Le phosphore limite-t-il la production intensive du riz dans la plaine de Bagré au Burkina Faso ?

Le phosphore (P) est un élément important dans la nutrition minérale du riz et dans l’élaboration du rendement paddy. Des essais soustractifs ont été conduits en milieu paysan dans la plaine rizicole de Bagré au cours de trois campagnes successives pour évaluer l’effet de l’application de P sur le rendement paddy. La capacité nutritive du sol en phosphore a varié entre 7 et 15 kg P ha-1. L’application de P a augmenté l’efficacité physiologique interne de P qui a varié entre 211 et 290 kg paddy kg-1 P (moyenne 249 kg kg-1). L’efficacité agronomique de P a été de 33,7 kg paddy kg–1 de P appliqué. L’augmentation de rendement due à l’application de phosphore a été de 19%. En moyenne, 70% du phosphore total absorbé est contenu dans les grains. L’évolution du rendement paddy indique que P est le second facteur limitant dans la plaine de Bagré après l’azote. L’application de P_engrais à une dose moyenne de 30 kg P ha-1 était suffisante pour compenser les pertes dues aux exportations. Le phosphore limite la production de riz à Bagré mais son application comme engrais contribue à améliorer les rendements paddy et à compenser les pertes de P du système.Mots clés : Capacité nutritive des sols, rizières, efficacité d’utilisation de nutriments, bilan minéral

Village Baseline Study: Site Analysis Report for Segou – Cinzana, Mali (MA0109)

The village baseline study of Tongo village in the CCAFS benchmark site of Cinzana, Mali took place from 12 to 14 July 2011. Focus group discussions were conducted separately for men and women. The village has an abundance of natural resources such as savannah, grassland, ponds, farmlands and several kinds of socio-economic infrastructure. Some of the natural resources, however, are in a state of progressive degradation due to increase in human population; indiscriminate felling of trees; clearing of forests and deforestation; lack of rainfall; drought; and animal pressure

The future of food security, environments and livelihoods in Western Africa. Four socio-economic scenarios. CCAFS Working Paper no. 130.

This working paper examines the development of regional socioeconomic scenarios for West Africa’s development, agriculture, food security and climate impacts. We present four globally consistent regional scenarios framed and outlined by regional experts who crafted narratives and determined key drivers of change. Stakeholders identified the type of actors driving change and the timeline of strategic planning as the most uncertain and most relevant factors of change affecting food security, livelihoods and environments in the region. The scenarios were linked to the IPCC community’s global Shared Socio-economic Pathways(SSPs) and quantified using two agricultural economic models, GLOBIOM and IMPACT, in interaction with drivers outlined by the SSPs and guided by semi-quantitative information from the stakeholders. The quantification of the scenarios has provided additional insights into the possible development of Western Africa in the context of a global economy as well as how the agricultural sector may be affected by climate change. The scenarios process highlights the need to combine socio-economic and climate scenarios, to base these scenarios in regional expertise, and ways to make scenarios useful for policy design. The objective of this working paper is to provide scenarios for future regional development for West Africa on the future of food security, environment, and rural livelihoods as well as offer details of the multi-stakeholder scenarios development process. Using both qualitative and quantitative scenarios we provide insights into the possible development of West Africa as well as a scalable framework for regional decision makers and the scientific community to use scenarios to build and test policies to make them more robust in the face of future uncertainty. In these scenarios, strong economic development increases food security and agricultural development. Increased crop and livestock productivity may lead to an expansion of agricultural areas within the region but productivity improvements may reduce the pressure on land elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population in combination with rising incomes may lead to increases in the region’s imports. For West Africa, climate change is likely to have negative effects on both crop yields and grassland productivity, and lack of investment in agriculture may exacerbate them. The aim of the regional scenarios is provide challenging contexts for policy makers to test and develop a range of national and regional policies. To date, the scenarios have been used in a number of policy design processes which include collaborations with ECOWAS priority setting, the National Plan for the Rural Sector for Burkina Faso (PNSR), and district and national level policy processes in Ghana

Decision support tools for site-specific fertilizer recommendations and agricultural planning in selected countries in sub-Sahara Africa

Peer Revie

Influence des phosphates naturels sur la qualité et la biodégradation d'un compost de pailles de maïs

Influence of Indigenous Phosphate on Maize Straw Compost Quality and Biodegradation. Soil organic matter and phosphorus scarcities are the main constraints for intensification of crop production in Burkina Faso. To propose an adequate method to produce good quality organic matter, a study, in controlled conditions, was conducted using a Lixisol to evaluate the biodegradation of composts made of maize straw, rock phosphate, animal manure and a synthesis inoculum (SI). Composts obtained from composting maize crop residues + manure ± SI had C/N of 19 and 18, respectively. Influence of composts produced on soil CO2 production was related to the type of compost and to nitrogen application. An increase of 53% of CO2 production due to nitrogen application was observed when compost produced with manure and SI was incorporated in the soil. This increase was 118% with incorporation of the compost obtained with manure, SI and rock phosphate. These results suggest that there is potential to produce high quality organic inputs by composting maize straw in presence of rock phosphate

Gestion améliorée de la jachère par l'utilisation de légumineuses de couverture

Dans IDL-1387

Le carbone et l'azote dans les différentes fractions granulométriques d'un sol brun eutrophe tropical sous irrigation de Bagré au Burkina Faso : effets de modes d’apports différents de matières organiques et minérales.

Objective: A study was carried out to evaluate the influence of cropping systems (modes of different contributions of organic and mineral fertilizers) on the qualitative evolution of soil organic carbon and nitrogen of a tropical eutrophic brown soil under irrigation of Bagré, Burkina Faso. Methodology and results: The granulometric soil organic matter fractionation method was used and allowed to follow the qualitative evolution of soil organic carbon and total nitrogen. The results show that rice cultivation leads to reduction of soil organic carbon and total nitrogen in the upper horizons (0-20 cm) while an accumulation is observed in lower horizons (20-50 cm). In the lower horizons, the importance of accumulation depends of organic manure restitution level. Conclusion and application: Contrary to results obtained under upland cropping systems, irrigated rice cultivation leads to an accumulation of soil organic carbon and nitrogen compared to "fallow". Even complete crop residues removing in irrigated soil may result in organic carbon accumulation. This result has a great interest in organic and fertilizer management all the more reason that soil organic carbon accumulation result of lower soil organic matter mineralization. Thereby, for irrigated crops like rice which is exigent to nutrients mostly nitrogen, the combination of mineral fertilizers with organic manure well decomposed could allow a better nutrient nutrition. Furthermore, despite the production of methane, irrigated rice system could all the same contribute to atmospheric carbon sequestration.Keywords: carbon; nitrogen; accumulation; irrigated soi

Rice Bacterial Leaf Blight in West Africa: Preliminary Studies on Disease in Farmers’ Fields and Screening Released Varieties for Resistance to the Bacteria

As little information is available in Africa on Xanthomonas oryzae pv. Oryzae, a highly destructive pathogen of rice, and its relationship with released rice varieties, a disease survey and samplings were carried out in Niger, Burkina Faso and Mali which indicated a wide spread of Bacterial Leaf blight (BLB) in farmers’ fields. Sixty pure BLB isolates cultures were obtained. Pathogenecity of 4 Malian isolates against four important rice varieties revealed differences in pathogenecity among isolates and resistance of the varieties tested. The results obtained in these initial studies revealed the future research directions to increasing rice production in West Africa