Um die anderen Arten von Veröffentlichungen zu diesem Thema anzuzeigen, folgen Sie diesem Link: Phosphatic fertilizers Testing.
Zeitschriftenartikel zum Thema „Phosphatic fertilizers Testing“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-25 Zeitschriftenartikel für die Forschung zum Thema "Phosphatic fertilizers Testing" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Zeitschriftenartikel für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
1
Fauzan, M., Sofyan Husein Siregar und Syafruddin Nasution. „EFFECT OF DIFFERENT TYPES OF FERTILIZER ON THE GROWTH OF MARINE PHYTOPLANKTON POPULATION Chlorella vulgaris“. Asian Journal of Aquatic Sciences 4, Nr. 1 (07.04.2021): 65–72. http://dx.doi.org/10.31258/ajoas.4.1.65-72.
Der volle Inhalt der QuelleAnnotation:
This research was conducted on October 13-26, 2019 in the Regional Technical Implementation Unit of the Seawater and Brackish Aquaculture Fisheries Office (UPTD BPBALP Teluk Buo), West Sumatra. This study aims to determine the effect of applying different types of fertilizers to the growth of Chlorella vulgaris microalgae populations on laboratory scale culture. The method used in this study was an experimental method in the laboratory using a completely randomized design (CRD) one factor, namely the difference in fertilizer types with 3 (three) replications. Fertilizers used are Walne fertilizer, ZA (Zwavelzure Ammoniak) and TSP (Triple Super Phosphate). The testing organism in this study was phytoplankton C. vulgaris. The container used was a glass jar (3 liter capacity). The parameters measured in this study include absolute growth, relative growth, specific growth, self-doubling time and water quality. The results of this study indicate that the best type of fertilizer for C.vulgaris population growth was TSP fertilizer, followed by ZA fertilizer and the lowest in Walne fertilizer.
2
Boyhan, George E., Reid L. Torrance, Ronald H. Blackley, M. Jefferson Cook und C. Randell Hill. „EVALUATION OF FERTILITY PRACTICES FOR VIDALIA ONIONS“. HortScience 40, Nr. 3 (Juni 2005): 885e—886. http://dx.doi.org/10.21273/hortsci.40.3.885e.
Der volle Inhalt der QuelleAnnotation:
Fertilizer rates of N, P, K were evaluated over 4 years (2000–03) as were different sources of experimental and commercial fertilizers. The highest total yields and yields of jumbos (≥7.6 cm) occurred with nitrogen rates of 140–168 kg·ha–1. Neither phosphorus nor potassium rates had an affect on total yield. Phosphorus rates of 0-147 kg·ha–1 and potassium rates of 0–177 kg·ha–1 were evaluated. Increasing nitrogen fertilizer resulted in increasing leaf tissue nitrogen, but did not affect P, K, Ca, or S. Increasing phosphorus fertilizer increased leaf tissue phosphorus only slightly (p = 0.060) with no affect on other leaf nutrient levels. Increasing potassium fertilizer did affect leaf tissue potassium 2 out of 4 years with none of the other leaf nutrient levels affected. Several fertilizers were also evaluated including an experimental fortified peat (10%N), calcium nitrate, ammonium nitrate, diammonium phosphate, 5–10–15 (56 kg·ha–1 N), 18-6-8 liquid, 14–0–12 8%S liquid, 19–8–19 slow-release at rates of 140 and 168 kg·ha–1 nitrogen. All were used to supply 168 kg·ha–1 nitrogen unless noted otherwise. P and K were supplied according to soil test recommendations unless they were part of the fertilizer formulation. There were no differences between the different fertilizer sources for total yield and differences in jumbo yields only occurred one year out of three years of testing and for medium (≥5.1 and <7.6 cm) yields there were differences two years out of three years of testing.
3
Bryla, David R., und Bernadine C. Strik. „Nutrient Requirements, Leaf Tissue Standards, and New Options for Fertigation of Northern Highbush Blueberry“. HortTechnology 25, Nr. 4 (August 2015): 464–70. http://dx.doi.org/10.21273/horttech.25.4.464.
Der volle Inhalt der QuelleAnnotation:
Northern highbush blueberry (Vaccinium corymbosum) is well adapted to acidic soils with low nutrient availability, but often requires regular applications of nitrogen (N) and other nutrients for profitable production. Typically, nutrients accumulate in the plant tissues following the same pattern as dry matter and are lost or removed by leaf senescence, pruning, fruit harvest, and root turnover. Leaf tissue testing is a useful tool for monitoring nutrient requirements in northern highbush blueberry, and standards for analysis have been updated for Oregon. Until recently, most commercial plantings of blueberry (Vaccinium sp.) were fertilized using granular fertilizers. However, many new fields are irrigated by drip and fertigated using liquid fertilizers. Suitable sources of liquid N fertilizer for blueberry include ammonium sulfate, ammonium thiosulfate, ammonium phosphate, urea, and urea sulfuric acid. Several growers are also applying humic acids to help improve root growth and are injecting sulfuric acid to reduce carbonates and bicarbonates in the irrigation water. Although only a single line of drip tubing is needed for adequate irrigation of northern highbush blueberry, two lines are often used to encourage a larger root system. The lines are often installed near the base of the plants initially and then repositioned 6–12 inches away once the root system develops. For better efficiency, N should be applied frequently by fertigation (e.g., weekly), beginning at budbreak, but discontinued at least 2 months before the end of the growing season. Applying N in late summer reduces flower bud development in northern highbush blueberry and may lead to late flushes of shoot growth vulnerable to freeze damage. The recommended N rates are higher for fertigation than for granular fertilizers during the first 2 years after planting but are similar to granular rates in the following years. More work is needed to develop fertigation programs for other nutrients and soil supplements in northern highbush blueberry.
4
Pauly, D. G., S. S. Malhi und M. Nyborg. „Controlled-release P fertilizer concept evaluation using growth and P uptake of barley from three soils in greenhouse“. Canadian Journal of Soil Science 82, Nr. 2 (01.05.2002): 201–10. http://dx.doi.org/10.4141/s01-021.
