The effects of direct drilling, shallow cultivation and ploughing on some soil physical properties in a long-term experiment on spring barley

1985 ◽  
Vol 104 (1) ◽  
pp. 125-133 ◽  
Author(s):  
K. Chaney ◽  
D. R. Hodgson ◽  
M. A. Braim
Keyword(s):  
Spring Barley ◽  
The Other ◽  
Clay Loam ◽  
Average Value ◽  
Structural Problems ◽  
Physical Measurements ◽  
Long Term Experiment ◽  
Direct Drilling ◽  
Air Capacity

SummaryPhysical measurements were made on the soil of a long-term cultivation experiment comparing direct drilling, tine cultivation and mouldboard ploughing for spring barley to investigate possible reasons for differences in yield. The soil was a typical argillio brown earth, approximately 90 cm of sandy clay loam topsoil and clay loam subsoil overlying magnesian limestone. For the three periods 1971–4, 1975–7 and 1978–80 the mean grain yields were marginally lower after direct drilling than after shallow cultivation or ploughing. There was an average decline in yield of 1·33 t/ha from the first to the last period, the decline being greater for direct drilling than the other two tillage systems. Although the surface horizon (0–5 cm) of direct-drilled soil had a higher content of organic matter than the ploughed, this did not increase the stability of the aggregates. Slaking tests had shown the soil to be inherently unstable and likely to suffer from structural problems. After the first 3 years bulk density of direct-drilled soil (0–15 cm) increased markedly to ca. l·5 g/cm8 and then remained relatively stable. In the ploughed soil, density increased steadily over the period to an average value of co. 1·45 g/cm8. Tine cultivation to 7–8 cm reduced cone resistance values in the surface compared with direct-drilled soil but below 15 cm there were no significant differences. Ploughing gave significantly lower values than direct drilling to a depth of 30 cm. Measurements of pore sizes in direct-drilled and ploughed soil were highly variable with few significant differences. Mean air capacity values (1978–80) tended to be lower in direct-drilled than in ploughed topsoil particularly for plots direct drilled after 7 years of deep tine cultivation. A limited number of root measurements in 1978 and 1980 showed that the length of root per unit of ground area was much less after direct drilling than after ploughing. Shallow cultivation, surprisingly, gave most root with a greater proportion of the root system below 20 cm than in the other two treatments. The classification of this soil according to its suitability for direct drilling cereals is discussed.

Effects of tillage and direct drilling on soil properties during the growing season in a long-term barley mono-culture system

1977 ◽  
Vol 88 (2) ◽  
pp. 431-442 ◽  
Author(s):  
J. D. Pidgeon ◽  
B. D. Soane
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Management Practices ◽  
Sandy Loam ◽  
Spring Barley ◽  
Equilibrium Density ◽  
Zero Tillage ◽  
Clay Loam ◽  
Cone Resistance

SUMMARYSoil responses to deep (30–35 cm) and normal (15–20 cm) mouldboard ploughing, chisel ploughing and zero-tillage have been compared for 7 years in a field experiment growing continuous spring barley near Edinburgh. The soil was of variable texture, from moderately well-drained sandy loam overlying loam to imperfectly to poorly drained sandy clay loam overlying clay loam, classified as stagnogleyic brown earth to cambio stagnogley soil. Soils of this type derived from Carboniferous till are widely used for cereal production in south-east Scotland. Measurements of soil physical properties were made at crop emergence, midseason and at harvest to characterize seasonal and long-term responses to tillage and traffic. After the first 3 years bulk density responses varied little within or between seasons, showing a compacted horizon from 0–15 cm under zero-tillage and a looser horizon from 21–33 cm under deep ploughing compared with normal ploughing. Immediately below the depth of normal ploughing there was no difference in bulk density between this treatment and zero-tillage while in some years the chisel-ploughing treatment was denser. Moisture content responses on a weight basis, together with air-filled porosity responses, showed large differences between treatments particularly at the time of crop emergency, indicating substantial alterations in the soil profile hydrology. Expressed on a volume basis the increased moisture content near the surface under zero-tillage became more pronounced and the other effects disappeared. Cone resistance responses were proportionately larger than those for bulk density and showed one major difference in that below the depth of ploughing cone resistance was greater for zero-tillage than normal ploughing in the sixth and seventh seasons, but not previously. For bulk density, but probably not for cone resistance, there were no increases after the third season of zero-tillage, the soil reaching an equilibrium density for the current management practices and machinery usage.

scholarly journals Transport of dissolved load in the hydrologically extreme conditions in the Crnica river basin

2012 ◽  
Vol 92 (4) ◽  
pp. 17-30
Author(s):  
Sanja Mustafic ◽  
Tanja Dobrosavljevic ◽  
Predrag Manojlovic ◽  
Milan Srejic
Keyword(s):  
The Other ◽  
Runoff Water ◽  
Water Mineralization ◽  
Average Value ◽  
Time Period ◽  
Average Water ◽  
Annual Frequency ◽  
Dissolved Load ◽  
Annual Amount

During 2010, 62065.3 t of the dissolved load were transported from the Crnica Basin, which was 5.1 times higher than the long-term average value. In hydrological terms the studied year was specific. In the period from January to May the amount of runoff water was significantly above the average perennial values, while in the period from August to November the amount was below the perennial average. According to the hydrological conditions in the period January-May 82.3% were transported, and in the period August-November only 5.1% of the annual dissolved load amount. Most of the year (54.2% of the time) the specific runoff was less than 10 l/s/km2, the average water mineralization was 374.9 mg/l, and in that time 13% of the total annual amount of the dissolved load was evacuated. On the other hand, the specific runoffs greater than 50 l/s/km2 represented 13.4% of the annual frequency, the average water mineralization was 263.3 mg/l, but for that time period even 53.9% of the annual quantity of the dissolved load was evacuated.

