Mixture Of NPK Research Articles

Rhizostimulation of Hydrocarbon Degrading Microorganisms Using Chrysopogon zizanioides and Eucalyptus camaldulensis Species During Bioattenuation of Hydrocarbon Polluted Soils

Background: This study was carried out to compare the rhizostimulation potentials of C. zizanioides and E. camaldulensis on microorganisms cfu during the phytoremediation of hydrocarbon contaminated potted soils. The objectives were to: i). determine the best treatment for the rhizostimulation of the microbial population in soils during the bioattenuation process. ii). examine the most efficient plant species in the Phytostimulation of hydrocarbon degrading microorganisms during the bioattenuation of hydrocarbon contaminated soils. iii). identify the various bacterial and fungal colonies associated with the bioattenuation of hydrocarbon. Materials and Method: The design was the Split-Split Plot experiment (4 x 4 x 2). The main plot factors were the crude oil contamination (4 levels), the sub-Plot factors were the soil amendments (4 levels) while the subsub-Plot factors were the plant species (2 levels). Results: Results indicated that there were significant differences (p < 0.05) in rhizostimulation potentials of the plant species in different crude oil contamination levels and in the different soil amendments for both bacteria and fungi. Although E. camaldulensis species was involved in biostimulation of microbial cfu, C. zizanioides was found better efficient (16.13 x 106 soil bacteria cfu g g -1 at 9 WAT and 10.04 x 106 soil fungal cfu g g -1 at 12 WAT respectively. Microorganisms found involved in bioattenuation of hydrocarbon include Bascillus spp., Staphylococcus spp., and Streptococcus spp for bacteria and Aspergillus spp., Rhizopus spp., and Penicillium spp for fungi. The most frequently occurred genus of microorganisms were Bacillus and Rhizopus. Conclusion: In conclusion, C. zizanioides was recommended as efficient rhizostimulating plant species. It was concluded that the mixture of both the grass and woody plant species are required for optimum growth and stimulation of hydrocarbon degrading microorganisms during phytoremediation procedure in the field. Additionally, bacterial and fungal cfu was observed to have increased with increasing hydrocarbon concentration under the influence of the two plant species and the applied landfarming treatments of a mixture of NPK (g g-1) and Cowdung (3:1 v/v) fertilizer. The most frequently occurred genus of microorganisms were Bacillus and Rhizopus.

Effect of Foliar Feeding of Nutrients, Salicylic Acid and Sea Weed Extract on Yield and Yield Attributes of Wheat Varieties under Tarai Region

A field experiment was conducted in the E-2 block of Norman E. Borlaug Crop Research Centre (NEBCRC) of Govind Ballabh Pant University of Agriculture and Technology (GBPUA&T), Pantnagar during rabi of 2021-2022. The experiment envisages study the growth and productivity and economic feasibility wheat under variable varieties and foliar nutrition management. The experiment was laid in Factorial Randomized Block Design with two varieties (DBW-17&WH-1105) and five foliar spray treatments viz., no spray (control), NPK mixture at 45 & 60 DAS (FN-1), Micro-nutrients mixture at 45 & 60 DAS (FN-2), salicylic acid at 45 & 60 DAS (FN-3) and seaweed extract at 45 & 60 DAS (FN-4). Variety WH-1105 recorded higher plant height, number of tillers/m2 and dry matter accumulation (g/m2) than DBW-17 at 60, 90 DAS. At harvest, variety WH-1105 indicated the effective tillers/m2, spike length, number of grains/spikes, number of spikelets/spike and grain weight per spike were higher by 2.7, 8.0, 4.6, 3.3 and 17.2%, respectively over variety DBW-17. Thousand grain weight and number of sterile spikelets/spikes was also exhibiting significant increase. Significantly higher grain yield, straw yield and biological yield were recorded under WH-1105 as compared to DBW-17 and the respective increase was 4.9, 4.3 and 5.0 percent. The net return and B:C ratio were improved by 5.6 & 5.7%, respectively at variety WH-1105 over variety DBW-17.

