Nutrient solution concentration and collection time in phytomass production,content, yield and chemical composition of essential oil of rosemary

Rosmarinus officinalis L. (rosemary), is a medicinal and aromatic species used in the cosmetics and food processing industries. The present study aimed to evaluate the biomass production, content, yield and chemical composition of the essential oil of rosemary in cultivation out of soil with different concentrations of nutrient solution in both harvests. The cultivation of rosemary was conducted in a protected system off the ground, with concentrations of nutrient solutions of 1, 2, 3, 4 and 5 dS.m^?1 for fertigation with collections of leaves 100 and 160 days after planting. Nutrient solution concentration influences phytomass production and the content and yield of essential oil of rosemary, though not its chemical composition. The collection time does not interfere in the content of essential oil; however, does interfere in the chemical composition; the production of phytomass and the yield of oil per plant are higher in collections at 160 days after planting.     

Effects of Foliar Application of FeSO4 and NaCl Salinity on Vegetative Growth,Antioxidant Enzymes Activity,and Malondialdehyde Content of Tanacetum balsamita L.

Salinity is one of the major environmental stressors which has deleterious effects on the growth, development, and yield of crops. Because of the gradual increase in soil and water salinity in the East Azarbaijan, Iran, Tanacetum balsamita L. cultivation in this region has always been associated with many problems. To study the effect of foliar spray of iron sulfate (FeSO₄) (0, 750, and 1500 mg L^?1) under sodium chloride (NaCl) salinity (0, 50, and 100 mM) on some physiological characteristics of Tanacetum balsamita L. plants, an experiment was conducted as a factorial based on complete randomized block design with three replications. Total soluble solids (TSS) and essential oil contents were significantly affected by the interaction effects of FeSO₄ foliar application and salinity levels. The highest TSS and essential oil content were found in the plants under NaCl₀ × FeSO₄ 1500 mg L^?1 treatment combination. Leaf length, leaf fresh and dry weights were influenced by both Fe foliar application and salinity levels. Foliar application of iron (Fe) positively affected leaf length, leaves fresh and dry weights, root fresh and dry weights and peroxidase (POD) content, especially at ₁₅₀₀ mg L^?1. Other traits such as leaf length, leaf fresh and dry weights, malondialdehyde (MDA), POD and catalase (CAT) contents were influenced by salinity levels. For POD, MDA, and CAT contents, the highest values were recorded with NaCl 50 and 100. The highest values of leaf length, leaf fresh and dry weights were found in the control plants.     

Towards sustainable production of peppermint (Mentha piperita L.) through integrated use of vermicompost and cowpea green manuring with synthetic nitrogen fertilization

A field experiment with peppermint (Mentha piperita L.) was conducted in a sandy loam (Typic ustifluvent) soil during 2007 and 2008 at Lucknow, India. Ten treatments consisting of control (no synthetic or organic nitrogen fertilization), synthetic nitrogen fertilization (SN) 75, 150 and 225 kg ha^?1 alone, vermicompost (VC) 3 t + 37.5 kg SN ha^?1, VC 6 t + 75 kg SN ha^?1 and VC 9 t + 112.5 kg SN ha^?1 and intercropping of one, two and three rows of cowpea for green manuring in combination with 50, 100 and 150 kg SN ha^?1, respectively, were evaluated in a randomized block design. Integrated use of VC 9 t with 112.5 kg SN ha^?1 produced maximum essential oil (94.3 kg ha^?1), increased the herb and essential oil yields by 104 and 89%, respectively, over control and reduced SN use by 50%, without affecting the quality of essential oil. Application of VC and intercropping of cowpea for green manuring significantly improved the organic carbon, available N, P and K content in soil over SN alone. To get sustainable production of peppermint, application of VC 9 t ha^?1 along with 112.5 kg N ha^?1 through synthetic fertilizer is recommended for light textured sandy loam soils.     

