Effets du scarifiage sur les propriétés du sol et l'ensemencement naturel dans une pessière noire à mousses de la forêt boréale québécoise

1996 ◽  
Vol 26 (1) ◽  
pp. 72-86 ◽  
Author(s):  
Marcel Prévost

Two types of scarification (cone and disk) were applied at two intensities (simple and double passes), in a randomized complete block design, established alongside buffer stands of spruce protective of water courses, that provided a natural seed source. Treatment effects on seedbed evolution, natural seeding of black spruce (Piceamariana (Mill.) BSP), competing vegetation, and soil physical and chemical properties were examined over a 3-year period. In situ nitrogen mineralization was also studied, using the buried-bag method. All scarification treatments created a surface horizon (0–10 cm) with 80% less organic matter content than the control treatment. However, treatments tended to loosen the exposed deep layers, creating microsites whose compactness appeared adequate for root development (1.07–1.22 Mg/m3). The organic matter loss mainly decreased exchangeable K and Mg in the surface 20 cm of scarified microsites. Scarification had little impact on total N of sampled profiles and clearcutting did not increase N mineralization with regard to the forest, during the first year after disturbance. The weak soil warming and the stability of temperatures under the unscarified humus suggest that clearcutting did not significantly enhanced microbial activity on the site. However, removal of the insulating humus layer allowed a significant summer soil warming in the furrows. Despite this, scarified microsites were characterized by N immobilization during the first growing season after treatment. However, net N production was positive during the winter period, presumably because of a N-flux phenomenon. Scarification improved black spruce regeneration by natural seeding. Three years after treatment, stocking levels reached 40 to 51% in the scarified sectors while they reached 31% in the controls, this gap being mainly attributed to the second germination year. The difference can be explained by the improved receptivity of bare mineral soil, well-decomposed humus, and mixed mineral–organic seedbeds that covered 12–20% of the scarified areas immediately after treatment. Generally, results indicate that microsites created by a light scarification are as receptive as microsites created by a severe perturbation. Finally, every scarification treatment efficiently controlled the ericaceous shrub cover during the first 3 years after treatment.

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
IGM Subiksa

Subiksa et al, 2018. Comparison Effect of Several Phosphate Contain Fertilizers to Nutrient Loss Trough Leaching on Peat Soil. JLSO 7(1): Peat soil have specific nutrient adsorption characteristics which are affected by soil pH dependent charge. Therefore, nutrient management on such soil should be done using different approach compared to mineral soil. Research on the comparison effects of several types of phosphate containing fertilizers to nutrient loss through leaching on peat soil has been carried out in greenhouse using a coulom experiment. The objective of study was to evaluate the rate of primary macro nutrient loss and look for fertilization technology which can reduced leaching rate.  The study used a randomized block design of 14 treatments with 3 replications. The treatments were complete control treatment, partial control and 4 types of P contain fertilizer, namely SP-36, NPK compound, Chrismast Island Phosphate Rock (CIRP), and Pugam each of them with 3 levels dose. The peat soil used was ombrogenous peat with hemic maturity level taken from OKI Regency, South Sumatra. Watering was done every 2 days with 350 ml ion-free water/pot. The results showed that N and K nutrients leaching, mostly was due to application rate of those nutrient, whereas type of fertilizer was not revealed significantly different. Meanwhile, P concentration in leachate water was significantly different among treatments. Leaching of P in the control treatment was very low because of P content of peat soil was low. The highest loss of P trough leaching rate was shown by the NPK treatment because NPK compound is belong to fast nutrient release fertilizer. CIRP and Pugam treatments showed low P loss trough leaching rates due to the slow release of P on CIRP and Pugam. The low leaching rates of CIRP and Pugam are also because of high content of Al and Fe as polyvalent cation that can promote new soil positive charges as site adsorption of P. It can be concluded that fertilization with a slow release type of phosphate fertilizer and contain sesquioxide as source of polyvalent cations such as CIRP and Pugam can reduced the rate of phosphate loss trough leaching.


Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 655 ◽  
Author(s):  
A. Conteh ◽  
G. J. Blair ◽  
I. J. Rochester

The contribution of cotton stubble to the soil organic matter content of Vertisols under cotton production is not well understood. A 3-year experiment was conducted at the Australian Cotton Research Institute to study the effects of burning and incorporating cotton stubble on the recovery of fertiliser nitrogen (N), lint yield, and organic matter levels. This study reports on the changes in soil organic matter fractions as affected by burning and incorporating cotton stubble into the soil. Soil samples collected at the start and end of the 3-year experiment were analysed for total carbon (CT), total N (NT), and δ13C (a measure of 13C/12C isotopic ratios). Labile carbon (CL) was determined by ease of oxidation and non-labile carbon (CNL) was calculated as the difference between CT and CL. Based on the changes in CT, CL, and CNL, a carbon management index (CMI) was calculated. Further analyses were made for total polysaccharides (PT), labile polysaccharides (PL), and light fraction C (LF-C). Stubble management did not significantly affect the NT content of the soil. After 3 years, the stubble-incorporated plots had a significantly higher content of CT, CL, and polysaccharides. Incorporation of stubble into the soil increased the CMI by 41%, whereas burning decreased the CMI by 6%. The amount of LF-C obtained after 3 years in the stubble-incorporated soil was almost double that obtained in the stubble-burnt soil. It was concluded that for sustainable management of soil organic matter in the Vertisols used for cotton production, stubble produced in the system should be incorporated instead of burnt.


2020 ◽  
Vol 17 (8) ◽  
pp. 545
Author(s):  
Jeonghyeon Ahn ◽  
Guiying Rao ◽  
Mustafa Mamun ◽  
Eric P. Vejerano

Environmental contextAssessing environmental and human health impacts of chemical spills relies on information about how chemicals move across multiple environments. We measured volatile contaminants in the air above soil saturated with water to provide estimates of air concentrations of selected chemicals released to soil from an oil refinery in Texas during Hurricane Harvey. Estimated concentrations were below recommended exposure limits, even in a worst-case scenario. AbstractThe emission of volatile organic compounds (VOCs) from soil into air is affected by soil moisture dynamics, soil temperature, solar irradiance and carbon availability. The high amount of water in soil can modify its properties, which changes how VOCs interact. We conducted a comprehensive measurement of the soil–air partition coefficient (KSA) of VOCs into water-saturated soil with both low and high water contents for polar, weakly polar and nonpolar VOCs into a mineral soil (S-clay) and soil containing a high amount of organic matter (S-om) under a water-saturated condition. Partitioning of non-polar substituted aromatics (1,2-dichlorobenzene and toluene) was sensitive to the organic matter content in water-saturated soil. 1,2-Dichlorobenzene and toluene had higher affinities to S-om than to S-clay at all investigated water contents because of their strong interaction with the organic matter in soil. KSA decreased with elevated water content only for non-polar substituted aromatic VOCs. Less hydrophobic VOCs (benzene and trichloroethylene) exhibited similar partitioning into both soils by sorbing onto the air-water interface and dissolving in soil water, while the organic matter did not affect partitioning. The weakly polar and polar VOCs (methyl tert-butyl ether and 1-butanol) showed similar partitioning into both soils by dissolving in soil water while sorption to the organic matter was significant only at high soil water contents. KSA of VOCs on soil with high organic matter content correlated strongly with psat and Koa, but not on mineral soil. Estimates of the air concentrations for a subset of VOCs released from one refinery during Hurricane Harvey in 2017 in Harris County, Texas were lower than the recommended exposure limits, even under a worst-case scenario.


2020 ◽  
pp. 124-132

An evaluation of the productivity of degraded alfisols at Makurdi and Otobi, Nigeria, using artificial desurfacing techniques (ADT) was carried out in 2012 and 2013 cropping seasons. The study was a split-split plot experiment arranged in a Randomized Complete Block Design with three replications. The soil was desurfaced at 0 – 5, 0 – 10, 0 – 15, 0 – 20 cm and the undesurfaced soil, 0 cm (control) depths. The restorative amendments were 9 t ha-1 of poultry dropping as an organic source of manure, N:P2O5:K2O as an inorganic source of manure and zero application as control. Soybean variety TGX 1448-2E and maize variety, Oba super II were used as test crop. Saturated hydraulic conductivity was significantly (P = 0.05) lower at 20 cm (29.08 cm hr-1 ), but did not differ significantly at 0 to 10 cm depths. Soil pH of 5.58 was recorded at 0 cm depth and it decreased to 5.05 at 20 cm depth. Also, organic matter content (1.71 – 1.00 g kg-1 ), total nitrogen (0.12 – 0.08 g kg-1 ) as well as CEC (7.39 – 6.24 cmol kg-1 ) recorded a significant decrease with increase in soil depth from 0 to 20 cm depths. Application of poultry manure increased total porosity and saturated hydraulic conductivity as well as organic matter content across desurfaced depths. Soybean number of leaves was significantly (P = 0.05) reduced at 4, 7, and 10 WAP with increased topsoil removal. The highest grain yield of soybean (1474 kg ha-1 ) was recorded on poultry manure treated plots which were significantly higher (p = 0.05) than other treatments. Application of poultry manure caused 20 % soybean yield reduction at 5 depth, and a 56 % reduction at 20 cm depth.


