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971.
A. Mozafar 《Plant and Soil》1994,167(2):305-311
A review of the literature showed that plants grown with organic fertilizers often contain higher concentrations of vitamins B1 (thiamin) and B12 (cyanocobalamin) as compared with plants grown with inorganic fertilizers. Since plant roots were recently shown to be able to absorb B1 and B12, it was thus suspected that organic fertilizers (such as manure of diverse sources or sewage sludges which often contain relatively high concentrations of several vitamins) introduce additional vitamins into the soil which in turn leads to increased vitamins in the plants. This possibility was studied by measuring the B12 content in the seeds of soybean and barley and in the leaves of spinach plants grown in soils amended with pure B12 or cow dung (which is naturally rich in B12). The addition of pure B12 or cow dung did not alter the B12 content in the soybean seeds but significantly increased that in the barley kernels and in the spinach leaves. For example, the addition of cow dung at the rate of 10 g kg–1 increased the B12 content in barley kernels by more than threefold (from 2.6 to 9.1 ng g–1 DW) and in spinach leaves by close to twofold (from 6.9 to 17.8 ng g–1 DW). Long-term addition of organic fertilizers to the soil also significantly increased the soil content of this vitamin. Since plants cannot synthesize B12 and thus plant foods are normally fully devoid of (or have very low concentrations of) this vitamin, the finding that plants grown with organic fertilizers may contain relatively higher concentrations of this vitamin may have nutritional consequences in that the consumption of these plants by humans would inadvertently increase their intake of this vitamin. This may be of special benefit to people living by choice or by necessity on strict vegetarian diets who are known to be in danger of B12 deficiency. 相似文献
972.
The study was conducted to determine Cd and Zn concentrations in soils with three different ages of oil palm trees (<10, >15, >20 years) and plant parts as affected by long-term application of phosphate rock fertilizers. To investigate this issue on Malaysia's oil palm plantations, six soil series that undergo a scheduled fertilizer program were collected. Jawa, Selangor, and Sedu Series were selected from a plantation in the coastal area, whilst Munchong, Rengam, and Segamat Series were collected from a plantation in the inland area. Fronds and fruitlets were also collected along with the soils (paired sampling). To verify the findings of the field study, Cd and Zn adsorption isotherms were prepared. Competitive adsorption between Zn and Cd was also conducted. There was no accumulation of Cd in all the soil series but Zn accumulated in the Selangor and Segamat Series. Fruitlets (edible part) show no increase in Cd and Zn concentrations, but Jawa and Selangor Series show increasing values of Zn concentrations in the fronds. A correlation study reveals that soil pH and clay content were the soil properties that controlled Cd and Zn concentrations in soils. Cadmium in soils and soil solutions most probably contributed to the Cd concentrations in fruitlets, whereas Cd and Zn in soils may influence the uptake of these elements by the oil palm trees. The highest Cd and Zn accumulation in Segamat Series Soil had been shown in the adsorption isotherm study. Cadmium adsorption was decreased in the presence of Zn, leading to no accumulation of Cd in all the soil series. 相似文献
973.
974.
JOHN W. TURNER JR. IRWIN K. M. LIU DOUGLAS R. FLANAGAN ALLEN T. RUTBERG JAY F. KIRKPATRICK 《The Journal of wildlife management》2007,71(2):662-667
ABSTRACT ABSTRACT Previous studies reported one year of contraception associated with a 1-injection porcine zona pellucida (PZP) vaccine. We have subsequently determined contraceptive effectiveness of a presumptive 1-injection, 2-year-duration PZP vaccine in free-roaming wild horses (Equus caballus) in Nevada, USA. In January 2000, we captured, freeze-branded, treated, and subsequently released 96 adult females that received 1) a primary dose of vaccine emulsion consisting of aqueous PZP and Freund's Complete Adjuvant, and 2) booster doses of PZP and adjuvant in controlled-release polymer pellets. We determined PZP release characteristics of pellets in vitro, prior to field use. We determined reproductive success in treated and untreated females through October 2004 via measurement of estrone sulfate and progesterone metabolites in fresh feces collected from the ground and by twice-annual foal counts. Among treated females, annual reproductive success from 2001 though 2004 sequentially was 5.9%, 14.0%, 32.0%, and 47.5%. Untreated females showed average reproductive success of 53.8 ± 1.3% across this period. This study revealed that: 1) PZP acted as an effective contraceptive for 2 years posttreatment; 2) some residual contraceptive effect remained in year 3; and 3) fertility returned to control levels by year 4 posttreatment. It appears that controlled-release technology can replace both the second(1-month) and annual booster injection of PZP vaccine, thereby decreasing cost and increasing efficiency of use of this vaccine in wild horse management. 相似文献
975.
