RESPONSE OF RAPESEED TO APPLIED NITROGEN, PHOSPHORUS, POTASSIUM AND SULFUR WHEN GROWN ABOVE 57 DEGREES NORTH LATITUDE

1968 ◽  
Vol 48 (6) ◽  
pp. 611-616 ◽  
Author(s):  
C. H. Anderson ◽  
A. G. Kusch
Keyword(s):  
Low Ph ◽  
Available P ◽  
Fertilizer Response ◽  
N Content ◽  
Available N ◽  
P Content ◽  
Seed Yields ◽  
Nitrogen Phosphorus ◽  
North Latitude ◽  
Applied Nitrogen

In a two-year study at three soil sites, 14 fertilizer treatments were applied to rapeseed grown on summerfallow. Phosphorus applied singly or in combination with N, with N and K, or with N, K and S significantly increased seed yields on a Rego Humic Gleysol soil of low pH status and on an Orthic Dark Gray Wooded soil of high available N content; there was no fertilizer response on a Rego Gleysol soil of variable texture and high available P content. While rapeseed did not respond to N alone, additional benefits did sometimes accrue from the addition of 11 kg/ha of N to P applications.

EFFECTS OF FERTILIZER AND AVAILABLE MOISTURE ON THE YIELD AND N AND P CONTENT OF WHEAT AND ON SOIL NUTRIENTS

1974 ◽  
Vol 54 (2) ◽  
pp. 187-193 ◽  
Author(s):  
W. C. HINMAN
Keyword(s):  
Soil Nutrients ◽  
Organic N ◽  
N Content ◽  
Available N ◽  
Organic C ◽  
Natural Rainfall ◽  
P Content ◽  
Added Water ◽  
Additional Water ◽  
Soluble P

Thatcher wheat was grown in tank-type lysimeters over a 7-yr period to determine the effect of fertilizer, two levels of available water and two cropping systems on the yield and nutrient content of grain and on some soil nutrients. Fertilizer did not change the yield of grain materially under natural rainfall. Added water only increased the yield by one-half and three-quarters of continuous wheat and fallow, respectively. Fertilizer with added water nearly doubled the yield of continuous wheat and increased by one-third the yield from the wheat-fallow rotation. The P content of the grain was not affected by fertilization, but was higher in the treatments to which additional water was applied than in those receiving natural rainfall only. It was also higher in continuous wheat than in fallow wheat. There was an interaction between the N and P uptake ratio and the N content of the grain. Fertilizer or additional water or both increased or decreased the N content, depending upon which way the N or P balance was shifted. Surplus available N not utilized by the crop grown with natural rainfall accumulated as nitrates at lower soil depths, particularly under the wheat-fallow system. All the NO3-N produced where supplemental water or water and fertilizer were applied was utilized and none accumulated. The organic N content of the surface soil increased along with a reduced loss in organic C where water and fertilizer were applied, as compared to the other treatments. Fertilizer application resulted in a sharp increase in NaHCO3 soluble P, particularly following the supplemental water plus fertilizer treatments where an excess of P was supplied with the fertilizer over that removed by the crop. There was an increased demand on soil P where water only was applied, and the soluble P content was appreciably reduced.

EFFECT OF NITROGEN, PHOSPHORUS, AND POTASSIUM ON YIELD, PERSISTENCE, AND NUTRIENT CONTENT OF TIMOTHY

1966 ◽  
Vol 46 (6) ◽  
pp. 577-582 ◽  
Author(s):  
E. A. Grant ◽  
A. A. MacLean
Keyword(s):  
Dominant Species ◽  
Nutrient Content ◽  
Nutrient Concentrations ◽  
N Content ◽  
Optimum Yield ◽  
P Content ◽  
P Application ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

High levels of both N and K from fertilizer were required to obtain optimum yield of timothy and also to maintain timothy as the dominant species in a grass sod. Phosphorus was required in relatively small amounts. Timothy degenerated when an imbalance of N and K was induced through fertilization and did so most rapidly when N was applied without K. Increasing N applications generally increased N content but the extent of the increase was modified when K was also applied, similarly K application increased K content but levels were modified downward when N was also applied. P content was affected only slightly by P application but levels were lowered when yields were increased by a combination of N and K. Critical nutrient concentrations of 1.6, 0.20, and 1.2% for N, P, and K respectively were determined for first-crop timothy cut at the fully headed stage. Higher levels of N and P were observed in second-cut material.

