首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Abstract

Long‐term potassium (K) fertilization practices are likely to affect the K content of soils. This study assessed the effect of long‐term K fertilization strategies for corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations on extractable K in the soil profile of a major Iowa soil type at two locations. The soil type was a Webster fine‐loamy, mixed, mesic, Typic Haplaquoll at both sites. Soil samples were collected from the 0–15, 15–30, 30–60, and 60–90 cm depths after 17 years (Site 1) or 19 years (Site 2) of K fertilization with combinations of two initial rates and four annual rates. The initial rates were 0 and 1,344 or 1,120 kg K ha‐1 at Site 1 and 2, respectively, and the annual rates ranged from 0 to 100 kg K ha‐1. Samples were analyzed for ammonium acetate‐extractable K (STK) and nitric acid (HNO3)‐extractable nonexchangeable K (HNO3‐K). Concentrations of STK and HNO3‐K in the top 0–15 cm soil layer at the two sites were higher for the high initial K rates and were linearly related with the annual K rate. Results for the subsoil layers varied between sites and extractants. At Site 1, annual rates of 30 kg K ha‐1 or higher resulted in a relative accumulation of HNO3‐K in the 15–30 cm layer. At Site 2, these rates resulted in relative accumulations of STK in the 30–60 cm layer and of HNO3‐K in the 60–90 cm layer, but with relative depletions of STK in the 15–30 and 60–90 cm layers. Thus, use of one extractant may not always be sufficient to evaluate cropping and fertilization effects on subsoil K. Long‐term K fertilization of corn and soybean rotations affected extractable K of both the topsoil and subsoil. The effects on subsoil K, however, were smaller compared with effects on the topsoil and varied markedly between sites, subsoil layers, and extractants.  相似文献   

2.
Four tomato (Lycopersicon esculentum Mill.) strains (203, 474, 546, and 576) that are equally efficient in potassium (K) absorption, but different in efficiency of K use were studied using a continuously flowing solution culture to determine the importance of K‐transport rate from root to shoot in relation to K‐use efficiency. Strains 203 and 546 are inefficient in K use, ratios of K in shoots to roots were found to be three times higher than those of the two K‐use efficient strains 474 and 576 when grown under low‐K stress (0.1 mM). In addition, both the K concentrations and rates of K flow in xylem exudates of decapitated strains 203 and 546 were significantly higher than those of strains 474 and 576. These results suggest that high rates of K transport from roots to shoots are unrelated to K‐use efficiency in the tomato strains grown under low‐K stress. Further studies of K distributions in leaves and stems found that K concentrations in matured leaves and stems of the two efficient strains 474 and 576 were markedly lower than those of the two inefficient strains 203 and 546, while K in young and expanding leaves of the efficient strains were significantly higher than those of the inefficient strains, indicating that the ability to mobilize K from matured leaves to young and expanding leaves is an important factor that contributes to K‐use efficiency in tomato plants grown under low‐K stress.  相似文献   

3.
Efficient use of potassium (K) by turf depends on the ability of roots to absorb a high proportion of the fertilizer K applied to the soil. Among turfgrass genotypes, variation in K absorption kinetics of roots and its inheritance is important in the development of genotypes that are more efficient in K absorption from the soil. Therefore, K uptake kinetics of six cultivars each of Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), and tall fescue (Festuca arundinacea Schreb.) were compared under greenhouse conditions. In 1990 and 1991, field studies of the same cultivars were conducted comparing clipping production rate, leaf blade K concentration, K recovery rate in clippings, K efficiency ratio and visual quality under a moderate K fertilization of 59 kg K/ha/year. Significant differences among species and cultivars were obtained for both absorption kinetics and field recovery of K. Significant correlations between some K uptake parameters and field performance were identified. These results show that genetic differences exist among turfgrasses for K utilization at both the interspecific and intraspecific levels and suggest that a screening program could be developed to identify turfgrass genotypes possessing superior K utilization.  相似文献   

