Comparative effects of Acacia albida and Kigelia africana trees on soil characteristics in Zambezi riverine woodlands

1991 ◽  
Vol 7 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Kevin M. Dunham

ABSTRACTSoil nutrient concentrations under Acacia albida and Kigelia africana trees growing in Zambezi riverine woodlands were compared with soils in the open, beyond tree canopies. Concentrations of N, C, P and K were higher under tree canopies. Concentrations of Ca and Mg were unchanged. Soils were slightly more acid under A. albida trees relative to open soil, but were less acid under K. africana. Soil P concentration was higher under K. africana than under A. albida. Otherwise, the two species had similar effects on soil fertility. Despite previous claims, A. albida is probably no more efficient at increasing soil fertility than other savanna trees.

2015 ◽  
Vol 12 (22) ◽  
pp. 18973-18998 ◽  
Author(s):  
X. Yang ◽  
X. Chi ◽  
C. Ji ◽  
H. Liu ◽  
W. Ma ◽  
...  

Abstract. Concentrations of leaf nitrogen (N) and phosphorus (P) are key leaf traits in ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on trees and grasses, leaving the knowledge gap for the stoichiometric patterns of shrubs. In this study, we explored the intra- and interspecific variations of leaf N and P concentration in relation to climate, soil property and evolutionary history based on 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China expanding 46.1° (86.7–132.8° E) in longitude and 19.8° (32.6–52.4° N) in latitude. The results showed that leaf N concentration decreased with precipitation, leaf P concentration decreased with temperature and increased with precipitation and soil P concentration. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentration was less conserved than leaf N concentration. At community level, climates explained more interspecific, while soil nutrient explained more intraspecific, variation of leaf nutrient concentrations. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits.


1984 ◽  
Vol 14 (6) ◽  
pp. 794-802 ◽  
Author(s):  
Ralph E. J. Boerner

To determine how soil nutrient availability influences nutrient cycling, fluxes of nutrients through litterfall and decomposition were determined for four forest stands similar in all respects except soil nutrient availability and microclimate, within Neotoma Valley, a small watershed in southern Ohio, U.S.A. Litterfall varied from 10 to 60% among sites while nutrient concentrations and masses in new leaf litter varied as a function of extractable soil nutrient levels. Mass loss from litterbags was significantly higher in more fertile sites. Stepwise regression indicated that initial litter nitrogen and phosphorus concentrations were strongly correlated with relative decomposition rate while lignin concentration and microclimate variables were only correlated weakly. Thus, both litterfall nutrient transfers and decomposition rates were under the control of soil nutrient levels. Nitrogen was immobilized in litter at all sites during the 1st year of decay; litter from more fertile sites mineralized nitrogen during the 2nd year, while that from less fertile sites continued to immobilize nitrogen. Phosphorus and calcium mineralization rates were strongly correlated with the availability of these elements in the soil. Magnesium and potassium were leached rapidly from litter; amounts mineralized were correlated with amounts in litterfall. Interrelations among soil fertility, litterfall, and nutrient mineralization, as well as litter redistribution, are discussed as processes important in the development and maintenance of the soil fertility gradient in this watershed.


2013 ◽  
Vol 29 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Hilton G. T. Ndagurwa ◽  
John S. Dube ◽  
Donald Mlambo

Abstract:This study investigated the effects of mistletoe infection on N cycling in a semi–arid savanna, south-west Zimbabwe. We established five plots (10 × 10 m) which each included three large canopy-dominantAcacia karrootrees infected by one of three mistletoes (Erianthemum ngamicum,Plicosepalus kalachariensisandViscum verrucosum) and non-infectedA. karrootrees. In each plot, we measured litterfall, litter quality (N, phenolics, tannins and lignin), soil nutrient concentrations and N transformations beneath tree canopies. Soil N, P and Ca were greatest beneath trees infected byP.kalachariensisthan beneath non-infected trees. Litterfall and litter N returns were 1.5, 2 and 1.4 times more beneathA. karrootrees infected byE.ngamicum,P.kalachariensisandV. verrucosum, respectively. Mineral N increased with mistletoe infection but did not exceed 20%. Soil N transformations were greater beneath trees infected byE.ngamicum(> 40%), and lower beneath trees infected byP.kalachariensis(<50%) andV.verrucosum(<48%) than beneath non-infectedA. karrootrees. Soil N transformations were negatively correlated with condensed tannins, lignin and lignin : N. We conclude that the improved N concentration can increase resource heterogeneity, which may alter the ecosystem structure and functioning in the semi-arid savanna.


