WINTER CHANGES IN SOIL NITRATE AND EXCHANGEABLE AMMONIUM

1970 ◽  
Vol 50 (2) ◽  
pp. 151-162 ◽  
Author(s):  
C. A. CAMPBELL ◽  
W. S. FERGUSON ◽  
F. G. WARDER
Keyword(s):  
Soil Moisture ◽  
Near Field ◽  
Field Capacity ◽  
Early Spring ◽  
Soil Nitrate ◽  
Regular Monitoring ◽  
Late Fall ◽  
Loam Soil ◽  
Field Plots

Cylinders of a loam soil were placed in the field in late fall and sampled in midwinter and early spring. In soil wetted to near field capacity, nitrate and moisture moved upwards in winter and downwards again in early spring. The amount of movement was negligible in a soil wet to near the wilting percentage. To inhibit nitrification, N-serve was applied in 10 cm of water to field plots (120 × 120 cm) in late fall. Other plots received water but no N-serve. Regular monitoring of soil nitrate, exchangeable ammonium, and soil moisture and temperature in the top 90 cm of these plots showed evidence of upward moisture and nitrate movement as the soil froze. Large and sudden unexplainable decreases in exchangeable ammonium occurred following steady fall build-up.

EFFECTS OF IRRIGATION AND NITROGEN ON A NATURAL PASTURE SWARD

1978 ◽  
Vol 58 (2) ◽  
pp. 347-356
Author(s):  
W. N. BLACK
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Sandy Loam ◽  
Field Capacity ◽  
Early Spring ◽  
Naturally Occurring ◽  
Natural Pasture ◽  
Loam Soil ◽  
Grazing Period

Irrigation and nitrogen (N) requirements of a natural pasture sward were studied on a Charlottetown sandy loam soil over a 5-yr period. The soil moisture content at the 0-to 15- and 15- to 30-cm depths was determined at from 7- to 10-day intervals, while irrometer soil moisture readings at 15-, 30-, and 45-cm depths were recorded more frequently during the grazing seasons. Soil moisture content in irrigated plots averaged 92 and 94% of field capacity, respectively, at 0- to 15- and 15- to 30-cm sampling depths. In non-irrigated plots, corresponding values were 77 and 82%. N treatments resulted in significant dry matter (DM) increases over untreated plots. Yield differences among plots receiving 56, 84, and 112 kg of N/ha in mid-June and again in mid-August were not significant. Early spring and September applications of N at 56 kg/ha, combined with mid-June and early August supplements of N at 84 kg/ha were superior to all other treatments in prolonging the grazing period. Neither irrigation nor N affected the characteristic yield decline of naturally occurring forage species in mid- and late-season. Mean DM production for the 5-yr period, and for years, showed no significant N treatment × moisture level interaction. While irrigation failed to increase yields significantly, livestock preferred to graze the irrigated plots. As a result of less competition from grasses, volunteer white clover became better established, and constituted a larger percentage of the sward than on non-irrigated plots.

EFFECTS OF SOIL MOISTURE AROUND NODULES ON NITROGEN FIXATION BY WELL WATERED SOYBEANS

1976 ◽  
Vol 56 (4) ◽  
pp. 811-815 ◽  
Author(s):  
D. J. HUME ◽  
J. G. CRISWELL ◽  
K. R. STEVENSON
Keyword(s):  
Nitrogen Fixation ◽  
Soil Moisture ◽  
Near Field ◽  
Soil Layer ◽  
Field Capacity ◽  
Dry Weight ◽  
Bottom Layer ◽  
Leaf Water ◽  
Sand Mixture ◽  
Water Potentials

