Production de litières et apport de bioéléments de quatre espèces fruitières locales des hautes savanes guinéennes du Cameroun

1 RÉSUMÉ Dans la perspective de contribuer à la gestion saine des agrosystèmes des hautes savanes guinéennes de Ngaoundéré, les litières ont été collectées sous 4 espèces fruitières locales, puis certains bioéléments ont été dosés dans la litière foliaire. Le dispositif expérimental exploité était un bloc complet randomisé à 4 répétitions. Les traitements correspondent aux 4 essences et les répétitions aux quatre localités. L’unité expérimentale était constituée de 4 arbres. La litière totale produite est de ,5541kg/m²/an. La litière foliaire (0,3745kg/m²/an) est la plus importante source de matière organique du sol. Cette production de litière varie significativement suivant les espèces (P˂0,000). Les espèces sont riches en calcium, mais pauvres en phosphore. Ximenia americana est l’espèce la plus riche en bioéléments (2378,12mg/100g de MS). X. americana (665,82mg/100g de MS) et Parkia biglobosa (354,47mg/100g de MS) sont les espèces les plus riches en éléments fertilisants. Ces résultats montrent que ces espèces fruitières produisent une litière foliaire fertilisante. Leur intégration dans les agrosystèmes serait très bénéfique pour la restauration des sols. Néanmoins, il serait nécessaire de suivre la dynamique de ces bioéléments dans les sols. ABSTRACT In In order to contribute to the healthy management of agro systems of the high Guinean savannahs of Ngaoundere, the litter of four local species of fruits tree was collected and certain bio elements were measured. A complete block randomized experimental device of four replications was used. Four treatments were considered and corresponded to the four local species of fruits trees tested. Each locality was considered as a replication. In each locality, four trees of each species were considered. The total litter produced was 0.5541kg/a/year. The foliar litter was the most important source of soil organic matter with 0.3745kg/a/year and varied significantly according to the species (p<0.000). All the species tested were rich in calcium and pover in phosphorus. Ximenia americana was the richest species in bio elements with 2378.12mg/100g of dry matter. X. americana and Parkia biglobosa were the richest species in nutrient with 665.82mg/100g and 354.47mg/100g of dry matter respectively. These results shown that, these species of fruit trees produce a fertilizing foliar litter and their integration in agro systems could contribute to soil restoration. Nevertheless, it would be necessary to monitor the dynamics of these bio elements in soils.

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Soil Restoration Practices Effects on Priming Effect Intensity and Carbon Fluxes

10.21203/rs.3.rs-1007330/v1 ◽

2021 ◽

Author(s):

Abdourhimou Amadou Issoufou ◽

Bachirou Hamadou Younoussa ◽

Sabiou Mahamane ◽

Idrissa Soumana ◽

Garba Maman ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Priming Effect ◽

Critical Role ◽

Carbon Fluxes ◽

Soil Restoration ◽

Strong Impact ◽

Priming Effects ◽

C Cycle ◽

Restoration Practices

Abstract BackgroundThe decomposition of soil organic matter (SOM) is one of the most important processes influencing the global carbon (C) cycle, the physico-chemical characteristics of soils, the mineralization of nutrients for plant growth and soil food webs. Yet, priming effects are considered to be large enough to influence ecosystem carbon fluxes. Here we have tested the effects of soil restoration practices on priming effect and carbon fluxes.ResultOur results suggest that indirect effects are such as altered stabilization of older C associated with the increased inputs of fresh plant inputs (‘priming’) add uncertainty to the prediction of future soil C responses. Far ahead restoration influence the amount and composition of the decomposer organisms, including soil fauna, as well as the soil microbial community, by inducing up to more CO2 emission with fresh millet straw addition in fresh state than pre-decomposed one. Restoration had a very strong impact (increase by 22.7%) on basal soil organic matter mineralization but not on priming effect. The PE of non-restored site was lower than that of restored site by 14.9–22.7%; the lowest mineralization per unit carbon was recorded in the non-restored. Through the “4 per 1000” initiative, it has been very recently demonstrated that priming effect could have a noticeable impact on soil carbon sequestration. ConclusionWe have shown in our study that the degraded soil played a dominant positive role in the soil organic carbon mineralization. Our results provide solid evidence that SOC content plays a critical role in regulating apparent priming effects, with important implications for the improvement of C cycling models under global change scenarios.

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The yield values of densimetric fractions from typical chernozems of different land use types

Dokuchaev Soil Bulletin ◽

10.19047/0136-1694-2020-103-85-107 ◽

2020 ◽

pp. 85-107

Author(s):

Yulian R. Farkhodov ◽

N. V. Yaroslavtseva ◽

M. A. Yashin ◽

S. F. Khokhlov ◽

B. S. Iliyn ◽

...

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Soil Restoration ◽

Land Use Types ◽

Typical Chernozems ◽

Soil Biochemistry ◽

Yield Values ◽

Sodium Polytungstate ◽

Heavy Liquids

One of the most justified and applied approaches to isolating pools of soil organic matter is fractionation in heavy liquids. The main problem with this approach is rather large losses in the separation of fractions at the stage of washing fractions from heavy liquids. The paper presents a densimetric fractionation protocol that can significantly reduce these losses. It is suggested to use 0.001 M HCl for washing. This approach, in comparison with distilled water, allows reducing losses of weight from 15 to 5% and of carbon from 7.5 to 2.5%. The paper provides a detailed protocol, used by the Laboratory of Soil Biochemistry of V.V. Dokuchaev Soil Science Institute, to isolate four densimetric fractions using sodium polytungstate solutions: free and occluded SOM with a density of <1.6 g/cm3, occluded SOM – of 1.6–2.0 g/cm3, and a mineral residue with a density >2.0 g/cm3. In the work we used samples of typical chernozems of different land use types. It was shown that the processes of soil restoration and degradation significantly affect the content of light occluded soil organic matter.

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