2020 ◽  
Vol 29 (2) ◽  
pp. 155-163
Author(s):  
Sk Musfiq Us Salehin ◽  
Gazi Md Mohsin ◽  
Tabassum Ferdous ◽  
Jobaed Ragib Zaman ◽  
Md Jashim Uddin ◽  
...  

Twenty soil and leaf samples from 20 orchards of mango (Mangifera indica L.) were collected from different locations of Rajshahi and Satkhira regions to evaluate soil texture, pH, organic matter, available and total nitrogen, phosphorus, potassium and sulfur of soils and the concentration of N and K in mango leaves. The pH of the soil varied from 6.3 - 7.9 and organic matter content varied from 0.72 - 3.60 per cent. The available nitrogen, phosphorus, potassium, and sulfur of the soils ranged from 190 - 510, 39 - 196, 36 - 206 and 25 - 235 mg/kg, respectively. The values of total N, P, K and S were 0.03 - 0.12, 0.022 - 0.210, 0.235 - 0.0.936 and 0.005 - 0.266 per cent, respectively. The dominant soil textural class was silty clay loam. The mean concentration of nitrogen (0.88%) and potassium (0.61%) in the leaf sample was low. The overall fertility status of the soils of Rajshahi and Satkhira regions in relation to mango cultivation is moderate. Dhaka Univ. J. Biol. Sci. 29(2): 155-163, 2020 (July)


DEPIK ◽  
2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Rugaya H. Serosero ◽  
Suryani . ◽  
Rina .

Abstrak. Penelitian ini bertujuan untuk mengetahui karakteristik habitat dan pola pertumbuhan kepiting kelapa (Birgus latro) di Takome Pulau Ternate dan Idamdehe Kecamatan Jailolo Propinsi Maluku Utara. Penelitian ini dilaksanakan pada bulan April-Juli 2014. Data yang dikumpulkan adalah tekstur substrat dengan metode pipet, penentuan kandungan nitrat danfosfat tanah dengan metode spektofotometer, pengukuran panjang + rostrum (cp+r) kepiting kelapa dan pola pertumbuhannya. Selain it juga diukur suhu udara, suhu lubang dan kelembaban udara. Hasil penelitian menunjukkan bahwa Idamdehe memiliki karakteristik pantai yang curam, bahkan di beberapa lokasi penangkapan sangat terjal, sedangkan  di lokasi Takome Pulau Ternate memiliki karakteristik pantai yang lebih landai. Tekstur substrat di lokasi Takome Pulau Ternate terdiri atas pasir (55,76 %), debu (18,4%) dan liat (25,84%) dan Stasiun Idamdehe memiliki tekstur pasir (49,17%), debu (25,61%) dan liat (25,22%)dankandungan bahan organik substrat (Total N) di Takome adalah 0,31% dan total P adalah 0,09% sedangkan di Idamdehe Total N adalah 0,19% dan Total P 0,02%. Suhu udara di lokasi Idamdehe berkisar 26-280C dan di Takome 27-280C. Kelembaban udara 73%-98% di Idamdehe dan 71%-90% di Takome. Parameter lingkungan berupa suhu udara, kelembaban udara, tekstur substrat dan kandungan bahan organik di kedua lokasi penelitian mendukung kehidupan kepiting kelapa di habitat alaminya. Pola pertumbuhan kepiting kelapa di kedua lokasi Idamdehe adalah allometrik negatif.Kata kunci: Karakteristik habitat, Idamdehe, Takome, Birgus latro, isometrik, allometrik negatifAbstract. This objectives of the present study were to evaluate the habitat characteristics and growth patterns of the coconut crabs in Takome and Idamdehe waters North Maluku Province. This study was conducted during April-July 2014. The collected data were the substrate texture, nitrate and phosphate contents of soil using spectrophotometric method, length + rostrum (cp+r) of coconut crabs and the growth patterns. In addition, the air temperature, hole temperature and humidity were also recorded during the study. The results showed that Idamdehe waters has precipitous coast, indeed very precipitous in several catching locations, while Takome waters in Ternate Island has sloping coast. The substrate texture of Takome waters in Ternate Island consisted of sands (55.76%), dusts (18.4%) and clays (25.84%), while Idamdehe waters has the substrate texture that consisted of sands (49.17%), dusts (25.61 %) and clays (25.22%). As for organic matter contents of the substrate, Takome waters has 0.31% in total N and 0.09% in total P, while Idamdehe waters has 0.19% in total N and 0.02 % in total P. The air temperature in Idamdehe waters ranged between 26-280C and in Takome waters ranged between 27-280C. Air humidity in Idamdehe waters was 73%-98% and in Takome waters was 71%-90%. The environmental parameters such as temperature, humidity, substrate texture and organic matter content in both locations are suitable for coconut crab growing. The growth pattern of coconut crabs in Idamdehe and Sulamadaha waters were allometric negative pattern.Keywords: Habitat characteristics, Idamdehe, Takome, Birgus latro, isometric, negative allometric.