Effect of Different Fertility Management Practices on Plant Population and Mortality in Chickpea (Cicer arietinum L.)

Aims: To assess the effect of Humic acid (HA), Plant growth-promoting bacteria (PGPR), and Recommended dose of fertilizer (RDF) alone or in combination on plant population and mortality percentage in Chickpea (Cicer arietinum L.).
 Study of Design: The experiment was laid out in Randomized block design (RBD) with three replications.
 Place and Duration: A field experiment was conducted during the rabi season in the year 2020-21 and 2021-2022 at D6 Block, Norman E. Borlaug Crop Research Center at G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand (India).
 Treatments Details: Total ten treatments were used. The details of the treatments are as follows:T1- Absolute control, T2 - Humic acid @ 2.5 kg/ha (soil application), T3 -Humic acid @ 20 g/kg of seed (seed treatment), T4 - PGPR @ 20 g/kg of seed (seed treatment), T5- RDF through 150 kg NPK mixture (12:32:16 Grade), T6 -RDF + HA (soil application), T7 -RDF +HA (seed treatment), T8- RDF +PGPR (Seed treatment), T9- HA (soil application) +PGPR (seed treatment), T10- RDF + HA (soil application)+PGPR (seed treatment).
 Methodology: For plant population, the number of plants that emerged in the second row from both sides of the field were counted at 30 DAS and at harvest stage then averaged and calculate the number of plants for 1 m2 area. The mortality percentage was calculated by using the following formula: 
 
 Results: Findings of the investigation revealed that the effect of different fertility management on plant population was found not significant, but it was found significant in mortality percentage. Among the sole application of treatments T2 (Humic acid @ 2.5 kg/ha (soil application) and T4 (PGPR @ 20 g/kg of seed (seed treatment) recorded minimum mortality percentage, while among the combination treatments, T10 (RDF+HA (soil application) + PGPR as seed treatment) recorded minimum percentage of mortality.

EFFICIENCY OF PHYTOREMEDIATION OF SOIL CONTAMINATED BY HEAVY METALS BY CULTIVATION OF SPOTTED MILK THISTLE

In contrast to air and water environments, soils do not have the ability to quickly clean, so toxic substances that enter it from the outside can be stored for a long time. At the same time, toxicants, being included in the food chain of soil - plants - living organisms, can reach high levels and have a long duration of action. It is known that the accumulation of heavy metals in the soil occurs under the influence of emissions from industrial enterprises, during irrigation with wastewater, removal of sludge to agricultural lands after wastewater treatment, due to the application of mineral and organic fertilizers, etc. When heavy metals affect soils, there is a change in the soil environment, the occurrence of erosion processes, contamination of agricultural products, etc., which necessitates the search for productive and safe methods of their cleaning. The article presents the results of a study of the effectiveness of phytoremediation of soil when growing milk thistle when it is fertilized in the conditions of the Right-Bank Forest-Steppe. Based on the results of the analysis of primary sources, the current problems of soil degradation, their contamination with heavy metals, and the role of phytoremediation are determined. As a result of the research, certain changes in the intensity of the removal of lead, cadmium and zinc from the soil were found when it was fertilized with mineral fertilizers - ammonium nitrate (60 kg/ha), simple superphosphate (60 kg/ha), potassium chloride (60 kg/ha), NPK mixture fertilizers (60/60/60 kg/ha) and organic fertilizers - humus (20 t/ha), sugar beet lime sludge compost (6 t/ha) and green manure (mustard). It was established that fertilizing gray forest soils with ammonium nitrate, simple superphosphate, potassium chloride, and a mixture of NPK fertilizers contributed to the increase of removal with vegetative mass and seeds of milk thistle: lead by 2.14 times, 54.3%, 52.2%, and 87.5 %; cadmium – 3.5 times, 41.9%, 71.1%, 2.2 times; zinc - 2.8 times, 22.7%, 20.1%, 2.6%, respectively. Fertilizing the soil with humus, sugar beet lime sludge compost, green manure increased lead removal from the soil by milk thistle by 60.1%, 42%, 3.9%; cadmium - by 58.0%, 31.3%, 3.2%, zinc - by 2.03 times, 24%, 13.6%, respectively.