4.
Abstract

In order to better understand some of the factors likely to affect measurements of KC1 extractable acidity, experiments were conducted using synthetic solutions and extracts from a wide range of contrasting soils. The reagents used for measuring exchangeable acidity (i.e., KC1 and KF) were also examined to evaluate the effects of chemical impurities on acidity measurements. Two commonly used titrimetric methods were adapted and tested to determine the accuracy and precision of acidity measurements. The exchangeable acidity of soil extracts was investigated by extraction methods, extractant concentration, and extractant volume. Results from the soil extract experiments indicated that continuous shaking has no significant effect on acidity measurements. Filtration, however, is critical, especially for acidic organic‐rich soils, since aluminum (Al) ions can be lost during centrifugation. Extractant concentration and volume had variable effects on the acidity measurements for individual soils. In general, the modified Yuan's method is preferable to the modified Thomas’ method for estimating exchangeable Al. To ensure successful determination of exchangeable acidity, we recommend using a wider KCl:soil ratio (>15:1, v/w) for organic soils with low base saturation and allophanic Andisols. In sum, potassium chloride and potassium fluoride extraction for estimating exchangeable acidity is applicable for most soils.  相似文献   

5.
Abstract

Calcium lignosulphonate (CaLS), a waste product from the pulp and paper industry, is expected to affect reaction of K fertilizer in the soil, thus influences their availability to crops. A clay soil (Typic Humaquept) was incubated with various amounts of CaLS (0 to 150 g kg‐1 soil) and potassium dihydrogen phosphate (0–25.64 mmol kg‐1 soil) for 240 h under moist conditions at 5 and 15°C. Subsamples were extracted with deionized water and the Mehlich‐III (M3) solution for the analyses of pH, and P, Ca, K and Mg concentrations and K adsorption (Kad). Higher temperature reduced M3 extractable K (KM3). CaLS and K additions increased M3 extractable Mg (MgM3) with Ca contributed more than did K as indicated by the standardized estimates. Additions of CaLS increased KM3. Potassium adsorption decreased with the increases in CaLS addition rates. Significant positive linear relationships were observed between Kad and the concentration ratio of [K+]/[Ca2+]½, suggesting that the potassium buffering capacity of the soil was reduced by the additions of CaLS, with the desugared CaLS being more effective than the non‐desugared CaLS. The increased slope values with the increases in CaLS additions of the linear relationships between KM3 and [K]/[Ca2+]½ indicated that CaLS improved the quantity and intensity relationships and increased the power of the soil supplying plants with K.  相似文献   

6.
There are substantial areas of dallisgrass (Paspalum dilatatum Poir.)‐common bermudagrass (Cynodon dactylon (L). Pers.) summer‐type pastures in the Southeastern Central Plain, but little information is available on their response to P and K fertilization. The purpose of this study was to measure the response of dallisgrass‐common bermudagrass pastures to P and K fertilization with and with‐ out N. Phosphorus and K were applied to two soils in May each year for three years. Yield data were collected by clipping a swath through the length of the plots when the minimum forage height was approximately 30 cm. Responses to P and K applications were obtained when the soil test levels were low to very low, but not when they were medium as determined by the Mississippi Soil Test (MST). Forage P concentration of the control in the medium P and K soil was within the adequate range of 2.8 to 3.4 g/kg, but forage K concentration was below the critical range of 16 to 18 g/kg. Forage P and K concentrations of the controls in the low P and K soil were below critical levels. At both locations forage P and K concentrations were increased by P and K fertilization. Available soil P increased with rate of P application but soil extractable K was unaffected by K application. No yield response to P and K are likely at medium soil test levels (MST) even at high rates of N. There was no response to P and K application without N.  相似文献   

7.
Abstract

Due to the discrepancy in metabolic sodium (Na) requirements between plants and animals, cycling of Na between humans and plants is limited and critical to the proper functioning of bio‐regenerative life support systems, being considered for long‐term human habitats in space (e.g., Martian bases). This study was conducted to determine the effects of limited potassium (K) on growth, Na uptake, photosynthesis, ionic partitioning, and water relations of red‐beet (Beta vulgaris L. ssp. vulgaris) under moderate Na‐saline conditions. Two cultivars, Klein Bol, and Ruby Queen were grown for 42 days in a growth chamber using a re‐circulating nutrient film technique where the supplied K levels were 5.0, 1.25, 0.25, and 0.10 mM in a modified half‐strength Hoagland solution salinized with 50 mM NaCl. Reducing K levels from 5.0 to 0.10 mM quadrupled the Na uptake, and lamina Na levels reached ‐20 g kg?1 dwt. Lamina K levels decreased from ‐60 g kg?1 dwt at 5.0 mM K to ‐4.0 g kg?1 dwt at 0.10 mM K. Ruby Queen and Klein Bol responded differently to these changes in Na and K status. Klein Bol showed a linear decline in dry matter production with a decrease in available K, whereas for cv. Ruby Queen, growth was stimulated at 1.25 mM K and relatively insensitive to a further decreases of K down to 0.10 mM. Leaf glycinebetaine levels showed no significant response to the changing K treatments. Leaf relative water content and osmotic potential were significantly higher for both cultivars at low‐K treatments. Leaf chlorophyll levels were significantly decreased at low‐K treatments, but leaf photosynthetic rates showed no significant difference. No substantial changes were observed in the total cation concentration of plant tissues despite major shifts in the relative Na and K uptake at various K levels. Sodium accounted for 90% of the total cation uptake at the low K levels, and thus Na was likely replacing K in osmotic functions without negatively affecting the plant water status, or growth. Our results also suggest that cv. Ruby Queen can tolerate a much higher Na tissue concentration than cv. Klein Bol before there is any growth reduction.  相似文献   