Der volle Inhalt der QuelleAnnotation:
Use of controlled-release P fertilizers to match the fertilizer P availability to crop requirement has potential for improvement of P uptake and crop production. Greenhouse experiments were conducted to evaluate the concept of controlled-release P fertilizer by using different coatings to regulate the release of P and to compare the growth and P uptake of barley (Hordeum vulgare L.) in three Alberta soils. Testing of different coatings in one experiment was followed by further evaluation of the promising treatments in two experiments. Commercial monoammonium phosphate (MAP) and diammonium phosphate (DAP) were coated with a polymer (thin-coated, 1.8% by weight or thick-coated, 2.2%) or enveloped in commercial packaging polyethylene film (shrink wrap, SW) with two, four or six pin-holes to control P release. Thin-coated treatment showed greater dry matter yield (DMY), P uptake (PU), net fertilizer P efficiency (NFPE) and net fertilizer releases efficiency of MAP compared to the uncoated, thick-coated or SW treatments in many cases. Coating of DAP did not consistently improve any of the above-mentioned parameters. In some cases, uncoated fertilizer had greater DMY, PU and NFPE than the polymer-coated treatments in early stages of crop growth (at the 13th, 26th, and 30th days), but coated treatments generally performed better during later stages of crop (at the 39th, 45th, 60th and 90th days). At 31.4 mg P pot-1 for example, thick-coated treatment had about 25% of its total PU during the 60th to 90th day, which resulted in greater spike yield accumulation in this treatment (8.4 g pot-1) compared to uncoated fertilizer (5.0 g pot-1). The P release rate was greater with thin-coated fertilizer than with thick-coated fertilizer during the 0 to 13th days (by 0.199 mg P kg-1d-1) and the 13th to 26th days (by 0.084 mg P kg-1d-1), but the opposite was true during the 26th to 39th days (by 0.112 mg P kg-1d-1) and the 39th to 52th days (by 0.064 mg P kg-1d-1). The polymer-coated, in particular the thin-coated, fertilizers delivered P in a manner that allowed the plants to use it more effectively than the uncoated MAP in several cases, which indicated a potential for improvement of fertilizer P efficiency and crop production. Key words: Barley growth, controlled-release P fertilizer, P uptake, yield
5
Rodrigues, Laís Maia, Ricardo Francisco Pires und Davi Leonardo de Souza. „Study of Granulated Gypsum Hardness Coming from the Granulation Process in Rotating Disk“. Materials Science Forum 899 (Juli 2017): 160–66. http://dx.doi.org/10.4028/www.scientific.net/msf.899.160.
Der volle Inhalt der QuelleAnnotation:
The granulation process is a unit operation with broad application in the fertilizer industry. The granular fertilizer has a better physical appearance, facility of agricultural application and elimination of fugitive dust in the production and bagging units. Phosphogypsum is a residue from the production of phosphate fertilizers. It known that for every 1 t of phosphate fertilizer produced, about 4 t of phosphogypsum are obtained, causing problems in storage and risks to the environment. Such problems may be minimized by granulating the waste phosphogypsum and using it in agriculture. This work aims at the construction of a laboratory-scale rotating disk granulator with a pre-established combination of reagents to promote granulation of the waste from phosphate fertilizer production. For construction of the equipment a theoretical study was performed in order to establish the principal variables influencing the granulation technique and the dimensions required for building the granulator. The equipment attained the expected results and the disc speed (22 to 250 rpm) and disc inclination (0 to 90 degrees) can be manipulated. In this paper three binders used were: Manioc starch, carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA), each at three different concentrations. The tests were conducted using a rotating disk granulator and hardness tests on a universal mechanical testing machine. The figures of merit used in this study were percentage particle size, hardness and sphericity of the granules obtained. With the analysis of the data, it can be concluded that the granulation process was adequate, considering the settings employed.
6
Mikkelsen, Robert L., und Thomas W. Bruulsema. „Fertilizer Use for Horticultural Crops in the U.S. during the 20th Century“. HortTechnology 15, Nr. 1 (Januar 2005): 24–30. http://dx.doi.org/10.21273/horttech.15.1.0024.
Der volle Inhalt der QuelleAnnotation:
Tremendous changes have occurred during the past century in the sources and methods for supplying nutrients for horticultural crops. Reliance on animal manure, cover crops, and animal tankage was insufficient to meet the crop nutrient demand for a rapidly expanding population. The Haber-Bosch process for ammonia synthesis (1910s) revolutionized the availability and affordability of nitrogen (N) fertilizer. Discovery of large-scale deposits of rock phosphate in South Carolina (1860s) and Florida (1880s) alleviated widespread nutrient deficiencies. Acidification of rock phosphate and bone material significantly improved phosphorus (P) availability for plants. Discovery of potassium (K)-bearing minerals in New Mexico (1920s) and later in Canada (1960s) now provide a long-term nutrient source. Modern fertilizer technology allows nutrients to be applied in the correct ratio and amount to meet crop needs. Advances in understanding plant nutrition, coupled with slow-release fertilizers, foliar fertilization, soluble nutrients, and the development of soil and tissue testing have all improved the yield and quality of horticultural crops. Future developments will likely focus on fertilization in an increasingly competitive global economy, while requiring sophisticated management to minimize environmental impacts.
7
McKenzie, R. H., E. Bremer, L. Kryzanowski, A. B. Middleton, E. D. Solberg, D. Heaney, G. Coy und J. Harapiak. „Yield benefit of phosphorus fertilizer for wheat, barley and canola in Alberta“. Canadian Journal of Soil Science 83, Nr. 4 (01.08.2003): 431–41. http://dx.doi.org/10.4141/s02-078.
