scholarly journals Requirement for magnesium fertilization in Finland

1981 ◽  
Vol 53 (4) ◽  
pp. 239-268
Author(s):  
Raili Jokinen

More magnesium, on average, is removed annually from agricultural soils in Finland in yields (10 kg/ha) and through leaching (20kg/ha) than is replaced as fertilizers (4 kg/ha), manure (7 kg/ha) and as wet or dry depositions from the atmosphere (1 kg/ha). The amount of magnesium which is applied in assosiation with liming agents (at the most 25 kg/ha) has a decisie effect on the magnesium balance of the soils, although liming itself reduces those magnesium reserves of the soil which are extractable in neutral ammonium acetate(1 M) or in calcium chloride (0,01 M). The effect of two amounts of nitrogen and potassium fertilizers on the spring cereal and cultivated ley yields, on the magnesium uptake and nutrient contents of the yields, and the effect of liming on the magnesium status of the soil was studied using field, pot and incubation experiments in order to gain an estimate of requirement for magnesium fertilization. The results obtained with magnesium sulphate fertilizer in the same experiments were also used as an indicator of requirement for magnesium fertilization. The ammonium acetate (1 M, pH 7) extractable magnesium in the soil appeared to be the most important source of magnesium for the plants and the best indicator of requirement for magnesium fertilization. For the intensive cultivation of grassland crops, the soil should contain about 15 mg/100g of this type of magnesium. In pot experiments, the plants took up only small amounts of not extractable magnesium. Increasing the nitrogen fertilizer dosage (pot experiments, 4,5 l soil: N1=1500 mg, N2=3000mg N per year, field experiments: N1=50 kg/ha, N2=100 kg/ha N per year) generally brought about an increase in the magnesium uptake and in the magnesium content of the grasses. When the experiments were carried out using coarse mineral soils, the magnesium uptake and magnesium content of the plants decreased during the second and third year as the amount of nitrogen fertilizer increased. This was caused by the low magnesium content of the soil (pot experiments: below 12 mg/100 g soil in neutral ammonium acetate extractable magnesium, field experiments: below 100 mg/l soil in acid ammonium acetate extractable magnesium). In these soils, magnesium fertilization (200 mg Mg for 4,5 l soil per year or 57 kg/ha per year) appeared to have a positive effect on the supply of magnesium to the plants. The heavy clay and sandy clays used in the pot experiment did not require magnesium fertilization. The magnesium in silty clays, which contain a high proportion of the silt fraction (0,02—0,2 mm), may be liberated too slowly for intensively cultivated grasses and it may be necessary to give additional magnesium as fertilizer. Increasing the potassium fertilizer level from 60 kg/ha to 240 kg/ha K per year significantly decreased the magnesium content of the plants. Judging by the quality of the crops, a high potassium fertilizer level appeared to increase the requirement for magnesium fertilization. In the case of muddy very finesand the yield and magnesium uptake of timothy decreased with an increase in the amount of potassium applied. Liming (90, 180 or 360 mg/100g soil Ca as CaCO3) decreased the amount of neutral ammonium acetate extractable magnesium, in seven mineral soils out of nine, by 2—24 % in comparison to the magnesium content of unlimed soils. Part of the fertilizer magnesium became not extractable, too.

2002 ◽  
Vol 11 (4) ◽  
pp. 257-271 ◽  
Author(s):  
I. SAARELA

Comprehensive research into phosphorus (P) in soils and crops began in Finland in the early 1900s. The average amount of total P in the ploughed topsoil layer of mineral soils was about two tonnes per hectare in the 1930s, before the abundant use of fertilisers. The main chemical fractions of P in mineral soils were organic matter, primary apatite and secondary complexes of the hydrous oxides of Al and Fe. Of the smaller amounts of P in light peat soils, as much as 80% was present in stable organic compounds. Field experiments showed that the native P reserves of Finnish soils are poorly available to plants, and that P fertilisers are inefficiently utilised because of the strong fixation of applied phosphate in soils. In evaluations before the late 1950s, all simple chemical tests appeared to be rather unreliable indicators of the supply of P from soils to plants, but later research has shown that the results were impaired by errors implicit in the research materials. Some soil test P values (STP)obtained from old samples stored for more than ten years evidently were too high, particularly for organic soils, and many of the soils studied were strongly acidic and therefore biologically less fertile than the chemical P tests indicated. The acid ammonium acetate method (pH 4.65) was introduced in the early 1950s and has since been used in routine soil testing in Finland, not only for P but for all macronutrients except N. In later evaluations of different methods used for estimating the requirement of P fertilisation, the acid ammonium acetate method has proven equal or superior to any other simple chemical method.;