8.
Studies were conducted to determine the efficacy of K salts in alleviating lime‐induced chlorosis. Greenhouse studies using a Gibbon silt loam [fine‐silty, mixed (calcareous), mesic Typic Haplaquoll] and a 1: 1 mixture of Gibbon soil and washed sand were conducted with KCl, KNO3, K2SO4, K2HPO4, or KHCO3 applied at rates of 0, 250, and 500 mg K/kg soil. An FeEDDHA treatment was included for comparison. Similar studies were conducted at two field sites known to produce lime‐induced chlorosis. Potassium salts were applied at 0, 20, and 40 g K/m of row. In the greenhouse, plants treated with KCl, KNO3, and K2SO4 on Gibbon soil were less chlorotic than controls or plants treated with K2HPO4, or KHCO3. No K treatment totally alleviated chlorosis except FeEDDHA. Chlorophyll correlated positively with chlorosis rating. No relationship was found between leaf Fe uptake and chlorosis. Plants grown in soil/sand exhibited no chlorosis and had lower Fe uptake than plants grown in Gibbon soil. Thus chlorosis was not due strictly to low soil‐Fe availability or inadequate Fe uptake. Bicarbonate in the soil solutions of both growth media treated with KCl was lower than controls which may explain the reduced chlorosis associated with this treatment.

One field site showed positive effects of K treatments on chlorosis rating, chlorophyll concentration, and seed yield. No treatment was as effective as FeEDDHA in influencing plant growth or yield. Total leaf Fe concentration was unrelated to leaf chlorophyll concentration. Inorganic cation/anion ratios in the plant were from 4.4–8.4 which could cause net H+ efflux by the plant and alkalinization of plant tissues. One possibility is that H+ efflux solubilizes P in the rhizosphere, which after uptake could immobilize Fe in the plant. Application of KCl, KNO3, and K2SO4 generally lowered HCO3 content of the upper 15 cm of both soils. High bicarbonate could increase rhizosphere P availability and increase immobilization of Fe in the plant.  相似文献   

9.
The effect of potassium (K)‐calcium (Ca) ratios on the cation nutrition of Vitis vinifera L. cv. Négrette was investigated on grafted vines grown hydroponically to gain a deeper insight into the origin of the lack of acidity of some wines. Four nutrient solutions were investigated for long duration experiments: a balanced K‐Ca nutrient solution (K=3.9 meq L‐1 ; Ca=4.8 meq L‐1) used as a reference, a low K (K=0.3 meq L‐1; Ca=8.4 meq L‐1) and a high K (K=7.1 meq L‐1; Ca=1.6 meq L‐1) nutrient solutions. Besides, the reference nutrient solution was enriched with Ca (K=3.9 meq L‐1; Ca=13.8 meq L‐1) so as to simulate the possible effects of liming. The experiments showed that, in spite of low K requirements, the high K storage capacity of cultivar Négrette might account for the low acidity of the wines. However, a strong Ca‐K antagonism was characterized: the Ca enrichment of the reference nutrient solution resulted in a 30% decrease in the K concentration of leaf blades and petioles. Liming can thus limit K uptake by the plant and contribute to increased acidity of the wines issued from cultivars grown in acid soils.  相似文献   

10.
Abstract

Field and greenhouse studies were conducted in Idaho in 1985 to document the maximum levels of a salt fluxing residue (slag) material that can be safely applied to agricultural soils without reducing spring wheat (Triticum aestivum) growth. The slag material, which contains significant quantities of Mg and K, was applied to Mission (coarse‐silty, mixed, frigid Andic Fragiochrepts) and Palouse (fine‐silty, mixed, mesic Pachic Ultic Haploxerolls) silt loam soils at rates ranging from 0 to 40,000 kg/ha. Parameters evaluated included: (1) germination, (2) plant vigor, (3) yield, and (4) soil and plant tissue K, Ca and Mg.