Physiological characteristics,gas exchange,and plant ion relations of quinoa to different saline groundwater depths and water salinity

The objective of this study was to investigate the influence of saline groundwater depths (SGDs) (0.3, 0.55, and 0.80 m) with salinity equivalent to irrigation water salinity (WS) and irrigation WS (10, 20, 30, and 40 dS m^?1) on physiological characteristics, gas exchange, and plant ion relations of quinoa in cylindrical lysimeters in greenhouse conditions. Root length density (RLD) in the soil layer close to the saline shallow groundwater decreased. Soil aeration was the key point for reduction in RLD by decreasing SGD that was intensified by the increase in WS. It is concluded that root of quinoa was sensitive to anaerobic soil conditions. Results showed that the mean value of leaf water potential (Ψ) dropped from ?1.53 to ?3.09 MPa by increasing WS from 10 to 40 dS m^?1. Increasing WS from the lowest to the highest level resulted in 48% decrease in leaf photosynthesis rate (A_n). Results revealed that leaf stomatal conductance (g_s) was more sensitive to salinity than A_n. Stomatal closure in quinoa started to occur when the Ψ value fell below approximately ?1.0 MPa. In general, increasing WS from 10 to 40 dS m^?1 resulted in about 4.6-fold, 2.1-fold, and 2.6-fold increase in plant Na⁺, Ca²⁺, and Cl^? concentration, respectively.     

Effects of foliar application of methanol on some physiological characteristics of Lavandula stoechas L. under NaCl salinity conditions

In order to study the effects of foliar applications of methanol (0, 15, and 30%) and NaCl salinity (0, 50, and 100?mM) on some physiological characteristics of Lavandula stoechas L. plants, a pot experiment was carried out at the Research Greenhouse of Azarbaijan Shahid Madani University. Physiological characteristics (stem and leaf dry weights, total phenolic and flavonoids compounds, chlorophyll a and K⁺ contents, and K⁺/Na⁺ ratio) were significantly affected by the interaction effects of Methanol foliar application and salinity levels. The highest K⁺ content, K⁺/Na⁺ ratio, chl a and stem dry weight, belonged to NaCl 0?×?Methanol 30% and NaCl 50?×?Methanol 30%. For the leaves’ dry weight, the greatest data were recorded for NaCl 0?×?Methanol 30% and NaCl 0?×?methanol 15%. Methanol spray promoted the total phenolic content, especially at NaCl 50?×?methanol 30% and NaCl 100?×?methanol 15% and 30% and flavonoid content at NaCl 50?×?methanol 30%. Anthocyanin content, essential oil percent, and flower dry weight were affected by NaCl salinity levels, and the highest amount of anthocyanin was recorded for the control treatment. The highest data for Essential oil was attained by the NaCl 0 and 50?mM. The Na⁺ content was affected by methanol foliar application and the highest amount was obtained in the control treatment. Both foliar application levels and salinity levels influenced the flower dry weight. The highest amount of the flower dry weight was recorded at 30% methanol spray level and 0?mM NaCl treatments. The results reveal that methanol application had significant effects on the physiological characteristics of Lavandula plants growing under salinity stress condition.     

Penconazole and calcium improves drought stress tolerance and oil quality in canola

In this study, the effects of penconazole (PEN) and calcium (Ca) on growth amelioration and quality of seed oil in canola (Brassica napus L.) under drought stress were investigated. Drought stress reduced the growth parameters (fresh weight and dry weight) in canola; however the application of PEN and Ca improved these parameters under drought condition. Inducing effect of Ca on protein content was more prominent than PEN. Proline content increased under drought stress and PEN and Ca treatment caused more induction it under drought. PEN and Ca alleviated the negative effects of drought stress in canola by inducing antioxidant defense. The application of PEN and Ca caused a significant reduction in lipid peroxidation and hydrogen peroxide and mitigation of the drought induced oxidative stress. Drought stress induced protein content, total phenol, flavonol content, soluble sugar, palmitic acid and palmitoloic acid, and reduced flavonoid content, oleic acid, linolenic acid, and linolonoic acid in canola seed. PEN and Ca increased palmitic acid, linoleic acid (Omega-6), linolenic acid (Omega-3), oleic acid, protein, and soluble sugar. Our results indicated that application of PEN and Ca enables canola plants to withstand the deleterious impact of drought stress and caused improvement of antioxidant capacity, essential fatty acids (linolenic acid and linolonoic acid) and oil quality in canola seed.     

