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41.
Christienne N. Kuczak Erick C.M. Fernandes Marco A. Rondon 《Soil biology & biochemistry》2006,38(3):553-560
We compared differences in soil phosphorus fractions between large earthworm casts (Family Glossoscolecidae) and surrounding soils, i.e., Oxisols in 10 year-old upland agroforestry system (AGR), pasture (PAS), and secondary forest (SEC) in the Central Brazilian Amazon. AGR and PAS both received low-input fertilization and SEC received no fertilization. We found that earthworm casts had higher levels of organic hydroxide P than surrounding soils, whereas fertilization increased inorganic hydroxide P. Inorganic P was increased by fertilization, and organic P was increased by earthworm gut passage and/or selection of ingested materials, which increased available P (sum of resin and bicarbonate fractions) and moderately available P (sum of hydroxide and dilute acid fractions), and P fertilizer application and land-use increased available P. The use of a modified sequential P fractionation produced fewer differences between earthworm casts and soils than were expected. We suggest the use of a condensed extraction procedure with three fractions (Available P, Moderately Available P, and Resistant P) that provide an ecologically based understanding of the P availability in soil. Earthworm casts were estimated to constitute 41.0, 38.2, and 26.0 kg ha−1 of total available P stocks (sum of resin and bicarbonate fractions) in the agroforestry system, pasture, and secondary forest, respectively. 相似文献
42.
Abstract Only a small portion of soil phosphorus (P) is available to plants on a short-term basis, and therefore, P taken up by crops in one growing season is small compared to total P (Pt) content of the soil. A group of soil microorganisms capable of transforming insoluble P into soluble and plant accessible forms. The objective of this study was to evaluate the changes in soil P-pools and P uptake by wheat crops as influenced by inoculation with Bacillus thuringiensis in two soils (Andisol and Ultisol), the experiment was conducted in pots under greenhouse conditions using a completely randomized design. Wheat plants were inoculated and re-inoculated at 20 and 46?days after sowing, respectively, with B. thuringiensis; and, plant sampling were performed after 46, 66 and 87 and soil at 87?days based on the Zadoks growth scale, and the soil was submitted by Hedley’s P fractions. The inoculation with B. thuringiensis affected significantly some P organic P (Po) and inorganic P (Pi) fractions in both soils (Andisol and Ultisol), improved P uptake by wheat crop in (Ultisol) and decreased significantly in (Andisol). The positive effect was more consistent in Ultisol than in Andisol, this strain can be solubilized P fraction extracted with conc. HCl-Po and HCl 1?mol. 相似文献
43.
Erick D Aguilar-Miranda Mercedes G López Clara Escamilla-Santana Ana P Barba de la Rosa 《Journal of agricultural and food chemistry》2002,50(1):192-195
The larva of the Tenebrio molitor, known as the yellow meal worm, is a plague of wheat and flours. Consumption of the raw insects is not well accepted because of their appearance. The objective of the present work was to grow T. molitor larvae under standard conditions, to analyze the chemical composition of the larvae powder, and to prepare supplemented maize tortillas. Protein and fat contents were performed with standard methods. Tenebrio larvae powder had a 58.4% protein content; this protein was rich in essential amino acids such as phenylalanine, tyrosine, and tryptophan; the found values satisfied those recommended by the Food and Agriculture Organization. Fatty acid composition was determined by GC-MS showing high contents of oleic acid and linoleic acid (19.8 and 8.51%, respectively). A large proportion of unsaturated fatty acids of longer chains was detected. Long-chain fatty acids having two or three double bonds have been claimed as highly beneficial to health. Tortillas supplemented with larvae powder had excellent consumer acceptance, and tortilla protein content increased by 2% as well as the amount of essential amino acids. These results show new ways to consume insects and at the same time increase the nutritional value of the original food products. 相似文献
44.
45.
