Respiration rates for determining the effects of urea on the soil-surface organic horizon of a black spruce stand

1976 ◽  
Vol 22 (9) ◽  
pp. 1328-1335 ◽  
Author(s):  
M. R. Roberge
Keyword(s):  
Incubation Period ◽  
Picea Mariana ◽  
Black Spruce ◽  
Soil Surface ◽  
Water Holding Capacity ◽  
Organic Horizon ◽  
Endogenous Respiration ◽  
Respiration Rates ◽  
Water Holding ◽  
Field Plots

The respiration rates of microflora of layers of soil-surface organic horizon of a black spruce (Picea mariana (Mill.) B.S.P.) stand have been studied manometrically under controlled conditions of moisture, temperature, and aeration in the presence of urea and other nitrogen and mineral amendments. L, F1, and F2 samples from field plots fertilized with 448 kg N/ha as urea in 1961 had still in 1971 greater respiration rates than similar samples from unfertilized field plots. In lab tests, addition of urea (112, 280, and 448 kg N/ha or 875, 2187, and 3500 ppm N) stimulated the endogenous respiration of each layer. The stimulation was greater when 2187 ppm N was applied and when moisture and temperature of the layers were maintained at 60% water-holding capacity and 20 °C during the 42-day incubation period. Addition of Mg, Ca, and K to urea-fertilized layers increased respiration while P and S decreased it. Addition of NH4NO3 and (NH4)SO4 impaired the endogenous respiration. The endogenous respiration and moisture, temperature, and fertilizer effects decreased in the order L, F1, and F2 layers.

Behavior of urease added to unsterilized, steam-sterilized, and gamma radiation-sterilized black spruce humus

1970 ◽  
Vol 16 (9) ◽  
pp. 865-870 ◽  
Author(s):  
M. R. Roberge
Keyword(s):  
Gamma Radiation ◽  
Picea Mariana ◽  
Black Spruce ◽  
Organic Horizon ◽  
Urea Fertilizer ◽  
Upper Limit ◽  
All Solutions ◽  
Mill Stand

Because of the widespread use of urea fertilizer, it became evident that an assessment of urease addition on natural ureolysis was pertinent. Samples of each layer of the surface organic horizon of a black spruce (Picea mariana Mill.) stand at Baie-Comeau, Quebec, were treated with urease then tested for ureolysis activity. Added urease was active in all samples; the increase of activity was affected by the type of sterilization treatment used and the layer of the surface organic horizon. Additional ureolysis was greatest in unsterilized samples, less in radiation-sterilized samples, least in steam-sterilized samples, and decreased with depth of layers. Autoclaving inhibited activity of urease added previously or subsequently while irradiation had a lesser effect. Every layer had an upper limit of urease adsorption and was characterized by a definite capacity to adsorb urease which increased with depth of layers. The pattern of ureolysis observed when urease was added to solutions obtained from layer samples was similar to that observed when urease was added to the layer samples themselves. All solutions inhibited the action of added urease.

Holocene Relict Woodlands at the Eastern Canadian Treeline

1993 ◽  
Vol 39 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Serge Payette ◽  
Claude Morneau
Keyword(s):  
Picea Mariana ◽  
Direct Evidence ◽  
Black Spruce ◽  
Strong Support ◽  
Organic Horizon ◽  
Hudson Bay ◽  
Humid Climate ◽  
Open Forest

AbstractWe present direct evidence for the relict nature of lichenspruce woodlands thriving at treeline, using 14C-dated stands growing in the humid climate of eastern Hudson Bay in northern Québec. Black spruce, Picea mariana (Mill.) BSP, forms two groups of relict stands: a Neoglacial group of postfire origin dating between 2000 and 900 yr B.P. and a pre-Neoglacial group most likely established between 4500 and 3200 yr B.P. The latter group shows no evidence of fire (absence of charcoal under topsoil organic horizon). The stands are exceptional because they probably are the direct lineages of the primeval forests that colonized the land sometime after deglaciation. The structure of the relict lichen-spruce communities gives strong support to the current thesis that considers lichen-spruce woodland as a self-perpetuating open forest, typical of the subarctic environment.

The response of root and microbial respiration to the experimental warming of a boreal black spruce forest

2014 ◽  
Vol 44 (8) ◽  
pp. 986-993 ◽  
Author(s):  
Jason G. Vogel ◽  
Dustin Bronson ◽  
Stith T. Gower ◽  
Edward A.G. Schuur
Keyword(s):  
Picea Mariana ◽  
Microbial Respiration ◽  
Black Spruce ◽  
Control Treatment ◽  
Prolonged Release ◽  
Spruce Forest ◽  
Experimental Warming ◽  
Soil Microbial ◽  
Respiration Rates ◽  
And Control

We investigated the effects of a 5 °C soil + air experimental heating on root and microbial respiration in a boreal black spruce (Picea mariana (Mill.) B.S.P.) forest in northern Manitoba, Canada, that was warmed between 2004 and 2007. In 2007, the 14C/12C signatures of soil CO2 efflux and root and soil microbial respiration were used in a two-pool mixing model to estimate their proportional contributions to soil CO2 efflux and to examine how each changed in response to the warming treatments. In laboratory incubations, we examined whether warming had altered microbial respiration rates or microbial temperature sensitivity. The 14C/12C signature of soil CO2 efflux and microbial respiration in the heating treatments were both significantly (p < 0.05) enriched relative to the control treatment, suggesting that C deposited nearer the atmospheric bomb peak in 1963 contributed more to microbial respiration in heated than control treatments. Soil CO2 efflux was significantly greater in the heated than control treatments, suggesting the acclimation to temperature of either root or microbial respiration was not occurring in 2007. Microbial respiration in laboratory incubations was similar in heated and control soils. This study shows that microbial respiration rates still responded to temperature even after 4 years of warming, highlighting that ecosystem warming can cause a prolonged release of soil organic matter from these soils.