Under field conditions slag application rates of 4,000 and 8,000 kg/ha reduced wheat stands and vigor; however, yields were not adversely affected when compared with the control. Application rates in excess of 8,000 kg/ha resulted in reduced germination, plant vigor, and yield and are consequently not recommended. Greenhouse studies provided further evidence to substantiate the field results.  相似文献   

11.
The hydroponic technique using expanded clay for the production of chrysanthemum was studied for possible use by Brazilian flower producers. Eight varying nutrient solution nitrogen (N):phosphorus (P):potassium (K) ratio treatments in a randomized block configuration with four replications were used. Six of the treatments supplied the same solution over the entire experimental period. The N:P:K ratios in the nutrient solution compared were: 1.0:0.3:1.0, 1.0:0.3:1.5, 1.0:0.3:2.0, 1.0:0.3:2.5, 1.5:0.3:1.0, and 2.0:0.3:1.0. The other two treatments consisted of N:P:K ratios of 2.0:0.3:1.0 during the juvenile stage and 1.0:0.3:1.5 or 1.0:0.3:2.0 ratios during the reproductive stage. There were two or three daily irrigations depending on plant need. The electrical conductivity (EC) and pH of the nutrient solution were checked once each day and the nutrient solution was chanced when 50% depleted. The plants were crown to the two‐stem stage under 50 long and 4.0 short days. Harvest was made 115 days after plant establishment. There were not expressive differences in plant characteristics among the treatments. The 1.0:0.3:2.5 N:P:K ratio gave the highest flower numbers per stem, stem length, and fresh and dry weights per plant.  相似文献   

12.
Abstract

Fertilizer placement for corn (Zea mays L.) has been a major concern for no‐tillage production systems. This 3‐yr study (1994 to 1996) evaluated fertilizer phosphorus (P) or potassium (K) rates and placement for no‐tillage corn on farmers’ fields. There were two sites for each experiment involving fertilizer P or K. Treatments consisted ofthe following fertilizer rates: 0,19,and 39 kg P ha‐1 or 0, 51, and 102 kg K ha‐I. The fertilizer was broadcast or added as a subsurface band 5 cm beside and 5 cm below the seed at planting. Early plant growth, nutrient concentrations, and grain yields were measured. At the initiation of the study, soil test levels for P and K at the 0–1 5 cm depths ranged from optimum (medium) to very high across sites. Effects of added fertilizer and placement on early plant growth and nutrient concentrations were inconsistent. Added fertilizer had a significant effect on grain yields in two of twelve site‐years. Therefore, on no‐tillage soils with high fertility, nutrient addition, and placement affected early plant growth and nutrient utilization, but had limited effect on grain yield. Consequently, crop responses to the additions of single element P or K fertilizers under no‐tillage practices and high testing soils may not result in grain yield advantages for corn producers in the Northern cornbelt regardless of placement method.  相似文献   

13.
Barley (Hordeum vulgare L. cv Doriru) leaf samples were collected from a field comprising three plots, plot F chemical fertilizer treated, plot S receiving sewage sludge and sawdust mixed compost, and plot H receiving sewage sludge and rice husk mixed compost. Relative concentrations of selected elements, potassium (K), calcium (Ca), and chloride (Cl) of young, mature, and old barley leaves were determined by microscopic energy dispersing X‐ray fluorescence (EDXRF). The objective of this investigation was to verify the applicability of EDXRF for rapid nutrient element diagnosis of plants. Typically whole leaves were washed in deionized‐distilled water and dried by ironing for analysis. Intact dried barley leaf sample irradiation was accomplished with X‐rays obtained from an X‐ray tube focused on an area <100 μm of the respective sample specimen surface. The EDXRF provided sufficient sensitivity for relative concentrations of K, Ca, and Cl. Element content data of all the elements investigated, specifically K, resulted in adequate plant nutrient element values to diagnose K insufficiency in barley leaves taken from plants in the sewage sludge receiving plots. Potassium was more densely accumulated in the new leaf than in mature and old leaves in case of plants from the S and H plots. In contrast, such K accumulation was more dense in old and mature leaves than young leaves in case of plants from the F plot. However, Cl and Ca coupling in barley leaves from all of the F, S, and H plots had shown the similar pattern of distribution and followed the order: old > mature > young. Therefore, EDXRF can be an easy, rapid, and practical method for diagnosing the elemental content of plant tissues and thereby help to aid plant growth and development through timely supplements of the required element(s).  相似文献   