Untapped amaranth (<Emphasis Type="Italic">Amaranthus </Emphasis>spp.) genetic diversity with potential for nutritional enhancement

Significant genetic diversity was observed in 218 out of a total of 1309 accessions of amaranth (Amaranthus hypochondriacus L.) and its seven wild relatives, A. spinosus L., A. dubius Mart. ex Thell., A. hybridus L., A. tricolor L., A. cruentus L., A. caudatus L., A. retroflexus L. for 24 nutritional parameters including total oil content, fatty acid profile, total protein content and amino acid profile. Diversity for total oil content (6.42–12.53%), linoleic acid (25.68–54.34%), oleic acid (21.97–42.01%) of the total fatty acids, total protein content (7.84–18.01%), among important essential amino acids; lysine content (0.66–11.12 g/16 g N), methionine (0.35–4.80 g/16 g N) and half cystine and (0.12–8.32 g/16 g N) was reported. The un-weighted pair-group method using arithmetic average cluster analysis based on pair wise Euclidean genetic distance grouped the accessions into seven major clusters. Histidine, half cystine, tyrosine, essential amino acids, total oil content, linoleic acid and oleic acid content were the major parameters contributing significantly to genetic diversity. Present findings indicate that significant diversity exists for nutritional parameters in amaranth germplasm. The promising accessions with higher multiple nutritive traits; protein content (>16%), oil content (>11%), lysine content (>7.5 g/16 g N) and EAA higher than the FAO reported values, were identified. This is the first report on detailed nutritional analysis of diversity collected worldwide. These could be used as potential breeding material for nutritional enhancement through genetic improvement. This will help in overcoming the “triple burden” of malnourishment, hidden hunger, and obesity.     

SELENIUM FERTILIZATION INFLUENCES BIOMASS,ELEMENTAL ACCUMULATIONS,AND PHYTOCHEMICAL CONCENTRATIONS IN WATERCRESS

Watercress (Nasturtium officinale R. Br.) produces carotenoids and sulfur-containing glucosinolates (GSs) beneficial to human health. Selenium (Se) imparts dietary health properties and substitutes for S in plant biochemical pathways. Experimental objectives were to determine the influence of Se fertilization on 1) biomass, 2) elemental accumulations, 3) carotenoids, and 4) glucosinolates in watercress leaf and shoot tissues. Watercress was greenhouse grown in solution culture with Se treatments of 0, 0.125, 0.25, 0.50, 1.0, 2.0, and 4.0 mg Se L^?1, delivered as sodium selenate (Na₂SeO₄). Fresh and dry biomass were unaffected while shoot tissue Se (P = 0.057) and S (P = 0.003) increased linearly in response to increasing Se treatments. Linear decreases were measured for β-carotene (P = 0.017) and lutein (P = 0.018) in response to increasing Se. Total levels of GS increased, then decreased quadratically (P = 0.003). Results indicate that Se supplementation can increase Se tissue concentrations and GS in watercress; however, carotenoids were negatively affected.     

