Atrazine persistence and phytotoxicity on wheat as affected by nitrogen and rotation-induced changes in soil properties

1989 ◽  
Vol 40 (6) ◽  
pp. 1143 ◽  
Author(s):  
ICR Holford ◽  
BM Haigh ◽  
IG Ferris
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Ph ◽  
Soil Nitrogen ◽  
Mineral Nitrogen ◽  
Yield Response ◽  
Grain Legume ◽  
Wheat Crop ◽  
Red Clay ◽  
Atrazine Concentration

Wheat growing in a rotation experiment on an alkaline black earth was severely damaged by atrazine residues, whereas wheat in an adjacent experiment on a slightly acid red clay, was undamaged. Atrazine at 1.8 kg a.i, ha-1 had been applied to both sites nine months before wheat sowing. Nitrogen fertilizer had also been applied as split-plot treatments to the previous crop in each rotation sequence. There were four rotations, each comprising grain sorghum with either lucerne, an annual grain legume, long fallow, or continuous cereal growing.There were significant rotation effects on soil organic matter, pH, mineral nitrogen and residual atrazine. Organic carbon was highest, and soil pH and atrazine were lowest in the lucerne rotation, while the opposite occurred in the long fallow treatment. Atrazine concentration was positively correlated with pH and negatively correlated with organic carbon. The numbers of dead plants on the black earth were positively correlated with atrazine levels, but mortality was lowered by increasing mineral nitrogen at any particular level of atrazine.Wheat yields varied from zero in two continuous cereal plots to over 3.0 t ha-1 in a long fallow plot, and were highly correlated with mineral nitrogen levels. At any level of nitrogen, however, wheat yields were depressed by increasing levels of atrazine. The very large yield response to nitrogen, whether from soil or fertilizer, resulted from its dual beneficial effect of lowering plant mortality and improving the nitrogen status of the surviving plants.These results show that in a wheat crop following atrazine-treated sorghum, significant atrazine damage may occur on soils of pH > 64, that atrazine persistence and phytotoxicity will increase as the pH increases, but that phytotoxicity will decrease as soil nitrogen fertility increases. Lucerne rotations will lower atrazine persistence by decreasing soil pH and increasing organic matter, and will lower phytotoxicity by raising soil nitrogen.

scholarly journals Effect of Ph and vegetation cover in soil organic matter structure at a high-mountain ecosystem (Sierra Nevada National Park, Granada, Spain)

2020 ◽  
Author(s):  
José A. González-Pérez ◽  
Gael Bárcenas.Moreno ◽  
Nicasio T Jiménez-Morillo ◽  
María Colchero-Asensio ◽  
Layla M. San Emeterio ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Sierra Nevada ◽  
Soil Ph ◽  
National Park ◽  
High Mountain ◽  
Analytical Pyrolysis ◽  
Organic Matter Dynamics

<p><strong>Keywords: </strong>Soil reaction, analytical pyrolysis, soil respiration, carbon stabilization</p><p>During the last decade, soil organic matter dynamics and its determining factors have received increased attention, mainly due to the evident implication of these parameters in climate change understanding, predictions and possible management. High-mountain soil could be considered as hotspot of climate change dynamic since its high carbon accumulation and low organic matter degradation rates could be seriously altered by slight changes in temperature and rainfall regimes associated to climate change effects. In the particular case of Sierra Nevada National Park, this threat could be even stronger due to its Southern character, although its elevated biodiversity could shed some light on how could we predict and manage climate change in the future.</p><p>In this study, a quantitative and qualitative organic matter characterization was performed and soil microbial activity measured to evaluate the implication of pH and vegetation in soil organic matter dynamics.</p><p>The sampling areas were selected according to vegetation and soil pH; with distinct soil pH (area A with pH<7 and area B with pH>7) and vegetation (high-mountain shrubs and pine reforested area). Soil samples were collected under the influence of several plant species representatives of each vegetation series. Six samples were finally obtained (five replicates each); three were collected in area A under<em> Juniperus communis</em> ssp. Nana (ENE), <em>Genista versicolor</em> (PIO) and <em>Pinus sylvestris</em> (PSI) and other three were collected in area B under<em> Juniperus Sabina</em> (SAB), <em>Astragalus nevadensis</em> (AST) and <em>Pinus sylvestris</em> (PCA).</p><p>Qualitative and quantitative analyses of soil organic matter were made to establish a possible relationship with microbial activity estimated by respiration rate (alkali trap) and fungi-to-bacteria ratio using a plate count method. Soil easily oxidizable organic carbon content was determined by the Walkley-Black method (SOC %) and organic matter amount was estimated by weight loss on ignition (LOI %). Analytical pyrolysis (Py-GC/MS) was used to analyse in detail the soil organic carbon composition.</p><p>Our results showed that the microbial and therefore the dynamics of organic matter is influenced by both, soil pH and soil of organic matter. So that the pH in acidic media prevail as a determining factor of microbial growth over soil organic matter composition conditioned by vegetation.</p><p><strong>Acknowledgement</strong>: Ministerio de Ciencia Innovación y Universidades (MICIU) for INTERCARBON project (CGL2016-78937-R). N.T. Jiménez-Morillo and L. San Emeterio also thanks MICIU for funding FPI research grants (BES-2013-062573 and Ref. BES-2017-07968). Mrs Desiré Monis is acknowledged for technical assistance.</p><p> </p>