Comparison between some fertilization treatments on growth and chemical composition of Foxtail palm (Wodyetia bifurcate A.K. Irvine) seedlings

This experiment was held at the nursery of Hort. Res. Inst., ARC, Giza, in 2018 and 2019 seasons to clarify the consequence of fertilization with NPK mixture (2:1:2) at the rates of 2 and 4 g/plant, osmocote slow-release fertilizer at the rates of 10 and 20 g/plant and humic acid (HA) liquid fertilizer at the rates of 10 and 20 cm3/l of water on growth and chemical composition of Foxtail palm cultured in 20-cm-diameter polyethylene bags. NPK mixture and HA fertilizers were applied as a soil drench, five times with one-month interval, while osmocote was incorporated into the soil, once at commencement of the season. The results indicated that means of various vegetative and root growth parameters were significantly increased in response to the different fertilization treatments used in this study over control in most cases of the two seasons. However, the dominance was for both NPK mixture and osmocote treatments, but the upper hand was for the high rates of both (4 g NPK and 10 g osmocote per plant). On the other hand, the least improvement was achieved by HA treatments, especially when applied at a low level (10 cm3/l). A similar effect was also obtained regarding chlorophyll a, b, carotenoids, N, P and K concentrations in the leaves, with few exceptions. Thus, to obtain a picturesque pot plant of Foxtail palm (Wodyetia bifurcata), it is recommended to fertilize with osmocote (the slow-release fertilizer active for 10 months) at 10 g/plant/season as one batch applied at beginning of the season.

Coupling Compost from Chicken Manure and Inorganic Fertilizer to Improve Cassava (Manihot esculenta Crantz) Growth and Yield on a Ferralitic Soil in Côte d‘Ivoire

This study aimed to evaluate the effect of compost from chicken manure, NPK fertilizer and the mixture of both fertilizers on agronomic parameters of four varieties of cassava (Yacé, Bonoua, Six mois and Alleda agba) in Côte d‘Ivoire. The field experiment was carried out under a randomized complete block design with three replicates on a ferralitic soil during two season-cycles. The results showed that the different fertilizers stimulated plants growth and tuberous roots production. The highest number of stems (3) and leaves (66) was obtained with the mixture of NPK and compost applied on the variety “Bonoua”. All varieties that received the compost mixed with NPK produced more leaves with a dominance of the Bonoua variety (65.57). The highest number of tuberous roots (5.58), the heaviest weight per root (6.13 kg) and the highest yield (61.37 t/ha) were obtained while using the mixture of compost and NPK as fertilizer and “Bonoua” as variety. Thus, mixing compost from chicken manure and NPK can be recommended to improve cassava productivity in Côte d'Ivoire on a ferralitic soil.

Effect of NPK Compound Fertilizer Normal and Nano on Some Growth Traits and Oil Content of Three Species of Apiaceae Plants