14.
Abstract

Determination of soil aluminum (Al), ammonium‐nitrogen (NH4‐N), and nitrate‐nitrogen (NO3‐N) is often needed from the same soil samples for lime and fertilizer recommendations, but Al has to be extracted and quantified separately from NH4‐N and NO3‐N according to present methods. The objective of this study was to develop a reliable method for simultaneous analyses of soil Al, NH4‐N and NO3‐N using a Flow Injection Autoanalyzer. Thirty‐five soil samples from different locations with wide ranges of extractable Al, NH4‐N and NO3‐N were selected for this study. Aluminum, NH4‐N and NO3‐N were extracted by both 1 M and 2 M potassium chloride (KCl), and quantified using a LACHAT Flow Injection Autoanalyzer simultaneously and separately. One molar KCl was found to be a suitable extractant for all three compounds when compared to 2 M KCl. The 1 M KCl extract proposed could aid in decreasing the costs associated with simultaneous NH4‐N, NO3‐N, and Al analyses. Results of those three compounds analyzed simultaneously were not statistically different from those analyzed separately in 1 M KCl solution. This new procedure of simultaneous determination of NH4‐N, NO3‐N, and Al increases efficiency and reduces cost for soil test laboratories and laboratory users.  相似文献   

15.
Abstract

Soil test nutrient concentrations vary with depth, especially in perennial cropping systems where fertilizer is broadcast on the soil surface without incorporation. The objective of this study was to determine the effect of fertilizer rate and sampling depth on soil test phosphorus (P) and potassium (K), and P and K fertilizer recommendations for alfalfa (Medicago sativa L.). Five rates of P and K (0, 56, 112, 224, and 336 kg ha‐1 P2O5 and K2O) were broadcast on established alfalfa stands at three sites with different soil properties and tillage and fertilization histories. In separate plots at one site the same rates of P and K were also incorporated to a depth of 15 cm prior to seeding alfalfa. Soil samples were collected at depths of 0 to 10, 0 to 15, and 0 to 30 cm during the growing season. Fertilizer rates and soil sample depth affected soil test P and K at all sites. Relative to the 30‐cm sample depth, soil test values were higher in fertilized treatments with 10 and 15 cm sample depths due to the concentration of immobile P and K near the soil surface. Sample depths of 10 and 15 cm frequently resulted in lower P and K fertilizer recommendations than those of the 30‐cm depth. Sample depth is an important consideration in routine soil sampling for the purpose of making fertilizer recommendations. If research data used for developing soil test‐based fertilizer recommendation are obtained using a standard sampling depth, routine sampling must also be to the same depth.  相似文献   

16.
Abstract

A procedure for the simultaneous extraction of phosphorus, potassium, calcium and magnesium from soils, by an ion‐exchange resin procedure applicable to large‐scale advisory soil testing, is described. The important steps are the disaggregation of soil by shaking in water during 15 minutes with a glass marble, the transference of the elements from the soil to a sodium bicarbonate treated mixture of anion and cation exchange resins during a 16‐hour shaking period, the separation of the resin from the soil by sieving and extraction of the elements from the resin.

The results of resin extractable calcium, magnesium and potassium were comparable to the results of these elements extracted with 1M NH4OAc, to calcium and magnesium extracted with 1M KCl, and to potassium extracted with 0.025M H2SO4.

For phosphorus the resin extractable values were not comparable to the results obtained by the former routine method, based on the extraction with 0.025M H2SO4. The results of resin extractable P presented closer correlation with cotton response to phosphorus application in 28 field experiments (r = 0.85**) as compared with 0.025M H2SO4 extractable P (r = 0.68**), and also with P uptake by flooded rice in a pot experiment with eight lowland soil samples (r = 0.98**), as compared with extraction with 0.0125M H2SO4 in 0.050M HCl, for which the correlation was not significant. The reasons for the superiority of the extraction of P with the described procedure are discussed.  相似文献   