scholarly journals Land Uses, Altitude and Texture Effects on Soil Parameters. A Comparative Study in Two Districts of Nagaland, Northeast India

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 171
Author(s):  
Gaurav Mishra ◽  
Rosa Francaviglia
Keyword(s):  
Soil Properties ◽  
Soil Texture ◽  
Soil Parameters ◽  
Available Phosphorus ◽  
Land Uses ◽  
Management Options ◽  
Available N ◽  
P Content ◽  
Significant Difference ◽  
Soc Stocks

Northeast (NE) India is a typical tropical ecosystem with a luxuriant forest vegetation cover, but nowadays forests are under stress due to exploitation and land use changes, which are known to affect soil health and productivity. However, due to a scarcity of data, the influence of land uses and altitude on soil properties of this peculiar ecosystem is poorly quantified. This study presents the changes in soil properties in two districts of Nagaland (Mon and Zunheboto) in relation to land uses (forest, plantation, jhum and fallow jhum), altitude (<500 m, 500–1000 m, >1000 m) and soil texture (coarse, medium, fine). For this, a random soil sampling was performed in both the districts. Results indicated that soil organic carbon (SOC) stocks and available potassium (K) were significantly influenced by land uses in the Mon district, while in Zunheboto a significant difference was observed in available phosphorus (P) content. SOC stocks showed an increasing trend with elevation in both districts. The influence of altitude on P was significant and the maximum concentration was at lower elevations (<500 m). In Mon, soil texture significantly affected SOC stocks and the available N and P content. The variability in soil properties due to land uses, altitudinal gradients and textural classes can be better managed with the help of management options, which are still needed for this ecosystem.

scholarly journals Phytotoxic effects of invasive Ageratina adenophora on two native subtropical shrubs in Nepal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tej Bahadur Darji ◽  
Barsha Adhikari ◽  
Seeta Pathak ◽  
Shristi Neupane ◽  
Lal B. Thapa ◽  
...  
Keyword(s):  
Low Ph ◽  
Potential Mechanism ◽  
Phytotoxic Effects ◽  
Seedling Length ◽  
Ageratina Adenophora ◽  
Ir Analysis ◽  
Allelopathic Interference ◽  
Phosphorus And Potassium ◽  
Native Shrubs ◽  
Nitrogen Phosphorus

AbstractThe response of native plants to allelopathic interference of invasive species may differ from species to species. In this study, the phytotoxic effects of Ageratina adenophora were tested on two native shrubs (Osbeckia stellata and Elsholtzia blanda) of Nepal. Both the shrubs were grown in pots under treatments of A. adenophora fresh leaves and root leachates, and litter. Then, the seedling length and biomass were compared among the treatments. The results show that A. adenophora litter has stimulatory effects but the leachates from fresh leaves and root are phytotoxic to the growth and development of native shrubs. Infrared Spectroscopy (IR) analysis confirmed the presence of O–H (Hydroxyl), N–H (Amines), C≡C (Alkynes), and C–H stretching (Aromatic) or C–O–C stretching (Ethers) in the leachates representing harmful allelochemicals. The invaded soil by A. adenophora had low pH and a high amount of organic matter, total nitrogen, phosphorus, and potassium than the uninvaded soil. The results indicate that the native O. stellata and E. blanda are harmed by A. adenophora in nature by leaching of allelochemicals and probably by reducing the soil pH. Overall, this study has provided valuable insights regarding the effects of A. adenophora invasion on native shrubs and revealing the potential mechanism of its invasiveness.

scholarly journals Using a One-Dimensional Convolutional Neural Network on Visible and Near-Infrared Spectroscopy to Improve Soil Phosphorus Prediction in Madagascar

2021 ◽  
Vol 13 (8) ◽  
pp. 1519
Author(s):  
Kensuke Kawamura ◽  
Tomohiro Nishigaki ◽  
Andry Andriamananjara ◽  
Hobimiarantsoa Rakotonindrina ◽  
Yasuhiro Tsujimoto ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Near Infrared ◽  
Soil Phosphorus ◽  
Predictive Ability ◽  
Available P ◽  
Accurate Estimation ◽  
One Dimensional ◽  
P Content ◽  
Soil Available P