An experiment was conducted under the conditions of Al-Diwaniya governorate in a special nursery was specially constructed for the experiment during the autumn season (2016–2017) in order to determine the effect of adding the different levels of NPK fertilizer balanced (20-20-20) normal and nano to the soil of three species of Apiaceae (Cumin, anise and sweet fennel) and their interference in growth and oil content of seeds. The factorial experiment that consist of two factor and with three replicates was designed by Randomized Completely Blocks Design (RCBD); the first factor consisted of three species of Apiaceae plant that abovementioned, while second factor included seven levels of the NPK compound fertilizer balanced (control, normal NPK, nano NPK, normal NPK, nano NPK, Mixture NPK (Normal + Nano), Mixture NPK (Normal + Nano)). The means of the treatments was compared with a significant difference in the use of the least significant difference (LSD) at the probability level (p ≤ 0.05). The results showed the superiority of sweet fennel plant in the following traits (plant height, total leaf area, dry weight of vegetative part) versus the superiority of the cumin plant in seed content of fixed oil, as well as anise plant was superiority in the number of branches per plant. The significant effect of soil-additive fertilizers from normal and nano compound fertilizer in the increase of the majority of the studied traits and recording the highest mean in the NPK mixture at the double recommended or recommended level. The interference between factors gave the same significant effect to the superiority of the individual factors, as well as the improvement traits of more than double in some of them and the difference of response between plants depending on the type of fertilizer.

NPK could alleviate the adverse effects of simulated acid rain in sunflower (Helianthus annuus L.)

ABSTRACTA study was conducted to determine the effect of macronutrients (NPK) in alleviating the adverse effects of simulated acid rain (SAR) on sunflower (Helianthus annuus L.). In addition to control (T0), three different treatments, i.e., SAR (HNO3) of pH 3 (T1), NPK (T2), and SAR + NPK (T3), were applied on two sunflower cultivars, i.e., FH-37 and FH-385. The experiment was set up in CRD (completely randomized design) with four replicates of each treatment. Chlorophyll a, b, total chlorophyll, carotenoids, ion contents (NPK), and gas exchange characters were determined. Acid rain remarkably reduced the chlorophyll pigments, NPK ionic content, photosynthetic rate, transpiration rate, and stomatal conductance, while an increase in internal CO2 concentration and water use efficiency was noted in both the cultivars. The mixture of NPK with SAR exhibited positive impact to lessen the toxicity caused by acid. Among cultivars, FH-385 showed better performance as compared to FH-37.

Methods of adding micronutrients to a NPK formulation and maize development

ABSTRACTMicronutrients are essential for plant development; however, micronutrient content in soil often is not sufficient. This study compared availability of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in the soil and their effect in developing maize plants, supplied from a physical mixture of nitrogen, phosphorus, and potassium (NPK) granules and micronutrients or from a granulated mixture of NPK coated with these micronutrients. The experiment was conducted in a greenhouse, with a Rhodic Acrustox soil and the formulation 4-30-10 [nitrogen-phosphorus pentoxide-potassium oxide (N-P2O5-K2O)] with 0.1% B, 0.2% Cu, 0.2% Mn, and 0.3% Zn. A randomized block design with four replicates was used and the NPK formula doses used were 0, 150, 300, 600, 1200, and 2400 kg/ha. Coated NPK increased Zn levels in soil in 0.5 mg/dm3 in relation to its initial content, also causing an increase in plant dry matter. Compared with mixture, this increase was more than three times greater. Cu and Zn accumulation and Zn absorption were greater when their supply was made via coated granules. The larger dose of B via coated granules resulted in a greater B accumulation in comparison to the mixture. No differences were observed for the other variables when comparing both sources. Coating NPK granules with micronutrients was better than the mixture when comparing B, Cu, and Zn concentrations in the soil. Dry matter production of maize shoots and the accumulation of B, Mn, Cu, and Zn in it was greater when the fertilizer was coated with micronutrients.

