Studies in citrus nutrition i. Leaf growth and composition

1956 ◽  
Vol 7 (4) ◽  
pp. 248 ◽  
Author(s):  
RF Williams ◽  
CT Gates
Keyword(s):  
Organic Matter ◽  
Treatment Effects ◽  
Nitrogen Nutrition ◽  
Leaf Growth ◽  
Dry Weight ◽  
Nitrogen Supply ◽  
Dominant Factor ◽  
Nitrogen And Phosphorus ◽  
Citrus Grove ◽  
Four Levels

Vegetative shoots from the spring flush of an experimental citrus grove tagged and sampled on three occasions at intervals of 6 months. The effects of four cultural treatments, four levels of nitrogen supply, four combinations of stock and scion, and of time on leaf area and dry weight, and on relative and absolute contents of water, nitrogen, and phosphorus are presented and discussed. While nitrogen nutrition is still the dominant factor, the evidence strongly suggests that phosphorus nutrition has become important as a determinant of treatment effects within the experimental grove. The possible relevance of soil temperature and soil organic matter for some of the cultural treatment effects is discussed.

scholarly journals Effect of nitrogen and phosphorus on the growth and yield performance of soybean

2015 ◽  
Vol 2 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Mst Anjumanara Begum ◽  
Md Aminul Islam ◽  
Quazi Maruf Ahmed ◽  
Md Anwarul Islam ◽  
Md Moshiur Rahman
Keyword(s):  
Seed Weight ◽  
Dry Weight ◽  
Growth And Yield ◽  
Nitrogen And Phosphorus ◽  
Combined Application ◽  
Stover Yield ◽  
Four Levels ◽  
Different Levels ◽  
Phosphatic Fertilizers ◽  
Number Of Branches

The experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh to study the effects of nitrogen and phosphorus on the performance of soybean. Three levels of nitrogen (0, 25 and 40 kg N ha-1) and four levels of phosphorus (0, 18, 36 and 54 kg P ha-1) were considered as treatment for the experiment. Soybean responded remarkably to the added nitrogenous and phosphatic fertilizers as the crop characters were significantly influenced by different levels of nitrogen and phosphorus. Significant effect on number of branches and seeds plant-1, plant height, number of filled pods plant-1, weight of seeds plant-1, dry weight of plant, stover weight plant-1, 1000-seed weight, seed and stover yield were obtained from the combined application of 25 kg N with 54 kg P ha-1.Res. Agric., Livest. Fish.2(1): 35-42, April 2015

Studies in soil fertility with special reference to organic manures. I. The field experiments.

1954 ◽  
Vol 5 (2) ◽  
pp. 181
Author(s):  
K Spencer
Keyword(s):  
Rice Straw ◽  
Field Experiments ◽  
Nitrogen Nutrition ◽  
Nitrogen Deficiency ◽  
Dominant Factor ◽  
Available Phosphorus ◽  
Biological Fixation ◽  
Nitrogen And Phosphorus ◽  
Organic Manures ◽  
Rice Hulls

The results for five field experiments with organic manures on three related soil types of the grey and brown soils group are reported. Four experiments were with irrigated summer crops and the fifth was a spring crop with supplemental irrigation. Pea trash and rice hulls were the main organic manures used, but chaffed lucerne and rice straw were also used in one of the experiments. Seedling emergence was delayed and reduced by rice straw when only one month was allowed for decomposition, but these effects were absent following three months of decomposition. Rice straw and rice hulls both induced more or less transitory symptoms of nitrogen deficiency in the absence of added nitrogen. Except in one experiment with pea trash on a near-virgin soil, pea trash, chaffed lucerne, and rice hulls all gave highly significant yield increases. Rice straw also gave yield increases when three months were allowed for decomposition. From an examination of the patterns of response in these experiments, together with data for soil water, nitrate nitrogen, and available phosphorus, it is concluded that phosphorus nutrition may be a dominant factor in yield determination, especially with rice hulls, and that nitrogen nutrition exerts a strong modifying influence in some circumstances. Hypotheses concerning the mineralization and biological fixation of nitrogen and phosphorus are discussed, but seem inapplicable to the specific conditions of these experiments. The origin of the additional phosphorus made available in the soil by organic manures with low content of that element emerges as a significant problem calling for solution. Current hypotheses on this point are considered, but it is contended that far more information than is usually obtainable from field experiments would be required to decide which of a number of possible mechanisms plays a significant role in the release or maintenance of this phosphorus.