Changes with time of crop yields in a long-term experiment

1988 ◽  
Vol 111 (2) ◽  
pp. 317-332 ◽  
Author(s):  
G. V. Dyke
Keyword(s):  
Winter Wheat ◽  
Crop Yields ◽  
Spring Barley ◽  
Wheat Variety ◽  
Term Experiment ◽  
Long Term Experiment

SummaryYields of the three ‘test’ crops, winter wheat, potatoes, spring barley in the Rothamsted Ley–Arable experiments 1949–69 increased by about 100%, 80%, 40% respectively, each in a period of 19 years. The wheat variety was changed once during the period and this change is enough to explain most of he increase of yield. For potatoes there was no change of variety; the estimated effects of changes in manuring, etc. explain less than one third of the observed increase. For barley two changes of variety explain about one third of the increase; most of the remainder may be explained by improved manuring of preceding crops, especially potatoes. After 1969 the cropping was drastically changed but a few recent yields from other experiments at Rothamsted indicate that the steady rates of increase may have continued at least up to 1980.

Yield variability trends of winter wheat and spring barley grown during 1932–2019 in the Askov Long-term Experiment

2021 ◽  
Vol 264 ◽  
pp. 108083
Author(s):  
J. Macholdt ◽  
S. Hadasch ◽  
H.-P. Piepho ◽  
M. Reckling ◽  
A. Taghizadeh-Toosi ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Spring Barley ◽  
Yield Variability ◽  
Term Experiment ◽  
Long Term Experiment

scholarly journals Liming impacts barley yield over a wide concentration range of soil exchangeable cations

2021 ◽  
Author(s):  
J. E. Holland ◽  
P. J. White ◽  
J. -N. Thauvin ◽  
L. Jordan-Meille ◽  
S. M. Haefele ◽  
...  
Keyword(s):  
Spring Barley ◽  
Relative Yield ◽  
Site Effect ◽  
Exchangeable Cations ◽  
Exchangeable Cation ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Negative Relationships ◽  
Mn Concentrations

AbstractLiming has widespread and significant impacts on soil processes and crop responses. The aim of this study was to describe the relationships between exchangeable cation concentrations in soil and the relative yield of spring barley. The hypothesis was that yield is restricted by the concentration of a single exchangeable cation in the soil. For simplicity, we focused on spring barley which was grown in nine years of a long-term experiment at two sites (Rothamsted and Woburn). Four liming rates were applied and in each year the relative yield (RY) and the concentrations of exchangeable cations were assessed. Liming had highly significant effects on the concentrations of most exchangeable cations, except for Cu and K. There were significant negative relationships (either linear or exponential) between the exchangeable concentrations of Mn, Cd, Cr, Al, Fe, Cu, Co, Zn and Ni in soil and soil pH. The relationships between RY and the concentrations of selected exchangeable cations (Mn, Ca and Al) were described well using log-logistic relationships. For these cations a significant site effect was probably due to fundamental differences in soil properties. At both sites the concentrations of exchangeable soil Al were excessive (> 7.5 mg kg−1) and were most likely responsible for reduced barley yields (where RY ≤ 0.5) with soil acidification. At Rothamsted barley yield was non-limited (where RY ≥ 1) at soil exchangeable Mn concentrations (up to 417 mg kg−1) greater than previously considered toxic, which requires further evaluation of critical Mn concentrations.

scholarly journals A Long Term Experiment with Rats on a Human Dietary

1935 ◽  
Vol 35 (4) ◽  
pp. 476-497 ◽  
Author(s):  
John Boyd Orr ◽  
William Thomson ◽  
R. C. Garry
Keyword(s):  
The Other ◽  
Reproductive Capacity ◽  
Dietary Survey ◽  
Human Diet ◽  
Green Food ◽  
Large Colony ◽  
Long Term Experiment ◽  
Haemoglobin Content ◽  
Increased Susceptibility

For 2¼ years a large colony of rats was maintained on a diet based on a dietary survey of a human population. One-half of the rats was fed on the human survey diet, or this diet with a small increase in milk, the other half on the same diet supplemented with additional milk and green food. Four generations of animals were reared, all from the same stock.The rats on the human diet with additional milk and green food were healthy in all respects so far as can be judged from our own rats on a stock diet and from the data of other workers.On the other hand, in spite of an exactly similar environment and heredity, the animals without additional milk and green food, showed:(1) a slightly impaired reproductive capacity;(2) a very markedly increased death-rate due to increased susceptibility to an infection to which all rats were equally exposed;(3) a definitely slower rate of growth;(4) a lower haemoglobin content in the blood; and,(5) a clinically poorer condition as judged by behaviour and state of the coat.These findings are discussed and the possibility of applying them to human dietetic problems briefly touched upon.