Der volle Inhalt der QuelleAnnotation:
Crop responsiveness to P fertilizers on the Canadian Prairies has likely declined during the past three to four decades due to regular application of P fertilizer and reduced tillage. Its relationship to extractable soil P as determined by various soil tests may also have changed. The objective of this study was to evaluate five soil test P methods for three major crops across a wide range of soil types and environmental conditions. Small-plot P fertilizer trials were conducted at 154 locations across Alberta from 1991 through 1993. At each location, fertilizer responses were determined for one, two, or three crops: barley (Hordeum vulgare L.), spring wheat (Triticum aestivum L.) or canola (Brassica napus L.). Fertilizer treatments consisted of seed-placed monoammonium phosphate at rates of 0, 6.5, 13.1 and 19.6 kg P ha-1. The average increase in seed yield due to application of P fertilizer was 10%, with little difference among crop types. Relative yield increases were significantly greater in Gray soils (Dark Gray Chernozemics, Dark Gray-Gray Luvisols) than in Black (Black Chernozemics) or Brown soi ls (Brown and Dark Brown Chernozemics). The maximum variation in P fertilizer response accounted for by any soil test P was 27% for barley, 15% for wheat and 7% for canola. The Kelowna method and its derivatives generally provided the best fit with P fertilizer response. Only a modest increase in the proportion of variation that could be accounted for by soil test was achieved by multiple regressions with soil pH, clay or organic matter or by separate analyses of different soil types or years. The probability of a profitable yield response due to P fertilizer application did decline with increasing soil test P. However, profitable yield responses were frequent at all levels of soil test P for the first increment of 6.5 kg P ha-1 and low at all levels of soil test P for the third increment of 6.5 kg P ha-1 (19.6 kg P ha-1). The poor relationship of soil test P to fertilizer response was attributed to frequent but variable starter effects of P fertilizer and the infrequent occurrence of highly responsive sites. Key words: Soil testing, Olsen, Bray, Kelowna, fertilizer response functions, Hordeum vulgare, Triticum aestivum, Brassica napus
8
Pathak, Enish, Arjun Sanjyal, Chhatra Raj Regmi, Saroj Paudel und Anima Shrestha. „Screening of Potential Plant Growth Promoting Properties of Bacillus Species Isolated from Different Regions of Nepal“. Nepal Journal of Biotechnology 9, Nr. 1 (31.07.2021): 79–84. http://dx.doi.org/10.3126/njb.v9i1.38672.
Der volle Inhalt der QuelleAnnotation:
The deleterious effects of intensive use of chemical fertilizers and pesticides in agriculture has led to the substantial research efforts on finding the alternatives to these agrochemicals. This study was aimed to isolate Bacillus species from soil of different regions of Nepal and screen for their ability to promote plant growth directly or indirectly by testing their ability to produce plant growth hormone indole acetic acid, hydrogen cyanide, ammonia and protease as well as phosphate solubilization. Thirty nine Bacillus strains were isolated from 25 soil samples of different regions of Kathmandu and Chitwan districts of Nepal. These isolates were tested for plant growth promoting traits in vitro. Among the total isolates, about 48.7% were indole acetic acid producers, 38.4% of the isolates showed the ability to solubilize the phosphate, 71.8% were able to produce ammonia and all the isolates had the ability to produce hydrogen cyanide and protease. The isolated strains showed positive results to maximum PGPR traits and exhibited a potential to be used as alternatives to chemical fertilizers and pesticides and could be used as low-cost bio-based technology to promote plant growth in the agricultural sector.
9
Johnston, Adrian M., und F. Craig Stevenson. „Field pea response to seeding depth and P fertilization“. Canadian Journal of Plant Science 81, Nr. 3 (01.07.2001): 573–75. http://dx.doi.org/10.4141/p00-166.
Der volle Inhalt der QuelleAnnotation:
A study was conducted at Melfort, SK, in 1998 and 1999 to determine whether seeding depth and P fertilization affect field pea (Pisum sativum L.) seedling emergence and grain yield. Treatments included a factorial combination of three seeding depths (38 mm, 76 mm, and 114 mm) with and without 25 kg P2O5 ha–1 as monoammonium phosphate. While seedling density was not affected by seeding depth at 3 wk after planting, the deepest seeding depth produced significantly fewer seedlings than the two shallower depths at 5 wk post-seeding. A year-by-seeding-depth interaction was recorded for grain yield, with deep seeding (114 mm) reducing yield by 8.5% in 1998, while no significant differences were recorded due to depth in 1999. Side-banded phosphorus fertilizer applications reduced seedling emergence at 3 wk; however, no difference was recorded by 5 wk after seeding. At harvest, addition of P fertilizer significantly increased grain yields on this high P testing soil; however, this response was small, averaging 138 kg ha–1. Results of this trial indicate that while field peas can tolerate deep seeding there appears to be little benefit from seeding deeper than 76 mm. Key words: Field pea, seeding depth, P fertilizer
10
Smagula, John M., und Scott Dunham. „Pruning Method Affects Lowbush Blueberry Yields“. HortScience 30, Nr. 4 (Juli 1995): 784C—784. http://dx.doi.org/10.21273/hortsci.30.4.784c.
Der volle Inhalt der QuelleAnnotation:
Flail mowing was compared to traditional pruning by oil fire over a 12-year period in two fertility experiments testing interactions with pruning method. In study one (1983–1986), urea at 0, 22.4, 44.8, 67.2, or 89.6 kg·ha–1 was applied preemergent in a split-block design with fertility as the main effect, and pruning method split within six blocks. Study two (1987–1994) continued the pruning and application of fertilizer on the treatment plots with similar rates, but diammonium phosphate (DAP) replaced urea as the fertilizer. Leaf tissue N concentrations were above the 1.6% standard and urea had no effect or decreased yield. There was no interaction of fertility and pruning and no effect of pruning method on yield. No interaction of fertility and pruning was found in study two, but DAP increased leaf P concentrations and yield and, after three cycles of mowing, yields had begun to decline in mowed plots compared to burned plots. No meaningful differences in leaf nutrient concentrations were found between plants in mowed and burned plots.
11
Stamford, Newton Pereira, Patrícia Ribeiro dos Santos, Adriana Muniz Mendes Freire de Moura, Carolina Etiene de Rosália e. Silva Santos und Ana Dolores Santiago de Freitas. „Biofertilzers with natural phosphate, sulphur and Acidithiobacillus in a siol with low available-P“. Scientia Agricola 60, Nr. 4 (Dezember 2003): 767–73. http://dx.doi.org/10.1590/s0103-90162003000400024.
