Can we use phytoliths in modern savanna soil to understand past ecosystems?

2018 ◽  
Author(s):  
Camilla Crifò Camilla Crifò
Keyword(s):  

2001 ◽  
Vol 277 (1-3) ◽  
pp. 57-68 ◽  
Author(s):  
John O. Agbenin ◽  
Peter Felix-Henningsen




2004 ◽  
Vol 68 (2) ◽  
pp. 117-125 ◽  
Author(s):  
John O. Agbenin ◽  
Peter Felix-Henningsen


2020 ◽  
Vol 57 (1) ◽  
pp. 31-46
Author(s):  
Rafaella Silveira ◽  
Thiago de Roure Bandeira de Mello ◽  
Maria Regina Silveira Sartori Silva ◽  
Ricardo Henrique Krüger ◽  
Mercedes Maria da Cunha Bustamante


1998 ◽  
Vol 34 (1) ◽  
pp. 73-83 ◽  
Author(s):  
S. O. OIKEH ◽  
V. O. CHUDE ◽  
R. J. CARSKY ◽  
G. K. WEBER ◽  
W. J. HORST

The contribution of root and leaf litter to soil nitrogen dynamics, nitrogen uptake and balance was evaluated under cereal–legume rotations in a tropical moist savanna soil. Two legumes, soyabean (Glycine max) and stylo (Stylosanthes hamata), and maize (Zea mays) as a control were grown in four farmers' fields of different native fertility in 1993. At the end of the season, soyabean grain and stover were harvested and stylo biomass was removed for fodder. At the beginning of the 1994 season levels of total mineral nitrogen at a soil depth of 0–30 cm were 75, 52 and 44 kg ha−1 following soyabean, stylo and maize respectively. Total nitrogen uptake by maize was over 25% higher following legumes than following maize. Maize yield was 20 and 24% higher when grown after stylo and soyabean than after maize in spite of the removal of the standing legume biomass from the plots. Sorghum grain yield and nitrogen uptake were not significantly affected by the previous crops. Nitrogen balance estimates indicated that loss of nitrogen, probably due to leaching, was lowest in the plots previously planted with stylo. Results indicated opportunities to integrate appropriate legume-based technologies into the farming systems based on an identification of inherent nitrogen-release patterns.



1999 ◽  
Vol 13 (4) ◽  
pp. 923-932 ◽  
Author(s):  
M. I. Bird ◽  
C. Moyo ◽  
E. M. Veenendaal ◽  
J. Lloyd ◽  
P. Frost


2002 ◽  
Vol 286 (1-3) ◽  
pp. 1-14 ◽  
Author(s):  
John O. Agbenin


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Lucien N'Guessan Diby ◽  
Bi Tra Tie ◽  
Olivier Girardin ◽  
Ravi Sangakkara ◽  
Emmanuel Frossard

Fertilization is an important management strategy of yams (Dioscoreaspp.) especially when grown in degraded soils. A field study evaluated the leaf numbers, leaf area indices, crop growth, yields, and nitrogen (N) and potassium (K) use efficiencies ofD. alataandD. rotundatain Côte d'Ivoire when grown in two contrasting soils with and without fertilizer.D. alatahad a lower number of leaves per vine, although leaf area indices were higher, and the leaves were retained for a longer period than inD. rotundata. In all situations, the yields ofD. alatawere significantly higher, and fertilizers promoted growth of shoots, roots, tubers, and, thus, final yields especially in the low fertile savanna soil. The beneficial impact of fertilizer on yields was significantly lower in the fertile forest soils. The nutrient use agronomic efficiencies indicated the impact of both N and K in promoting yields especially under nonfertilized conditions.



1976 ◽  
Vol 12 (1) ◽  
pp. 69-79 ◽  
Author(s):  
M. J. Jones

SUMMARYChanges in soil moisture and nitrate content in the top 75 cm of soil in bare and cropped plots were followed throughout the growing season in a Ferruginous savanna soil. A low leaching efficiency, of 0.38–0.66 cm/cm rainfall, was related to very slow wetting of the subsoil, a phenomenon which could be explained satisfactorily only by assuming that part of the rain passed through the profile relatively quickly in the larger pores. However, losses of fertilizer nitrate to deep drainage by this rapid percolation were only 25% of that applied, at most, the greater part remaining in the top 45 cm of soil for almost the whole growing season, thus explaining why only small responses have been obtained at this site to delayed or split applications of nitrogen.



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