scholarly journals Population Densities of Tylenchulus semipenetrans Related to Physicochemical Properties of Soil and Yield of Clementine Mandarin in Spain

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 445-450 ◽  
Author(s):  
Francisco Javier Sorribas ◽  
Soledad Verdejo-Lucas ◽  
Joaquín Pastor ◽  
Cesar Ornat ◽  
Joan Pons ◽  
...  
Keyword(s):  
Organic Matter Content ◽  
Relative Yield ◽  
Damage Function ◽  
Matter Content ◽  
Population Densities ◽  
Second Stage ◽  
Tylenchulus Semipenetrans ◽  
Physicochemical Soil Properties ◽  
Citrus Nematode ◽  
The Relationship

A survey was conducted from April to June 2002 in 62 orchards of clementine mandarin grafted on Troyer or Carrizo citrange rootstock in Catalonia (northeastern Spain) to determine the relationship between physicochemical soil properties and Tylenchulus semipenetrans population densities. Soil was analyzed to determine texture, pH, electric conductivity, organic matter content, N, P, K, Mg, calcium carbonate, and calcium oxide. Also, trials were conducted in 2003 and 2004 in three drip-irrigated orchards of clementine mandarin cv. Clemenules (El Pla and Mariclaire) or cv. Hernandina (Martorella) to determine the relationship between citrus nematode densities and yield of mandarin. T. semipenetrans was detected in 77% of the surveyed orchards. The number of second-stage juveniles + males in soil was related to N and K soil content (3.57953 – 0.001305 N + 0.00113 K, R2 = 0.1620, P < 0.0157). The relationship between relative yield of clementine mandarin cv. Clemenules and densities of females per gram of root in spring was described by the Seinhorst damage function model (0.035 + 0.965 (0.9995)(Pi – 287), R2 = 0.4782, P < 0.0001).

EXTRACTABLE PHOSPHORUS IN SURFACE AND SUBSURFACE LAYERS OF STE. ROSALIE AND ST. BLAISE SOIL SERIES IN QUEBEC

1976 ◽  
Vol 56 (4) ◽  
pp. 345-356
Author(s):  
E. G. BEAUCHAMP ◽  
K. MacMILLAN ◽  
H. A. HAMILTON
Keyword(s):  
Organic Matter Content ◽  
Relative Yield ◽  
Soil Characteristics ◽  
Matter Content ◽  
Stepwise Multiple Regression ◽  
Curvilinear Relationship ◽  
Soil Series ◽  
Surface Soils ◽  
Extractable P ◽  
The Relationship

The relationship between extractable P and soil characteristics including pH, clay content (CLAY), cation exchange capacity (CEC), organic matter content (OM), and phosphorus retention (PRET) was determined using stepwise multiple regression analysis. Similarly, the influence of pH, CLAY, CEC, OM and PRET on the relationship between extractable P and relative yield (Yo/Yp) of young corn plants in the greenhouse was determined. Surface (0- to 20-cm) and subsurface (20- to 40-cm) layers from two soil series (St. Blaise and Ste. Rosalie) were collected from farm fields in the region south of Montreal. Twenty-eight sites of the St. Blaise series and 25 sites of the Ste. Rosalie series were sampled from fields of which the majority were in cultivation for 100–200 yr. Three P extractants were used: Bray 1 (P1) (0.03 N NH4F, 0.025 N HCl), Bray 2 (P2) (0.03 N NH4F, 0.1 N HCl) and 0.5 M NaHCO3 (P3). Extractable P by all three extractants was negatively correlated with pH of the St. Blaise surface soils. However, extractable P by the P2 extractant was positively correlated with pH of the Ste. Rosalie surface soils. Although significant, the R2 values for these relationships were low, ranging from 0.15 to 0.17 for the surface soils. Extractable P was related, to variable extents, to one or more of pH, PRET, OM and CEC of the subsurface soils depending on the soil series and P extractant in an unexplainable manner. However, the R2 values were generally much higher for the subsurface than surface soils suggesting that extractable P in subsurface soils was more closely related to the measured soil characteristics. There was no relationship between extractable P with any extractant and CLAY for either series. The highest correlation between relative yield (Yo/Yp) and extractable P occurred with P3 for the surface soils of both series. None of the soil characteristics was included with P3 in the regressions with the surface soils. PRET was included along with P2 in the regression with Yo/Yp for the St. Blaise surface soils, whereas a P × CLAY interaction term occurred with the P1 and P2 extractants for the Ste. Rosalie surface soils. A linear relationship was obtained between Yo/Yp and P1 or P3 for the Ste. Rosalie surface soils and P2 for the St. Blaise surface soils. A curvilinear relationship was obtained with P1 or P3 for the St. Blaise surface soils and with P2 for the Ste. Rosalie surface soils. Extractable P was not included as an independent variable in any of the regressions with Yo/Yp as the dependent variable for the subsurface soils. This suggests that extractable P with any of the extractants used in this study does not reflect the availability of P in subsurface soils.