Dajun Ren Yaohui Cheng Chaofan Huang Zhaobo Wang Shuqin Zhang Xiaoqing Zhang 《Soil & Sediment Contamination》2021,30(2):201-215
ABSTRACT In this paper, laccase is immobilized by the cross-linking method, using organic fertilizer as a carrier and glutaraldehyde as a cross-linking agent. Here, the optimal conditions of laccase immobilization were explored and the optimal operating conditions and stabilities of free laccase and immobilized laccase were also studied. Then, free laccase and immobilized laccase were applied to the soil remediation. Meanwhile, the effect of soil improvement treated with immobilized laccase was studied through ecological evaluation. The results showed that the optimal conditions for laccase immobilization were: the volume fraction of glutaraldehyde was 5%, the amount of enzyme added was 15 mL, and the immobilization time was 6 h. Under the same conditions, thermal stability and acid-base stability of immobilized laccase were better than free laccase. Under the optimal conditions, using laccase to treat 2,4-dichlorophenol in the soil, it was found that the free laccase group degraded 44.4% within 5 days, while the immobilized laccase group degraded 58.6%. Although both the degradation trends and route are the same, the degradation effect of the latter is obviously better. Ecological evaluation showed that organic fertilizer carrier had an impact on soil physical and chemical properties and soil enzymes, playing a positive role in soil ecological security and improving the soil. 相似文献
976.
Shivaraman N. Vaidya A.N. Waghmare S.V. Paunikar W.N. Tankhiwale A. Padoley K. 《World journal of microbiology & biotechnology》2001,17(5):447-453
A two-stage non-conventional bench scale biological treatment system was investigated for the treatment of the wastewater laden with ammonium nitrate. The first stage which consisted of a fixed film anoxic reactor effected denitrification of nitrate ion, while the second stage consisting of a pond effected ammonia removal. Dissimilatory denitrification requires external carbon source as an electron donor. Methanol was used as electron donor in this system. The system exhibited substantial nitrate and ammonia removal. The influent nitrate-N concentration which was on average 193.87 ± 12.68 mg/l was reduced to 5.86 ± 4.86 mg/l in the denitrification unit. There was only a marginal reduction of ammonia in the denitrification unit and most of the ammonia-N was removed in the pond. The ammonia-N was reduced from an average value of 104.87 ± 3.49 mg/l at denitrification unit inlet to 33.37 ± 8.12 mg/l at the pond outlet. There was no corresponding increase in the nitrite or nitrate concentration in proportion to ammonia reduction in the pond. The average nitrate concentration in the pond outlet was 2.4 ± 0.93 mg/l. Microbiological investigation of the system revealed the presence of significant populations of denitrifying organisms in the first stage, and denitrifying, nitrifying and algal populations in the second stage. The system also sustained wastewater of pH as low as 3.87 and appears to be very promising for larger scale industrial wastewater treatment. 相似文献
977.
M. Georgi S. Voerkelius A. Rossmann J. Graßmann W. H. Schnitzler 《Plant and Soil》2005,275(1-2):93-100
In this paper we discuss the use of isotope ratios as indicators of organic production. Few studies have investigated the
influence of plant nutrition on the isotopic signatures of plants. As plant nutrition is often significantly different between
integrated and organic production systems the isotope ratios in the plants may reflect this. Plant samples from a 2-year field-experiment
were analyzed for 15N, 13C and 34S content of the bulk-material and 18O-content of the leaf water. In this experiment cabbages (Brassica oleracea v. capitata f. alba cv. Rolly), onions (Allium cepa cv. Alisa Craig), lettuces (Lactuca sativa v. capitata cv. Ponchito) and Chinese cabbage (Brassica pekinesis cv. Parkin) were cultivated according to good agricultural practices for integrated and organic production. No differences
in the δ
34S and δ
18O values of the plants grown under the two production systems were observed. The organically produced vegetables were significantly
enriched in 15N and depleted in 13C compared to those grown under the integrated system. 相似文献
978.