Soybeans (Glycine max (L.) Merr.) were grown at various soil moisture levels around nodules so effects on nitrogen fixation could be studied. Plants were grown in a growth room in 35-cm diam pots. Pots contained two layers of loam–sand mixture separated by a layer of coarse silica, intended to restrict capillary movement of soil moisture from the bottom to the top soil layer. At the beginning of seed development, pots received 200 ml water on the surface, 200 ml in the bottom layer through plastic tubes or 100 ml each way. Plants with good root development in the bottom soil layer maintained leaf water potentials greater than − 6 bars, while soil moisture around nodules varied from 4 to 20%. In three individual experiments, in which only plants with leaf water potentials greater than − 6 bars were considered, there was no relationship between soil moisture around nodules and mg N2[C2H2] fixed/g nodule dry weight × h. When results of two experiments with similar fixation means were combined, there was a barely significant (R2 =.19*) quadratic relationship, with very dry soil or soil near field capacity around nodules decreasing fixation slightly. Percent moisture in soil around nodules did not affect nodule moisture content, indicating that nodule moisture status was maintained if plants received adequate moisture from below the nodule zone.

EFFECTS OF DIFFERENT SOIL MOISTURE TENSIONS ON FLAX AND CEREALS

1966 ◽  
Vol 46 (3) ◽  
pp. 213-216 ◽  
Author(s):  
S. J. Bourget ◽  
B. J. Finn ◽  
B. K. Dow
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Winter Wheat ◽  
Plant Species ◽  
Spring Wheat ◽  
Soil Moisture Content ◽  
Near Field ◽  
Correlation Coefficients ◽  
Field Capacity

Young seedlings of flax and cereals, grown in a greenhouse, were subjected to 0, 12.5, and 25.0 cm of soil moisture tension for periods of 7, 14, and 21 days The grain, straw, and root yields of all plant species, except barky, increased with increasing soil moisture content was maintained near field capacity during the growth of plants. The yields of oats, winter wheat, and fall rye decreased with increasing duration of flooding, whereas those of barley, flax and spring wheat were variable. Correlation coefficients between yields of tops and roots were positive.

scholarly journals 683 PB 236 WATER STRESS REDUCES ASPARAGUS GROWTH

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 531d-531
Author(s):  
Dan Drost
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Root Zone ◽  
Near Field ◽  
Field Capacity ◽  
Fresh Weight ◽  
Irrigation Rate ◽  
Growing Period ◽  
Long Term Study ◽  
Irrigation Treatments

In 1992, a long term study was initiated to determine water use of asparagus and to assess water stress effects on asparagus growth. Asparagus (Syn 4-56) crowns were planted and maintained at soil moisture levels near field capacity during the first year. In 1993, irrigation treatments based on 60, 40, and 0 percent of evapotranspiration (ET) were applied to asparagus during the fern growing period (mid-June to October). Soil moisture, shoot and root growth, and fern water potentials were measured throughout the year. Prior to the irrigation treatments, asparagus had 39 buds per plant with a shoot and root fresh weight of 573 and 270 grams, respectively. Soil moisture in the root zone (0 to 60 cm) approached the permanent wilting point in the 40%. and 0% of ET treatments by mid-August. A decrease in irrigation rate from 80 to 0% of ET had no effect on fern fresh weight at the end of the growing season. However, as irrigation rate decreased from 80 to 0% of ET, root fresh weight (586, 533, 415 grams) and bud number (78, 59, 53) decreased linearly. These results suggest yield and growth may be reduced in 1994.

The Influence of Soil Moisture on the Foliar Activity of Diclofop

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 534-539 ◽  
Author(s):  
W. A. Dortenzio ◽  
R. F. Norris
Keyword(s):  
Soil Moisture ◽  
Near Field ◽  
Field Capacity ◽  
Herbicide Application ◽  
Wild Oats ◽  
High Soil Moisture ◽  
Herbicide Activity ◽  
Moisture Conditions ◽  
Soil Moisture Status ◽  
Wilting Point