RESPONSE OF PEPEROMIA OBTUSIFOLIA (L.) A. DIETR CV. VARIEGATA PLANT TO SOME FERTILIZATION TREATMENTS

An experiment was established under plastic house at the nursery of Hort. Res. Inst., ARC, Giza, Egypt during 2012 and 2013 seasons to find out the effect of foliar spraying with active dry yeast solution at 0, 1, 3 and 5 g/l, soil drenching with NPK mixture (2:2:1) at 2 g/pot and the interaction between each level of yeast and that of NPK mixture on growth and chemical composition of 3- months-old transplants of Peperomia obtusifolia (L.) A. Diter. grown in 14-cm-diameter plastic pots filled with about 1 kg of an equal mixture of washed sand, clay and peatmoss (1:1:1, by volume.) The obtained results indicated that various single and combined treatments improved all vegetative and root growth parameters with various significant differences compared to the control in both seasons. Active dry yeast alone at 3 g/l treatment gave better result than the other individual ones, whereas comparing between any level of dry yeast combined with NPK (2 g/pot) was more effective in improving vegetative and root growth of plants than all the individual treatments, the interaction between 3 g/l active dry yeast and 2 g/pot NPK recorded the best growth at all in both seasons. On the same line were those results of pigments content in the leaves reached maximum by 3 g/l dry yeast, but the opposite was right regarding the percentages of total soluble sugars, N, P and K content those reached the highest values by the level of 5 g/l dry yeast in most cases of both seasons. However, content of those constituents was doubled by connecting between active dry yeast at any level and NPK mixture 2 g/pot, with the prevalence of 3 g/l active dry yeast plus 2 g/pot NPK combination, that gave the highest content in the two seasons. Hence, it can be recommended to fertilize Peperomia obtusifolia cv. Variegata plants cultivated in 14-cm-diameter plastic pots with active dry yeast at 3 g/l (as a foliar spray) plus NPK mixture (2:2:1) at 2 g/pot (as a soil drench), 5 times with one month interval to obtain the best vegetative growth and high pot plant quality

Impact of different types of fertilizers to reduce the population density of the sap sucking pests to bean plants

The experiment was laid out in a randomized complete block design with three replicates. The aim of the work is to investigate the effect of different fertilizers on the rates of beans infestation by different piercing sucking pests Tetranychus urticae, T. cucurbitacearum, Bemisia tabaci and Thrips tabaci and on the resulting crop yield. The fertilizer treatments are Ammonium sulfate, Calcium super phosphate, Potassium sulfate, a mixture of NPK and Micro-elements (Zn, Mn, Fe, Cu, Bo & Mo). Results showed that means of green pods yielded by NPK fertilizer was significantly higher than other fertilizers in the two seasons

THE EFFECT OF DIFFERENT TYPES AND RATES OF FERTILIZERS ON THE POPULATION DENSITY OF SAP SUCKING PESTS INHABITING COWPEA FIELDS

This study was carried out during 2012 and 2013 seasons in the Horticultural Research Station at Kanater El- Khairiya, Qualiobeya Governorate to throw light on the effect of different types and rates of fertilizer treatments on the rates of infestation of the cowpea plants, Vigna unguiculata L. by different pests Tetranychus urticae, T. cucurbitacearum (eggs and motile stages), Bemisia tabaci (eggs, nymphs, pupae & adults), Thrips tabaci (nymphs & adults) and green Jassids and on the resultant crop yield. Data revealed that treatment with NPK mixture recorded the highest infestation rate by T. urticae Koch, T.cucurbitacearum (Sayed) and T. tabaci in the two seasons, while the K2O fertilizer revealed the lowest infestation rates. Moreover, the N2 fertilizer recorded the highest infestation with whitefly and Jassids. The brown scale insects, Coccus hesperidium Linnaeus were firstly recorded in Egypt on cowpea plants but throughout the first season only. The mixture treatments resulted highest yield (2428.3 &2675 Kg./fed.) followed by Micro-element treatments (1500 &1658.3 Kg./fed.) then K2O fertilizer treatment (1416.7 & 1553.3 Kg. /fed.) in 2012 and 2013, respectively; being significantly higher than control which recorded (756.0 & 845.0 Kg. / fed.) for the two seasons. However, the results showed a significant improvement in the uptake of NPK over the control, so it increased the production.