以湖北当阳柑橘园杂草群落为对象,研究绿肥种植(自然生草和间种光叶苕子)下配施减量氮肥处理(当地推荐施氮肥量的0%、70%、85%、100%)对橘园杂草群落组成和多样性的影响,并运用Pearson相关分析和典范对应分析探究土壤因子对不同处理下杂草多样性和物种组成的影响。结果显示:(1)经样方调查,试验区共记录杂草植物21科29属30种,以禾本科和菊科为主,稗(Echinochloa crusgalli(L.)Beauv.)、酢浆草(Oxalis corniculata L.)、野老鹳草(Geranium carolinianum L.)等是所有处理中的共有种,自然生草下以匙叶鼠麴草(Gnaphalium pensylvanicum Willd.)和稗为优势种,间种光叶苕子(Vicia villosa Roth.var.glabrescens Koch.)下以酢浆草为优势种;(2)不同氮肥施入量下柑橘园草本物种Margalef指数、Patrick指数、Shannon-Wiener多样性指数和Pielou均匀度指数均无显著差异;相同施肥量下,间种光叶苕子能显著降低柑橘园杂草群落的物种多样性指数;(3)速效磷是显著影响柑橘园草本植物多样性指数的土壤因子;(4)不同处理下影响杂草物种分布的主要土壤因子是速效磷、pH值、含水率和温度。本研究认为无论减施氮肥与否,间种光叶苕子比自然生草更能显著降低杂草群落的物种多样性,从而避免恶性杂草与果树争肥。 相似文献
979.
Wafa Atma Mohammed Larouci Boumedienne Meddah Khéloufi Benabdeli Pascal Sonnet 《International journal of phytoremediation》2017,19(4):377-386
This study investigates the accumulation and distribution of nickel in Arundo donax L. parts to assess the potential use of this plant in phytoremediation of Ni-contaminated soils. The effect of ethylene diamine tetra-acetic acid (EDTA) and nutrient solution containing NPK on the plant was proped. A 35-day pot experiment was performed in the laboratory and the pots were irrigated with Ni-contaminated solution combined or not with EDTA and NPK. The growth of plants was evaluated at the end of the experiment. The accumulation of Ni was analyzed by atomic absorption spectroscopy (AAS). The obtained results indicate that the plant was able to survive with high Ni content. The growth and the concentrations of Ni in the plant tissues were less affected. In the absence of the amendments, Ni was accumulated in the stems and leaves. However, the addition of NPK significantly reduced Ni concentration in the stems and leaves. The application of EDTA enhanced Ni uptake in roots. The translocation factor (TF) was greater than 1, which categorizes A. donax L. as a great candidate for Ni phytoextraction. A. donax L. is suitable for phytoremediation of Ni. This investigation contributes to the studies on the potential of phytoremediation technologies in Algeria. 相似文献
980.
Niharika Rahman Thilde Bech Bruun Ken E. Giller Jakob Magid Gerrie W. J. van de Ven Andreas de Neergaard 《Global Change Biology Bioenergy》2019,11(9):1056-1074
A continuous rise in the global demand for palm oil has resulted in the large‐scale expansion of oil palm plantations and generated environmental controversy. Efforts to increase the sustainability of oil palm cultivation include the recycling of oil mill and pruning residues in the field, but this may increase soil methane (CH4) emissions. This study reports the results of yearlong field‐based measurements of soil nitrous oxide (N2O) and CH4 emissions from commercial plantations in North Sumatra, Indonesia. One experiment investigated the effects of soil‐water saturation on N2O and CH4 emissions from inorganic fertilizers and organic amendments by simulating 25 mm rainfall per day for 21 days. Three additional experiments focused on emissions from (a) inorganic fertilizer (urea), (b) combination of enriched mulch with urea and (c) organic amendments (empty fruit bunches, enriched mulch and pruned oil palm fronds) applied in different doses and spatial layouts (placed in inter‐row zones, piles, patches or bands) for a full year. The higher dose of urea led to a significantly higher N2O emissions with the emission factors ranging from 2.4% to 2.7% in the long‐term experiment, which is considerably higher than the IPCC standard of 1%. Organic amendments were a significant source of both N2O and CH4 emissions, but N2O emissions from organic amendments were 66%–86% lower than those from inorganic fertilizers. Organic amendments applied in piles emitted 63% and 71% more N2O and CH4, respectively, than when spread out. With twice the dose of organic amendments, cumulative emissions were up to three times greater. The (simulated) rainwater experiment showed that the increase in precipitation led to a significant increase in N2O emissions significantly, suggesting that the time of fertilization is a critical management option for reducing emissions. The results from this study could therefore help guide residue and nutrient management practices to reduce emissions while ensuring better nutrient recycling for sustainable oil palm production systems. 相似文献