Erick Zagal Cristina Muñoz Soledad Espinoza Jorge Campos 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):263-272
Abstract Soil organic carbon (SOC) plays a key role in crop productivity and soil quality. Conservation agriculture has a positive effect on SOC accumulation in the surface soil horizons, but little information is available regarding the effect of the removal of crop residues by burning. This study aimed to assess the impact of different types of crop residue management practices on the total C distribution and natural abundance of 13C (‰, δ13C). Two volcanic soils, located in the Mediterranean temperate zone of Southern Chile, were studied: an Ultisol (Collipulli Series, CPL) and an Andisol (Santa Bárbara Series, SBA). Both soils had been cultivated under direct-drilling and a typical annual crop rotation system for a long period of time. Two different types of crop residue management practices were imposed in both soils: (i) crop residue burning (CPL-B; SBA-B) and (ii) crop residue retention over the soil (CPL-R; SBA-R), corresponding to treatments B and R, respectively. Soil profile distribution of the C content and natural abundance of 13C were analysed for bulk soils (down to 100 cm depth) and three particle-size fractions of the soils (down to 20 cm of soil depth): (a) ≤ 53 µm, (b) 53-212 µm and (c) ≥ 212 µm. It was found that the effect of crop residue management can be observed in the variations of C content and δ13C in the soil profile in both volcanic soils. Crop residue burning (B treatment) increased the C content in bulk soil and the particle-size fractions. On the other hand, soil organic matter of crop residue retention (R treatment) showed higher natural abundance of 13C (δ13C) compared with residue burning (B treatment) in the two volcanic soils. R treatment enriched the particle-size fractions (except ≥ 212 µm fraction of CPL soil) with 13C. Factors that could account for these findings are also discussed here. 相似文献
46.
Erick K. Cheruiyot Louis M. Mumera Wilson K. Ng'etich Ahmed Hassanali Francis N. Wachira 《Journal of plant nutrition》2013,36(1):115-129
A study to determine the association of fertilizer with soil water deficit in tea [Camellia sinensis (L.) O. Kuntze] was conducted in a rain-out shelter using potted plants, in which five rates of fertilizer (0, 75, 150, 225 and 300 kg Nitrogen ha?1) and six levels of soil water content (38, 34, 30, 26, 22 and 18% v/v) were applied in a complete randomized design and replicated three times. The soil water treatment was maintained for a period of 12 weeks during which shoot growth, plant water relations, and dry matter partitioning in tea were determined. A parallel field experiment with the above fertilizer rates was conducted at three sites in which shoot density and shoot weight were determined during the dry season. Fertilizer improved leaf-to-root and leaf-to-total mass ratios (P < 0.001), reduced shoot growth, shoot water potential and specific leaf area (P < 0.001). The fertilizer exacerbated drought effect on tea through disproportionate assimilate partitioning which consequently weakened the ability of tea to tolerate water stress. Results suggest an indirect contribution of fertilizer supply to drought susceptibility in tea. 相似文献
47.
Mang’era Samwel Mnyoro Erick V. G. Komba Aviti J. Mmochi 《Journal Of Applied Aquaculture》2020,32(1):70-80
ABSTRACTFishing is among the main economic activities of the people of Zanzibar. Few fish dealers are transforming this sector into mariculture. Among the farmed fish is milkfish. Diseases are among the limiting factors in the development of the mariculture industry. Among other zoonotic diseases, vibriosis is caused by bacteria from the genus Vibrio. This study aimed to establish the occurrence of Vibrio cholerae and Vibrio parahaemolyticus among milkfish farms in Zanzibar. A total of 380 milkfish were sampled. Swabs were collected from gills, intestine, and kidney of each sampled milkfish. Preliminary identification of V. cholerae and V. parahaemolyticus was done by biochemical tests. PCR was run on 16S rRNA, outer membrane protein W, and collagenase genes to confirm Vibrio species, V. cholerae, and V. parahaemolyticus respectively. Almost one-third (32.1%) of all sampled milkfish were found to contain targeted Vibrio; 18% and 29.5% of the sampled milkfish were positive for V. cholerae and V. parahaemolyticus respectively. 相似文献
48.
J. Brad Case DVM MS DACVS Ross Palmer DVM MS Diplomate ACVS Alex Valdes‐Martinez DVM Diplomate ACVR Erick L. Egger DVM Diplomate ACVS Kevin K. Haussler DVM DC PhD Diplomate ACVSMR 《Veterinary surgery : VS》2013,42(4):355-360
Objective
To report clinical findings and outcome in a dog with gastrocnemius tendon strain treated with autologous mesenchymal stem cells and a custom orthosis.Study Design
Clinical report.Animal
A 4‐year‐old spayed female Border Collie.Methods
Bone‐marrow derived, autologous mesenchymal stem cells were transplanted into the tendon core lesion. A custom, progressive, dynamic orthosis was fit to the tarsus. Serial orthopedic examinations and ultrasonography as well as long‐term force‐plate gait analysis were utilized for follow up.Results
Lameness subjectively resolved and peak vertical force increased from 43% to 92% of the contralateral pelvic limb. Serial ultrasonographic examinations revealed improved but incomplete restoration of normal linear fiber pattern of the gastrocnemius tendon.Conclusions
Findings suggest that autologous mesenchymal stem cell transplantation with custom, progressive, dynamic orthosis may be a viable, minimally invasive technique for treatment of calcaneal tendon injuries in dogs. 相似文献49.
50.