Soil C and N dynamics and maize (Zea may L.) yield as affected by cropping systems and residue management in North-western Pakistan     

Mohammad Shafi  Jehan Bakht  Mohammad Tariq Jan  Zahir Shah 《Soil & Tillage Research》2007,94(2):520-529

This paper presents the results of irrigated rotation experiment, conducted in the North West Frontier Province (NWFP), Pakistan, during 1999–2002 to evaluate effects of residues retention, fertilizer N and legumes in crop rotation on yield of maize (Zea mays L.) and soil organic fertility. Chickpea (Cicer arietinum L) and wheat (Triticum aestivum L) were grown in the winters and mungbean (Vigna radiata) and maize in the summers. Immediately after grain harvest, above-ground residues of all crops were either completely removed (−residue), or spread across the plots and incorporated by chisel plough by disc harrow and rotavator (+residue). Fertlizer N rates were nil or 120 kg ha⁻¹ for wheat and nil or 160 kg ha⁻¹ for maize. Our results indicated that post-harvest incorporation of crop residues significantly (p < 0.05) increased the grain and stover yields of maize during both 2000 and 2001. On average, grain yield was increased by 23.7% and stover yield by 26.7% due to residue incorporation. Residue retention also enhanced N uptake by 28.3% in grain and 45.1% in stover of maize. The soil N fertility was improved by 29.2% due to residue retention. The maize grain and stover yields also responded significantly to the previous legume (chickpea) compared with the previous cereal (wheat) treatment. The legume treatment boosted grain yield of maize by 112% and stover yield by 133% with 64.4% increase in soil N fertility. Similarly, fertilizer N applied to previous wheat showed considerable carry over effect on grain (8.9%) and stover (40.7%) yields of the following maize. Application of fertilizer N to current maize substantially increased grain yield of maize by 110%, stover yield by 167% and soil N fertility by 9.8% over the nil N fertilizer treatment. We concluded from these experiments that returning of crop residues, application of fertilizer N and involvement of legumes in crop rotation greatly improves the N economy of the cropping systems and enhances crop productivity through additional N and other benefits in low N soils. The farmers who traditionally remove residues for fodder and fuel will require demonstration of the relative benefits of residues return to soil for sustainable crop productivity.  相似文献   

Growth,survival, and heavy metal (Cd and Ni) uptake of spinach (Spinacia oleracea) and fenugreek (Trigonella corniculata) in a biochar‐amended sewage‐irrigated contaminated soil          下载免费PDF全文

Uzma Younis  Muhammad Farooq Qayyum  M. Hasnain Raza Shah  Subhan Danish  Ahmad Naeem Shahzad  Saeed Ahmad Malik  Seema Mahmood 《植物养料与土壤学杂志》2015,178(2):209-217

Irrigation of arable land with contaminated sewage waters leads to the accumulation of trace metals in soils with subsequent phyto‐/zootoxic consequences. In this study, biochar derived from cotton sticks was used to amend an agricultural silt‐loam soil that had been previously irrigated with trace metal contaminated sewage waters. Metal accumulation and toxicity to spinach (Spinacia oleracea) and fenugreek (Trigonella corniculata) was investigated by measuring concentrations of Cd and Ni in plant tissues and various photosynthetic and biochemical activities of plants. Positive impacts of biochar on both spinach and fenugreek were observed in terms of biomass production that increased from 29% to 36% in case of spinach, while for fenugreek this increase was 32% to 36%. In the control treatment there was an increase in malondialdihyde, soluble sugar, and ascorbic acid contents, indicating heavy metal stress. Biochar applications increased soluble proteins and amino acids in plants and reduced the uptake of Cd from 5.42 mg kg^?1 at control to 3.45 mg kg^?1 at 5% biochar amended soil and Ni (13.8 mg kg^?1 to 7.3 mg kg^?1 at 5% biochar) by the spinach plants. In fenugreek, the Cd was reduced from 7.72 mg kg^?1 to 3.88 mg kg^?1 and reduction in Ni was from 15.45 mg kg^?1 to 9.46 mg kg^?1 at 5% biochar treated soil, reducing the possibility of transfer up the food chain. This study demonstrates that the use of biochar made from cotton‐sticks, as an amendment to arable soils that have received contaminated irrigation water, could improve plant growth and decrease Cd and Ni uptake to crops, alleviating some of the negative impacts of using sewage waters on arable land.  相似文献   

ULTRASONOGRAPHIC DETECTION OF FOREIGN BODIES IN SOFT TISSUES USING TURKEY MUSCLE AS A MODEL     

Zahid R.  Shah  MD  Jeffrey R.  Crass  MD  Dubravka C.  Oravec  MD  Errol M.  Bellon  MD 《Veterinary radiology & ultrasound》1992,33(2):94-100