scholarly journals Spatial Variations in Water-Holding Capacity as Evidence of the Need for Precision Irrigation

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2208
Author(s):  
Mohd Shahkhirat Norizan ◽  
Aimrun Wayayok ◽  
Ahmad Fikri Abdullah ◽  
Muhammad Razif Mahadi ◽  
Yahya Abd Abd Karim
Keyword(s):  
Soil Depth ◽  
Irrigation Management ◽  
Soil Surface ◽  
Water Holding Capacity ◽  
Physical Analysis ◽  
Sampling Point ◽  
Depth Ranges ◽  
Gis Software ◽  
The Impact ◽  
Water Holding

Malaysia receives a lot of water from its two main monsoon periods. Generally, there is a lot of precipitation throughout the year, with drought periods lasting less than three months. To date, irrigation has been treated homogenously, even though soil properties can vary spatially over a field, requiring site-specific applications. The aim of this study was to establish an irrigation management zone (IMZ) covering 23.4 ha, which was previously determined under the same soil series. Soil sampling was done according to a grid system over an area of 100 m × 100 m. Three soil depth ranges were examined for every sampling point, namely 0–30, 30–60, and 60–90 cm from the soil surface. Samples were taken to a laboratory for physical analysis and determination of the available water-holding capacity (AWHC). Delineation of AWHC values was achieved using GIS software and the Kriging method. Estimated irrigation depth (EID) data for the plantation were collected for the years 2016 and 2017. Afterward, EID and total net irrigation (TNI) data were simulated in the FAO Cropwat model and compared. The results showed that clay, sand, and organic matter (OM) distributions varied with soil depth; however, no strong correlation was found between these variable with AWHC. The IMZ was classified into three areas named zones A, B, and C, ranging from 79 to 167 mm. The crop water requirement (CWR) was 667 mm in 2016 but only 260 mm in 2017. Based on the AWHC values, the EID for 2016 was found to be below the TNI requirement range of about 106 to 110 mm. In contrast, the EID range was approximately 34 to 62 mm and above TNI requirements for 2017. This study indicates that water inputs for irrigation can be optimized with knowledge of the water-holding capacity of a specific soil. Subsequently, this can be related to crop yield and the impact on sustainable agriculture.

Kualitas Fisik Daging Ayam Broiler yang Diberi Minyak Buah Merah dalam Pakan Komersial

2019 ◽  
Vol 6 (1) ◽  
pp. 20
Author(s):  
Abdul Rahman Ollong ◽  
Rizki Arizona ◽  
Rusli Badaruddin
Keyword(s):  
Moisture Content ◽  
Broiler Chickens ◽  
Broiler Chicken ◽  
Ph Value ◽  
Cooking Loss ◽  
Water Holding Capacity ◽  
Broiler Meat ◽  
Fruit Oil ◽  
Water Holding ◽  
Range Test

ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh penambahan minyak buah merah (MBM) pada pakan terhadap kualitas fisik daging ayam broiler. Seratus ekor ayam broiler umur sehari (DOC) ditempatkan pada lima kelompok perlakuan pakan yang berbeda, yaitu: P1 (pakan kontrol/tanpa penambahan minyak), P2 (2% MBM), P3 (4% MBM), P4 (6% MBM) dan P5 (6% Minyak kelapa sawit). Setiap kelompok perlakuan terdiri dari empat ulangan masing-masing dengan lima ekor. Ayam broiler dipelihara selama 35 hari. Rancangan yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan analisis variansi pola searah dan diuji lanjut dengan Duncan’s New Multiple Range Test (DMRT). Hasil penelitian menunjukkan bahwa semua variable yang diamati menunjukkan adanya pengaruh nyata (P<0,05) terhadap perlakuan yang diberikan. Dari hasil penelitian ini dapat disimpulkan bahwa penggunaan minyak buah merah (MBM) dalam pakan mampu memberikan pengaruh terhadap pH Daging, Daya Ikat Air (DIA), susut masak dan keempukan daging ayam broiler.Kata kunci : daging ayam broiler, daya ikat air, keempukan daging, pH daging, susut masakABSTRACT The experiment was conducted to study the effect of red fruit oil (RFO) onphysical quality  of broiler chicken. One hundred day old chicken (DOC) were placed in four groups of different treatments, of from levels of RFO (P1 (diet without addition of RFO), P2 (2% RFO), P3 (4% RFO) and P4 (6% RFO) and P5 (6% Palm oil)). The treatment group consisted of fivereplications with five birds each. Broiler chickens were reared for 35 days. Statistical analysis used Completely Randomized Design (CRD) and followed by Duncan’s New Multiple Range Test (DMRT). The results showed that the pH value, moisture content, water holding capacity, and cooking loss was significant differences. It could be concluded that the addition of red fruit oil in the diet give effect  of broiler chicken meat.Keywords: broiler meat, cooking loss, moisture content, pH value, water holding capacity

Image Enhancement Applied to Water Holding Capacity Images

2020 ◽  
Author(s):  
Renan G. de Andrade ◽  
Mariah C. Durval ◽  
Isaura M. Ferreira ◽  
Robson C. Antunes ◽  
Andre R. Backes
Keyword(s):  
Image Enhancement ◽  
Water Holding Capacity ◽  
Water Holding
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