Biochars produced from different feedstocks (such as wood, pig manure) possess varying physical and chemical properties, which have influence on crack and evaporation rate of biochar-amended soil (BAS). Furthermore, influence of compaction state and drying-wetting cycles on evaporation rate and cracking of BAS has not been investigated comprehensively. The objective of this study was to investigate the effects of biochar types, compaction state of BAS, and drying-wetting cycles on crack propagation and retained water (or evaporation rate).
Material and methods
An animal and plant feedstock-based biochars were produced in-house from pig manure (PM) and wood (W), respectively. In addition, nano structured chalk and wheat biochar (CWB) were also produced. Soil amended with individual biochars was compacted in petri-glass discs at two densities. Disc specimens were subjected to multiple drying-wetting cycles, and evaporation rate of specimens and crack area were monitored throughout the experimental period (70 days). Images were captured after every 24 h and processed using image processing technique to obtain the crack intensity factor (CIF).
Results and discussion
The results show that plant-based W BAS showed the high water retention, i.e., low evaporation rate and low CIF. Furthermore, the crack potential of CW BAS was seen to be higher. In dense compacted soil, maximum CIF% can be reduced from 3.9 to 0.4% for W BAS, from 3.9 to 1.7% for PM BAS, and from 3.9 to 1.6% for CW BAS.
Conclusion
WB was able to resist cracking more efficiently than other types of biochar. Evaporation was found to be minimal for plant-based W BAS at 10% biochar percentage. Higher biochar content in soil was seen to increase the water retention of BAS significantly. Dense state of BAS at high biochar content (i.e., 10%) was effective in reducing evaporation rate and crack progression.
ABSTRACT Nitrogen uptake being part of nitrogen use efficiency (NUE) is largely decided by root traits. Root traits variability has hardly been explored by breeders mainly because of difficulties in scoring. The hydroponic system requiring lesser space for precise phenotyping of large numbers of genotypes independently of the growing season can be a suitable alternative. However, the effectiveness of hydroponic screening methods needs to be verified under the soil condition of the field or pot. In the present study, root traits and NUE were investigated in 19 genotypes under two conditions (hydroponic and pipe filled with soil). Both environments revealed large variability for root traits and NUE under high and low N conditions establishing the absence of any direct selection for these traits in the past. Under both sets of experimentation, NUpE was largely responsible for improved nitrogen efficiency mainly because of higher root biomass. The significant association between the two screening methods i.e. hydroponic and pot filled with soil under both low and high N condition support large scale screening for root traits under hydroponic condition. 相似文献
Impact of aeration on growth of silver barb, Puntius gonionotus during fingerling rearing was studied through a 100‐d rearing experiment conducted in 18 concrete tanks of 50 m2 (10 × 5 × 1.2 m) size. Fry (0.74 ± 0.27 g, 35 ± 6 mm) were stocked in the experimental tanks at three stocking densities (25, 50, and 75 fry/m2) and were evaluated with and without provision of 6 h (2400–0600 h) of night time aeration. Aeration resulted in higher pH and dissolved oxygen regime and increased fingerling length and weight. The results suggest a rearing density of 75/m2 to be ideal for rearing fry to fingerling of this species when aeration is provided, whereas, under non‐aerated condition, rearing the fry to fingerling stage at 50/m2 was found advantageous over those at 25 and 75/m2. 相似文献
Only a little is known about the studies done with filariasis in relation to blood groups. The present communication reports the results of a preliminary study carried out to investigate any relationship of ABO and Rho(D) blood groups in persons with circulating microfilariae (mf) in blood and with disease manifestations compared with healthy normal controls within a population in similar epidemiological and ecological conditions. Blood groups ABO and Rho(D) were investigated among 271 persons with filarial disease and 172 normal subjects from an endemic area of bancroftian filariasis. No relationship was observed between infection and blood groups. It appeared that blood groups and filarial infection were independent of each other. Also the sex of the individual and stage of the infection, i.e. persons with circulating mf only without manifestations and persons with established manifestation without mf, has no bearing on blood group inheritance. There were 95.05% of Rh-positive and 4.95% of Rh-negative persons in the whole studied population. The observations are similar to other studies. 相似文献
The photochemical degradation of the herbicide isoproturon in aqueous and non-aqueous solutions and in soils has been investigated. Four new photometabolites were formed in non-aqueous solution and three in soil. These were characterised by spectroscopic methods and identified by comparison with authentic synthetic samples such as 3-(4-isopropylphenyl)-1-methylurea; 3-(4-isopropylphenyl)urea; 4,4′-diisopropylazobenzene and 4,4′-diisopropylazoxybenzene. The pathway of formation of these photo products is depicted. 相似文献
Lyophilized somatic antigens obtained from fourth-stage larvae of Bunostomum trigonocephalum induced significant resistance against the development of L4 from L3 and adults from L4. The higher antigen dose (1,000 LE) significantly reduced the number of adults developed from L4 as compared to the lower dose (600 LE) which did so only insignificantly. Inflammation of the intestinal tissue and loosening of the intestinal luminal contents were characteristics of the immunized animals. 相似文献
Mycoplasma synoviae (MS) was isolated from a flock of commercial tom turkeys in which a small percentage of the birds exhibited clinical signs and lesions typical of MS synovitis. However, serologic testing of such flocks revealed poor to inconsistent reactivity by agglutination, enzyme-linked immunosorbent assay (ELISA) or hemagglutination inhibition; isolation of MS from such flocks proved to be very difficult. Turkeys were challenged with one of the isolates (K4463B) either by aerosol or systemically by a combination of intravenous, foot pad, and eyedrop routes. Turkeys challenged by the systemic route responded normally to all serologic tests, whereas those challenged by aerosol either responded very poorly on all serologic tests or were seronegative up to 6 wk postchallenge even though they were positive for MS by tracheal culture. These results suggest that turkeys may harbor an upper respiratory infection with MS while remaining serologically negative. 相似文献
A donor program for procuring dogs and cats to meet the needs of anatomical instruction was initiated six years ago at Tufts University School of Veterinary Medicine. The program was initiated in order to comply with state regulations that preclude the use of shelter animals and to satisfy ethical objections of students and faculty. The donor program has successfully met the animal needs for teaching gross anatomy and, in addition, provides opportunities to integrate clinical perspectives and ethics beginning from the first year of veterinary education. 相似文献