As a proximal soil sensing technique, laboratory visible and near-infrared (Vis-NIR) spectroscopy is a promising tool for the quantitative estimation of soil properties. However, there remain challenges for predicting soil phosphorus (P) content and availability, which requires a reliable model applicable for different land-use systems to upscale. Recently, a one-dimensional convolutional neural network (1D-CNN) corresponding to the spectral information of soil was developed to considerably improve the accuracy of soil property predictions. The present study investigated the predictive ability of a 1D-CNN model to estimate soil available P (oxalate-extractable P; Pox) content in soils by comparing it with partial least squares (PLS) and random forest (RF) regressions using soil samples (n = 318) collected from natural (forest and non-forest) and cultivated (upland and flooded rice fields) systems in Madagascar. Overall, the 1D-CNN model showed the best predictive accuracy (R2 = 0.878) with a highly accurate prediction ability (ratio of performance to the interquartile range = 2.492). Compared to the PLS model, the RF and 1D-CNN models indicated 4.37% and 23.77% relative improvement in root mean squared error values, respectively. Based on a sensitivity analysis, the important wavebands for predicting soil Pox were associated with iron (Fe) oxide, organic matter (OM), and water absorption, which were previously known wavelength regions for estimating P in soil. These results suggest that 1D-CNN corresponding spectral signatures can be expected to significantly improve the predictive ability for estimating soil available P (Pox) from Vis-NIR spectral data. Rapid and accurate estimation of available P content in soils using our results can be expected to contribute to effective fertilizer management in agriculture and the sustainable management of ecosystems. However, the 1D-CNN model will require a large dataset to extend its applicability to other regions of Madagascar. Thus, further updates should be tested in future studies using larger datasets from a wide range of ecosystems in the tropics.

scholarly journals Phosphorus forms in leaves and their relationships with must composition and yield in grapevines

2017 ◽  
Vol 52 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Rogério Piccin ◽  
Rafael da Rosa Couto ◽  
Roque Júnior Sartori Bellinaso ◽  
Luciano Colpo Gatiboni ◽  
Lessandro De Conti ◽  
...  
Keyword(s):  
The Other ◽  
Available P ◽  
Anthocyanin Content ◽  
P Fractionation ◽  
Cabernet Franc ◽  
Phosphorus Forms ◽  
Yield Parameters ◽  
P Content ◽  
Total P

Abstract: The objective of this work was to evaluate phosphorus forms in grape leaves and their relationships with must composition and yield in grapevines grown in a Typic Hapludalf with different available P contents. Two experiments were carried out with Vitis viniferacultivars, one with 'Tannat' and the other with 'Cabernet Franc' grapes. Experiment 1 consisted of two vineyards of 'Tannat', with the following P content in the soil: V1, 11.8 mg kg-1 P; and V2, 34.6 mg kg-1 P. Experiment 2 consisted of two vineyards of 'Cabernet Franc', with the following P content in the soil: V1, 16.0 mg kg-1 P; and V2, 37.0 mg kg-1 P. Leaves were collected at flowering (FL) and veraison (V), and, after their preparation, P forms were evaluated. Yield and must composition were assessed. The highest yield was observed in V2 of experiment 1 and in V2 of experiment 2. Total P content and P forms in leaves at FL and V have no relationship with yield parameters; however, total P content in leaves has a relationship with anthocyanin content in the must of 'Tannat' grapevines. Therefore, P fractionation in leaves predicts neither grapevine yield nor must composition.