Symbiotic parameters,growth, nutrient accumulation,productivity and profitability as influenced by integrated nutrient management in lentil (Lens culinaris)

Field experiments evaluated the effects of integrated nutrient management on symbiotic parameters, growth, nutrient accumulation, productivity and profitability of lentil (Lens culinaris Medikus). Application of recommended dose of nutrients (RDN, 12.5 kg N ha^?1 + 40 kg P₂O₅ ha^?1) + 25 kg ZnSO₄ ha^?1 + seed inoculation with biofertilizers [Rhizobium + phosphate solubilizing bacteria (PSB) + plant growth promoting rhizobacteria (PGPR)] + 1.0 g ammonium molybdate kg^?1 seed recorded the highest number & dry weight of nodules, leghaemoglobin content, root & shoot dry weight, plant height, number of pods plant^?1 and 100-seed weight. The next best treatment was RDN + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg^?1 seed. On the basis of mean of three-year data, the treatment of RDN + 25 kg ZnSO₄ ha^?1 + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg^?1 seed proved the best in realizing the highest grain yield (34.0%), gross returns (34.0%) and net returns (54.8% higher over control). Nitrogen, phosphorus and potassium in the grains and straw were significantly improved where RDN was applied in combination with seed inoculation, basal application of ZnSO₄ and seed treatment with 1 g ammonium molybdate than their single applications.     

Insecticidal activity of two formulations of essential oils against the cereal leaf beetle

Purpose: Plant-derived essential oils and their encapsulations have recently received increasing interest as an alternative to synthetic biopesticides suitable for integrated pest management and organic farming. In this study, combinations of essential oils (EO) from Rosmarinus officinalis with Cymbopogon citratus and Pelargonium graveolens with Thymus vulgaris in two formulations including encapsulate were tested for their potential for wheat protection against adults and larvae of Oulema melanopus (L.).

Materials and methods: The chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of insecticidal activity of the evaluated substances was conducted with 2.5?ml of tested combinations of EOs sprayed on the paper. Ten adults or larvae of O. melanopus were placed into a vessel. Control of mortality of O. melanopus specimens was assessed after 24?h after establishment of the experiment.

Results and conclusions: Tarsal contact toxicity assay showed the effectiveness of EO in concentration against O. melanopus larvae and adults in both formulations (essential oil and encapsulation) causing 100% mortality within 24?h. These results indicate the great potential of these essential oils and their encapsulations for future use in crop protection against insect pests.     

Effect of sulphur on biochemical parameters of rapeseed (Brassica campestris L.) in grey terrace soil

An experiment was conducted to study the biochemical response of rapeseed (Brassica campestris L.) to sulphur (S) fertilization at grey terrace soil. There were five treatments: S₀ (control), S₁ (20 kg S ha^?1), S₂ (40 kg S ha^?1), S₃ (60 kg S ha^?1) and S₄ (80 kg S ha^?1). Chlorophyll content in the leaf was determined at 30, 40, 50 and 60 days after emergence (DAE). The biochemical properties were found responsive to S. The highest chlorophyll content of mustard leaves was found in 60 kg S ha^?1 at 50 DAE. The same treatment also showed the maximum N content in the leaves at 45 DAE. The highest oil content was recorded in 60 kg S ha^?1. Other chemical characters such as acid value, peroxide and saponification values were lowest in 60 kg S ha^?1 while iodine value was found highest in the same S level. Non-essential fatty acids such as palmitic, stearic and erucic acid were increased in the rapeseed with decrease in S level, whereas essential fatty acids were maximum in 60 kg S ha^?1. Therefore, 60 kg S ha^?1 can be recommended to produce quality rapeseed in grey terrace soil of Bangladesh.     

Effects of salinity,drought, and priming treatments on seed germination and growth parameters of Lathyrus sativus L.

Germination of plants is one of the most important stages during their growth, which is often influenced by environmental stresses, especially drought and salinity. This study was conducted to investigate the effects of salinity and drought on seed germination and growth of Lathyrus sativus. The experiment was laid out in a completely randomized design with factorial arrangement in four replications. Salinity treatments were 0, 2, and 4 dS/m and drought treatments included 0, 0.4, 0.8, and 1.2 MPa. Salinity and drought treatments were prepared by using sodium chloride and polyethylene glycol 6000, respectively. The results showed that salinity and drought stresses decreased germination percentage, and root and radicle length.     