The relationship between apparent retention time in the rumen, voluntary intake, and apparent digestibility of legume and grass diets in sheep

1973 ◽  
Vol 24 (6) ◽  
pp. 889 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson
Keyword(s):  
Organic Matter ◽  
Retention Time ◽  
Daily Intake ◽  
Organic Matter Content ◽  
Matter Content ◽  
Apparent Digestibility ◽  
Jaw Movements ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
The Relationship

Eight grasses and six legumes were fed ad libitum at hourly intervals to wethers fitted with large rumen fistulas to determine voluntary intake, apparent digestibility, and the apparent retention time of organic matter in the rumen, as well as the quantity of rumen digesta and the organic matter content of the rumen digesta. The voluntary intake of legumes was 28% higher than that of equally digestible grasses. This difference was caused by a shorter retention time (17%) and a higher amount of organic matter (14%) in the rumen digesta from legume diets than from grass diets. The weight of wet digesta in the rumen of sheep fed on legumes was 7% lower than from those fed on grass. Neither the quantity of digesta nor the quantity of organic matter in the rumen was related to the voluntary intake, digestibility, or retention time of organic matter in the rumen. Number of jaw movements each day and rate of cotton thread digestion were not related to the retention time of the diets either. Daily intake of digestible organic matter (DOMI, g/day) was closely correlated with retention time (RTOM, hr) for the feeds in this study (r = –0.93) and the same relation applied to both temperate and tropical feeds, viz. DOMI = 1276–50.7 RTOM (r=0.96) Differences in voluntary intake between grasses and legumes were attributed to differences in retention time and the density to which the food was packed in the rumen.

The relationship between digestibility or energy losses as methane and metabolisable energy content of whole crop wheat

1996 ◽  
Vol 1996 ◽  
pp. 41-41
Author(s):  
A.T. Adesogan ◽  
E. Owen ◽  
D.I. Givens
Keyword(s):  
Organic Matter ◽  
Energy Content ◽  
Organic Matter Content ◽  
Matter Content ◽  
Energy Losses ◽  
Digestible Organic Matter ◽  
Metabolisable Energy ◽  
The Cost ◽  
The Relationship

Estimates of the metabolisable energy (ME) content of whole crop wheat (WCW) derived using measured energy losses as methane (ELMm) are lacking due to the cost of measuring ELMm. Published ME values of WCW are largely calculated using predicted energy losses as methane (ELMp, Blaxter and Clapperton, 1965) or digestible organic matter content (DOMD) in vivo. However, there appears to be no published information about the accuracy with which DOMD in vivo or ELMp predicts the ME content of WCW. Therefore, this study assessed the validity of such ME predictions by comparing them with ME contents calculated using ELMm.

scholarly journals The Relationship between Mollusks and Oxygen Concentrations in Todos Santos Bay, Baja California, Mexico

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
J. Gabriel Kuk-Dzul ◽  
Victoria Díaz-Castañeda
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Bottom Water ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Matter Content ◽  
The Other ◽  
Natural Conditions ◽  
The Relationship ◽  
Oxygen Concentrations

This study describes the relationship between mollusks, physicochemical properties of seawater, and sediments under natural conditions of low impact. Thirty-nine stations were sampled in October 1994 using a Van Veen grab (0.1 m−2). Temperature, salinity, and dissolved oxygen (DO) concentrations of bottom water were obtained with a CTD. Organic matter content and sediment grain analysis were determined. A total of 836 mollusks were collected. Gastropoda was the most abundant (52%) and diverse class with 27 genera, followed by Bivalvia with eight genera and Scaphopoda with only one genus. According to CCA analysis, dominant mollusks were significantly related with high DO concentrations.Donax,Natica,Acteocina,Bulla,Anachis,Odostomia, andCrucibulumcan be classified as sensitive genera because they were found mainly in high oxygen concentrations (3.1–5.6 mL L−1); on the other hand,Cardiomya,Nuculana,Laevicardium,Chione,Truncatella, andDentaliumcan be classified as tolerant genera (1.0–5.6 mL L−1). Todos Santos Bay hosts a diverse malacological fauna (36 genera); our results show that the dominant genera were mainly related to high dissolved oxygen concentrations. Mollusks can be a useful tool in environmental monitoring programs related with oxygen depletion in coastal areas.