Foreign bodies in the soft tissues are frequent problems in both veterinary and human medical practice. Radiography has been the principle tool for diagnosis, but is unable to define many foreign bodies. This study was undertaken to compare the sonographic and radiographic visualization for a variety of foreign bodies. Fresh turkey muscle (pectoral and thigh) with skin was used as the soft tissue model. Assorted foreign bodies were introduced 1 cm into the muscle. Materials examined were small wood fragments, steel wire, glass, nails, graphite, rock, BB pellets, and polystyrene plastic. Following introduction of the foreign bodies radiographs were obtained and the specimens were studied sonographically at 5.0 mHz and 7.5 mHz. All foreign bodies were visible with sonography. A bright echo with either acoustic shadowing or reverberations was present for all specimens. Radiographically metallic foreign bodies were visible but wood, some graphite, and plastic were not seen. We conclude that radiography should remain the primary imaging modality for foreign body detection because of its general availability and low cost. If radiography is negative ultrasound can detect and guide the removal of radiolucent foreign bodies.  相似文献   

Safety and efficacy of an oil-adjuvant vaccine against haemorrhagic septicaemia in buffalo calves: cross-protection between the serotypes B:2,5 and E:2,5.     

N H Shah  A A Jacobs  N H Shah  F K de Graaf 《The Veterinary record》2001,149(19):583-587

The safety, efficacy and duration of immunity of an improved oil-adjuvant vaccine against haemorrhagic septicaemia, containing inactivated cells of Pasteurella multocida serotype B:2,5, were tested in young buffalo calves in Pakistan. For safety testing, five buffalo calves were vaccinated intramuscularly with twice the normal dose, and six weeks later with a normal dose. Except for a transient rise in rectal temperature at six hours after the vaccinations, no systemic reactions were observed. The buffaloes remained in good condition and had a normal appetite. No local reactions were observed at the injection site. For efficacy testing two trials were carried out. In the first, buffalo calves were vaccinated intramuscularly either with two doses two-and-a-half months apart, or with a single dose, or left unvaccinated. They were challenged subcutaneously with virulent P multocida after eight, 13 or 15 months. After challenge at eight months the four buffaloes given two doses and the buffalo given one dose were protected, whereas the control animal developed the typical signs of the disease. After the challenges at 13 and 15 months, the vaccinated animals were still protected whereas the control animals died. In the second trial, buffalo calves were vaccinated intramuscularly either with two doses two months apart, or with a single dose at two months or left unvaccinated. The buffaloes were challenged after eight or 14 months. After challenge at eight months the four control animals died, whereas three of the four buffaloes given a single dose were protected. After challenge at 14 months, the three control animals died, whereas four of the five buffaloes given two doses and both the buffaloes given a single dose were protected. To test for cross-protection against the heterologous serotypes E:2,5 and B:3,4, groups of mice were vaccinated once or left unvaccinated. Four weeks later, the vaccinated and control groups were challenged with a dilution series of the different challenge cultures. The vaccine appeared to induce protection against challenge with different strains of serotypes B:2,5 and E:2,5 but not against strains of serotype B:3,4.  相似文献   

Stephanofilarial dermatitis in India     

M. C. Agrawal  H. L. Shah 《Veterinary research communications》1984,8(1):93-102

Four species ofStephanofilaria have been reported from India causing various forms of dermatitis in cattle, buffalo, goat and elephant. However, additional work is needed to establish their identity as separate species. The lesions appear to flare up following reinfection, while the application of a petroleum jelly alone reduces them. In vitro tests have shown organophosphorous compounds to possess stephanofilaricidal action in addition to their insecticidal activity. Aspects where further work is needed are indicated.  相似文献   

Spatial Patterns of Viable Spore Deposition of Gibberella zeae in Wheat Fields     

Schmale DG  Shah DA  Bergstrom GC 《Phytopathology》2005,95(5):472-479

ABSTRACT An increased understanding of the epidemiology of Gibberella zeae will contribute to a rational and informed approach to the management of Fusarium head blight (FHB). An integral phase of the FHB cycle is the deposition of airborne spores, yet there is no information available on the spatial pattern of spore deposition of G. zeae above wheat canopies. We examined spatial patterns of viable spore deposition of G. zeae over rotational (lacking cereal debris) wheat fields in New York in 2002 and 2004. Viable, airborne spores (ascospores and macroconidia) of G. zeae were collected above wheat spikes on petri plates containing a selective medium and the resulting colonies were counted. Spores of G. zeae were collected over a total of 68 field environments (three wheat fields during 54 day and night sample periods over 2 years) from spike emergence to kernel milk stages of local wheat. Spatial patterns of spore deposition were visualized by contour plots of spore counts over entire fields. The spatial pattern of spore deposition was unique for each field environment during each day and night sample period. Spore deposition patterns during individual sample periods were classified by spatial analysis by distance indices (SADIE) statistics and Mantel tests. Both analyses indicated that the majority (93%) of the spore deposition events were random, with the remainder being aggregated. All of the aggregated patterns were observed during the night. Observed patterns of spore deposition were independent of the mean number of viable spores deposited during individual sample periods. The spatial pattern for cumulative spore deposition during anthesis in both years became aggregated over time. Contour maps of daily and cumulative spore deposition could be compared with contour maps of FHB incidence to gain insights into inoculum thresholds and the timing of effective inoculum for infection.  相似文献   