Content and composition of essential oil and content of rosmarinic acid in lemon balm and balm genotypes (<Emphasis Type="Italic">Melissa officinalis</Emphasis>)

Lemon balm (Melissa officinalis L.) is used since ancient times because of its sedative, spasmolytic and antiviral effects. Its therapeutic impact is due to the content of essential oil and rosmarinic acid. A set of 68 M. officinalis genotypes was evaluated for content and composition of essential oil and the content of rosmarinic acid. For all genotypes the level of ploidy was determined. The 68 genotypes were clone plants grown and evaluated for two years at Quedlinburg. For analysis of secondary metabolites distillation, gas chromatography and high performance liquid chromatography was used. The content of essential oil varied in this study in ranges from 0.03 to 0.33% for the second cut 2010 and 0.01–0.35% for the second cut 2011. The rosmarinic acid content ranged in the year 2010 from 3.67 to 7.55% and in the year 2011 from 4.92 to 8.07%. Via statistical analyses two chemotypes of essential oil were found: chemotype citral and chemotype β-caryophyllene oxide. Ploidy was determined for all genotypes and two cytotypes were found: diploid 2n = 2x = 32 (62 of 68 genotypes) and triploid 2n = 3x = 48 (6 of 68 genotypes).     

Screening different crested wheatgrass (Agropyron cristatum (L.) Gaertner.) accessions for drought stress tolerance

A pot experiment was conducted in a greenhouse to evaluate the effect of drought stress on growth and turf quality of 24 accessions of crested wheatgrass (Agropyron cristatum (L.) Gaertner.) and ‘Rembrandt’ tall fescue, and to find the most drought-tolerant accession(s) of crested wheatgrass. The grasses were treated in well-watered or exposed to drought stress by withholding water for 20 days. Visual turf quality of drought-stressed plants had no significant differences with well-watered plants until day 8 of drought and 1727 P10 had the highest turf quality at day 20 of drought. Cluster analysis classified the accessions and Rembrandt into five clusters comprised of drought tolerant (I), intermediate (II, IV and V) and susceptible (III) in response to soil drying. Turf quality, green tissue, relative water content and electrolyte leakage of cluster I (1727 M, 208 M, 4056, 2854 and 1727 P1) were 1.8-, 2.0-, 1.6- and 0.6-fold of cluster III (Rembrandt) under drought stress conditions, respectively. Genetic diversity of cluster I could be used for plant breeding programmes and introduction of the drought-tolerant accessions to turfgrass breeders for drought tolerance varietal development programme.     

Nitrogen application method for improving yield and protein content of “Kitanokaori”, a new variety of winter wheat for bread use in Hokkaido

(Jpn. J. Soil Sci.Plant Nutr., 77, 273–281, 2006)

“Kitanokaori” is a new variety of winter wheat (Triticum aestivum L.) for bread use bred at the National Agricultural Research Center for Hokkaido Region. The grain protein content of wheat for bread use should be higher than 120 g kg?1. Much nitrogen application is necessary to obtain high grain protein content. Therefore, it is necessary to determine the optimum amount of nitrogen to obtain the required protein content and to prevent nitrogen from remaining in the soil. Field experiments were conducted for four years from sowing in 2000 to study the effect of the amount of nitrogen and the time of top-dressing. In the experiment in which sowing was carried out in 2003, nitrogen treatments were 40, 40–60, 40–60–0–60, 40–60–0–60–30, 40–60–0–60–60, 40–60–60–60, 40–60–60–60–30, 40–60–60–60–60, 40–60–30–30, 40–60–30–30–30 and 40–60–30–30–60 (each value showing the amount of applied nitrogen at sowing · re-growing stage · panicle formation stage · flag leaf stage · full heading stage, kg ha?1). The experiments were conducted in Andosol, which has moderate nitrogen fertility, and in Histosol, which is fertile soil.