17.
Three‐week‐old nodulated faba bean plants were subjected to two levels of water stress (0.5 and 0.25 field capacity; soil water content of 20 and 10%) for five weeks. Half of the stressed plants was treated with potassium chloride (KC1) at 10 (K1) and 150 mg (K2)/kg soil at the beginning of water deficit. Nodulation was examined and some nodule activities were assayed. Nodulation, nitrogenase activity, total nitrogen (N), and dry matter yield were significantly decreased by increasing stress but were significantly higher with the two levels of potassium (K) supply. Leghaemoglobin and protein contents of cytosol as well as nodule protease and invertase were severely depressed by drought stress. Soluble carbohydrate contents of nodules, however, was significantly increased. Protein and leghaemoglobin contents and enzyme activities were greater with K fertilization but less soluble carbohydrate was accumulated. The results indicate that K supply, particularly at the 150 mg/kg soil level, increased faba bean resistance to water stress.  相似文献   

18.
Abstract

Efficient soil fertility management is essential for sustained production of high crop yields. Field experiments were conducted on an Entisol soil during 1984 to 1987 at Bidhan Chandra Agricultural University, West Bengal, India, to study the changes in soil N, P, and K in sub‐humid tropics under irrigated intensive cropping in rice‐potato‐mung bean (Oryza sativa L.‐ Solanum tuberosum L.‐ Vigna radiatus Roxb.) and rice‐potato‐sesame (O. sativa L.‐ S. tuberosum L.‐ Sesamum indicum L.) cropping sequences. The crops were grown with or without application of farmyard manure and with or without incorporation of crop residues. Different quantities of inorganic fertilizers based on locally recommended practices for fertilization were applied to rice and potato, and their residual effects on succeeding mung bean or sesame crops were assessed. At the end of experimentation, the total N status of soil improved more under the rice‐potato‐mung bean sequence than under the rice‐potato‐sesame sequence. The available phosphorus status of soil showed a positive balance in both sequences except in the treatment receiving 50% of the recommended amounts of N, P, and K. A reduction in the recommended fertilization without a compensating application of manure or crop residues resulted in the depletion of soil‐available K. All treatments reduced nonexchangeable K, and depletion was low wherever manure or crop residues were added into the cropping system. Integration of inorganic fertilizers with organic fertilizers, such as manure or crop residues, maintained soil N, P, and K under intensive agriculture and sustained soil productivity.  相似文献   

19.
Abstract

The potassium (K) supplying capacity of a deeply weathered profile developed over granite from Peninsular Malaysia was investigated by employing the quantity‐intensity (Q/I) approach. The values of potential buffering capacity (PBCK), labile K (KL), specific K (KO), and specific K sites (KX) were considerably higher in the saprolite zones as compared to the solum layers. This indicated that depletion of K on cropping would be faster in the solum materials than in the saprolites. Potassium equilibrium activity ratio was in the sequence: solum > middle saprolite > upper saprolite. Free energy values showed low, but sufficient, level of available K reserve in this profile. The relationships of Q/I parameters with physico‐chemical characteristics and clay mineralogy of the profile were discussed. The changes in the Q/I parameters as a function of depth were found to be associated with the contents of clay and organic matter in the solum, while in the saprolites, the clay mineralogy which composed mainly of K‐feldspar, mica, and mica‐smectite seemed to be the main factor.  相似文献   

20.
Pre‐ and post‐transplant growth of bedding plants is affected by seedling nutrition. However, there is little information available on how seedling nutrition affects the growth of ornamental bedding plants. In this study, we quantified the effects of nitrogen (N) (8 to 32 mM) and phosphorus (P) and potassium (K) concentration (0.25 to 1 mM) of the seedling fertilizer on pre‐ and post‐transplant growth and nutrient element content of salvia (Salvia splendens F. Sellow ex Roem. & Schult.) and vinca (Catharanthus roseus L.) seedlings. Shoot growth of salvia and vinca increased with increasing concentrations of N in the pre‐transplant fertilizer and these differences lasted until the end of the study at 15 days after transplanting. Pre‐transplant root dry mass of these species was not affected by the N concentration of the fertilizer, but root dry mass at 12 days after transplanting was positively correlated with the N concentration of the pre‐transplant fertilizer. Increasing N concentrations in the seedling fertilizer increased tissue N levels of salvia and decreased tissue K level of vinca at transplanting. Increasing P and K concentrations in the pre‐transplant fertilizer increased tissue P level of salvia and P and K levels of vinca, but had little effect on seedling growth. Leaf area and root dry mass at transplanting decreased slightly with increasing P and K concentration in the fertilizer. There were no lasting effects of pre‐transplant P and K concentration of the fertilizer. These results indicate that salvia and vinca seedlings can benefit from high concentrations of N (up to 32 mM) in the fertilizer, while only low concentrations of P and K (0.25 mM) are needed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号