2004 ◽  
Vol 5 (1) ◽  
pp. 31 ◽  
Author(s):  
Ana María Serralde O. ◽  
María Margarita Ramírez G.

<p>Mediante el seguimiento de cultivos experimentales en suelos ácidos de los Llanos Orientales, durante un periodo de cinco años consecutivos (1997-2001), se evaluaron las poblaciones nativas de hongos micorrícicos arbusculares (MA) asociados con dos variedades de maíz: ICA- Sikuani V-110 y la variedad regional criolla Clavito, analizando su comportamiento bajo distintos tratamientos con abono orgánico (gallinaza), abono verde (Caupí) y testigo sin aplicación de materiales orgánicos, para un total de seis tratamientos. De 7.924 esporas analizadas se aislaron veinticuatro morfotipos identificados morfológica y molecularmente. Se determinó la relación de las condiciones del suelo (pH, los contenidos de materia orgánica, P, K, Al+++ y % saturación Al) con el comportamiento de las poblaciones de MA. Con la aplicación del Análisis de Regresión Múltiple (Stepwise), se obtuvieron coeficientes significativos (P≤ 0.001 y R2 ≥ 83) para todas las variables y se seleccionaron como variables predictivas principales el pH y la materia orgánica del suelo, que presentaron coeficientes significativos para cinco y cuatro de los siete modelos establecidos, respectivamente. La técnica molecular empleada basada en la Reacción en Cadena de la Polimerasa (PCR), con el uso de primers específicos, permitió la identificación confirmatoria de las esporas aisladas de los géneros <em>Glomus, Entrophospora </em>y <em>Gigaspora</em>. Además, mediante el uso de esta metodología se logró identificar la presencia del género <em>Glomus</em>en raíces de maíz altamente colonizadas.</p><p> </p><p><strong>Mycorrhiza populations analysis in corn (<em>Zea mays</em>) cultivated in acid soils under different agronomic treatments</strong></p><p>A study was carried out to evaluate the populations of native arbuscular mycorrhizas (AM) fungi on established crops on acid soils of the Colombian Eastern Plains, for a period of five years (1997-2001). Fungi spores were isolated from the crop-fungi association of two maize cultivars: ICASikuani V-110 and the regional cultivar Clavito. The mycorrhizal behavior was evaluated under six different organic fertilization treatments, which included green manure (cowpea), chicken manure and a control treatment (no application). From a total of 7924 spores, 24 different types of mycorrhiza were characterized using morphological and molecular analysis. The relation between soil conditions (pH, organic matter contents, P, K, Al+++ and % Al saturation) and AM fungi populations was analysed using a Stepwise Multiple Regression model. According to the regression coefficients obtained (P≤ 0.001 y R2 ≥ 0.83), soil pH and organic matter content were the independent variables that explained most of the variation observed in AM populations. The molecular methodology was based on the Polymerase Chain Reaction (PCR) and the use of specific primers allowed to identify spores from <em>Glomus</em>, <em>Entrophospora </em>and <em>Gigaspora</em>. This methodology also provided the identification of fungi from the <em>Glomus </em>genera in highly colonized maize roots.</p>