Kitanokaori did not lodge with high-applied nitrogen, and both yield and protein content increased with an increase in applied nitrogen. In a moderate climate, Kitanokaori reached a protein content of 120 g kg?1 when the amount of absorbed nitrogen was about 190 kg ha?1, and the yield was about 7·8 Mg ha?1 at that time.

The top-dressing at the panicle formation stage was effective to raise the yield and the top-dressing at the full heading stage was effective to raise the grain protein content. It is recommended that the amount of applied nitrogen should be 160 kg ha?1 until the flag leaf stage, and additional nitrogen should be applied at the full heading stage to obtain a grain protein content of more than 120 g kg?1. Nutritional diagnosis at the full heading stage will be necessary to determine whether more nitrogen is needed to achieve the required protein content.

When the amount of total applied nitrogen did not exceed 220 kg ha?1, the amount of absorbed nitrogen was over 90% of applied nitrogen, and there was little inorganic nitrogen in the soil after harvest. Therefore, it was considered that the residue of nitrogen in the soil was small within 220 kg ha?1 of nitrogen application, while favorable growth and high yield were obtained.     

Zinc Sulfate Foliar Application Effects on Some Physiological Characteristics and Phenolic and Essential Oil Contents of Lavandula stoechas L. Under Sodium Chloride (NaCl) Salinity Conditions

Lavandula stoechas L. plant is a perennial evergreen used as a fragrant ornamental and medicinal plant. In order to study the effect of foliar spray of zinc sulfate (ZnSO₄) (0, 1000, and 2000 mgL^?1) and sodium chloride (NaCl) salinity (0, 75, and 150 mM) on some physiological characteristics of Lavandula stoechas L. plants, a pot experiment was carried out at the Research Greenhouse of Azarbaijan Shahid Madani University, Iran. Physiological characteristics [root and leaf dry weights, total soluble solids (TSSs), total anthocyanins, chlorophyll b, Zn²⁺, potassium (K⁺) contents, and K⁺/Na⁺ ratio] were significantly affected by the interaction effects of ZnSO₄ foliar application and salinity levels. The highest root dry weight, chlorophyll b, anthocyanin, and Zn contents as well as TSS were found in the plants with NaCl₀ × ZnSO_{4 2000} mgL^?1. For Na⁺, the greatest value was recorded with NaCl ₁₅₀ × ZnSO₄₀. The highest K⁺/Na⁺ ratio was found in the control plants. Foliar application of ZnSO₄ promoted the total phenolic content, especially at 2000 mgL^–1. The highest amounts of flower dry weights were recorded at NaCl₀. Chlorophyll a, total flavonoids, stem dry weight, and essential oil content were affected with ZnSO₄ treatment and salinity levels. The highest values for the essential oil content, chlorophyll a content, and stem dry weight were attained by the nonsaline treatment. Both foliar application levels positively influenced the essential oil and flavonoid contents of the plants. The results reveal that zinc application had marked effects on the physiological characteristics of Lavandula stoechas L. plants growing under salinity stress conditions.     

Improvement of yield,yield components and oil quality in sesame (Sesamum indicum L.) by N-fixing bacteria fertilizers and urea

Experiments were conducted in 2009–2010 at the Agricultural and Natural Resources Research Center of Yazd, Iran, to study the effect of nitrogen levels and plant growth-promoting rhizobacteria (PGPR) containing Azotobacter sp. and Azospirillum sp. on seed yield, its components and quality traits of sesame cultivars. Treatments were arranged in a factorial experiment based on randomized complete block design with nitrogen rates (0 (control), 25 and 50 kg N ha^?1), cultivars (Darab-14, GL-13 and local) and N-fixing bacteria levels (non-inoculation and inoculation) were applied with three replications. Nitrogen fertilizer significantly increased yield and yield components, but reduced oil content in 2010. Inoculating seeds with PGPR increased yield and yield components of sesame cultivars compared to the control treatment. Seed yield in PGPR inoculation with half a rate of N fertilizer treatment was more than seed yield in the full rate of N fertilizer without a PGPR inoculation treatment. N fertilizer and PGPR application significantly decreased saturated fatty acids (palmitic and stearic acid) while it significantly increased unsaturated fatty acids (oleic and linoleic acid). Oleic acid had a significant negative correlation with linoleic acid (r = ?0.79). The result showed that an application of PGPR could be usefully applied to reduce use of chemical fertilizer.     

