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251.
《Communications in Soil Science and Plant Analysis》2012,43(10):1449-1467
The status of available macronutrients [phosphorus (P) and potassium (K)] and soil organic carbon (SOC) of the surface soil under a rice–wheat cropping system was studied in 40 districts of the Indo-Gangetic Plains (IGP) of India. The soil samples were collected from the farmers' fields in four transects (Trans-, Upper, Middle, and Lower Gangetic Plains) of the IGP. The selection of farmers, villages, blocks, and districts within an agro-climatic zone (ACZ) was done on the basis of a multistage statistical approach. The available macronutrients were characterized as low, medium, and high. In Trans-Gangetic Plains, SOC, available P, and available K were in the ranges of 0.06–0.86%, 6.7–85.1 kg ha?1, and 50–347 kg ha?1, respectively. In Upper Gangetic Plains, the respective values were in the ranges of 0.05–2.55%, 4.5–155.0 kg ha?1, and 45 to 560 kg ha?1. Similarly, in Middle Gangetic Plains, these values were in the ranges of 0.04–2.01%, 4.7–183.7 kg ha?1, and 72–554 kg ha?1, respectively. In Lower Gangetic Plains, respective values were 0.12–1.78%, 2.2–112.0 kg ha?1, and 83–553 kg ha?1. In Trans-Gangetic plains, the majority of the soils in the midplains ACZ representing intensively cultivated rice–wheat system area were low to medium in SOC and available P, whereas available K status was medium to high. Irrespective of the agroclimatic variations, more than 90% of the soils were low to medium in SOC and available P with a marginal deficiency of K. The majority of the coarse-textured soils in Shiwaliks were found to have low to medium SOC and available P, whereas less intensively cultivated arid zone soils were high in SOC, available P, and available K. In Upper and Middle Gangetic Plains, the majority of the soils tested medium for SOC and medium to high in available P and K. The dominance of medium status of available P in these soils could be due to mining of soil P by the rice–wheat cropping system practiced in these regions for more than 300 years. In Lower Gangetic Plains, the SOC was medium to high in most of the soils, whereas available P and K were high. Recent introduction of the rice–wheat system on intensive scale in these traditionally rice-growing areas resulted in less mining of SOC, P, and K. 相似文献
252.
L. Ai Z. H. Li Z. X. Xie X. L. Tian A. E. Eneji L. S. Duan 《Journal of Agronomy and Crop Science》2008,194(5):360-368
We studied the effects of coronatine (COR), a structural and functional analogue of jasmonates, on the drought tolerance of two rice cultivars, Handao 297 (a drought-tolerant upland rice) and Yuefu (a drought-sensitive lowland rice). Seedlings were treated with COR at the three-leaved stage at 0.01 and 0.1 μm for 24 h, followed by imposition of water deficit induced with 20 % polyethylene glycol (PEG). Water stress reduced the biomass of both cultivars and increased leaf lipid peroxidation and solute leakage. Pre-treatment with COR significantly increased the activities of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase in leaf tissues of water-stressed Handao 297 (0.01 μm ) and Yuefu (0.1 μm ) seedlings. COR supplement also increased the accumulation of 44 and 32 kDa polypeptides in water-stressed Handao 297 (0.01 and 0.1 μm ) and Yuefu (0.1 μm ) and significantly induced the expression of 29 kDa polypeptide in Handao 297. The results suggest that COR might alleviate drought stress by activating antioxidant enzymes and inducing proteins, thereby preventing membrane peroxidation and denaturation of bio-molecules. Thus, membrane permeability decreased substantially by 24–27 % in Handao 297, and 22–29 % in Yuefu. The optimal concentrations conferring drought resistance were 0.01 for the upland rice and 0.1 μm for the lowland cultivar. 相似文献
253.
Tung Thanh Nguyen Ken-ichi Kakuda Hiroshi Fujii 《Soil Science and Plant Nutrition》2020,66(1):116-124
ABSTRACT In Japan, rice straw (RS) is commonly incorporated into the soil after harvest to maintain the fertility of paddy soil. However, in mixed crop–livestock systems, RS is collected to feed livestock and then cow dung compost (CDC) is applied to the fields. We found in previous research that CDC supplied more N to the fields than RS, but the soil total N and available N of fields to which CDC was applied were similar to those receiving conventional RS application. To identify the reason for this result, we investigated the N inputs (organic matter, fertilizer, N fixation), N outputs (plant N uptake, N leaching loss), and the N balance of RS application (RS treatment) and RS removal plus CDC application (CDC treatment) in 10 neighboring paddy field pairs in Mamurogawa town, Yamagata Prefecture, Japan. The N fertilizer contributed the highest percentage to total N input, followed by organic matter and N fixation. The amounts of N fertilizer and N fixation in the RS treatment were similar to those in the CDC treatment. CDC contributed significantly more N to the fields than RS, but the total N input was similar between treatments. The N output from plant N uptake and leaching loss were higher in the CDC treatment than the RS treatment, but the difference was not significant. Plant N uptake was the main N output, accounting for 98% of total N output. The N balance was positive and similar between treatments. Therefore, the non-significant differences in total N input, total N output, and N balance between treatments explain the similarity in soil total N and available N. 相似文献
254.