1984 ◽  
Vol 56 (1) ◽  
pp. 97-100
Author(s):  
Raili Jokinen

Eight mineral soils (pH(CaCl2) 4.6—6.1, clay 4—65 %, org. C 1.9—5.7 %) were treated with ammonium nitrate and magnesium sulphate solutions adding 0, 20 or 40 mg mineral N and 0 or 4 mg Mg per 100 g soil. The soils were incubated for seven weeks at a constant temperatureof 20°C and a 25 % moisture level. After incubation, the exchangeable Mg was extracted with 1 M neutral ammonium acetate. The exchangeable magnesium content seemed to increase in some soils and to decrease in other soils with increasing ammonium nitrate amounts. The applied magnesium was fixed in a non-exchangeable form, especially at the highest ammonium nitrate level, in two clay soils taken from the rapakivi area of south-eastern Finland. In the other soils all applied magnesium was exchangeable irrespective of the amount of ammonium nitrate.


1981 ◽  
Vol 53 (2) ◽  
pp. 126-137
Author(s):  
Raili Jokinen

Nine mineral soils were incubated in laboratory without lime (Ca0) or limed (Ca1) with calcium carbonate (lab.reag.), and without magnesium fertilizer (Mg0) or fertilized with MgSO4*7H20 (Mg1 = 4 mg/100 g soil Mg). The incubation covered a period of seven weeks in aerobic conditions at constant 20 °C temperature. The relative increase in the effective cation exchange capacity (ECEC) caused by liming seemed to be in coarse mineral soils greater than in clay soils. The differences in pH (CaCl2) values between soil types was not so evident. In seven soils of the nine, liming decreased the 0,01 M CaCl2 extractable magnesium content more than in 1 M KCI or in 1 M neutral ammonium acetate extractable magnesium contents. The limed soils contained ammonium acetate extractable magnesium 2—24 % less than the unlimed soils. The decrease in magnesium content was greatest in acid muddy silt (Littorina soil) and in acid silty clay. Without lime the I M KCI extractable (Al+H) contents of these soils were 6,6 and 2,2 me/100 g soil and pH (CaCl2) 3,9 and 4,5, respectively. In finesand soils liming seemed to increase the magnesium content although not significantly. In limed soils 17—73 %of the fertilizer magnesium was extractable in 0,01 M CaCl2, 67—100 % extractable in 1 M KCI and 57—100 % extractable in 1 M neutral ammonium acetate. The equivalent ratio of exchangeable (1 M ammonium acetate, pH 7) calcium to magnesium in the soils may give pointers to the choice of liming agents, especially in the liming of low cation exchange capacity soils.


1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.


2007 ◽  
Vol 11 (1) ◽  
pp. 61-76 ◽  
Author(s):  
B. Reynolds

Abstract. In the UK, as organo-mineral soils are a significant store of soil organic carbon (SOC), they may become increasingly favoured for the expansion of upland forestry. It is important, therefore, to assess the likely impacts on SOC of this potentially major land use change. Currently, these assessments rely on modelling approaches which assume that afforestation of organo-mineral soils is "carbon neutral". This review evaluates this assumption in two ways. Firstly, UK information from the direct measurement of SOC change following afforestation is examined in the context of international studies. Secondly, UK data on the magnitude and direction of the major fluxes in the carbon cycle of semi-natural upland ecosystems are assessed to identify the likely responses of the fluxes to afforestation of organo-mineral soils. There are few directly relevant measurements of SOC change following afforestation of organo-mineral soils in the UK uplands but there are related studies on peat lands and agricultural soils. Overall, information on the magnitude and direction of change in SOC with afforestation is inconclusive. Data on the accumulation of litter beneath conifer stands have been identified but the extent to which the carbon held in this pool is incorporated into the stable soil carbon reservoir is uncertain. The effect of afforestation on most carbon fluxes is small because the fluxes are either relatively minor or of the same magnitude and direction irrespective of land use. Compared with undisturbed moorland, particulate organic carbon losses increase throughout the forest cycle but the data are exclusively from plantation conifer forests and in many cases pre-date current industry best practice guidelines which aim to reduce such losses. The biggest uncertainty in flux estimates is the relative magnitude of the sink for atmospheric carbon as trees grow and mature compared with that lost during site preparation and harvesting. Given the size of this flux relative to many of the others, this should be a focus for future carbon research on these systems.


1979 ◽  
Vol 59 (4) ◽  
pp. 423-429 ◽  
Author(s):  
R. B. McKERCHER ◽  
W. R. McGREGOR

Applications of Ca to soil in both growth chamber and field experiments increased triallate [S-(2,3,3-trichloroallyl)-diisopropylthiocarbamate] activity. Ca appears to affect the distribution of triallate between the colloid and soil solution causing a shift of triallate toward the solution phase. These effects are measurable in pot experiments at Ca additions of about 1 meq/100 g soil or at field applications of 2.5 tonnes per hectare (1 ton per acre) of Ca(OH)2.