scholarly journals The elements of productivity and their contribution to high level of crop yield (based on spring barley researches)

2021 ◽  
Vol 843 (1) ◽  
pp. 012005
Author(s):  
L M Eroshenko ◽  
O V Levakova ◽  
O V Gladysheva ◽  
E V Gureeva ◽  
M M Romakhin ◽  
...  
Keyword(s):  
Spring Barley ◽  
Maximum Yield ◽  
Breeding Value ◽  
Breeding Lines ◽  
Average Value ◽  
New Varieties ◽  
Competitive Test ◽  
High Level ◽  
Value Ranking

Abstract The analysis of long-term data showed that in various agrometeorological conditions, the average yield of the selected numbers of the competitive test was 6.76 t/ha and varied from 6.15 t/ha for the line 4/3-12h 933 to 7.04 t/ha for the Noble variety. The maximum yield was shown in 2016 in the varieties Znatny, Nadezhny and breeding lines 30/3-12h 983 and 135/2-12h 1068 at the level of 8.91 to 9.52 t/ha. The differences between the samples in terms of the level of crop structure elements were revealed. In the group of high-yielding genotypes, breeding lines 141/1-09 h 746, 135/2-13 h 1068, 4/3-12 h 933 were distinguished, the weight of 1000 grains in which was 1.7-5.6 g higher than the average value. Ranking by the complex of the most important productivity characteristics determined the high breeding value of Yaromir, Nadyozhny, Znatny varieties and lines 30/3-12h 983, 135/2-13h 1068 as a source material for breeding to increase the yield of new varieties.

Comparison of direct drilling, reduced cultivation and ploughing on the growth of cereals: 3. Winter wheat and spring barley on a calcareous clay

1979 ◽  
Vol 93 (2) ◽  
pp. 391-401 ◽  
Author(s):  
F. B. Ellis ◽  
J. G. Elliott ◽  
F. Pollard ◽  
R. Q. Cannell ◽  
B. T. Barnes
Keyword(s):  
Moisture Content ◽  
Winter Wheat ◽  
Clay Soil ◽  
Spring Barley ◽  
The Other ◽  
Root Penetration ◽  
Uncultivated Soil ◽  
Direct Drilling ◽  
Uncultivated Land ◽  
Resistance To Penetration

SUMMARYMouldboard ploughing, deep and shallow tined cultivation followed by conventional seed-bed preparation, and direct drilling were compared from 1972 to 1976 on a calcareous clay soil in two experiments, one on winter wheat and the other on spring barley.At sowing the moisture content, bulk density and resistance to penetration in the surface layer of soil of uncultivated land were all greater than in soil that had been ploughed or cultivated deeply. Below 10 cm moisture content was less and root penetration was greater in the uncultivated soil. In all years winter wheat established and yielded well following direct drilling and shallow cultivation. In two dry autumns wheat establishment following ploughing was slower and less complete than with direct drilling, and in 1 year the yield was less. Spring barley established and yielded well without consistent differences in all years with all treatments.

scholarly journals Effects of periodic bottlenecks on the dynamics of adaptive evolution in microbial populations

2021 ◽  
Author(s):  
Minako Izutsu ◽  
Devin M. Lake ◽  
Zachary W. D. Matson ◽  
Jack P. Dodson ◽  
Richard E. Lenski
Keyword(s):  
Simple Model ◽  
The Other ◽  
Population Bottlenecks ◽  
Final Size ◽  
Beneficial Mutations ◽  
Resource Limited ◽  
Long Term Experiment ◽  
The One ◽  
The Impact

Population bottlenecks are common in nature, and they can impact the rate of adaptation in evolving populations. On the one hand, each bottleneck reduces the genetic variation that fuels adaptation. On the other hand, fewer founders can undergo more generations and leave more descendants in a resource-limited environment, which allows surviving beneficial mutations to spread more quickly. Here we investigate the impact of repeated bottlenecks on the dynamics of adaptation in experimental populations of Escherichia coli. We propagated 48 populations under four dilution regimes (2-, 8-, 100-, and 1000-fold), all reaching the same final size each day, for 150 days. A simple model in which adaptation is limited by the supply rate of beneficial mutations predicts that fitness gains should be maximized with ~8-fold dilutions. The model also assumes that selection acts only on the overall growth rate and is otherwise identical across dilution regimes. However, we found that selection in the 2-fold regime was qualitatively different from the other treatments. Moreover, we observed earlier and greater fitness gains in the populations subjected to 100- and 1000-fold dilutions than in those that evolved in the 8 fold regime. We also ran simulations using parameters estimated independently from a long-term experiment using the same ancestral strain and environment. The simulations produced dynamics similar to our empirical results under these regimes, and they indicate that the simple model fails owing to the assumption that the supply of beneficial mutations limits adaptation.

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