Der volle Inhalt der QuelleAnnotation:
The production of mineral fertilizers is a expensive process, since it requires high energy consumption, and cannot be produced by small farmers. Laboratory assays were conducted to produce P-biofertilizers from natural phosphate (B5, B10, B15, B20), applying sulphur at different rates (5; 10; 15 and 20%) inoculated with Acidithiobacillus (S*) and testing increasing periods of incubation. A greenhouse experiment was carried out to evaluate the effect of the biofertilizers in a soil with low available P (Typic Fragiudult) from the "Zona da Mata" of Pernambuco State, grown with yam bean (Pachyrhizus erosus) in two consecutive harvests. The treatments were: Natural Phosphate (NP); biofertilizers produced in laboratory (B5, B10, B15, B20) with sulphur and Acidithiobacillus (NP+S*); natural phosphate with sulphur (20%) without Acidithiobacillus (NP+S); triple super phosphate (TSP) and a control without phosphorus. Plants were inoculated with a mixture of rhizobia strains (NFB 747 and NFB 748) or did not receive rhizobia inoculation. In bioassays pH and available P in the biofertilizers were analyzed. In the greenhouse experiment shoot dry matter, total N and total P in shoots, soil pH and available P were determined. Higher rates of available P were obtained in biofertilizers with sulphur and Acidithiobacillus (NP+S*) and in triple super phosphate (TSP), and biofertilizers with sulphur and Acidithiobacillus (FN+S*) and triple super phosphate (TSP) increased plant parameters. Native rhizobia were as effective as the strains applied in inoculation. After the two harvests soil presented lower pH values and higher rates of available P when the biofertilizers B15 and B20 with sulphur and Acidithiobacillus were applied.
12
Zlata, Holečková, Kulhánek Martin, Hakl Josef und Balík Jiří. „Use of active microorganisms of the Pseudomonas genus during cultivation of maize in field conditions“. Plant, Soil and Environment 64, No. 1 (16.01.2018): 26–31. http://dx.doi.org/10.17221/725/2017-pse.
Der volle Inhalt der QuelleAnnotation:
The aim of this research is to estimate the influence of a bioeffector (BE) application on dry matter yield and nutrient content (P, K, Ca, Mg, S) in maize (Zea mays L.). Between 2014 and 2016, a field experiment with silage maize as a testing plant was realized on sandy loam Cambisol. The application of Pseudomonas sp. in combination with phosphorus (rock phosphate (RP) or triple superphosphate (TSP)) and nitrogen fertilizers (ammonium nitrate with urea, ammonium nitrate with limestone, calcium nitrate or ammonium sulfate with a nitrification inhibitor) and with different application strategies was studied. The effects of a bioeffector application on the increase of dry matter yields were not confirmed. An important influence on the BE application and its activity was probably those of soil and site conditions and competition of the researched microorganisms with other present microorganisms. Higher yields of dry matter were shown in treatments where P fertilizers were applied. There was almost no difference between the application of RP and TSP. This could be caused by the fact that the soil had a slightly acidic pH value. In this case, the RP showed similar results to the TSP. The application of bioeffector significantly increased Mg, K and S contents in maize above-ground biomass. An increase of the Ca content was almost significant and a tendency towards a higher average content of phosphorus was also recorded.
13
Fu, Ruimin, Fang Lin, Hong Zhang, Wenhui Xing, Huiping Chang und Wuling Chen. „Optimization for Fermentation of Cattle Manure to Produce Bio-Fertilizer by Inoculating Complex Microbial Agents“. Open Biotechnology Journal 9, Nr. 1 (02.11.2015): 225–29. http://dx.doi.org/10.2174/1874070701509010225.
Der volle Inhalt der QuelleAnnotation:
In this study, in order to determine the optimization technology of bio-fertilizer, the aerobic fermentation test was conducted by using fresh manure and rice husk powder as materials. The inoculation, moisture content, C/N ratio and turning frequency analysed by single-factor test. Following this, the optimal conditions in the first fermentation were obtained through orthogonal experiments. After the first fermentation, the second fermentation was carried out by adding complex microbes with the ability to release potassium, dissolve phosphate and fix nitrogen. The termination time of second fermentation was determined by testing the growth condition of beneficial bacteria in the fermentation process. The results show, that the optimal parameter in the first fermentation contained moisture content of 70%, C/N ratio of 20:1, inoculation of 3%, and turning frequency of once every three days. After a period of fifteen days of fermentation, the germination index reached 91.3%. Following this, second fermentation was conducted at the sixth day and the germination index was increased to 98.8%. Under this optimum condition, the material could heat up fast and the top temperature could be high with a long duration.
14
Diagne, Mababa. „Use of alumina phosphate waste to produce building materials“. Bulletin de la Société Géologique de France 184, Nr. 3 (01.03.2013): 267–72. http://dx.doi.org/10.2113/gssgfbull.184.3.267.
Der volle Inhalt der QuelleAnnotation:
Abstract The generation of a fine fraction of sedimentary alumina phosphate before the manufacturing process of phosphoric acid –used as fertilizer– poses a crucial environmental issue related to the large quantities of fines stored for a long time in the wildlife without treatment or recycling in the region of Thiès in Sénégal by the Industries Chimiques du Sénégal (ICS) and the Société Sénégalaise des Phosphates de Thiès (SSPT). This work deals with the use of the fines particles of phosphate generated by the physical processing (crushing, transport and screening) of the raw material by the both mining companies. These fines particles of phosphates cover all the fauna and flora surrounding the sector with whitish dust particularly during the Harmattan, a hot and dry wind, while they can be leached during the rainy season to contaminate groundwater and then cause diseases to the populations who drink that water. Indeed, these materials, which are stored in large quantities as “waste”, and which pollute, the space and the environment, can be recycled as refractory materials useful in manufacturing such as bricks or paving blocks. The purpose of this study is to find, from these discarded fines that are not yet processed, a good and new material in terms of physical and mechanical characteristics that will meet a customary standard. This will allow not only to reduce their potential hazard by reducing the pollution for the consumption of the fines in order to generate a useful material especially in the surrounding villages of the mining sector, but also to employ young people in working age in this fines recycling process, to create jobs and therefore additional economic resources that allow a better life because the majority of the youngsters from these areas are unemployed. The formulation of a well-known mixture containing fines of sedimentary alumina phosphate of particles size ranging between 0.063 mm to 5 mm, with chemical composition similar to that of volcanic slag, sodium silicate called water-glass as binder of mineral elements; and water, led to the manufacturing of geomaterials blocks with 20×10×6 cm3 size by baking them several hours on an oven at the constant temperature of 225°C. The sodium silicate density was 1.4. Good mechanical and physical characteristics were achieved through systematic testing. Strength splitting rupture tests, total water content determination, size measurements of the blocks (length, width and thickness) as well as the loss on ignition on ambient atmosphere were achieved on the blocks after treatment for a complete identification. Average values of 3.03 MPa and 2.5% were obtained as results respectively for the splitting rupture strength and for the total water content. Negative variations of −2.05 mm, −0.59 mm and 1.69 mm on average values were obtained respectively on their length, their width and their thickness for a value of 5.30% of loss on ignition. The blocks are exposed on the fire on their upper surface whilst the heating effect falls of rapidly at the other side. The deduction of the compressive resistance strength from the average value of splitting rupture gave a value of 40.5 MPa. This value testifies very good mechanical resistance strength of the material which is made by the fines of phosphate. These characteristics obtained are compared here to the European Standard values EN 1338 for paving blocks. The values obtained for all the tests attest good manufacturing material. This new material can also be used as refractory materials in the ovens and in pottery materials.