Effects of pasture improvement with superphosphate on soil pH, nitrogen and carbon in a summer rainfall environment

1991 ◽  
Vol 31 (2) ◽  
pp. 221 ◽  
Author(s):  
GJ Crocker ◽  
ICR Holford
Keyword(s):  
Organic Carbon ◽  
Predominantly White ◽  
Soil Ph ◽  
Soil Nitrogen ◽  
New South ◽  
New South Wales ◽  
Summer Rainfall ◽  
Buffering Capacity ◽  
Fixed Nitrogen ◽  
South Wales

The effects of pasture improvement on soil pH, total nitrogen, organic carbon and extractable phosphorus (P) were determined by analysing adjacent soils from improved and unimproved pastures at 67 sites on the Northern Tablelands of New South Wales. Pasture improved sites contained at least 1 clover species, predominantly white clover, and had received at least 125 kg P/ha over periods of 15-45 years. The majority of pasture improved sites contained more soil nitrogen, carbon and phosphorus and were of lower soil pH than adjacent unimproved sites. However, the decreases in pH were not statistically significant and not usually related to the magnitude of the increases in other soil fertility parameters nor to the amounts of superphosphate applied or duration of fertiliser history. The largest decline in soil pH and largest increase in organic carbon were on granitic soils which had received more than 250 kg P/ha. The relatively small decreases in soil pH and lack of relationship with fertiliser history, compared with soils from southern New South Wales, were attributed to: (i) re-cycling of legume-fixed nitrogen by summer-growing grasses; (ii) the naturally lower pH, higher nitrogen content and higher buffering capacity of many northern soils. Soil acidification therefore seems to be much slower and less frequent in the perennial pasture systems of the Northern Tablelands of New South Wales.

Nitrogen availability in a Darling Downs soil following cereal, oilseed and grain legume crops. 1. Soil nitrogen accumulation

1986 ◽  
Vol 26 (3) ◽  
pp. 347 ◽  
Author(s):  
WM Strong ◽  
J Harbison ◽  
RGH Nielsen ◽  
BD Hall ◽  
EK Best
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Grain Legumes ◽  
Mineral Nitrogen ◽  
Grain Legume ◽  
Nitrogen Accumulation ◽  
Soil Mineral N ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Mineral N

Available soil mineral nitrogen (N) was determined in a Darling Downs clay at intervals of 4-6 weeks throughout summer and autumn after harvest of two cereals (wheat and oats), two oilseeds (rapeseed and linseed), and four grain legumes (chickpea, fieldpea, lupin and lathyrus). Soil mineral N (0-1.2 m) at 40,68, 107, 150 and 185 days after harvest was affected (P < 0.05) by the prior crop. At 40 days it was generally higher following grain legumes (34-76 kg/ha N) than following oilseeds or cereals (16-30 kg/ha N). Net increase during the next 145 days was in the order of cereals (2 1-27 kg/ha N) < oilseeds (40 kg/ha N) <grain legumes (53-85 kg/ha N). These differences are partly accounted for by differences in the quantities of N removed in the grain of these crops. However, a large quantity of mineral N accumulated following lupin even though a large quantity (80 kg/ha) was removed in the grain.

