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11.
B. Vanlauwe K. Aihou S. Aman B. K. Tossah J. Diels O. Lyasse S. Hauser N. Sanginga R. Merckx 《Biology and Fertility of Soils》2000,30(5-6):440-449
The impact of land use (unfertilized continuous maize cropping, unfertilized and fertilized alley cropping with maize, Gliricidia sepium tree fallow, natural fallow) on the soil organic matter (SOM) status and general soil fertility characteristics were investigated
for a series of soils representative for the West African moist savanna zone. Three soils from the humid forest zone were
also included. In an associated pot experiment, relationships between maize N and P uptake and SOM and general soil characteristics
were developed. Soils under natural fallow contained the highest amount of organic C (1.72%), total N (0.158%), and had the
highest effective cation exchange capacity (ECEC) [8.9 mEq 100 g–1 dry soil], while the Olsen P content was highest in the fertilized alley cropping plots (13.7 mg kg–1) and lowest under natural fallow (6.3 mg kg–1). The N concentration of the particulate organic matter (POM) was highest in the unfertilized alley cropping plots (2.4%),
while the total POM N content was highest under natural fallow (370 mg N kg–1) and lowest in continuously cropped plots (107 mg N kg–1). After addition of all nutrients except N, a highly significant linear relationship (R
2=0.91) was observed between the total N uptake in the shoots and roots of 7-week-old maize and the POM N content for the savanna
soils. POM in the humid forest soils was presumably protected from decomposition due to its higher silt and clay content.
After addition of all nutrients except P, the total maize P uptake was linearly related to the Olsen P content. R
2 increased from 0.56 to 0.67 in a multiple linear regression analysis including the Olsen P content and clay content (which
explained 11% of the variation in P uptake). Both the SOM status and N availability were shown to be improved in land-use
systems with organic matter additions, while only the addition of P fertilizer could improve P availability.
Received: 9 April 1999 相似文献
12.
Impact of residue characteristics on phosphorus availability in West African moist savanna soils 总被引:1,自引:0,他引:1
O.?C.?NwokeEmail author B.?Vanlauwe J.?Diels N.?Sanginga O.?Osonubi 《Biology and Fertility of Soils》2004,39(6):422-428
The role of residue characteristics in enhancing the availability of P was investigated in a greenhouse study using two soils from the northern Guinea savanna (NGS) and four from the derived savanna (DS) zones of the West African moist savanna. Eight organic residues of varying C-to-P ratio were used and maize ( Zea mays) was grown for 7 weeks. The effect of the organic residues on P availability (measured as resin P and maize P accumulation) differed among the soils. On average, the increase in resin P, calculated as {[(soil+residue)–control]/(control)×100}, was between 8% (Davié, DS) and 355% (Danayamaka, NGS). Maize P accumulation was increased by ca. 11% in Davié and Niaouli (DS) soils and 600% in Danayamaka soil. The increase in maize total dry matter yield (DMY) ranged from 2% to 649%. Residues with C-to-P ratio >200 produced lower DMY than those with lower ratios. Residue organic P (Po) extractable with 0.2 N H2SO4 (acid-Po) accounted for 92% ( P =0.0001) of the variation in DMY in a step-wise regression with residue parameters as independent variables and mean DMY as the dependent variable. The residue Po extractable with 0.5 M NaHCO3 (HCO3-Po) correlated significantly with DMY in Danayamaka and Davié soils, and with P accumulation in Danayamaka soil. The relationships between the residue Po and DMY might imply that Po fractions in decomposing residues contribute to P availability. However, the suitability of using the Po content of organic residues to predict their agronomic value with respect to P nutrition needs further evaluation. 相似文献
13.
B. K. Tossah D. K. Zamba B. Vanlauwe N. Sanginga O. Lyasse J. Diels R. Merckx 《Agroforestry Systems》1998,42(3):229-244
The moist savanna of West-Africa is characterized by a wide range of climates and soil types. The impact of the biophysical
environment on hedgerow N uptake, wood production and maize grain yield was assessed for three years in three alley cropping
trials with a selected number of hedgerow species in Glidji (Southern Togo), Amoutchou (Central Togo), and Sarakawa (Northern
Togo). Senna siamea hedgerows accumulated significantly more N in the first pruning in Glidji (129−138 kg N ha−1) and Sarakawa
(102−185 kg N ha−1) than in Amoutchou (17–26 kg N ha−1). This difference in N uptake was attributed to the infertile subsoil
in Amoutchou, which was sandy up to 1 m and had a shallow groundwater-table. The amount of N accumulated in the Gliricidia
sepium biomass varied between 38 kg N ha−1 in Glidji and 142 kg N ha−1 in Amoutchou. Averaged over all species and sites,
9 to 29% and 9 to 39% of the annual N accumulation in the hedgerow biomass is incorporated in the second, respectively third
pruning. The Gliricidia trees produced between 12 and 26 ton fresh matter ha−1 of wood and the Senna trees between 4 and 38
ton fresh matter ha−1. Maize grain yield in Glidji was not affected by treatments (3196 kg ha−1, on average). In Amoutchou,
the highest grain production was observed in the Gliricidia treatment (2774 kg ha−1 vs 1007 kg ha−1 in the control), while
in Sarakawa, the Gliricidia (3786 kg ha−1) and Senna (3842 kg ha−1) plots produced a greater grain yield than the control
plots (2123 kg ha−1). Maize yield increase in the alley cropping systems relative to the control plots was related to the
soil total N content. Top and sub-soil characteristics were shown to be an important modifier of the functioning of alley
cropping systems and should be taken into account when deciding on whether to use alley cropping and when selecting the hedgerow
species.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
14.
K. Aihou N. Sanginga B. Vanlauwe O. Lyasse J. Diels R. Merckx 《Agroforestry Systems》1998,42(3):213-227
The potential of alley cropping systems supplied with a limited amount of fertilizer to restore crop productivity on a degraded
site and to maintain crop productivity on a recently cleared, non-degraded site on ‘terre de barre‘ soils in Southern Bénin
was investigated from 1994 to 1996. Leucaena leucocephala, Senna siamea and Gliricidia sepium were used as hedgerow species.
Maize yields of the no-tree control plots dropped from the initial (1990) 401 kg ha−1 and 2181 kg ha−1 on the degraded and
non-degraded sites, respectively, to 109 kg ha−1 and 1346 kg ha−1 in 1996, even with application of a minimal amount of mineral
fertilizer. The alley cropping systems produced on average (mean of three treatments and three years) 107% more grain than
the initial 1990 values on the degraded site and 11% less grain than the initial 1990 values on the non-degraded site. Especially
the Senna and to a lesser degree the Leucaena treatment yielded consistently more grain than the control. The Senna trees
contained a larger amount of N and produced more wood during the first pruning on the degraded site (155 kg N ha−1 and 14.0
ton fresh wood ha−1) than on the non-degraded site (49 kg N ha−1 and 6.6 ton fresh wood ha−1) most likely because of differences
in subsoil fertility, as indicated by the higher clay, exchangeable bases, and N content between 60 and 125 cm cm. N accumulation
and wood production by the Leucaena and Gliricidia trees was similar in both sites (82 and 36 kg N ha−1 and 4.6 and 9.3 ton
fresh wood ha−1, respectively). When a limited amount of fertilizer is available, Senna appears to be the best choice as hedgerow
species on sites with a relatively fertile subsoil. For other soils, a N2-fixing species may be a better choice.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献