15
SOON, Y. K. „COMPARISON OF PARAMETERS OF SOIL PHOSPHATE AVAILABILITY FOR THE NORTHWESTERN CANADIAN PRAIRIE“. Canadian Journal of Soil Science 70, Nr. 2 (01.05.1990): 227–37. http://dx.doi.org/10.4141/cjss90-024.
Der volle Inhalt der QuelleAnnotation:
A greenhouse experiment was conducted to evaluate several P availability parameters using 17 soils from the Peace River region of northwestern Canada. Only one soil was calcareous; the rest were acidic. The extractants tested included alkaline bicarbonate, acidic fluoride and 0.01 M CaCl2 solutions, and an anion exchange resin. Other availability indices evaluated were phosphoric acid potentials, phosphate buffer capacity and single point P sorption indices. The phosphoric acid potentials gave the highest correlation with percent relative yield of barley dry matter obtained after about 7 wk of growth. P sorption indices were not correlated with any crop response index. The phosphate buffer capacity and resin-extractable P performed at least as well as three chemical extractants: Olsen, Kelowna and Miller-Axley (modified) extractants. These three extractions were further evaluated using yield data from 11 field experiments with barley and 10 with rapeseed. There was little to choose from between these three extractants; however, the Kelowna extractant is a multi-element extractant and more convenient to use than the Olsen method. The Kelowna extractant also has a better buffering capacity, thus giving it a slight advantage over the modified Miller-Axley method for calcareous soils. These soil tests are, however, not fully satisfactory. In the greenhouse study, the Kelowna and Olsen methods made two errors and the modified Miller-Axley method three errors in prediction of P fertilizer requirement or non-requirement for the experimental soils. Key words: Soil testing, phosphate potential, chemical extractants, P sorption index, critical level
16
Jeksen, Julianus. „Uji Efektifvitas Cendawan Mikoriza Lokal Gerogak Lahan Kering dan Komersial Pada Tanaman Jagung (Zea mays L.)“. AGRICA 5, Nr. 2 (22.07.2020): 77–85. http://dx.doi.org/10.37478/agr.v5i2.448.
Der volle Inhalt der QuelleAnnotation:
Dryland in Indonesia has been dominated by acid soils, so that availability of phosphate (P) becomes the main obstacle in improving outcomes and only 10-30% of fertilizer P can be utilized by plants. One of the solution to meet the needs of phosphate is by utilization of mycorrhizal biofertilizer. These experiments were divided into several phases: 1) Looking for phases of mycorrhizal, 2) the laboratory analysis, 3) Testing phase on plants that were carried out by using polybags with sterile soil. The experiment was designed with a complete randomized block design (RAKL) by using a factor that consists of 6 treatments that are: 1) Without mycorrhizal inoculum (M0), 2) Mycorrhizal inoculum 5 g + 50 Spores (M5), 3) Mycorrhizal inoculum 10 g + 50 spores (M10), 4) Mycorrhizal inoculum 15 g + 50 spores (M15), 5) Mycorrhizal inoculum 20 g + 50 spores (M20), 6) Commercial mycorrhizal 10 g (Mk). All treatments were repeated four times so that the total 24 pot experiment. The experiment results show that mycorrhizal treatment given on the corn crop has very significant (P <0.01) to the number of leaf age of 35, 49, 63 days after, leaf wide have age 49 days after plant, fresh weight, oven-dry weight, absorb P, number of spores, mycorrhizal infection and significant effect (P <0.05) to plant height age of 35, 49, 63 day after plant, 63 days after plant, leaf wide, and P-available. Based on the results of this study will be suggested, in order to enhance the growth of corn plants can be used locally mikroiza a dose of 10 g + 50 spores.
17
Bennett, James P., Kyei Sing Kwong, Hugh Thomas und Rick Krabbe. „A New Generation of Refractories to Enable Gasifier Fuel Flexibility“. Advances in Science and Technology 70 (Oktober 2010): 179–92. http://dx.doi.org/10.4028/www.scientific.net/ast.70.179.
Der volle Inhalt der QuelleAnnotation:
Gasification is used by industry to convert low cost carbon into materials for producing electricity and chemical products such as fertilizer, plastics, and Fischer-Tropsch liquids. It is considered a critical technology in the success of the DOE’s Near Zero Emissions Advanced Fossil Fuel Power Plants, could play a key role in defining long-term energy security in both power and liquid fuels, and is considered a leading candidate for H2 production in a hydrogen based economy. Molten slag originating from mineral impurities in the carbon feedstock is of concern to slagging gasifier operation, with some gasifiers generating over 100 tons per day. Molten slag attacks and wears away the internal lining of the gasifier vessel by two major mechanisms, chemical dissolution and spalling. The main component in current refractory linings is chrome oxide. NETL is researching new types of refractory materials as an alternative to the high chrome oxide refractories currently used, with the goal of improving performance and providing a predictable service life. It has previously developed and patented the use of phosphate additives to improve the wear and spalling resistance of high chrome oxide refractories, and is exploring chrome and non-chrome oxide materials through laboratory testing and the use of thermodynamic modeling. In this paper, the results of a different additive (carbon) was evaluated by laboratory testing and found to improve slag penetration resistance. Data on this evaluation will be presented, and is proposed as a means of improving the molten slag wear resistance of the refractory. The use of it as a means of improving refractory service life in the field is patent pending.
18
Björkman, Thomas, und Stephen Reiners. „Meeting Initial Snap Bean Seedling Requirements with Starter Phosphorus or Bicarbonate to Solubilize Soil Phosphorus in High-phosphorus Soils“. HortScience 50, Nr. 4 (April 2015): 590–96. http://dx.doi.org/10.21273/hortsci.50.4.590.
