Spatial Distribution of Surface Soil Acidity,Electrical Conductivity,Soil Organic Carbon Content and Exchangeable Potassium,Calcium and Magnesium in Some Cropped Acid Soils of India     

Sanjib Kumar Behera  Arvind Kumar Shukla 《Land Degradation \u0026amp; Development》2015,26(1):71-79

Land degradation is a global problem. Best management of degraded land can be done by evaluating the spatial variability of soil properties including chemical properties of degraded land and mapping such variations. Since, a significant portion of arable land in India is chemically degraded due to soil acidity; the present study was conducted to study the spatial variability of soil acidity (pH), electrical conductivity (EC), soil organic carbon (OC) content, exchangeable potassium (K⁺), calcium (Ca²⁺) and magnesium (Mg²⁺) contents in some cropped acid soils of India. A total of four hundred (one hundred from each series) representative surface (0–0.15 m depth) soil samples were collected from arable soils representing four soil series namely Hariharapur, Debatoli, Rajpora and Neeleswaram situated in Orissa, Jharkhand, Himachal Pradesh and Kerala states of India, respectively, and were analyzed. Soil acidity (pH between 3.90 and 6.45) showed a low variability, in contrast to other soil properties, which showed moderate variability. The coefficients of variation varied from 32.4 to 74.3, 31.2 to 50.9, 45.6 to 100, 71.9 to 93.0 and 59.0 to 79.8% for EC (mean between 0.05 and 0.09 dS m⁻¹), OC (mean between 0.29 to 1.86%), exchangeable K⁺ (mean between 39.1 and 77.7 mg kg⁻¹), Ca²⁺ (mean between 148 and 293 mg kg⁻¹) and Mg²⁺ (mean between 111 and 191 mg kg⁻¹), respectively. Soil pH and OC content were positively and significantly correlated with exchangeable K⁺, Ca²⁺ and Mg²⁺ content. Geostatistical analysis revealed that the best fit models were gaussian, exponential and spherical for different soil properties with moderate to strong spatial dependency. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Symptoms in slash pine seedlings following inoculation with the cone rust fungus Cronartium strobilinum     

A. N. Shukla  R. A. Schmidt  T. Miller 《Forest Pathology》2001,31(6):345-352

Six‐week‐old seedlings of slash pine (Pinus elliottii) were inoculated with sporidia of Cronartium strobilinum, which is the cause of southern cone rust disease, by wounding the apical tips of the seedlings. Pycnial sori developed abundantly within 1 month of inoculation on the epicotyl and primary needles. The progress of the pathogen was confirmed histologically within the cells of the stem and haustoria were observed near the nucleus of the cells. In the needles, pycnial pustules developed and the fungus was abundant in the mesophyll.  相似文献   

Properties of red maple laminated veneer lumber impregnated with waterborne micronized and two soluble copper formulations     

S. R. Shukla  D. P. Kamdem 《Wood material science & engineering》2020,15(2):64-75

ABSTRACT

Certain important quality parameters of red maple (Acer rubrum) laminated veneer lumber (LVL) impregnated with three waterborne formulations: copper azole (CA-B), micronized copper azole (MicroCA or MCA) and alkaline copper quaternary (ACQ-D) bonded with phenol formaldehyde or cross-linked polyvinyl acetate (XPVAc) adhesives were evaluated. Pre-dipping of veneers before LVL production and two post-manufacturing procedures, viz., vacuum-pressure and post-dipping of LVL, were applied. Maximum copper retention in pre-dip-treated, vacuum-pressure and post-dip-treated LVL was 1.4, 9.7 and 1.7?kg/m³, respectively. Copper retention in MCA-treated LVL was relatively lower than soluble formulations. Various physical, mechanical and bonding properties of treated LVL such as density, water absorption, swelling, flexural properties, hardness, tensile shear strength, delamination and wood failure (%) were studied and compared with untreated LVL. Little to negligible deleterious effect was observed on properties of LVL due to these chemical treatments. Analysis of variance results showed that most of properties of red maple LVL were not significantly different compared with those of untreated LVL. Therefore, vacuum-pressure impregnation process can be used to treat the red maple LVL with novel micronized copper formulations for increasing the service life of such products against biodegradation without affecting techno-mechanical quality parameters.  相似文献   

Axial variations in anatomical properties and basic density of Eucalypt urograndis hybrid (Eucalyptus grandis 3 E. urophylla) clones     

S K Sharma  S R Shukla  S Shashikala  V Sri Poornima 《林业研究》2015,(3)

We studied two clones of Eucalypt urograndis hybrid (Eucalyptus grandis 9 E. urophylla), GR283 and GR330, grown in Tumkur district of Karnataka (India), and felled 5–6 years old three trees of each clo...  相似文献   

Comparative study on growth,wood quality and financial returns of teak (Tectona grandis L.f.) managed under three different agroforestry practices     