Effects of Arbuscular Mycorrhizal Fungi on Seedling Growth and Physiological Traits of Melilotus officinalis L. Grown Under Salinity Stress Conditions

This study was conducted to determine the effects of arbuscular mycorrhizal (AM) inoculation on the leaf relative water content (LRWC), survival capacity, mycorrhizal dependency (MD), essential oil content and total protein content of Melilotus officinalis grown in a greenhouse under salinity stress. The experiment was conducted in a completely randomized factorial arrangement design using five replications. Zero (0), 50, 100, 150 and 200 mM sodium chloride (NaCl) and two AM fungal levels were applied. Control (without inoculation) and inoculated (with AM fungi) treatments were considered two mycorrhizal levels. LRWC and survival capacity values in AM Melilotus officinalis were significantly higher than that in the non-AM-inoculated plants. Generally, MD, essential oil content and total protein content values were significantly higher in the AM-inoculated Melilotus officinalis compared with the non-AM-inoculated plants in all treatments. Results suggest that Melilotus officinalis could be used for the economic usage of the saline lands.     

不同氮水平对生姜产量和品质及氮素吸收的影响

采用田间试验研究不同基础肥力土壤、不同氮肥水平对生姜产量和品质及氮素吸收的影响。结果表明,氮肥对生姜根茎产量及品质有明显的影响,合理施氮能显著提高根茎产量,改善其营养及安全品质。两种不同基础肥力土壤下,生姜根茎产量均表现为随施氮量的加大先增加后降低,呈抛物线关系,所有处理中N450获得了最高根茎产量。品质分析结果显示,施用适量氮肥能明显提高生姜根茎蛋白质、维生素C、糖分和姜精油含量,有效控制硝酸盐及亚硝酸盐含量。其中,维生素C含量,基础肥力较高土壤以N225处理最高;肥力较低土壤N450处理达到高峰。粗蛋白含量,肥力较高土壤N225处理最高,N450最低;肥力较低土壤,随施氮量的增加,根茎粗蛋白含量相应提高,N600处理达最大值。糖分和姜精油含量,两种肥力土壤下分别是N600和N450处理最高。根茎硝酸盐和亚硝酸盐含量随施氮量的增加而升高,与氮肥用量呈极显著正相关。施用氮肥后生姜地上部茎、叶和地下根茎含氮量明显提高,氮素吸收量显著增多。     

Spring camelina N rate: balancing agronomics and environmental risk in United States Corn Belt

Camelina (Camelina sativa (L.) Crantz) seed oil has desirable properties for producing advanced biofuels and as a healthy cooking oil. It has been grown for centuries, but basic recommendations for nitrogen (N) fertilizer requirements are still needed to support widespread industrial cultivation across North America. A replicated N-response plot-scale study was conducted on a northern Mollisol soil for two growing seasons to 1) determine seed and oil yield, seed oil content, and vegetative response; 2) determine indices of N use efficiency; and 3) measure post-harvest residual inorganic soil N as an index of environmental risk. Seed and oil yield response to N fertilization was described with a quadratic function, which predicted maximum seed yield (1450 kg ha^?1) and oil yield (580 kg ha^?1) at about 130 kg N ha^?1. However, seed and oil yield did not differ significantly among N-rates above 34 kg N ha^?1. Seed oil content averaged 400 g kg^?1 among all N rates. Agronomic efficiency declined above 34 kg N ha^?1, which coincided with an increase of post-harvest soil nitrate-N plus ammonium-N (residual N). Considering N use efficiency, simple cost analysis, and risk associated with residual N, a rate of 34 kg N ha^?1 is recommended.