Teodulo González-Quirino José Alberto Delgadillo José Alfredo Flores Jesús Vielma Gerardo Duarte Manuel de Jesús Flores Angélica Terrazas Luis Angel Zarazaga Alexis Adrián Vargas-Cruz Ricardo Avilés Horacio Hernández 《Animal Science Journal》2021,92(1):e13646
The present experiments on goats were conducted with the aim of verifying (a) whether the identity of the goat kids can affect the characteristics of milk let-down during suckling (Study 1) and (b) whether the presence of the goat kids may improve the milk let-down during hand milking (Study 2). In Study 1, 16 lactating goats with twins and 12 with single kids were used. Dams with single goat kids ejected more milk when suckling their kids at Days 5 and 20 of lactation, than when suckling aliens. Dams with twins ejected more milk when suckling their own kids than aliens only at Day 5 of lactation. Taking into account all the dams, they ejected more milk with more fat, protein, and lactose during suckling their own litter than when suckling aliens. In Study 2, when dams (n = 13) were hand milked in the presence of their own litter or in its absence, they ejected more milk with more fat, protein, and lactose than when milked in the presence of alien kids. We conclude that milk let-down in goats can be influenced by the type of stimuli applied or to which they are exposed to during suckling and milking. 相似文献
255.
《Wood material science & engineering》2013,8(3-4):220-228
Abstract This study focuses on the water absorption and mechanical properties of composites made from softwood sawdust and plastics, such as virgin and recycled polypropylene and polylactic acid (PLA). The composites were processed by extrusion, and their properties were investigated by a water immersion test, mechanical tests and a cyclic test for moisture resistance. Scanning electron microscopy was used to study the morphology of the fracture surfaces of the composites. The composites made with recycled polypropylene had the lowest water absorption and thickness swelling of the studied composites. The PLA composites made with heat-treated sawdust showed the highest flexural strength. Of the polypropylene based composites, virgin polypropylene resulted in composites with higher flexural strength. The Charpy impact strength of the composites was found to have an inverse trend compared to flexural strength. Cyclic treatment of the studied composites resulted in 20–60% loss of flexural strength, depending on type of composite. 相似文献
256.
Optimal conditions for assaying hemolytic complement of goat (caprine) and swine (porcine) sera were determined. Effects of the following were tested: pH, ionic strength, calcium and magnesium ion concentrations, time and temperature of incubation, and ethylenediamine tetracetate concentration. Guinea pig erythrocytes sensitized with goat or cattle antibodies were the most sensitive target cells for goat complement. Sheep and cattle erythrocytes sensitized with rabbit hemolysin were the best target cells for swine complement. Barbital buffer, pH 7.3, ionic strength of 90 nmM relative salt concentration, containing 0.5 mM CaCl2 and 1 mM MgCl2 was the best for swine complement assay. Goat complement lysed best in a barbital buffer, pH 8, ionic strength of 90 to 120 mM of relative salt concentration, in presence of 0.5 mM CaCl2 and 1 mM MgCl2. The optimal incubation temperature was 37 degrees C for both complements. The complement dependent lysis required 75 minutes to reach its maximum. Ethylenediamine tetracetate in 4 mM concentration completely inhibited lysis by both species complements. The CH50 for goat sera varied between 18 and 75 per ml, in swine sera between 75 and 210 per ml. 相似文献
257.
A. M. Silvera A. Wallenbeck A. Butterworth H. J. Blokhuis 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2016,66(3):161-167
The present study was designed to investigate the effects of additional human contact (AHC) on the human–animal relationship (HAR) in broilers and on the birds’ productivity. A total of 1558 broiler one-day-old chicks were distributed into 12 equally sized pens at two different stocking densities (SDs), calculated on estimated weight at slaughter (4 pens with 32?kg/m2 and 8 pens with 16?kg/m2). Six groups (2 high and 4 low SDs) received AHC, which consisted of 30-min sessions with visual human contact three days/week. The remaining six groups received as little human contact as possible and served as controls. A touch test was used to assess the human–broiler relationship and the production parameters measured were growth rate, mortality, feed consumption and feed conversion. The AHC treatment had a positive effect on the quality of the HAR but failed to affect any production parameter. 相似文献
258.
Sarah Spencer Caroline Wheeler-Jones Jonathan Elliott 《Journal of veterinary pharmacology and therapeutics》2020,43(3):243-267
There is a growing body of experimental and clinical evidence supporting mineralocorticoid receptor (MR) activation as a powerful mediator of renal damage in laboratory animals and humans. Multiple pathophysiological mechanisms are proposed, with the strongest evidence supporting aldosterone-induced vasculopathy, exacerbation of oxidative stress and inflammation, and increased growth factor signalling promoting fibroblast proliferation and deranged extracellular matrix homeostasis. Further involvement of the MR is supported by extensive animal model experiments where MR antagonists (such as spironolactone and eplerenone) abrogate renal injury, including ischaemia-induced damage. Additionally, clinical trials have shown MR antagonists to be beneficial in human chronic kidney disease (CKD) in terms of reducing proteinuria and cardiovascular events, though current studies have not evaluated primary end points which allow conclusions to made about whether MR antagonists reduce mortality or slow CKD progression. Although differences between human and feline CKD exist, feline CKD shares many characteristics with human disease including tubulointerstitial fibrosis. This review evaluates the evidence for the role of the MR in renal injury and summarizes the literature concerning aldosterone in feline CKD. MR antagonists may represent a promising therapeutic strategy in feline CKD. 相似文献
259.
A 10-day-old Standardbred filly sustained a complex Salter–Harris type III fracture of the right, lateral, distal femoral condyle. The lateral condyle was fractured in transverse, sagittal and frontal planes. The filly was treated by restricting it and its dam to a small, level paddock until lameness was no longer apparent. The filly, when weaned at 7 months of age, was turned out to pasture with three other weanlings. The filly entered race training as a 2-year-old, qualified to race as a trotter, was placed second in its first start and won its third race. Conservative treatment should be considered as an option for a young horse with a minimally displaced, Salter–Harris type III fracture of the distal lateral femoral condyle. 相似文献
260.