Loss in activity of foliar-applied methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} occurred under low soil moisture conditions. A loss in control of yellow foxtail [Setaria lutescens(Weigel) Hubb.], wild oats (Avena fatuaL.), little-seed canarygrass (Phalaris minorRetz.), and barnyardgrass [Echinochloa crus-galli(L.) Beauv.], was observed under greenhouse and growth chamber conditions. When soil was maintained at 2 to 3% above wilting point as compared to near field capacity, herbicide activity was decreased by 15 to 50%. High soil moisture (at or above 67% of field capacity) for at least 2 to 4 days following treatment was needed to achieve maximum effectiveness of the herbicide. Daily furrow irrigations for a period of 10 days following treatment of barnyardgrass in the field resulted in highest activity as compared to that under single irrigation regimes within the 10-day period. The effect of low soil moisture was minimized by increased rates of herbicide application. Hoe-29152 {methyl-2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoate} showed similar losses in activity associated with low soil moisture. No consistent changes in uptake or translocation of14C-labeled diclofop could be detected in association with altered soil moisture status.

scholarly journals Preventive Control of Annual White Grubs on a Golf Course Fairway, 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 337-337
Author(s):  
F. P. Baxendale ◽  
J. A. Kalisch ◽  
R. E. Gaussoin
Keyword(s):  
Near Field ◽  
Field Capacity ◽  
Golf Course ◽  
Silty Clay ◽  
White Grubs ◽  
Preventive Control ◽  
Time Of Application ◽  
Water Ph ◽  
Plot Area ◽  
Loam Soil

Abstract The study was conducted in Lincoln, NE on a perennial rye golf course fairway. The turf (100% perennial rye) was maintained at a mowing height of 5/s inches and thatch accumulation in the plot area was 0.5 inches finger compressed, 0.25 inches). Field conditions at the time of application were: soil type, silty clay loam; soil organic matter, 3-5%; soil pH, 6-7; water pH, 7.0; soil moisture, near field capacity. Plots were 8 × 8 ft, and the experimental design was a RCB with 5 replications. Insecticide treatments were applied 19 Apr. Liquid insecticides were applied using a CO2 sprayer with an LF-4 tip at 24 psi and delivering 5 gal finished spray/1000 ft2. The granular formulation of Merit was applied with a pre-calibrated Gandy 24H12 spreader. Immediately following applications, the test area was irrigated with approximately 0.5 inches of water. A total of 20.68 inches of rain fell during the post-treatment period. Product efficacy was evaluated 3 Sep (137 days after treatment) by removing from each plot six, 8-inch diameter turf-soil cores (2.1 ft2 total area) to a depth of 3 inches and counting the number of surviving grubs.

scholarly journals Control of Buffalograss Chinch Bugs with Beauvarja Bassiana and Entomopathogenic Nematodes, 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 328-328
Author(s):  
F. P. Baxendale ◽  
A. P. Weinhold ◽  
T. P. Riordan
Keyword(s):  
Entomopathogenic Nematodes ◽  
Near Field ◽  
Field Capacity ◽  
Silty Clay ◽  
Clay Loam Soil ◽  
Silty Clay Loam ◽  
Time Of Application ◽  
Water Ph ◽  
Plot Area ◽  
Loam Soil

Abstract The study was conducted on a buffalograss lawn in Lincoln, NE. The turf was maintained at a mowing height of 3.5 inches and thatch accumulation in the plot area was 0.25 inches. Field conditions at the time of application were: soil type, silty clay loam; soil organic matter, 3-5%; soil pH, 6-7; water pH, 7.0; soil moisture, near field capacity. Plots were 4 × 4 ft and the experimental design was a RCB with 3 replications’. Insecticide treatments were applied 2 Sep. Prior to application, the plot area was mowed to 1.5 inches. Treatments were applied with a CO2 sprayer using a LF-4 tip at 24 psi and delivering 5 gal finished spray/1000 ft2. Immediately following application, plots were syringed with 0.25 inches water. A total of 0.29 and 0.68 inches of rain fell respectively, during the 7 and 14 day post-treatment periods. Product efficacy was evaluated 9 and 16 Sep (7 and 14 DAT) by removing from each plot three turf-soil cores to a depth of 1 inch with a 4.25-inch diam cup cutter (0.3 ft2 total area per plot). Cores were returned to the laboratory and placed in Berlese funnels. Extracted chinch bugs were counted after 48 hr.

scholarly journals Effects of Plant Residue Additives and Soil Moisture on Growth and Mn Content of Soybean Seedlings

