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1.
Abstract

Absorption and accumulation of calcium in hydro— ponic solutions, deficient or not in calcium, are studied on whole plants of Sorghum (Sorghum dochna F.), In deficient lots, calcium is replaced either by magnesium (Ca/Mg lot), or by potassium (Ca/K lot). The limit threshold of defiency retained, does not modify, on the 26 day of culture (end of the experience) the yield of different lots compared with the control. The principal modifications in cation content are noted in leaves: plants grown in the Ca/Mg solution show a higher Ca content than plants in a Ca/K solution. As a consequence of saturation with potassium the substitution of Ca in the two deficient lots is effected by magnesium.  相似文献   

2.
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   

3.
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   

4.
5.
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   

6.
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   

7.
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   

8.
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   

9.
Abstract

Grain sorghum plants were grown in nutritive solution culture under variable potassium concentrations from 0.5 to 6.0 meq/l, Na replacing K in deficient solutions. Leaves were analysed for K+, Na+, Ca++ and Mg++.

Potassium deficiency has no effect on the total amount of cations, but the decrease of K in deficient leaves is correlated with an increase of Na+, Ca++ and Mg++. Evidence of antagonism between K and divalent cations in given, but, in the most deficient leaves, magnesium instead of calcium balances for the diminution of potassium.  相似文献   

10.
Abstract

Nutrient solutions containing three levels of phosphate, nitrate, and chloride were applied to cigar‐wrapper tobacco (Nicotiana tabacum L.) plants growing in sand culture for a period of 18 days. Concentrations of other nutrient elements in the nutrient solutions were held constant and the solutions were applied to pots as needed to maintain favorable moisture conditions for plant growth. Plants were in the two leaf stage when transplanted and were maintained on a single nutrient solution for 38 days before treatments were started. At the end of an eight weeks growing period, plant leaves were harvested and analyzed for Ca, Mg, and Mn. Dry matter yield was significantly (P=0.01) increased when 2 mM/1 of Ca(NO3)2 replaced an equivalent amount of Ca(H2PO4)2 or CaCl2 in the nutrient solution. Nitrate significantly (P=0.05) increased Ca and Mg content and decreased Mn concentration in leaf tissue in comparison to chloride. Calcium and Mg content were significantly (P=0.05) decreased and Mn content of tobacco leaves was increased by phosphate in comparison to nitrate and chloride.  相似文献   

11.
Abstract

An Investigation was conducted to determine the content and distribution of total and DTPA‐extractable Zn in the genetic horizons of 72 agriculturally important soils from the six major mineral soil areas in Louisiana.

The concentration of total Zn appeared to vary more with the clay constituents of the soils and the amount of the element in the parent materials than with soil depth. The majority of the soils had the largest amounts of total Zn in the subsurface horizons. The range in total Zn for all soils and horizons was from 7.0 to 150.0 ppm.

The DTPA‐extractable Zn in all of the soils and horizons ranged from 0.08 to 4.22 ppm. In the majority of the soil profiles the highest concentration of extractable Zn was in the surface horizons. There was a decrease in the extractable Zn with increasing soil depth. The alluvial soils along the Ouachita and Mississippi Rivers, and the Mississippi Terrace soil areas contained relatively large amounts of DTPA‐extractable Zn.

In some soils the extractable Zn significantly correlated with total Zn. There was also a close relationship between extractable Zn and organic matter content, especially in the Ap horizons.  相似文献   

12.
Abstract

The purposes for this research were: to examine the long‐term residual effects of farmland applications of municipal sludges from four treatment technologies on the total and extractable Zn, Cu, Mn, Fe, Pb, Ni and Cd concentrations in Coastal Plain soils; to investigate the effects of sludge sources and rates on the effectiveness of soil extractants to remove the various metals; and to determine correlation coefficients for soil extractable versus plant accumulation in tobacco. The extractants evaluated were Mehlich 1 and 3, and DTPA‐pH 7.3. Composite Ap horizon soil samples and tobacco leaf samples were obtained in 1984 from research plots at two sites in Maryland that were established in 1972 and 1976, respectively, using sludge materials from three wastewater treatment facilities in the Washington, D.C. metropolitan region. Similar application rates were used at both sites.