2018 ◽  
Vol 48 (3) ◽  
pp. 316-322 ◽  
Author(s):  
Flávia Levinski-Huf ◽  
Vilson Antonio Klein

ABSTRACT Soil management practices and uses, in the integrated crop-livestock-forestry (ICLF) production system, influence the soil properties in different ways. This study aimed to assess the organic matter content and physical properties of a Red Latosol (Oxisol), in the forestry and crop components of an ICLF system. A split-plot randomized block design was used, with six blocks containing two main plots (forestry and crop) and eight split plots (sampled soil layers), totaling 16 treatments and 96 samples. The following variables were analyzed: organic matter, soil density, relative density, pore size distribution, Atterberg limits and aggregate stability. The presence of the forestry component improves the mean weight and geometric mean diameters, as well as the aggregates stability index of the Red Latosol, at five years after the implementation of the system. The aggregates stability in water and the Atterberg limits are the soil physical properties that better express the changes in the soil, with the inclusion of the forestry component. Including this component in the production system, throughout the years (> 5 years), improves the soil properties.


2021 ◽  
pp. 48-56
Author(s):  
Abhanzioya M.I ◽  
James T .V

The assessment of abattoir effluent on the physicochemical and microbiological properties of the soil cultivated with flint maize was conducted in the Teaching and Research Farm of Ambrose Alli University, Ekpoma. The experiment was a randomized complete block design (RCBD) with five levels of abattoir effluent (0, 32 x 103, 64 x 10 3, 96 x 103, 128 x 103L/ha) and each was replicated three times. The effluent was collected and analyzed for its chemical properties, the number and types of bacteria and fungi before and at the end of the experiment. Soil samples were collected before planting and at the end of the experiment and analyzed for physicochemical properties as well as the number and types of bacteria and fungi. Maize variety; Samma – 38 was used as a test crop. Results showed that more bacteria and fungi counts were found in the abattoir effluent than in the soil. At 15 weeks after application, the plot treated with 64 x 103 L/ha of abattoir effluent had more bacteria isolated and the least bacteria count. The plot that received the 32 x 103L/ha had the least fungi count. The soil was slightly acidic except for the strongly acidic control. The soil after the applications of abattoir effluent was high in organic matter. Abattoir effluent increased the total N, K, Mg, and Ca with the highest recorded at the applications of 96 x 103L/ha and 128 x 103L/ha. Organisms such as Penicillium and Aspergillus spp were isolated, and these enhanced nitrogen and phosphorous fixation, thereby increasing soil fertility for suitable crop production.


2016 ◽  
Vol 29 (2) ◽  
pp. 290-295 ◽  
Author(s):  
JOSÉ EGÍDIO FLORI ◽  
GERALDO MILANEZ DE RESENDE

ABSTRACT: Banana is one of the most consumed fruits in the world, which is grown in most tropical countries. The objective of this work was to evaluate the main attributes of soil fertility in a banana crop under two cover crops and two root development locations. The work was conducted in Curaçá, BA, Brazil, between October 2011 and May 2013, using a randomized block design in split plot with five repetitions. Two cover crops were assessed in the plots, the cover 1 consisting of Pueraria phaseoloides, and the cover 2 consisting of a crop mix with Sorghum bicolor, Ricinus communis L., Canavalia ensiformis, Mucuna aterrima and Zea mays, and two soil sampling locations in the subplots, between plants in the banana rows (location 1) and between the banana rows (location 2). There were significant and independent effects for the cover crop and sampling location factors for the variables organic matter, Ca and P, and significant effects for the interaction between cover crops and sampling locations for the variables potassium, magnesium and total exchangeable bases. The cover crop mix and the between-row location presented the highest organic matter content. Potassium was the nutrient with the highest negative variation from the initial content and its leaf content was below the reference value, however not reducing the crop yield. The banana crop associated with crop cover using the crop mix provided greater availability of nutrients in the soil compared to the coverage with tropical kudzu.


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