scholarly journals Environmental factors affecting splash erosion in the mountain area (the Western Polish Carpathians)

2018 ◽  
Vol 36 ◽  
pp. 97-111
Author(s):  
Małgorzata Kijowska-Strugała ◽  
Krzysztof Kiszka
Keyword(s):  
Environmental Factors ◽  
Erosion Rate ◽  
Organic Matter Content ◽  
Matter Content ◽  
Slope Gradient ◽  
Mountain Area ◽  
Factors Affecting ◽  
Splash Erosion ◽  
Polish Carpathians ◽  
The Relationship

The aim of this study was to examine the effects of various environmental factors on splash erosion based on the funnel method under natural conditions. The relationship between splash and wash erosion were also studied. The intermediate timescale study (2012–2016, from May to October) was conducted in the Western Polish Carpathians where Inceptisols predominate. The splash erosion rate (kg m−2) was variable and showed a strong correlation with environmental factors, including rainfall parameters, land use (black fallow, meadow), slope gradient (0°, 11°), and also the particle size of soil and usage time (organic matter content, OM). The splash erosion rate on the slope with black fallow was 95 times higher than in the meadow and up to 20 times higher than in flat area. The average downslope splash erosion was 75% higher than the upslope splash erosion, and the soil particles were detached to maximum heights of 50 cm (downslope). There was a positive correlation between splash erosion and wash and a negative correlation between splash erosion and OM.

Adsorption of pesticides by some Australian soils

Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 61 ◽  
Author(s):  
GG Briggs
Keyword(s):  
Aqueous Solution ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
North American ◽  
Water Distribution ◽  
Organic Matter Content ◽  
Matter Content ◽  
Organic Chemicals ◽  
The Relationship

Adsorption of non-ionized organic chemicals from aqueous solution by 17 Australian soils was related to the organic matter content of the soils. The soil organic matter/water distribution (Kom) for each chemical was similar in all soils and could be predicted from the octanol/water distribution (Kow) of the chemical. The relationship between these two distributions, log Kom = 0.52log Kow, + 0.69, is similar to that reported for European and North American soils.

THE AVAILABLE BORON CONTENT OF THE GENETIC HORIZONS OF SOME ONTARIO SOILS: I. THE RELATIONSHIP BETWEEN WATER-SOLUBLE BORON AND OTHER SOIL PROPERTIES

1966 ◽  
Vol 46 (2) ◽  
pp. 133-138 ◽  
Author(s):  
N. S. Miljkovic ◽  
B. C. Matthews ◽  
M. H. Miller
Keyword(s):  
Organic Matter ◽  
Boron Content ◽  
Organic Matter Content ◽  
Clay Content ◽  
Important Variable ◽  
Matter Content ◽  
Parent Material ◽  
Water Soluble ◽  
Hot Water ◽  
The Relationship

The available boron content of the genetic horizons of eight Ontario soils was determined using a hot-water extraction and a sunflower test. The available boron was highest in the surface horizons and decreased in the zones of eluviation to a level equal to or lower than that in the parent material. The content in the horizons was generally higher than that in the C horizons.The water-soluble boron was closely related to the organic matter content in a quadratic regression (R2 = 0.691). When pH and clay content were included in regressions, a positive organic matter × pH component was the single most important variable, explaining 64.4% of the variability. Additional terms involving clay content and pH did not greatly increase the R2 value.

ESTIMATING THE ATTERBERG LIMITS OF SOUTHERN SASKATCHEWAN SOILS FROM TEXTURE AND CARBON CONTENTS

1990 ◽  
Vol 70 (4) ◽  
pp. 543-554 ◽  
Author(s):  
E. DE JONG ◽  
D. F. ACTON ◽  
H. B. STONEHOUSE
Keyword(s):  
Organic Matter Content ◽  
Matter Content ◽  
Soil Survey ◽  
Atterberg Limits ◽  
Matric Potential ◽  
Correlation And Regression Analysis ◽  
Independent Variable ◽  
The Relationship ◽  
Water Contents