1973 ◽  
Vol 45 (2) ◽  
pp. 121-215
Author(s):  
Johan Korkman

A method for determining total sulphur in plant material and soil samples using the induction furnace technique and subsequent turbidimetric determination of sulphate sulphur was discussed. A procedure for extracting sulphur from soil samples with ammonium acetate (pH 4.65), the interference of the organic matter being reduced by oxidation of the extract with H2O2, was proposed. Sulphur balance in Finnish cultivated soils was estimated by taking into account the average amounts of emitted (8 kg S/ha/yr.), precipitated (8 kg S/ha/yr.) and leached (8 kg S/ha/yr.) sulphur. The actual situation in the cultivated soils seems thus to be depending, on an average, on the uptake by plants and the sulphur applied (12 kg S/ha/yr. in the early 1970s). In 104 samples of cultivated soil, the content of total sulphur showed a slight correlation with the content of organic carbon. The amounts of sulphur extracted in various ways were not predictable by means of the soil characteristics used (pHCaCl2, org. C and texture). Extracted sulphur did not correlate sufficiently with the development and sulphur uptake of plants. Under field conditions in northern Finland, sulphur application produced a relatively distinct result in respect both to the ley yields on Carex peat, and their sulphur content. On mineral soils in southern Finland the yields were unaffected by supplementary fertilization with sulphur. In the pot experiments performed a fairly close relationship between sulphur and nitrogen was demonstrated.


1962 ◽  
Vol 42 (2) ◽  
pp. 266-272 ◽  
Author(s):  
T. E. Barber ◽  
B. C. Matthews

The non-exchangeable potassium released by soil after equilibration with cation-exchange resin was determined by extraction of the mixture with neutral ammonium acetate at room temperature and compared with a similar extraction in the absence of resin. The difference obtained following a 2-day equilibration period was called moderately-available potassium.Simple linear regression of yield on exchangeable potassium or exchangeable plus moderately-available potassium accounted for only 16 and 27 per cent respectively of the variability in yield response of corn, wheat, oats and potatoes to potassium fertilizer in the field. Multiple linear regression of yield on exchangeable and moderately-available potassium accounted for an average of 37 per cent of the variation in crop response; but a multiple quadratic regression of Log (100-per cent yield) on exchangeable and moderately-available potassium accounted for an average of 56 per cent of the variability in Log (100-per cent yield). Multiple quadratic regression of absolute yield or per cent yield on exchangeable and moderately-available potassium accounted for 46 and 50 per cent, respectively, of the variability in crop response to potassium fertilizer.


1993 ◽  
Vol 7 (4) ◽  
pp. 934-939 ◽  
Author(s):  
Cathy A. Morton ◽  
R. Gordon Harvey ◽  
James J. Kells ◽  
Douglas A. Landis ◽  
William E. Lueschen ◽  
...  

Field experiments were conducted in Michigan, Minnesota, and Wisconsin in 1990 to explore interactions between nicosulfuron applied POST and terbufos insecticide at 0.06 or 0.11 g ai/m of row applied in-furrow on ‘Pioneer 3751’ field corn and ‘Jubilee’ sweet corn. Nicosulfuron at 0, 70, and 140 g ai/ha plus nonionic surfactant and 28% nitrogen fertilizer was applied to both corn types. Field corn response to nicosulfuron and terbufos was similar at all locations, whereas sweet corn injury varied with location. Nicosulfuron injured field corn more when applied at the four-leaf than the three-leaf stage. Injury to both corn types increased as nicosulfuron rate increased or when applied following terbufos. Nicosulfuron at 140 g/ha without terbufos did not reduce yield of either corn type; however, corn previously treated in-furrow with terbufos reduced yield.


1971 ◽  
Vol 76 (2) ◽  
pp. 269-275 ◽  
Author(s):  
A. P. Draycott ◽  
M. J. Durrant

SUMMARYThe concentration of nitrogen, phosphorus, potassium, sodium, calcium and magnesium was measured in the dry matter of sugar beet from four field experiments (1966–9). All combinations of four amounts of nitrogen fertilizer (0–1·8 cwt/acre), four plant populations (8800–54000 plants/acre) and irrigation were tested, which gave a wide range of plant size and yield. Nutrient concentration and uptake by the crop were also greatly affected by the treatments.Nitrogen fertilizer and irrigation increased uptake of nitrogen by the crop but increasing the plant population had little effect on uptake and decreased the concentration of nitrogen. Sugar yield was related to the total nitrogen concentration in tops and roots and to uptake. There were optimal values of nitrogen concentration for maximal sugar yield, but the optima were greatly affected by plant population. Leaf colour was a good guide to nitrogen concentration.Phosphorus concentration was affected little by the treatments but cation concentrations were greatly affected. In general, uptake of all the elements was increased by all treatments – the exception was sodium, which decreased as the plant population increased but this was balanced to somo extent by increased potassium uptake.


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