Der volle Inhalt der QuelleAnnotation:
Starter phosphorus (P) is often recommended for warm-season vegetables sown in cool soil, even if soil P index levels are already high. The cost and environmental risk associated with excessive P fertilization justify re-examination of the practice. The objective of the study was to confirm that performance of early plantings of snap bean (Phaseolus vulgaris L.) is improved by starter P application and to test whether solubilizing soil P with potassium bicarbonate (KHCO3) can serve as an alternative in western New York soils. Addition of starter fertilizer at either recommended (15 kg·ha−1) or supraoptimal (35 kg·ha−1) P rates did not generally improve seedling tissue P concentration, early growth (biomass at flowering), or pod yield. Starter P application increased tissue P in only two of 11 experiments, and it never increased yield. Application of 6 kg·ha−1 KHCO3 to release soil-bound phosphate was not phytotoxic to snap beans. In the two experiments in which starter P increased tissue P, KHCO3 application had a smaller effect in one and no effect in the other. KHCO3 application did not increase yield in any of the six experiments where it was tested. A direct test of the contribution of P limitation to the poorer performance of early plantings showed that neither starter P nor KHCO3 application increased yield at early planting. Seasonal differences in crop performance could not be attributed to mineralization of soil phosphate after soil warmed. Water-extractable soil P was not lower in the spring than in summer, remaining constant at all 11 bean fields that were sampled from mid-April through mid-July. In these trials, P was likely not growth-limiting in the cool soils tested. Because starter P may not be necessary in vegetable soils testing high or very high for P, vegetables would also not likely benefit from bicarbonate application under high P conditions.
19
Demydenko, O., V. Prybluda, Yu Zapasna und V. Velychko. „Agrogenesis of regraded chernozem and the performance of grain crops under organic system of fertilization“. Agricultural Science and Practice 4, Nr. 3 (15.12.2017): 50–61. http://dx.doi.org/10.15407/agrisp4.03.050.
Der volle Inhalt der QuelleAnnotation:
Aim. To conduct complex agrophysical, physical-chemical substantiation of the effi ciency of the organic fer- tilization system in terms of nitrogen balance and organic carbon in the agroecosystem of a fi ve-fi eld grain- growing and weeding crop rotation fi lled with cereals and legumes up to 40 % and the use of by-products for fertility restoration and improvement of the agrogenesis of regraded chernozem in the central part of the Forest-Steppe of Ukraine. Methods. Laboratory-analytical, experimental fi eld, computational, statistical. Results. The systematic application of the organic system of fertilization in a short grain-growing and weeding crop rotation with the use of by-products as organic fertilizers promotes the increase in the points of exchange neutrality and the decrease in the unsaturation of regraded chernozem with the alkali of the tilled layer, while the increase in microaggregation and structure-building is conditioned by the approximation of potential acid- ity to the isoelectric state of soil colloids which is a feature of the process of biologization and simulation of natural soil formation in agroecosystems of the central part of the Forest-Steppe of Ukraine. Under the organic fertilization system the decrease in the agroecosystem performance is related to the decrease in the volume of nitrogen balance which testifi es to the decrease in the intensity of its circulation in agroecosystem: the processes of enhancing the humifi cation of by-products and the formation of prohumus substances prevail, ac- companied with the intensifi cation of atmospheric CO 2 involvement in the formation of the total phytomass of the harvest, and the agroecosystem transforms into a stock system, which may be characterized as a basic sys- tem for organic production of plant cultivation. Conclusions. The elaborated system of organic fertilization of crops in a fi ve-fi eld grain-growing and weeding crop rotation allows avoiding the use of organic fertilizers and perennial grasses and using by-products of plant cultivation instead to saturate the crop rotation with legumes up to 30–40 %, the application of nitrogen-fi xing and phosphate-mobilizing preparations allows ensuring the production of organically pure products with simultaneous restoration of both fertility and the natural model of the chernozem agrogenesis of the central part of the Forest-Steppe of Ukraine.
20
Eltarabily, Mohamed Galal, John M. Burke und Khaled M. Bali. „Effect of Deficit Irrigation on Nitrogen Uptake of Sunflower in the Low Desert Region of California“. Water 11, Nr. 11 (08.11.2019): 2340. http://dx.doi.org/10.3390/w11112340.
Der volle Inhalt der QuelleAnnotation:
Nitrogen (N) accounts for more than 80% of the total mineral nutrients absorbed by plants and it is the most widely limiting element for crop production, particularly under water deficit conditions. For a comprehensive understanding of sunflower Helianthus annuus N uptake under deficit irrigation conditions, experimental and numerical simulation studies were conducted for full (100% ETC) and deficit (65% ETC) irrigation practices under the semi-arid conditions of the Imperial Valley, California, USA. Plants were established with overhead sprinkler irrigation before transitioning to subsurface drip irrigation (SDI). Based on pre-plant soil N testing, 39 kg ha−1 of N and 78 kg ha−1 of P were applied as a pre-plant dry fertilizer in the form of monoammonium phosphate (MAP) and an additional application of 33 kg ha−1 of N from urea ammonium nitrate (UAN-32) liquid fertilizer was made during the growing season. Soil samples at 15-cm depth increments to 1.2 m (8 layers, 15 cm each) were collected prior to planting and at three additional time points from two locations each in the full and deficit irrigation treatments. We used HYDRUS/2D for the simulation in this study and the model was calibrated for the soil moisture parameters (θs and θr), the rate constant factors of nitrification (the sensitive parameter) in the liquid and solid states (μw,3, and μs,3). The HYDRUS model predicted cumulative root water uptake fluxes of 533 mm and 337 mm for the 100% ETC and 65% ETC, respectively. The simulated cumulative drainage depths were 23.7 mm and 20.4 mm for the 100% ETC and 65% ETC which represented only 4% and 5% of the applied irrigation water, respectively. The soil wetting profile after SDI irrigation was mostly around emitters for the last four SDI irrigation events, while the maximum values of soil moisture in the top 30 cm of the soil profile were 0.262 cm3 cm−3 and 0.129 cm3 cm−3 for 100% ETC and 65% ETC, respectively. The 16.5 kg ha−1 (NH2)2CO (50% of the total N) that was applied during the growing season was completely hydrolyzed to NH4+ within 7 days of application, while 4.36 mg cm−1 cumulative decay was achieved by the end of the 98-day growing season. We found that 86% of NH4+ (74.25 mg cm−1) was nitrified to NO3− while 14% remained in the top 50 cm of the soil profile. The denitrification and free drainage of NO3− were similar for 100% ETC and 65% ETC, and the maximum nitrate was drained during the sprinkler irrigation period. By the end of the growing season, 30.8 mg cm−1 of nitrate was denitrified to N2 and the reduction of nitrate plant uptake was 17.1% for the deficit irrigation section as compared to the fully irrigated side (19.44 mg cm−1 vs. 16.12 mg cm−1). This reduction in N uptake due to deficit irrigation on sunflower could help farmers conserve resources by reducing the amount of fertilizer required if deficit irrigation practices are implemented due to the limited availability of irrigation water.