1980 ◽  
Vol 58 (14) ◽  
pp. 1601-1606 ◽  
Author(s):  
P. E. Pope

Inoculation of Platanus occidentalis seedlings with Glomus fasciculatus significantly increased plant dry weight and foliar phosphorus (P) concentration when compared with the uninoculated control. After 12 weeks inoculated seedlings were 73% taller and 200% greater in total dry weight. The largest dry weight increase was recorded for foliage (212%) followed in order by stem (202%) and root (171%). Averaged overall nutrient treatments, foliar P concentration was 22% greater for the inoculated seedlings. Nutrient regimes representing 1×, 2×, and 4× Hoagland's No. 2 solution and a control significantly influenced seedling height, dry weight, percentage of foliar N, P, and K, and the degree of root colonization. Maximum growth and foliar nutrient concentrations were associated with the 2× Hoagland's nutrient regime followed in order by the 4× and 1× nutrient treatments and the control. Degree of root colonization by G. fasciculatus increased from 42% of the root length in the unfertilized control to 48% at the 1× Hoagland's regime and sharply declined at the 2× and 4× levels. Total dry weight of inoculated seedlings was significantly greater than the noninoculated control at each nutrient level. Incremental differences were 2.71, 4.03, 4.37, and 3.08 g for the control, 1×, 2×, and 4× Hoagland's nutrient regimes, respectively. Seedling growth attributed to G. fasciculatus is directly related to degree of mycorrhizal colonization and inversely related to the amount of extractable soil P.


2004 ◽  
Vol 84 (3) ◽  
pp. 323-332 ◽  
Author(s):  
Stefanie von Westarp ◽  
Hans Schreier, Sandra Brown ◽  
P. B. Shah

Agricultural intensification in the Nepalese Middle Mountains has caused concern that soil inputs are insufficient to meet the higher nutrient demands of increased crop rotations, that increased chemical fertilizer dependency will cause soil acidification, and that soil fertility will decline. To examine changes in soil fertility dynamics over time and between land-use groups soil samples, farm surveys, and nutrient budgets were determined for less intensive irrigated and rainfed sites in 1994 and for intensive irrigated and rainfed sites in 2000 in the Jhikhu Khola watershed. Changes in fertilizer policy and in cropping rotation (introduction of potatoes and tomatoes and a decline in the use of a pre-monsoon fallow) have contributed to unbalanced and inadequate soil nutrition. Farmers in 2000 used significantly more compost and fertilizer (particularly diammonium phosphate) than in 1994. In irrigated sites, a significant increase in available soil P, a significant decline in exchangeable soil K, and a decline in base cation content was observed in sites sampled in 2000 versus 1994. Farmers intensively cultivating irrigated land need to address exchangeable soil K deficits, while reducing excess P inputs and taking measures to reduce the potential for soil acidification. In contrast, intensive rainfed sites have large surpluses in N, P, and K budgets for sites sampled in 2000, with significant increases in soil K, base saturation, and available soil P between 1994 and 2000. Given current crop yields, soil inputs to rainfed sites could be reduced to minimize unnecessary economic expenditures and eutrophication problems without depleting the soil nutrient pool. Key words: Agricultural intensification, soil fertility, phosphorus, potassium


2019 ◽  

<p>In order to investigate the effect of treated wastewater on heavy metals and fecal coliform in plant and soil, a field experiment was conducted in RCBD with three treatments in four replications during 2016-2017 in Borkhar, Isfahan (Iran). Treatments including well water, semi-treated wastewater and combination of well water and wastewater were applied in consecutive cultivation of wheat and forage corn. The amount of heavy metals in the soil did not change after two seasons of wastewater application compared to well water. The amount of fecal coliform in both plants was increased in the irrigation water treatment compared to the well water, which was more evident in the corn plant, which is related to the high moisture content of this plant at harvest stage. Due to the improvement of soil nutrient concentrations after two seasons of continuous application of wastewater and no increase in the amount of heavy metals in the soil, the use of wastewater for agricultural production is permissible. But according to the fecal coliform index, it is recommended not to be used for the production of crops harvested at high humidity and conditions for the survival of pathogens.</p>


2008 ◽  
Vol 88 (2) ◽  
pp. 363-366 ◽  
Author(s):  
K. R. Sanderson ◽  
L. J. Eaton

Pressure on growers to protect the environment and reduce input costs has increased the need to more effectively use fertilizers. Two experiments were conducted to evaluate the response of wild blueberries to soil-applied P on loamy sand to sandy loam Orthic Podzol soils in Prince Edward Island over three cropping cycles from 1992 to 1997. The sites had soil test (Mehlich-3) P levels from 33 to 44 µg P g-1, which are rated as L- for blueberries in the PEI Soil and Feed Testing Laboratory Standards. Treatments consisted of soil-applied P at 0, 10, 20, 30 and 40 kg ha-1 applied to the same plots in the sprout year in each of three consecutive cropping cycles. There was a positive linear relationship between application rate of P and extractable soil P and leaf tissue P concentration. Over the 6 yr of the study, soil extractable P increased on average 1.1 µg P g-1 for each kg of soil-applied P compared with the control where no soil P was applied. Increases in levels of tissue P concentration were less dramatic. Plant growth and yields were not affected by rate of soil-applied P fertilizer. This study indicates that on sites with low soil test P, application of soil-applied P did not benefit wild blueberry production. By conserving P fertilizer, growers can also reduce the potential for environmental damage caused by the buildup of soil P. Key words: Phosphorus, soil and leaf nutrient concentrations, wild blueberry, Vaccinium angustifolium Ait., yield