Appraisal by Numerical and Statistical Techniques of the Interaction of Moisture Stress and Phosphorus in the Development of the Tropical Legume Macroptilium atropurpureum (Dc.) Urb

1980 ◽  
Vol 28 (6) ◽  
pp. 621 ◽  
Author(s):  
CT Gates ◽  
RL Sandland
Keyword(s):  
Water Stress ◽  
Dry Weight ◽  
Moisture Stress ◽  
Growth Potential ◽  
Nodule Development ◽  
Nitrogen And Phosphorus ◽  
Active Growth ◽  
Macroptilium Atropurpureum ◽  
Four Levels ◽  
Rates Of Growth

The interaction of two levels of soil moisture and four levels of phosphorus on the development of Macroptilium atropurpureurn was studied for 18 harvests at 2-day intervals beginning on day 29 after sowing. Variates studied were fresh weight. dry weight, nitrogen and phosphorus contents for the laminae. stem plus petioles, root and nodules. The responses to treatment of these variates were shown by preliminary analyses of variance to contain complex patterns of interaction. The important facets of these interactions were then appraised by an extension of the usual univariate methods and the overall pattern of the interaction was delineated by a classificatory analysis. On the basis of the 14 attributes studied, there were six groups of responses to treatment. The lowest of these groups corresponded to failure to grow at low levels of phosphorus. The next group represented the response of nodules to treatment. Subsequent groups represented higher growth potential following efficient functioning of the nodules. Effects on nodulation were thus primary to subsequent patterns of plant development. Water stress greatly impaired both plant and nodule development, particularly at the higher two levels of phosphorus, whereas active growth occurred in normally watered plants. At these two phosphorus levels the effect of water stress was on development rather than on chemical composition, there being large absolute but small relative effects on chemical data. The lower levels of phosphorus supply contrasted with the two higher levels in having much lower rates of growth and of water loss.

Beberapa Sifat Kimia Tanah Akibat Pemberian Ekstrak Krandalit dan Fraksi Bahan Organik pada Humic Hapludults

Agrotek ◽  
2018 ◽  
Vol 2 (3) ◽  
Author(s):  
Ishak Musaad
Keyword(s):  
Organic Matter ◽  
Dry Weight ◽  
Treatment Unit ◽  
Organic C ◽  
Exchangeable Al ◽  
Main Plot ◽  
Organic Fractions ◽  
Four Levels ◽  
Humic Fractions ◽  
Humic Fraction

The aims of this research were to study pH, C-organic, exchangeable Al, P_available (Bray II), and Fe-DTPA, due to applications of crandallite extract and organic matter fraction of peat and chicken dung on Humic Hapludults. This research was conducted at Jatinangor. The laboratory experiment was rranged in a factorial split plot design consisted of two kinds or organic matter (peat and chicken dung) as main plot, three levels organic fractions namely: without organic fraction, humic fraction and fulfic fractions as sub-plot and four levels crandallite extract (0, 50, 100 and 150 kg P2O5 per hectare) as sub-plots. Each treatment unit was replicated three times so it produced 72 experiment units. Results showed that humic fraction application at different level of crandillate extract increased soil pH, Fe-DTPA, dry weight of root and shoot. Crandallite extract application increased P-available (3 mg per kg). HUmic fractions increased organic C in soils (0,63%), dry weight shoot (4,71 g per plant) and decreased exchangeable Al (0,10 cmol per kg).

Responses of triticale, wheat, rye and barley to nitrogen fertilizer

1983 ◽  
Vol 23 (120) ◽  
pp. 73 ◽  
Author(s):  
RD Graham ◽  
PE Geytenbeek ◽  
BC Radcliffe
Keyword(s):  
Grain Yield ◽  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Nitrogen Nutrition ◽  
Early Stage ◽  
South Australia ◽  
Dry Weight ◽  
Nitrogen Supply ◽  
Dry Matter Production ◽  
Matter Production

A hexaploid triticale from Mexico and local cultivars of wheat, rye and barley, each at five levels of fertilizer nitrogen (0, 35, 70, 105 and 140 kg N/ha) with four replications, were grown in a field experiment at Mintaro, South Australia. A visually discernible response to nitrogen fertilizer by all four genotypes from an early stage was confirmed by quantitative sampling at tiliering, anthesis and maturity. Responses in plant dry weight to 105 kg N/ha were maintained until anthesis but grain yield responses were significant only at 35 kg N/ha. Total dry matter production responses at maturity to more than 35 kg N/ha were small. Numbers of tillers and heads were increased by nitrogen additions up to 140 and 105 kg N/ha, respectively, and plant height measurements showed general increases to 70 kg N/ha with significant lodging at higher nitrogen levels in both rye and triticale. For all genotypes, thousand grain weight decreased with increasing level of nitrogen supply while grain and straw nitrogen increased up to levels of 140 and 105 kg N/ha, respectively. Nitrogen supply had little effect on maturity, plants at 0 and 140 kg N/ha reaching anthesis less than a day apart. The lack of a significant nitrogen x genotype interaction in nearly all the data suggests that the triticale does not differ in its nitrogen nutrition from the traditional cereals. Triticale consistently outyielded the other cereals in total dry matter production followed by the rye, wheat and barley in that order. Grain yield was highest in the wheat and least in the rye, the latter also being the least responsive to nitrogen. The advantage of the triticale lay in its high grain protein and lysine content combined with good yield.