21
Li, Hongjun, Yuming Zhang, Yuping Lei, Vita Antoniuk und Chunsheng Hu. „Evaluating Different Non-Destructive Estimation Methods for Winter Wheat (Triticum aestivum L.) Nitrogen Status Based on Canopy Spectrum“. Remote Sensing 12, Nr. 1 (26.12.2019): 95. http://dx.doi.org/10.3390/rs12010095.
Der volle Inhalt der QuelleAnnotation:
Compared to conventional laboratory testing methods, crop nitrogen estimation methods based on canopy spectral characteristics have advantages in terms of timeliness, cost, and practicality. A variety of rapid and non-destructive estimation methods based on the canopy spectrum have been developed on the scale of space, sky, and ground. In order to understand the differences in estimation accuracy and applicability of these methods, as well as for the convenience of users to select the suitable technology, models for estimation of nitrogen status of winter wheat were developed and compared for three methods: drone equipped with a multispectral camera, soil plant analysis development (SPAD) chlorophyll meter, and smartphone photography. Based on the correlations between observed nitrogen status in winter wheat and related vegetation indices, green normalized difference vegetation index (GNDVI) and visible atmospherically resistant index (VARI) were selected as the sensitive vegetation indices for the drone equipped with a multispectral camera and smartphone photography methods, respectively. The correlation coefficients between GNDVI, SPAD, and VARI were 0.92 ** and 0.89 **, and that between SPAD and VARI was 0.90 **, which indicated that three vegetation indices for these three estimation methods were significantly related to each other. The determination coefficients of the 0–90 cm soil nitrate nitrogen content estimation models for the drone equipped with a multispectral camera, SPAD, and smartphone photography methods were 0.63, 0.54, and 0.81, respectively. In the estimation accuracy evaluation, the method of smartphone photography had the smallest root mean square error (RMSE = 9.80 mg/kg). The accuracy of the smartphone photography method was slightly higher than the other two methods. Due to the limitations of these models, it was found that the crop nitrogen estimation methods based on canopy spectrum were not suitable for the crops under severe phosphate deficiency. In addition, in estimation of soil nitrate nitrogen content, there were saturation responses in the estimation indicators of the three methods. In order to introduce these three methods in the precise management of nitrogen fertilizer, it is necessary to further improve their estimation models.
22
Shahzoda, Turdialieva, Alimov Umarbek Kadyrbergenovich, Namazov Shafoat Sattarovich, Seytnazarov Atanazar Reypnazarovich und Beglov Boris Mikhaylovich. „Concentrated Np- and Npk-Fertilizers Based on Kyzylkum Evaporated Phosphoric Acid, Carbamide and Potassium Chloride“. Chemical Science International Journal, 25.03.2019, 1–8. http://dx.doi.org/10.9734/csji/2019/v26i230089.
Der volle Inhalt der QuelleAnnotation:
In the paper the processes of carboammophos and carboammophos potassium preparation based on the ammonization of the samples by evaporated wet phosphoric acid (WPA) (35.92; 40.85; 46.41; 51.07% P2O5) to pH = 5.3 (to obtain ammophos pulp) and pH = 7.0 (to obtain diammophos pulp) with subsequent addition of 70% solution of urea and crystalline potassium chloride (60% K2O) were studied. Moreover, for urea-phosphate, weight ratio of the N: P2O5: K2O ranged from 1: 0.5 to 1: 1: 1 for the N: P2O5: K2O urea-phosphate-potassium from 1: 0.7: 0.3 to 1: 1: 1. To avoid loss of ammonia, the drying of NP- and NPK slurry based on diammonium phosphate (DAP) were produced not higher than 60 °C, and monoammonium phosphate (MAP) - first at 60°C, then at 100°C to constant weight (less than 1% H2O). It is shown that on the basis of both MAP and DAP slurry are obtaining, samples of urea-phosphate similar in composition and properties. And all brands of urea-phosphate-potassium contain a high concentration of nutrients (up to 19.7% N. 19.7% P2O5 and 19.7% K2O). Phosphorus in them is in a form digestible for plants. The strength of both NPK and NPK fertilizer granules satisfies the requirements of agriculture. Such fertilizers in agriculture are in great demand
Experimental Design: Determination of total,l digestible, and water soluble forms of phosphorus (P2O5total, P2O5deg. P2O5water) was performed on KFK-3 (λ= 440 nm) as phosphorus-vanadium-molybdenum complex. This method is based on measuring the light transmission of yellow phosphorus-vanadium-molybdenum complex relative to the reference solution containing a certain amount of phosphates. Slurry pH was adjusted and determined by potentiometric method on ionometer I-130M (Russia). The mass was cooled, and then scattered by the size of the particles. Granules with a size of 2-3 mm were subjected to strength testing. The static strength of the granules was determined according to State standard 21560.2-82. This method based on crushing the granules using for that specified weights on scale called MIP 10-1 (Russia), which indicate kgf/cm2 per granule. Further dried granules of the fertilizer were performed chemical analysis. Digestible forms of P2O5 were determined by solubility in both 2% citric acid and 0.2 M solution of Trilon B (EDTA). The nitrogen content in the products was determined by Kjeldahl — distillation of ammonia in an alkaline medium with Devard alloy followed by titration of 0.1N NaOH.
Findings: Preparation process consists of as follow:
First slurry of ammophos and diammophos were prepared by neutralization of evaporated WPA containing 35.92; 40.85; 46.41; 51.07% P2O5 to pH = 5.3 (to obtain ammophos pulp) and pH = 7.0 to obtain diammophos pulp; Second to obtain NP fertilizer 70% solution of carbamide was added to MAP and DAP slurry at 60° C followed by stirring thorough. Then NP slurry was dried not higher than 100 °C for MAP and not higher than 60 °C for DAP, respectively; Third to prepare NPK fertilizer 70% solution of urea and crystalline potassium chloride (60% K2O) were added to MAP and DAP slurries. Next NPK slurry was dried not higher than 100 °C for MAP and not higher than 60 °C for DAP, respectively; Fourth NP and NPK fertilizer were tested on static strength accordingly above mentioned study design using State standard 21560.2-82; Fifth dried granules NP and NPK fertilizers were analyzed on various form of P2O5 including N and K2O. The latter was evaluated by calculation from difference N and P2O5 accordingly weight ratio N:K and N:P2O5:K2O equal to 1:0.5; 1:0.7; 1:1 and 1:0.3:1; 1:0.5:1; 1:1:1 respectively.