1969 ◽  
Vol 61 (2) ◽  
pp. 221-229
Author(s):  
A. Vélez-Ramos ◽  
L. Standifer
Keyword(s):  
Soil Moisture ◽  
Near Field ◽  
Field Capacity ◽  
Plant Residue ◽  
Flooded Soil ◽  
Soybean Seedlings ◽  
Glycine Max L ◽  
Alfalfa Meal ◽  
Mn Content ◽  
Germination And Growth

Greenhouse experiments were conducted to study the effects of decomposing alfalfa meal additives and soil moisture on the Mn content of soybean seedlings (Glycine max L.). Soybean seedlings were grown in soil to which alfalfa meal was added in quantities from 0 to 4%. After the seedlings were established, the soil was subjected to flooding or near field capacity moisture for 7 days. In the absence of alfalfa meal, seedling growth was similar at both soil moisture levels. Increased levels of alfalfa meal progressively reduced germination and growth rate of seedlings. These effects were more pronounced in the flooded soil. Flooding resulted in a marked increase of seedling Mn content, whereas increasing alfalfa meal caused no definite change.

scholarly journals Influence of Hm-8902 Combined with Fn-5354 Or Naf-53 for Control of Annual White Grubs, 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 319-319
Author(s):  
F. P. Baxendale ◽  
A. P. Weinhold ◽  
R. E. Gaussoin
Keyword(s):  
Near Field ◽  
Field Capacity ◽  
Kentucky Bluegrass ◽  
Silty Clay ◽  
Clay Loam Soil ◽  
White Grubs ◽  
Time Of Application ◽  
Water Ph ◽  
Plot Area ◽  
Loam Soil

Abstract The study was conducted in Lincoln, NE on a Kentucky bluegrass and perennial rye golf course fairway. The turf (50% Kentucky bluegrass and 50% perennial rye) was maintained at a mowing height of % inches and thatch accumulation in the plot area was 0.75 inches (finger compressed, 0.5 inches). Field conditions at the time of application were: soil type, silty clay loam; soil organic matter, 3—5%; soil pH, 6—7; water pH, 7.0; soil moisture, near field capacity. Plots were 6 × 6 ft and the experimental design was a RCB with 4 replications. Insecticide treatments were applied 24 Aug using a CO2 sprayer with an LF-4 tip at 24 psi and delivering 5 gal finished spray/1000 ft2. Immediately following applications, the test area was irrigated with approximately 0.5 inches of water. A total of 4.61 inches of rain fell during the post-treatment period. Product efficacy was evaluated 14 Sep (21 DAT) by removing from each plot three 8-inch diam turf-soil cores (1.05 ft2 total area) to a depth of 3 inches and counting the number of surviving grubs.

Soil Moisture Influence on Treatment and Extraction of DDT from Soils

1972 ◽  
Vol 55 (3) ◽  
pp. 532-536 ◽  
Author(s):  
R G Nash ◽  
W G Harris
Keyword(s):  
Soil Moisture ◽  
Extraction Method ◽  
Near Field ◽  
Field Capacity ◽  
Clay Soils ◽  
Extraction Column ◽  
Alkaline Soils ◽  
Moist Condition ◽  
Moisture Influence ◽  
Column Extraction

Abstract An investigation was conducted to determine techniques which prevented p,p’-DDT conversion to p,p’-DDE during (a) extraction of highly alkaline soils and (b) DDT treatment of highly alkaline soils. Moistening soils to near field capacity reduced DDT conversion to DDE during treatment and a new column extraction method was developed which prevented further conversion during extraction. Column extraction is more rapid than Soxhlet or shake extraction and requires less expensive equipment. However, column extraction was less efficient: about 4% DDT remained after extraction of incubated soils, whereas only about 1% remained in Soxhlet-extracted soils, except for clay soils in which both methods of extraction were low. Alkaline soils apparently can be extracted safely with either Soxhlet or column extraction without conversion of DDT to DDE, providing the soils have equilibrated in a moist condition.

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