea + 150Kg / ha NPK on sorghum; 200Kg / ha + 100Kg / ha NPK BP 200Kg / ha BP + 50Kg / ha Urea). It is therefore advisable to produce enriched composts with a view to intensification. Organo-mineral manure is essential for the peasants in a perspective of sustainable intensification and in their agro-socio-economic criteria. The agronomic effectiveness of rock phosphate associated with mineral fertilizers (Urea, NPK especially) on cowpeas is perceived and seems a less expensive alternative.Judicious management of local resources (natural phosphates, organic matter) combined with good cultivation techniques (crop associations and rotations) can be an alternative to the use of imported fertilizers and an approach for the development of sustainable agriculture.