23
„The interactions between the supplies of water and of nutrients available to crops: implications for practical progress and for scientific work“. Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences 316, Nr. 1537 (13.02.1986): 331–46. http://dx.doi.org/10.1098/rsta.1986.0012.
Der volle Inhalt der QuelleAnnotation:
Many experiments have shown that the interactions between the supplies of water and of plant nutrients have large effects on crop production and on the efficiencies of both irrigation and fertilizers. Biological constraints, such as pests and diseases, also affect the returns from these inputs. High efficiency in the use of water is only achieved when crops have access to adequate supplies of nutrients. Similarly, full returns from fertilizers are obtained only when water supplies are sufficient for the needs of the crop; but water applied in excess or at inappropriate times may cause large losses of mobile nutrients, particularly of nitrogen, from the system. Water status regulates the processes of mass flow and diffusion of solutes in soils, which determine nutrient uptake. Water-use efficiency depends on physiological processes in plants and these are affected by nutrients. Nitrogen is often responsible for rapid increases in leaf area so that photosynthesis is increased and evaporation of water from the soil surface is reduced. Potassium ions have a vital role in osmotic processes in the plant, and particularly in stomatal regulation. The effects of drought are often associated with reduced phosphate uptake. Water supplies also regulate the microbiological processes involved in soil fertility, and particularly the biological fixation of nitrogen. Experiments have shown that the method and timing of irrigation affects the efficiency of fertilizers. Therefore the practical management of crop nutrition and irrigation should be carefully coordinated to secure the maximum return from both inputs to the system. Drip (trickle) irrigation systems make it possible to apply both inputs in one operation to the roots of the crop (‘fertigation’) so that maximum fertilizer efficiency is achieved. There is a case for further investigations on subsurface irrigation for appropriate crops and conditions. In the further research that is required to achieve high efficiency in irrigated production systems the emphasis must be on multidisciplinary field experimentation, testing water, fertilizers, and other inputs needed in the system. The experiments will also form a basis for the work needed in both plant physiology and soil science. This research should lead to the development of models of the production systems, which will be used as a basis for the improved recommendations to farmers on the use of water and of fertilizers which are needed to improve food production.
24
Gebremichael, Yohannes, und Gebremedhen Gebretsadikan. „Effect of Mineral Nitrogen and Phosphorus Fertilizer Rates on Marketable Yield and Economic Return of Tomato (Lycopersicon esculentum Mil) at Northwestern Zone of Tigray“. Asian Research Journal of Agriculture, 06.12.2019, 1–7. http://dx.doi.org/10.9734/arja/2019/v11i430070.
Der volle Inhalt der QuelleAnnotation:
A field experiment was conducted to study the effect of different nitrogen and phosphorus fertilizer rates on the growth and yield tomato at Northwestern Zone of Tigray during 2016-2017 cropping season under irrigation condition. It is the most cultivated and high market value of vegetable crops in Tigray Northern Ethiopia. However, tomato production is limited due to low fertility of soil and inappropriate fertilizer rate. Six different levels of nitrogen (0, 23, 46, 69, 92 and 115 kg N /ha) and six different levels of phosphorus (0, 46, 69, 92,115 and 138 kg P2O5/ ha) were used and laid out in randomized complete block design with three replication. (Melkasalsa) tomato variety was used as a testing variety. The current findings showed that the highest marketable tomato fruit yield (61.16 t/ha) were obtained in 115 kg N/ha (250 kg urea/ha) and 92 kg P2O5 (200 kg Di Ammonium Phosphate DAP /ha). But, the profitable yield obtained was at N2P2 (46 kg N & 69 P2O5 kg ha-1) that is 100 kg/ha of Urea combined with 150 kg/ha of DAP yield was obtained 48.25 t ha-1 and the profit was 235502 birr per ha with the maximum Marginal Rate of Return of 26.16%. Therefore, 100 kg/ha of urea with 150 kg/ha of DAP was recommended for the growers to improve tomato fruit productivity in the study area.
25
„Selection of Best Frequency Range for Soil Urea Prediction“. International Journal of Innovative Technology and Exploring Engineering 9, Nr. 3 (10.01.2020): 1934–36. http://dx.doi.org/10.35940/ijitee.c8904.019320.
Der volle Inhalt der QuelleAnnotation:
Soil is a complex system and its nature determines the types of crops that can be cultivated. Soil testing plays an important role in determining its ability to grow crops. Conventional soil testing methods are found to be cumbersome and expensive and also time consuming. Hence there is a need for methods which can give fast results and help in effective crop cultivation. Soil exhibits both spatial and temporal variability. The traditional methods of soil testing do not take into account the variability of the soil and uniform application of external inputs is done. This leads to over or under use of fertilizers, which in turn results into soil turning infertile, ground water getting contaminated etc. Precision Farming technique makes use of new technologies to take into consideration the variability exhibited by soil and is also called as site specific management. Soil nutrient testing is an important aspect of soil testing which helps in finding out the available soil nutrients and which in turn determines the crops that can be cultivated. Various techniques have been developed to determine the soil nutrients but most of these techniques are found to be time consuming. Hence there is a need to develop techniques which can give real time measurements of soil nutrients. This paper discusses about the use of RF spectra for predicting the soil nutrients. The RF spectra are obtained using a cell which is designed based on the principle of dielectricity. Samples were prepared in the laboratory by mixing five different components namely urea, potash, phosphate, lime and salt in distilled water. RF spectra of different samples having varying concentrations of the components were recorded. Multivariate analysis based on the Partial Least Square Regression technique was used to predict the amount of urea in a sample. The prediction of urea was done using two different frequency ranges i.e 10MHz-500MHz and 500MHz – 1000MHz and analysis of the results was done to determine which frequency range gives better results. The results show that percentage error of urea prediction is better in the frequency range of 500MHz-1000MHz as compared to 10MHz-500MHz.