Bioremediation of highly contaminated oilfield soil: Bioaugmentation for enhancing aromatic compounds removal

This study evaluated the effectiveness of different amendments—including a commercial NPK fertilizer, a humic substance (HS), an organic industrial waste (NovoGro), and a yeast-bacteria consortium—in the remediation of highly contaminated (up to 6% of total petroleum hydrocarbons) oilfield soils. The concentrations of hydrocarbon, soil toxicity, physicochemical properties of the soil, microbial population numbers, enzyme activities and microbial community structures were examined during the 90-d incubation. The results showed that the greatest degradation of total petroleum hydrocarbons (TPH) was observed with the biostimulation using mixture of NPK, HS and NovoGro, a treatment scheme that enhanced both dehydrogenase and lipase activities in soil. Introduction of exogenous hydrocarbon-degrading bacteria (in addition to biostimulation with NPK, HS and NovoGro) had negligible effect on the removal of TPH, which was likely due to the competition between exogenous and autochthonous microorganisms. Nonetheless, the addition of exogenous yeast-bacteria consortium significantly enhanced the removal of the aromatic fraction of the petroleum hydrocarbons, thus detoxifying the soil. The effect of bioaugmentation on the removal of more recalcitrant petroleum hydrocarbon fraction was likely due to the synergistic effect of bacteria and fungi.

Effect of organic and mineral fertilization on proximate composition of three leafy vegetables harvested at different periods

Leafy vegetables are part of natural resources traditionally harvested from forests in Benin. Some of these wild plants foods have been introduced in the small scale production system. The low productivity and the increasing demand for such products urged to use fertilizers. However, the impact of such practices on the nutritional properties of these leaves was poorly documented. In this study Sesamum radiatum, Ceratotheca sesamoides and Justicia tenella were cultivated using NPK, cowpat and mixture of NPK plus cowpat. Leaves harvested at 6, 9, 10, 12 or 14 weeks after transplanting were analyzed for proximate composition. Protein content ranged from 17.2 to 33.8 g/100 g DW; ash from 7.7 to 20.4 g/100 g; fat from 1.2 to 7.3 g/100 g, fiber from 5.6 to 13.1 g/100 g and polyphenols content from 0.24 to 1.33 g GAE/100 g (DW). Significant effects of species, fertilizer and cutting time were evidenced. Whereas ash content increased by 1 to 25.8% ratio in fertilized S. radiatum leaves, it showed a downward trend (-1 to -22%) during the two first cutting times of C. sesamoides followed by an upward trend (12.7 to 14.3%) at the last cutting time, in comparison to the non fertilized leaves. © 2013 International Formulae Group. All rights reserved. Keywords: Fertilization, composition, Sesamum radiatum , Ceratotheca sesamoides, Justicia tenella

Ammonium chloride as nitrogen source in sugarcane harvested without burning

The great difficulty of incorporation of N fertilizers into the "green sugarcane" system causes concern and since urea is the most commonly used source, there is the risk of loosing NH3 through volatilization. For this reason, a field experiment was undertaken (in a Hapludox Typic) with the objective of evaluating the agronomic efficiency of ammonium chloride on stubble of the second ratoon (SP89 1115), as well as its residual effect on the subsequent cycle (third ratoon). The experimental design was randomized blocks with four replications. Treatments consisted of three N rates (60, 120 and 180 kg ha-1 N) in the form of NH4Cl, in addition to a control treatment without the addition of N fertilizer. The ratoon cane of the second cutting was harvested in November 2006 and the treatments were applied in December 2006. The second ratoon was harvested mechanically in November 2007 and in December 2007, 450 kg ha-1 of the NPK mixture 20-05-19 was applied, providing 90, 22 and 86 kg ha-1 N, P2O5 and K2O, respectively, for the purpose of evaluating the effect of residual-N from the treatments implanted in December 2006. An increase in the rates of N-NH4Cl had a positive effect on the leaf concentrations of P, Mg and S. Stalk yield (MSS - Mg ha-1 of sugarcane stalks) and sugar (MSH - Mg ha-1 of sucrose) in the November 2006 harvest responded linearly to the increase of N doses in the form of NH4Cl. In relation to the effect of residual-N in the 2007/2008 harvest, it was observed, in general, that the concentrations of macronutrients in the sugarcane leaf +1 were within the range considered adequate in the state of São Paulo, Brazil. The residual-N of the NH4Cl doses resulted in a significant reduction in stalk (MSS) and sugar (MSH) production. It may be concluded that the NH4Cl source at a dose of 120 kg ha-1 N in ratoon fertilization of the second cutting was agronomically efficient, presenting, however, less efficiency of residual-N in the subsequent cycle.