Changes in nitrogen and organic carbon of wheat growing soils after various periods of grazed lucerne, extended fallowing and continuous wheat

Soil Research ◽  
1981 ◽  
Vol 19 (3) ◽  
pp. 239 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Organic Carbon ◽  
Soil Nitrogen ◽  
New South ◽  
Mineral Nitrogen ◽  
Soil Types ◽  
First Year ◽  
Fixed Nitrogen ◽  
Total Soil ◽  
South Wales ◽  
Total Soil Nitrogen

Changes in total and mineral nitrogen and organic carbon were measured over a nine year period in two contrasting soils of northern New South Wales after various durations of grazed lucerne, extended fallowing and continuous wheat growing. At least 2 1/2 years of lucerne ley were required to raise the total soil nitrogen above the original level on both soil types. For each year of lucerne growth the average increase (above the control treatments) in total soil nitrogen (0-15 cm) was equivalent to about 140 kg nitrogen ha-1 in the black earth and about 110 kg nitrogen ha-1 in the red-brown earth. Significantly higher levels of soil nitrogen were maintained after the lucerne treatments throughout the 9 years of measurement on the black earth and for 5 years on the red-brown earth. Lucerne had a much larger effect on nitrogen than on organic carbon, which was significantly increased only in the black earth. There were very large increases in mineral nitrogen (0-15 cm) in the first year of measurement after lucerne. Levels remained greater than they were originally for the first 4 years, and they were greater for 7 years in the black earth and 4 years in the red-brown earth following lucerne than following continuous wheat or extended fallow. The decline in mineral nitrogen during wheat cropping after lucerne was greatly increased by excessive rainfall (574 mm or more) during the fallow. Leaching was greater in the red-brown earth than in the black earth, and this explained occasional differences in nitrogen uptake by wheat between the two soil types. Some evidence suggested that under moderately moist conditions nitrogen mineralization from lucerne-fixed nitrogen was greater in the red-brown earth than in the black earth but under drier conditions it was less.

Comparison of legume-based cropping systems at Warra, Queensland. 2. Mineral nitrogen accumulation and availability to the subsequent wheat crop

Soil Research ◽  
1996 ◽  
Vol 34 (2) ◽  
pp. 289 ◽  
Author(s):  
SA Hossain ◽  
WM Strong ◽  
SA Waring ◽  
RC Dalal ◽  
EJ Weston
Keyword(s):  
Grain Yield ◽  
Fertility Restoration ◽  
Cropping Systems ◽  
N Uptake ◽  
Mineral Nitrogen ◽  
Yield Response ◽  
Wheat Crop ◽  
Nitrogen Accumulation ◽  
Mineral N ◽  
Yield Increase

Mineral nitrogen release following legume-based cropping systems for restoring the fertility of a Vertisol and the yield response and N uptake of subsequent wheat crops was studied. Legume phases of pastures, including a 4 year grass+legume ley, and lucerne and medic leys (~1 year) were terminated in October 1988 or 1989 and rotated with wheat. Chickpea-wheat rotations matched those of lucerne and medic leys. Mineral N accumulations during a subsequent fallow period were determined by core sampling to 1.5 m in October, February and May. Grain yield and N uptake of wheat enabled comparisons of the fertility restorative effects of the various systems relative to continuous wheat cropping. Averaged for two fallow periods, increases in mineral N down to 1.2 m depth were 93, 91, 68, and 37 kg/ha following grass+legume, lucerne and medic leys, and chickpea, respectively, compared with the continuous wheat treatment. Wheat yields were generally lower in 1989 (1.85–2.88 t/ha) than in 1990 (2.08–3.59 t/ha) following all leys and crops due to seasonal conditions. There was a grain yield increase of 0.11 and 0.52 t/ha in 1989 and 1.23 and 1.26 t/ha in 1990 following lucerne and medic leys, respectively and 0.85 t/ha in 1990 following a 4 year grass+legume ley. Following chickpea there was a yield increase of 0.81 and 1.36 t/ha in 1989 and 1990 respectively. Nitrogen uptake by wheat was increased by 40 and 49 kg/ha in 1989 and 48 and 58 kg/ha in 1990 following lucerne and medic leys respectively and 63 kg/ha in 1990 following a 4 year grass+legume ley. Following chickpea N uptake by wheat was increased by 27 and 32 kg/ha in 1989 and 1990 respectively. Grain protein concentration of wheat was substantially higher following all pasture leys (11.7–15.8%) than following wheat (8.0–9.4%) or chickpea (9.4–10.1%). Therefore, there was substantial evidence of the effectiveness of pasture leys in soil fertility restoration, as reflected in mineral N, yield response and N uptake by subsequent wheat crops.