S. R. Shukla  S. Viswanath 《Agroforestry Systems》2014,88(2):331-341

Growth, wood quality parameters and productivity estimations of 12-year-old teak (Tectona grandis L.f.) grown under three agroforestry systems, namely unmanaged block (B_um), unmanaged line on the farm boundary (L_um) and intensively managed block (B_im) plantations are studied. Mean annual increment (MAI) of 0.020, 0.006 and 0.016 m³ tree^?1 year^?1 was recorded in L_um, B_um and B_im, respectively. Overall growth performance of teak raised in L_um, plantation appears to be better than two block plantations (B_um and B_im). For evaluating various wood quality parameters, tree logs from each plantation were tested for different physical and mechanical properties according to the standard procedures. The wood quality of B_um was found to be comparatively superior to B_im and much better than those of L_um. The 12-year-old farm teak trees from three systems exhibited lower average values of different wood quality parameters compared to mature forest teak. Since physical and strength properties of B_um were inferior compared to L_um and B_im, its exploitation is not advisable at this stage. Line plantation, however, releases land for cultivation of arable crops and does not demand any special silvicultural management as required by B_im. Although, total extractable volume of teak wood available after 12-years of age from B_um was much smaller compared to B_im or L_um, its commercial exploitation at an early age may be preferred over other two practices due to better wood quality and lower management cost. For optimum economic utilization and mechanical maturity of wood, harvesting of block plantation may be delayed for about 10-15 years because growth volume and strength properties are expected to improve with age of tree.  相似文献   

Multiple Induced Spawnings of the Indian Catfish Heteropneustes fossilis (Bloch) within a Prolonged Spawning Season     

Deoraj  Alok  T. Krishnan    G. P. Talwar    Lalit C.  Garg 《Journal of the World Aquaculture Society》1998,29(2):252-258

Abstract Singhi, the Indian catfish Heteropneustes fossilis , attained gonadal maturity repeatedly in a single spawning cycle by photothermal treatment. After the first spawning, maintenance at 30 C and 14 h light/10 h dark for 3 wk induced recruitment of the next batch of mature oocytes for subsequent spawnings. The number of eggs released declined with each spawning. However, fertilizability of the eggs was maintained until the fifth spawning. Mature fish were induced to spawn by D-Lys⁶ salmon gonadotropin-releasing hormone agonist administration. The dose of salmon gonadotropin-releasing hormone agonist for the second and subsequent spawnings was determined to be 25-fold less compared to the dose administered for the first spawning. Fish released the maximum number of eggs upon induction when they were maintained continuously at 30 C and 14 h light/10 h dark for 6 wk. The result obtained in the present study points to a possibility of obtaining multiple spawnings from those species of farmed fish which spawn once a year.  相似文献   

Genomic regions associated with grain yield under drought stress in wheat (Triticum aestivum L.)     

Sanyukta Shukla  Kalpana Singh  Rajendra V. Patil  Suhas Kadam  Sudhakar Bharti  Pratti Prasad  Nagendra Kumar Singh  Renu Khanna-Chopra 《Euphytica》2015,203(2):449-467

  相似文献   

Molecular identification and virulence analysis of AVR genes in rice blast pathogen,Magnaporthe oryzae from Eastern India     

Jahangir Imam  Shamshad Alam  Nimai Prasad Mandal  Pratyoosh Shukla  Tilak Raj Sharma  Mukund Variar 《Euphytica》2015,206(1):21-31

  相似文献   

A new gene for resistance in rice to Asian rice gall midge (Orseolia oryzae Wood Mason) biotype 1 population at Raipur, India     

M. N. Shrivastava  Arvind Kumar  Sandeep Bhandarkar  B. C. Shukla  K. C. Agrawal 《Euphytica》2003,130(1):143-145

The Asian rice gall midge, Orseolia oryzae Wood Mason (Diptera: Cecidomyiidae), is a major pest of rice in several South and South East Asian countries. The maggots feed internally on the growing tips of the tillers and transform them into tubular galls, onion leaf-like structures called ‘silver shoots’ resulting into severe yield loss to the rice crop. We studied the mode of inheritance and allelic relationships of the resistance genes involved in resistant donor Line 9, a sib of a susceptible cultivar ‘Madhuri’. The segregation behaviour of F₁, F₂ and F₃ populations of the cross between Line 9 and susceptible cultivar MW10 confirmed the presence of a single dominant gene for resistance. Tests of allelism with all the known genes giving resistance to this population indicated that Line 9 possessed a new gene which was designated Gm 9 This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Genotypic variability in vegetable amaranth (Amaranthus tricolor L for foliage yield and its contributing traits over successive cuttings and years     

S. Shukla  A. Bhargava  A. Chatterjee  A. Srivastava  S. P. Singh 《Euphytica》2006,151(1):103-110

Summary Twenty nine strains of vegetable amaranth (Amaranthus tricolor were grown for two successive seasons to study different selection parameters for foliage yield and its nine contributing morphological and quality traits. The strains AV-38 (5.06 kg/plot) and AV-31 (5.04 kg/plot) recorded highest foliage yield, followed by AV-30 (4.78 kg/plot) and AV-23 (4.70 kg/plot). The protein and carotenoid content averaged 1.24 ± 0.03 mg/100 mg and 0.83 ± 0.02 mg/g respectively. The leaves of A. tricolor also have considerable quantities of ascorbic acid (112.33 ± 5.00 mg/100 g) and fibre (8.39 ± 0.10%). The mean of individual cuttings for plant height, leaf size, stem diameter, foliage yield, protein, ascorbic acid and fibre content increased with successive cuttings till third cutting and thereafter showed a decline. Genotypic coefficient of variation (GCV) values ranged from 6.80 to 28.25%. However, the fibre content, branches/plant, leaves/plant, plant height and stem diameter showed lowest values of GCV. The values of heritability estimates were high for all the traits in all the cuttings as well as on pooled basis and ranged from 0.89 for branches/plant to 0.98 for foliage yield. Highest expected genetic advance was noticed for ascorbic acid (57.48%), followed by foliage yield (48.30%) and leaf size (29.51%).  相似文献