Comparative field performance of some agricultural crops under a canopy of Populus deltoides and Ulmus wallichiana     

Tariq Hussian Masoodi  Nasir Ahmad Masoodi  Sajad Ahmad Gangoo  Shah Murtaza Mushtaq  Hillal Ahmad 《林业研究》2013,24(4):783-790

The performance of maize, beans and sunflower was evalu-ated under a canopy of Populus deltoides and Ulmus wallichiana at Fac-ulty of Agriculture, Wadura. The germination, growth and yield of the three...  相似文献   

Sources and Ecological Risks of Heavy Metals in Soils Under Different Land Uses in Bangladesh     

Mohammad Saiful ISLAM  Mohammad Kawser AHMED  Mohammad Habibullah AL-MAMUN  Shah Mohammad Asraful ISLAM 《土壤圈》2019,29(5):665-675

Soil heavy metal pollution, influenced by both natural and anthropogenic factors, significantly reduces environmental quality. In this study, Cr, Ni, Cu, As, Cd, and Pb in eight different land-use soils from Patuakhali District in Bangladesh were assessed. Concentrations of Cr, Ni, Cu, As, Cd, and Pb in soils were 1-87, 5-271, 4-181, 0-80, 0.2-24.0, and 5-276 mg kg^-1, respectively, measured using an inductively coupled plasma-mass spectrometer. The enrichment factor, pollution load index (PLI), and contamination factor (C_fⁱ) of metal i were used to assess the ecological risk posed by metals in soils. The PLI ranged from 0.78 to 2.66, indicating baseline levels to progressive deterioration of soil due to metal contamination. However, C_fⁱ of Cd ranged from 1.8 to 12.0, which showed that the studied soils were strongly impacted by Cd. Considering the severity of the potential ecological risk of a single metal, the descending order was Cd > As > Pb > Cu > Ni > Cr. Soils under all land uses showed moderate to very high potential ecological risk.  相似文献   

Potassium distribution in root and non‐root zones of two cotton genotypes and its accumulation in their organs as affected by drought and potassium stress conditions     

Xiao Wang  Ibrahim Mohamed  Maha Ali  Mohamed H. H. Abbas  Ghulam Mustafa Shah  Fang Chen 《植物养料与土壤学杂志》2019,182(1):72-81

A rhizobox experiment was conducted to compare the differences of soil potassium (K) distribution and absorption between two cotton (Gossypium hirsutum L.) genotypes under drought and K‐deficit conditions. Treatments included two levels of water (drought and optimum soil moisture: 25% and 35% volumetric water content) and K fertilizer rates (0 and 0.48 g potash kg^?1 soil) applied to two cotton genotypes (namely HEG and LEG). Both the genotypes showed significant differences in total K accumulation without exogenous K addition. After absorption, soil content of the readily available potassium (RAK) decreased rapidly. This promoted the conversion of the mineral K into slowly available potassium (SAK). Drought significantly decreased the cotton growth and K use efficiency, and thereby reduced the effect of K fertilizer. Consequantly, the contents of RAK and SAK were greatly increased. However, K bioavailability was decreased under water stress conditions. Differences in root parameters and soil microorganisms between two cotton genotypes were significantly increased and had marked relations with available soil K contents. This study provides important information for understanding the mechanism of K use efficiency, especially under water and K stress.  相似文献   

Effects of lactulose supplementation on the growth of bifidobacteria and biotransformation of isoflavone glycosides to isoflavone aglycones in soymilk     

Pham TT  Shah NP 《Journal of agricultural and food chemistry》2008,56(12):4703-4709

Bifidobacterium animalis subsp. lactis bb12 and B. longum 20099 were used to hydrolyze isoflavone glycosides (IG) to biologically active forms, which are isoflavone aglycones (IA), in soymilk (SM) prepared from soy protein isolate (SPI) and SM supplemented with 0.5% (w/v) of lactulose (SML). Supplementation of lactulose significantly ( p < 0.05) enhanced the viable counts of B. animalis subsp. lactis bb12 and B. longum 20099 up to 2.34 and 2.15 log CFU/mL, respectively. Bifidobacterium animalis subsp. lactis bb12 and B. longum 20099 utilized 3.32 and 3.75 mg/mL of lactulose at 24 h of incubation, respectively. Supplementation of lactulose also appeared to be a key factor in decreasing the pH of SML. The biotransformation of IG to IA was enhanced significantly by 6.8-17.1% and 12.8-13.5% in SML by B. animalis subsp. lactis bb12 and B. longum 20099, respectively. However, the presence of lactulose in SML showed the stimulating effect on B. longum 20099 only after 12 h of incubation. Isoflavone aglycones ranged from 69.5 to 77.1% of total isoflavone compounds in SML after incubation.  相似文献