The long term effects of rotation, tillage and stubble management on soil mineral nitrogen supply to wheat

Soil Research ◽  
1992 ◽  
Vol 30 (6) ◽  
pp. 977 ◽  
Author(s):  
DP Heenan ◽  
KY Chan
Keyword(s):  
Soil Nitrogen ◽  
Subterranean Clover ◽  
Mineral Nitrogen ◽  
Wheat Crop ◽  
Wagga Wagga ◽  
Long Term Effects ◽  
Soil Mineral Nitrogen ◽  
Percent Recovery ◽  
Direct Drilling

Wheat was grown as a monoculture or in rotation with lupin or subterranean clover in a long-term rotation, stubble and tillage experiment established in 1979, on a red earth (Gn 2 . 12) at Wagga Wagga, N.S.W. The effect of rotation, tillage and stubble management on the supply of soil nitrogen, and amounts leached were studied by in situ sequential soil sampling during the wheat phase of the rotation in years 10 and 11. Of the rotations, grazed subterranean clover-wheat accumulated higher mineral nitrogen levels during the wheat phase than a lupin-wheat rotation, which in turn produced higher levels than wheat-wheat. The mean seasonal total of net soil nitrogen mineralized (0-15 cm) was 239 kg N ha-1 for subterranean clover-wheat, 165 kg N ha-1 for lupin-wheat and 99.5 kg N ha-1 for wheat-wheat. In a lupin-wheat rotation, retention of stubble increased the net amount of nitrogen mineralized in both seasons. Direct drilling also increased net mineralization in 1990 but the results were inconsistent in 1989. Losses from the surface 15 cm were closely related to the amounts mineralized, with the highest recorded in subterranean clover-wheat rotations. Percent recovery of soil mineralized nitrogen by the above-ground wheat crop following lupin ranged from 57% to 83%, with both direct drilling and stubble retention reducing recovery. While total plant uptake of nitrogen in a wheat-wheat rotation was low, percent recovery was high (77%), compared with that in a subterranean clover-wheat rotation (60%).

Effects of eight year rotations of grain sorghum with lucerne, annual legume, wheat and long fallow on nitrogen and organic carbon in two contrasting soils

Soil Research ◽  
1990 ◽  
Vol 28 (2) ◽  
pp. 277 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Nitrogen Fixation ◽  
Organic Carbon ◽  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Grain Sorghum ◽  
Grazing Pressure ◽  
Red Clay ◽  
Positive Effects ◽  
South Wales ◽  
Sparing Effect

Soil nitrogen and organic carbon levels during 8-year rotations of grain sorghum (4 years) with lucerne (4 years), annual legume (faba beans or cowpeas in alternate years), wheat (4 years) and long fallow (alternate years) were measured on a black earth and a red clay in northern New South Wales. Total soil nitrogen (0-15 cm) increased at about 100 kg ha-1 yr-1 in the lucerne leys, but it maximized after 2 years on the red clay and then declined at about the same rate, suggesting that nitrogen fixation had ceased in response to heavy grazing pressure and drought conditions. The positive effects of lucerne on total nitrogen and organic carbon were maintained during 4 years of subsequent sorghum growth on the black earth, but effects on the red clay were not significant. Sorghum, when its residues were incorporated, had a much larger effect than lucerne in raising soil organic carbon. Concentrations of soil nitrate were much higher immediately after the lucerne than after continuous cereal, and they remained higher in the lucerne rotations after 2 years of sorghum. Accumulation of nitrate during long fallows was much larger after sorghum, with incorporated residues, than after no-tilled wheat, and the magnitude of this difference suggested biological nitrogen fixation by free-living bacteria during the sorghum long fallows. Fluctuations in nitrate were generally larger in the red clay than in the black earth, but sorghum yields and nitrogen uptake were less responsive to high nitrate in the red clay, apparently because of its lower nitrate buffering capacity and poorer soil structure. In comparison with continuous cereal growing, the annual legume rotation had no significant effect on organic carbon or total nitrogen, but it sometimes increased nitrate during the sorghum rotation, probably by a nitrate sparing effect during the cowpea crop.