The soil water contents at the liquid and plastic limits (the Atterberg limits) are widely used in the classification of soils for engineering purposes. Approximately 500 soil samples (129 Ap horizons and 417 B and C horizons) collected over several years as part of the ongoing soil survey program in Saskatchewan were analyzed for texture and Atterberg limits. On about half of the samples water retention (−33 kPa and −1500 kPa matric potential and air dryness), and organic and inorganic C were also determined. The relationship between the Atterberg limits and soil properties was explored through correlation and regression analysis. Clay and organic matter content explained most of the observed variation in the Atterberg limits of the Ap horizons. Clay was the most important independent variable in the B and C horizons, while inorganic C had only a relatively small impact. Key words: Atterberg limits, texture, organic and inorganic C

scholarly journals KEANEKARAGAMAN MOLUSKA BERDASARKAN TEKSTUR SEDIMEN DAN KADAR BAHAN ORGANIK PADA MUARA SUNGAI BETAHWALANG, KABUPATEN DEMAK (Molluscs Diversity based on Sediment Texture and Organic Matter Content in Betahwalang Estuary, Demak Regency)

2017 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Hana Nisau Shalihah ◽  
Pujiono Wahyu Purnomo ◽  
Niniek Widyorini
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Survey Method ◽  
Sediment Texture ◽  
Positive Correlation ◽  
Purposive Sampling ◽  
Relationship Of ◽  
The Relationship ◽  
Contaminant Load

 Muara Sungai Betahwalang merupakan ekosistem yang mendapat masukan dari kegiatan penduduk daerah pemukiman sekitar dan dari Sungai Jajar. Muatan pencemar akan mempengaruhi kondisi muara terutama substrat dasar pada sungai Betah walang. Tekstur dan kandungan bahan organik di dalam sedimen menentukan keberadaan moluska. Tekstur sedimen merupakan tempat untuk menempel dan merayap atau berjalan, sedangkan bahan organik merupakan sumber makanan bagi moluska. Tujuan dari penelitian ini adalah untuk mengetahui keanekaragaman moluska, tekstur sedimen dan kadar bahan organik, serta untuk mengetahui hubungan antara variabel. Metode yang digunakan adalah metode survey dengan pengambilan sampel menggunakan metode Purposive Sampling. Sampel diambil pada 5 stasiun dan masing-masing stasiun terdiri dari 3 titik. Hasil penelitian menyebutkan bahwa terdapat 10 genera dari kelas Gastropoda yaitu Littorina, Cerithidea, Turritella, Clathrodrillia, Fasciolaris, Conus, Filopaludina, Pila, Melanoides dan Telescopium dan 4 genera dari kelas Bivalvia yaitu Anadara, Mesodesma, Mytilus dan Donax. Karakteristik substrat di muara Sungai Betahwalang adalah liat dan liat berpasir dengan kadar bahan organik berkisar antara 6,2-17,4 %. Hubungan moluska dengan tekstur sedimen terutama liat mempunyai korelasi positif dengan persamaan y = 6.94x + 224.0 (r = 0.535). Hubungan moluska dengan bahan organik mempunyai korelasi positif dengan persamaan y = 33.44x + 271.1 (r = 0.507) dan R2 = 0.257   Betahwalang Estuary is an ecosystem that gets input from the activities of the surrounding residents area and from the Jajar River. Contaminant load from upstream will affect the condition of the substrate in Betah walang river. Texture and organic matter content in the sediments determine the presence of molluscs. Sediment texture is a place for molluscs to stick, crawl or walk, while organic matter is a source of food for them. The purpose of this research is to know the diversity of molluscs, sediment textures and organic matter content, and to know the relationship between those variables. The method used is survey method with sampling using Purposive Sampling method. Samples were taken at 5 stations and each station consisted of 3 spots. The results show that 10 genera of the Gastropod class were Littorina, Cerithidea, Turritella, Clathrodoillia, Fasciolaris, Conus, Filopaludina, Pila, Melanoides and Telescopium and 4 genera of Bivalves class were Anadara, Mesodesma, Mytilus and Donax. Betahwalang estuary are characterized by clay and sandy clay with organic material content between 6,2-17,4%. The relationship of molluscs with sediment texture, especially clay, has a positive correlation with the equation y = 6.94x + 224.0 (r = 0.535). The relationship of molluscs with organic matter has a positive correlation with the equation y = 33.44x + 271.1 (r = 0.507). 

Sign in / Sign up

Export Citation Format

Share Document