Influence des matières végétales et des engrais NPK sur la biologie deAedes aegypti(Diptera : Culicidae)

In this laboratory study, we investigated the attractiveness of gravid Aedes aegypti females for aquatic habitats containing either NPK fertilizer or plant matter or a mixture of both. The development of larvae, adult emergence and weight of emerged adults were measured for each group and physicochemical analysis of water was made for the dosage of minerals and organic compounds. After 23 days experiment, NPK solution remained as attractive as the mixture of NPK + plant matter but did not ensure suitable development of larvae. The plant matter infusion showed less attractiveness for laying eggs than NPK but provided larvae with sufficient organic nutrients for their development. The combination of both NPK + plant matter provided the greatest attractiveness for gravid females and sufficient organic substance allowing mosquito larvae to grow. Physicochemical analyses of water containing NPK showed minerals only (NH4(+)+NO3(-)+P+K) whereas plant matter showed high content of carbon and nitrogen. The NPK + plant matter mixture contained both organic and minerals elements that favoured the proliferation of bacteria and then the development of mosquito larvae. These findings could lead to the development of new traps that could attract females mosquitoes and killed hatched larvae if mix with appropriate larvicides.

Fertilising Eucalypt Plantations on the Brazilian Savannah Soils

SYNOPSIS Eucalypt plantations have been the main source of wood for pulp and charcoal in Minas Gerais State, Brazil. A considerable part of these plantations is located in the savannah area where soil fertility is low and fertiliser application is necessary to increase forest productivity. Initially, eucalypt fertilisation consisted of applying 100–150g of a NPK mixture (10–28-6) per plant regardless of soil type, species or time of planting. Later, field trials on fertilisation indicated that further growth increase could be obtained if rock phosphate was broadcasted (at about 1,0 t/ha) or banded (at about 0,5 t/ha) in addition to the NPK mixture. The amount of K-fertiliser needed depended on soil K level and site quality and could be as high as 200 kg of K2O/ha. Eucalypt response to N is restricted to sandy soils with low (less than 1,5%) levels of organic matter. In most cases, S application increased eucalypt yield by more than 50%. Species such as Eucalyptus camaldulensis and E. citriodora, when plan...

An Experimental Approach to the Reclamation of a Limestone Quarry Floor: The First Three Years

‘Three-inch [7.5 cm] crusher-run’ limestone proved entirely suitable as a substratum for the rapid establishment of pioneer vegetation on a quarry floor, but only with the addition of fertilizers. A manure derived from sewage and an NPK fertilizer mixture proved suitable additives. A grass variety (Festuca rubra var. fallax Hack.) was sown, and became established on the substratum treated with either additive. Immigrant mosses soon became dominant in a grass/moss community on the manured substratum, whilst F. rubra retained its ascendancy on the NPK-treated material. The moss-dominated community was not attractive to Rabbits, whereas the grass-dominated community proved attractive to these animals which are accepted as beneficial for conservation in this particular context.Further observations are required to assess (a) whether the by-passing of a cryptogamic stage in the prisere encouraged by the NPK mixture is a worthwhile objective, (b) whether the observed dominance of mosses encouraged by manure will be broken by F. rubra, and (c) whether the establishment of desirable immigrant species occurs differentially between the treatments. Meanwhile a perceptible degree of rehabilitation within three years may be claimed as a result of treatments producing a total plant cover of between 40% and 70%.