Author(s):  
Luitgard Schwendenmann ◽  
Beate Michalzik

Kauri dieback, caused by Phytophthora agathidicida, is an ecosystem disturbance that poses a recent threat to the survival of kauri (Agathis australis) forests in New Zealand. Throughfall and stemflow play an important role in meeting the nutrient requirements of kauri forests. However, the effects of kauri dieback on canopy nutrient deposition remain unknown. Here we measured throughfall, stemflow and forest floor water yield and nutrient concentrations and fluxes (potassium, calcium, magnesium, manganese, silicon, sulphur, sodium, iron) of ten kauri trees differing in soil P. agathidicida DNA concentration and health status. We did not observe an effect of soil P. agathidicida DNA concentration on throughfall and stemflow water yield. Throughfall and forest floor nutrient concentrations and fluxes tended to decrease (up to 50%) with increasing soil P. agathidicida DNA concentration. Significant effects were found for potassium and manganese fluxes in throughfall, and calcium and silicon fluxes in forest floor leachate. The decline in nutrient input will have implications on plant nutrition, tree health and susceptibility to future pathogen infection in these ecologically unique kauri forests. Given our findings and the increasing spread of Phytophthora species worldwide, research on the underlying physiological mechanisms linking dieback and plant-soil nutrient fluxes is critical.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jerome A. Dogbatse ◽  
Alfred Arthur ◽  
Godfred K. Awudzi ◽  
Amos K. Quaye ◽  
Sampson Konlan ◽  
...  

Sustainable cacao cultivation in Ghana has been seriously hampered by high seedling mortality due to the low soil fertility of lands used for the establishment of new cacao farms. Alleviating the low soil fertility to enhance sustainable cacao cultivation requires the use of fertilizers. A study was therefore conducted at the Cocoa Research Institute of Ghana to determine the effect of integrated application of poultry manure (PM) and sulphate of ammonia (SOA) fertilizers on survival, growth, and nutrient uptake by cacao seedlings under marginal field conditions. A randomized complete block design with four replications was used to evaluate the effects of six treatments. Traits assessed were percentage survival, height, trunk cross-sectional area (TCSA), and nutrient uptake. Results from the study showed no significant differences in soil N and K among the treatments. PM-amended plots had significantly higher soil P than nonamended control and SOA alone. Seedling survival rate ranged from 73.3 to 89.3% with a higher proportion of surviving plants in PM amended soils. The application of PM alone and its combination with SOA improved growth. Cacao trees of T4 (75% recommended dosage of SOA + PM) had the largest TCSA increment, which was significantly different from the other soil treatments. Leaf nutrient concentrations in cacao of T4 were higher than the other soil treatments. It was therefore concluded that T4 could be used during cacao establishment in marginal areas for improved plant survival and growth.


2007 ◽  
Vol 23 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Israel Cárdenas ◽  
Julio Campo

The tree Lysiloma microphyllum (Fabaceae) dominates in the seasonally tropical dry forests of central Mexico. In this study foliar N and P concentrations (on leaf mass basis), foliar N and P resorption efficiency and proficiency, as well as the decomposition of senescent leaves of L. microphyllum were studied in primary and in regenerating, secondary seasonally tropical dry forests. Our study included an area of early successional forest (10 y old), with phosphorus-poor soils and comparatively abundant nitrogen, an area of late-successional forest (∼60 y old), in which soil P and N were comparatively abundant, and an area of primary forest, in which soil P was comparatively abundant and N was less abundant than in the secondary counterparts. N and P concentrations in mature leaves varied across forests, reflecting soil nutrient availability. Nitrogen concentration in senescent leaves did not change among sites, which led to very different patterns of N resorption. In contrast, P concentration in senescent leaves was lower in the early than in late-successional and primary forests, which resulted in similar patterns of resorption. Leaf decomposition increased from 70% mass loss in the first year in the early successional to ∼80% in the same period in late-successional and primary forests. The element loss during decomposition change across forests in the following order: for N, early successional = late-successional > primary forest, and for P, primary forest > late-successional > early successional forest. Overall, the pattern of variation in leaf chemistry and nutrient release on the forest floor among sites is consistent with soil nutrient availability along this sequence, while decomposition rate may be related with the P concentration in senescent leaves.


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