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu
Keyword(s):  
Microcystis Aeruginosa ◽  
Regulatory Protein ◽  
Acid Synthesis ◽  
Nutrient Supply ◽  
Nitrogen Supply ◽  
Nitrogen And Phosphorus ◽  
Comprehensive Description ◽  
Amino Acid Synthesis ◽  
High Nutrient ◽  
Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

Potential Contribution of Nutrients and Polycyclic Aromatic Hydrocarbons from the Creeks of Cootes Paradise Marsh

1996 ◽  
Vol 31 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Barb Crosbie ◽  
Douglas Bryant ◽  
Brian McCarry
Keyword(s):  
Aromatic Hydrocarbons ◽  
Laboratory Experiments ◽  
Dry Weight ◽  
Common Source ◽  
Potential Contribution ◽  
Nitrogen And Phosphorus ◽  
Engine Combustion ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Derivatives Of

Abstract During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.

Fish farming in Denmark: environmental impact of regulative legislation

1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen
Keyword(s):  
Organic Matter ◽  
Environmental Impact ◽  
Freshwater Fish ◽  
Aquatic Environment ◽  
Action Plan ◽  
Fish Farming ◽  
Fish Farms ◽  
Nitrogen And Phosphorus ◽  
Local Impact ◽  
The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply

Deinking sludge influences biomass, nitrogen and phosphorus status of several grass and legume species

1997 ◽  
Vol 77 (4) ◽  
pp. 693-702 ◽  
Author(s):  
A. Fierro ◽  
J. Norrie ◽  
A. Gosselin ◽  
C. J. Beauchamp
Keyword(s):  
Soil Amendment ◽  
Mineral Soil ◽  
Nitrogen And Phosphorus ◽  
Agropyron Elongatum ◽  
Festuca Ovina ◽  
Melilotus Officinalis ◽  
Medicago Lupulina ◽  
Wide Range ◽  
Galega Orientalis ◽  
Four Levels

In a greenhouse study, deinking sludge was evaluated as a soil amendment supplemented with four nitrogen (N) fertilization levels for the growth of the grasses Agropyron elongatum (Host.) Beauv. (tall wheatgrass), Alopecurus pratensis L. (meadow foxtail), Festuca ovina var. duriuscula (L). Koch (hard fescue), and four levels of phosphorus (P) for the growth of the legumes Galega orientalis Lam. (galega), Medicago lupulina L. (black medic), Melilotus officinalis (L.) Lam (yellow sweet clover). Fertilizers were applied on the basis of sludge level to maintain uniform carbon (C)/N or C/P ratios across sludge treatments. In one experiment, sand was mixed with 0, 10, 20 or 30% sludge while, in a second experiment, mineral soil was mixed with 0, 27, 53 or 80% sludge (vol/vol). In sand mixtures of 30 and 20% sludge, grasses had similar or greater growth than in unamended mineral soil when N was added at about 6.5 and 8.4 g kg−1 deinking sludge, respectively. For all legumes but Medicago lupulina, P at about 0.8 g kg−1 sludge was required for these sand mixtures. In soil mixtures of 53 and 27% sludge, grasses grew well when supplemental N was about 5.3 and 6.9 g kg−1 sludge, respectively. Legumes required P at 0.5 and 1.2 g kg−1 sludge, respectively. In general, growth was closely related to total amount of added N or P in spite of the wide range of C/N or C/P ratios. When growing in media amended with sludge, grasses needed higher tissue N concentration for an equivalent growth than in control soil; legumes had similar tissue P concentration. The grasses Agropyron elongatum and Alopecurus pratensis as well as the legumes Melilotus officinalis and Galega orientalis are promising species for field testing, based on dry matter production. Deinking sludge can be used as soil amendment when adequate N and P supplements are provided. Key words: Soil amendment, papermill sludge, Agropyron elongatum, Alopecurus pratensis, Festuca ovina, Medicago lupulina, Galega orientalis, Melilotus officinalis

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