Geomorphic controls on aluminium in acid soils of the Axe Creek catchment, Victoria

Soil Research ◽  
1998 ◽  
Vol 36 (6) ◽  
pp. 951 ◽  
Author(s):  
A. Ruth ◽  
B. B. Johnson ◽  
T. J. Fowler
Keyword(s):  
Organic Matter ◽  
Surface Layer ◽  
Organic Carbon ◽  
Soil Ph ◽  
Acid Soils ◽  
Pyrocatechol Violet

This study investigates the influence of terrain, including steepness and position in slope, on soil pH, extractable aluminium (Al), and organic carbon (OC) in the Axe Creek catchment, Victoria. Both soil pH and Al were determined by use of 1 : 5 soil : 0·01 M CaCl2 extracts, with Al measured colorimetrically using a modified pyrocatechol violet method. Although all soils were acidic, the Al concentration was highest on the hilltops (>10 mg/kg) and lowest at base-of-slope sites (<1 mg/kg). The concentration of Al was generally inversely related to soil pH. However, on average, a lower Al concentration was found in the top 10 cm than in the interval from 10 to 30 cm, even though the soil pH remained relatively constant throughout the top 30 cm. The lower Al concentration in the surface layer corresponded to a substantially higher level of OC near the surface, suggesting the formation of Al-organic matter complexes.

Leys and soil organic matter: II. The accumulation of nitrogen in soils under different leys

1967 ◽  
Vol 69 (1) ◽  
pp. 133-138 ◽  
Author(s):  
C. R. Clement ◽  
T. E. Williams
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Soil Nitrogen ◽  
White Clover ◽  
Nitrogen Fertilizer ◽  
Annual Increment ◽  
Fertilizer Nitrogen ◽  
Grass Sward ◽  
Clover Content

1. The nitrogen content of an arable soil to 15 cm depth, sown to a ryegrass/white clover sward increased on average by 0·005 % N each year.2. Under a grass sward without clover and without fertilizer nitrogen, there was an increase of 0·017 % N in 3 yeais in the top 7·5 cm of soil; an annual addition of about 70 kg N/ha.3. Including white clover in grass swards not receiving nitrogen fertilizer resulted in an increase over 3 years of 0·026% N to 7·5 cm depth in one experiment, and 0·014% N to 15 cm depth in another, an annual increment of 100–110 kg N/ha.4. The increase was greater under ryegrass/white clover swards than under cocksfoot/white clover swards. A similar difference was found both in accumulation of organic carbon and in clover content. In an experiment comparing many different grasses it was not possible to distinguish differences in the level of soil nitrogen, after 4 years under grass, which could be ascribed to species or strains.There was no significant effect of nitrogen fertilizer applied at rates of up to 314 kg N/ha per year for 3 consecutive years.

Nitrogen nutrition of cereals in a short-term rotation. I. Single season treatments as a source of nitrogen for subsequent cereal crops

1981 ◽  
Vol 32 (5) ◽  
pp. 703 ◽  
Author(s):  
I Papastylianou ◽  
DW Puckridge ◽  
ED Carter
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Subterranean Clover ◽  
Residual Effects ◽  
Yield Response ◽  
Wheat Crop ◽  
First Year ◽  
Fertilizer Nitrogen ◽  
The Third ◽  
Second Year

The residual effects of one season of five cultural treatments common in southern Australian dryland farming were examined with respect to soil water and nitrogen, and the production of cereals in the next two years. The initial treatments were medic or subterranean clover pasture, faba beans, oats or bare fallow. In the second year barley, wheat and triticale were grown on the same plots, with 0,30,60 or 90 kg ha-1 of fertilizer nitrogen. Wheat was sown over the whole area for the third season. The medic and subterranean clover pastures contributed approximately 100 kg ha-1 of nitrogen in top growth, but this remained on the surface until cultivation. Oats and fallow plots declined in total soil nitrogen by about 70 kg ha-1. The nitrogen content of the faba bean stubble showed that this crop has the potential of providing equivalent nitrogen to a good legume pasture. At the beginning of the second season the previous plots of fallow, beans, subterranean clover and medic had 36,27, 14 and 12 mm more water in the top metre of soil than oat plots. Cereals after oats apparently did not respond to fertilizer nitrogen because of the dry conditions, but on other plots the yield response was not proportional to the additional water. Although first year treatments affected growth of the three cereals in the second season, the new cereal, triticale, showed no evidence of different adaptation to growing conditions than wheat or barley. The effects of first and second year treatments carried through to the wheat crop in the third season. There were marked differences in nitrogen availability, but evidence that the second crop was depleting soil nitrogen reserves. Nitrogen from first year legume residues was available earlier in the season than second year fertilizer nitrogen which had been leached from the surface soil.

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