Relationship of soil phosphorus fractions to phosphorus soil tests and fertilizer response

2003 ◽  
Vol 83 (4) ◽  
pp. 443-449 ◽  
Author(s):  
R. H. McKenzie ◽  
E. Bremer
Keyword(s):  
Available P ◽  
Soil Test ◽  
Strongly Correlated ◽  
P Fractions ◽  
Soil Tests ◽  
Fertilizer Response ◽  
Inorganic P ◽  
Soil P ◽  
P Fertilizer ◽  
Soil Test P

Soil tests for available P may not be accurate because they do not measure the appropriate P fraction in soil. A sequential extraction technique (modified Hedley method) was used to determine if soil test P methods were accurately assessing available pools and if predictions of fertilizer response could be improved by the inclusion of other soil P fractions. A total of 145 soils were analyzed from field P fertilizer experiments conducted across Alberta from 1991 to 1993. Inorganic P (Pi) removed by extraction with an anion-exchange resin (resin P) was highly correlated with the Olsen and Kelowna-type soil test P methods and had a similar relationship with P fertilizer response. No appreciable improvement in the fit of available P with P fertilizer response was achieved by including any of the less available P fractions in the regression of P fertilizer response with available P. Little Pi was extractable in alkaline solutions (bicarbonate and NaOH), particularly in soils from the Brown and Dark Brown soil zones. Alkaline fractions were the most closely related to resin P, but the relationship depended on soil zone. Inorganic P extractable in dilute HCl was most strongly correlated with soil pH, reflecting accumulation in calcareous soils, while Pi extractable in concentrated acids (HCl and H2SO4) was most strongly correlated with clay concentration. A positive but weak relationship as observed between these fractions and resin P. Complete fractionation of soil P confirmed that soil test P methods were assessing exchangeable, plant-available P. Key words: Hedley phosphorus fractionation, resin, Olsen, Kelowna

DISPONIBILITÉ DU PHOSPHORE DANS LES SOLS NEUTRES ET CALCAIRES DU QUÉBEC EN RELATION AVEC LEURS CARACTÉRISTIQUES CHIMIQUES ET PHYSIQUES

1987 ◽  
Vol 67 (1) ◽  
pp. 1-16 ◽  
Author(s):  
T. SEN TRAN ◽  
M. GIROUX
Keyword(s):  
Anion Exchange ◽  
Calcium Phosphates ◽  
Relative Yield ◽  
Available P ◽  
Anion Exchange Resins ◽  
P Fixation ◽  
Exchangeable Ca ◽  
P Content ◽  
Fixation Capacity ◽  
Exchange Resins

Seven chemical methods (Bray-II, Bray-I, North Carolina DA-4, DA10, Mehlich II, Mehlich III and Olsen) and two anion exchange resins (F− and [Formula: see text] forms) were evaluated on 43 soils with pH varying from 6.4 to 7.88. A greenhouse experiment was carried out with ryegrass receiving two treatments (without P fertilization and 150 mg kg−1 soil) on these soils. The Olsen's method and the two anion resins used as reference ones were effectively the better correlated with P uptakes (r = 0.83**–0.87**) and relative yield (R2 = 69.3–70.2%). The Mehlich II, Mehlich III and to a lesser extent Bray-I methods showed good correlations with these reference methods (r = 0.77**–0.83**) and with plant P uptakes (r = 0.73**–0.79**) or relative yields (R2 = 48.9–55.1%). The Bray-II, DA-4 and DA-10 methods may dissolve some calcium phosphates such as apatites or tricalcium phosphate in some soils and thus overestimated their available P content. The P amounts extracted by these methods were less correlated with P uptakes (r = 0.57*–0.67**) or relative yields (R2 = 14.4–31.4%). On the other hand, the DA-4 extractability was diminished in soils containing more than 3% of carbonates. Although the Ca-P was the predominant form in these soils, the P fixation capacity (M) and maximum P buffer (Mb) capacity were mostly related with Al and Fe-oxalate contents. However, the low Mb values obtained from these soils indicated that the P concentration in soil solution is more favored with respect to adsorbed P. Organic matter and clay contents, pH (H2O), exchangeable Ca and carbonate contents had some effects on the extraction capability of some methods without affecting plant P uptakes. Key words: Available P, soil testing, anion exchange resins, soil properties, P fixation

Effect of C-sources and urea on the available N-content and urease activity of a calcareous sandy soil

1988 ◽  
Vol 143 (4) ◽  
pp. 317-321 ◽  
Author(s):  
M. Antal ◽  
A. Anton ◽  
T. Németh ◽  
F. Gulyás
Keyword(s):  
Sandy Soil ◽  
Urease Activity ◽  
N Content ◽  
Available N
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