A wide range in soil pH values was found among treatments at each site. Significant (p ≤ 0.05) increases were observed in total Zn, Cu, Fe, Pb, Ni, and Cd for all sludge sources with increased rates; however, values for total soil Mn exhibited high variability in all cases. The rankings among the extractants varied for some elements depending on the sludge sources. For Zn, the rankings were Mehlich 1 > Mechlich 3 > DTPA‐pH 7.3 across all sources and rates. For Cu, Mehlich 3 > Mehlich 1 > DTPA‐pH 7.3 was found for soils amended with Blue Plains digested (BPD) and Piscataway limeddigested (PLD) sludges but Mehlich 1 ≥ DTPA pH 7.3 > Mehlich 3 for Blue Plains limed compost (BPLC) and Annapolis Fe and heat treated (AFH) sludges. Concerning extractable Mn, Mehlich Mehlich 1 > Mechlich 3 > DTPH pH 7.3 was the order for BPLC and AFH sludges but Mehlich 3 > Mehlich 1 > DTPA‐pH 7.3 was observed for BPD and PLD sludges. The rankings among extractants for Fe (Mehlich 3 > Mehlich 1 > DTPA‐pH7.3), Ni (Mehlich 3 ≥ Mehlich 1 > DTPA‐pH 7.3), Pb (Mehlich 3 > DTPA‐pH 7.3 > Mehlich 1) and Cd (Mehlich 1 > Mehlich 3 > DPTA‐pH7.3) were somewhat similar across all sludge sources. Significant correlation coefficients were obtained for all three extractants for soil extractable vs. plant Zn, Cu, Ni, and Cd at both sites; however, Mehlich 3 was not significant for Mn. Also, neither of the extractants produced significant coefficients for Fe and Pb.  相似文献   

13.
Abstract

Extractants employed for routine soil analysis vary from one laboratory to another. Lack of a universal soil extractant is a serious limitation for interpretation of analytical results from various laboratories on nutritional status of a given soil. This limitation can be overcome by developing functional relationships for concentrations of a given nutrient extractable by various extradants. In this study, extractability of Ca, Mg, P, and K in a wide range of soils (0–15 cm) from citrus groves in Florida representing 21 soil series, with varying cultural operations, were compared using Mehlich 3 (M3), Mehlich 1 (M1), ammonium acetate (NH4AOc), pH = 7.0 (AA), 0.2M ammonium chloride (NH4Cl), and ammonium bicarbonate‐DTPA (AB‐DTPA) extractants. Soil pH (0.01M CaCl2) varied from 3.57 to 7.28. The concentrations of Ca or Mg extractable by M3, M1, AA, and NH4Cl were strongly correlated with soil pH (r2 = 0.381–0.482). Weak but significant correlations were also found between AB‐DTPA extractable Ca or Mg and soil pH (r2 = 0.235–0.278). Soil pH relationships with extractable K were rather weak (r2 = < 0.131) for M1 and NH4Cl but non‐significant for M3, AB‐DTPA, and AA. Concentrations of Ca, Mg, and K extractable by M3 were significantly correlated with those by either M1, AA, or NH4Cl extractants. Mehlich 3‐P was significantly correlated with P extractable by M1 extractant only. Mehlich 3 versus AB‐DTPA relationship was strong for K (r2 = 0.964), weaker for Mg and P (r2 = 0.180–0.319), and non‐significant for Ca. With the increasing emphasis on possible use of M3 as an universal soil extractant, data from this study support the hypothesis that M3 can be adapted as a suitable extractant for routine soil analysis.  相似文献   

14.
Circumstantial evidence exists for non‐N‐mineral element transfer in legume‐grass associations. Three experiments were conducted in an effort to directly demonstrate transfer of a non‐N‐mineral element in alfalfa (Medicago sativa L.)‐maize (Zea mays L.) and alfalfa‐grain sorghum (Sorghum vulgare Pers.) associations in two rooting media. Associations were established in double‐tube apparatus so that a single alfalfa plant was rooted in media of top‐ and bottom‐tubes, while an associated grass plant was rooted exclusively in the top‐tube (Intact treatment). Severed treatments (the control) were identical to the Intact treatments except the alfalfa roots in an air gap between the top‐and bottom‐tubes were excised.

86Rb was dispensed onto the medium of bottom tubes with movement of the radioisotope determined by analyzing the legume and grass tissues over time. 86Rb was detected in: i) soil‐grown maize associated with alfalfa within a 40‐day treatment period; ii) sand‐grown maize associated with alfalfa within 20 days after treatment and iii) sand‐grown sorghum associated with alfalfa within 10 days. Detection of 86Rb in grass plants associated with alfalfa demonstrated that transfer of this potassium analog can occur via the root systems of legume‐grass associations.  相似文献   

15.
Little is known about the effect of varying levels of potassium (K) on the mineral element concentration, growth, and gas exchange, characteristics of woody ornamental plants. The commercially important woody ornamental species Hibiscus rosa‐sinensis L. cv. Leprechaun was evaluated for K response in a series of three experiments with full strength Hoagland's nutrient solution, which supplied 0 to 10 mM K. Plants grown with 4 mM K in nutrient solution (2.4% leaf tissue K) had the greatest shoot growth and root extension. Gas exchange rates (net photosynthesis, transpiration, and stomatal conductance) were also highest at 4 mM K compared to the control (0 mM K /0.6% leaf tissue K), 0.2, 2.0 and 10 mM K treatments. The application of 4 mM K increased net photosynthesis and tranpiration by 2.1 fold and stomatal conductance by 4.5 fold over 0 mM K controls. Increasing K in nutrient solution correlated positively with tissue K, manganese (Mn), and zinc (Zn), but negatively with nitrogen (N), phosphorus (P), calcium (Ca), and magnesium (Mg). There was a stronger sink for K in yonger leaves (the first to fourth fully expanded leaf from the shoot apex) which had higher K concentration than older leaves (the eighth to twelfth fully expanded leaf from the shoot apex). However, with increasing K in nutrient solution, K concentration in leaf tissue increased regardless of leaf age, and the difference between the younger and older leaf was constant. Daily application of 10 mM K resulted in 6.9% leaf tissue K and caused a decrease in plant total dry matter, net photosynthesis, compared to 4 mM K treated plants. However, these parameters remained higher in 10 mM K plants, which retained high ornamental quality than in 0 mM controls. Plants fertilized with 10 mM K, had the highest leaf tissue K and Zn, but lowest P, Ca, Mg, iron (Fe), copper (Cu) and boron (B). Nevertheless, the 10 mM K treated plants exhibited no morphological differences or deficiency symptoms; rather those plants had similar vegetative vigor and flower bud formation rate as those at 4 mM K.  相似文献   

16.
The experiment was conducted to evaluate the effects of various nitrate/ chloride (NO3/Cl) ratios on growth, nitrate accumulation, and mineral absorption in carrot, Daucus carota L., plants in a controlled environment. The experiment included two Cl sources [potassium chloride (KC1) and calcium chloride (CaCl2)] and five NO/Clratios at 100/0, 90/10, 80/20, 70/30, and 60/40 with total‐nitrogen (N) concentration of 400 mg NO3 kg‐1 soil in 100/0 treatment. Fresh and dry weights of shoots and storage roots, and length and diameter of storage roots increased significantly with mixed NO3/C1 treatments with both Cl sources as compared to single NO3 (100/0) treatment. Growth was enhanced up to the 80/20 NO3/C1 treatments. With Cl present in the treatments, the concentration of total‐N unchanged and NO3 decreased in plants, and Cl and potassium (K) increased with the Cl sources. In KC1 treatments, Na absorption decreased. Calcium (Ca) content of the plants significantly differed by the treatments. It was concluded that N fertilization provided with combined Cl forms and NO3/Cl rates can enhance production of better quality carrot and at the same time decrease of the N fertilizer input.  相似文献   

17.
Abstract

Effects of fertilizer timing and placement on the grain yield and leaf nutrients of uninoculated sole‐crop cowpeas in two experiments during the minor cropping season on Njala upland soil of Sierra Leone were studied. Timing and placement and their interaction had no significant effects on grain yield. Placement affected highly significantly lamina Mg, Cu and Co and significantly lamina N and Ca. Placement and timing x placement interaction affected highly significantly petiole N and petiole P respectively. Timing affected highly significantly petiole N, which decreased as fertilizer application was delayed. The spectrum of nutrient distribution in both lamina and petiole was decidedly different. Multiple regression studies indicated that variability in only petiole Mg, Cu and Co significantly contributed to grain yield variability. By the introduction of 15 nutrients (6 lamina and 9 petiole) after examining the linear regression coefficients into a composite multiple regression study, lamina Ca, petiole Fe and petiole Co were selected as significant contributors to grain yield variability with marked improvement in R2. Removal of the effects of the correlated variables produced significances in the effects of fertilizer placement and timing x placement interaction on grain yields.  相似文献   

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