scholarly journals The nitrogen effect of peat addition in clay soil

1978 ◽  
Vol 50 (2) ◽  
pp. 78-84
Author(s):  
Martti Salonen ◽  
Jorma Kähäri

The nitrogen effect of ligno Carex peat addition to heavy clay with a low content of organic matter was investigated in a pot experiment of eight years. The test plant was oats. The nitrogen effect proved to be very small. It was evident that the positive effect of an addition of peat to mineral soil, which in some cases can be very marked in field conditions, is mainly physical. Primarily it may be due to improved soil moisture conditions.

1996 ◽  
Vol 21 (1) ◽  
pp. 352-352
Author(s):  
Stanley R. Swier

Abstract The trial was conducted 10 May on a golf course rough, Amherst, NH. Plots were 10 X 10 ft, replicated 4 times, in a RCB design. Merit WP was applied in 4 gal water/1000 ft2 with a watering, can. Merit G granules were applied with a homemade salt shaker. Treatments were irrigated with 0.5 inch water after application. Plots were rated 30 Sep by counting the number of live grubs per 1 ft2. Conditions at the time of treatment were: air temperature 70°F; wind, 3 MPH; sky, clear; soil temperature, 1 inch, 60°F; thatch depth, 0.5 inch soil pH, 5.4; slope 0%; soil texture, silt loam, 47% sand, 50% silt, 3% clay; soil organic matter, 6.9%; soil moisture, 21.8%.


1996 ◽  
Vol 21 (1) ◽  
pp. 343-344
Author(s):  
Stanley R. Swier

Abstract A large plot efficacy trial was conducted at Rutland Country Club, Rutland, VT on a golf course fairway. Plot size was 14 X 75 ft., arrayed in an RCB design, replicated 4 times. Treatments were applied 8 June at 0800 with an FMC hydraulic sprayer using 8004 nozzles delivering 3.6 gal. water/1000 ft2. Within 30 minutes of application, 0.2 inch irrigation water was applied to the plots. Plots were 60% annual bluegrass and 40% bentgrass. Larvae were predominantly third instar. Plots were rated at 7 and 14 DAT. Five cup cutter plugs were then taken per plot and analyzed in the lab. The number of live larvae were recorded. Conditions at the time of treatment were: air temperature 64.4°F; wind, 2 MPH; sky, clear; soil temperature, 1 inch –66°F; thatch depth, 0.25 inch soil pH, 5.2; slope, 3%; soil texture, loam: 48% sand, 42% silt, 10% clay; soil organic matter, 7.5%; soil moisture, 21.3%; post-treatment precipitation, 0.2 inch every other day.


2019 ◽  
Vol 34 (3) ◽  
pp. 362-370
Author(s):  
Jose V. Fernandez ◽  
D. Calvin Odero ◽  
Gregory E. MacDonald ◽  
Jason A. Ferrell ◽  
Brent A. Sellers ◽  
...  

AbstractDissipation of S-metolachlor, a soil-applied herbicide, on organic and mineral soils used for sugarcane production in Florida was evaluated using field studies in 2013 to 2016. S-metolachlor was applied PRE at 2,270 g ha−1 on organic and mineral soils with 75% and 1.6% organic matter, respectively. The rate of dissipation of S-metolachlor was rapid on mineral soils compared with organic soils. Dissipation of S-metolachlor on organic soils followed a negative linear trend resulting in half-lives (DT50) ranging from 50 to 126 d. S-metolachlor loss on organic soils was more rapid under high soil-moisture conditions than in corresponding low soil-moisture conditions. On mineral soils, dissipation of S-metolachlor followed an exponential decline. The DT50 of S-metolachlor on mineral soils ranged from 12 to 24 d. The short persistence of S-metolachlor on mineral soils was likely attributed to low organic matter content with limited adsorptive capability. The results indicate that organic matter content and soil moisture are important for persistence of S-metolachlor on organic and mineral soils used for sugarcane production in Florida.


2001 ◽  
Vol 57 (12) ◽  
pp. 1127-1134 ◽  
Author(s):  
Colin D Brown ◽  
Chris J Fryer ◽  
Allan Walker

Weed Science ◽  
1972 ◽  
Vol 20 (5) ◽  
pp. 486-489 ◽  
Author(s):  
J. H. Hunter ◽  
E. H. Stobbe

The movement and persistence of 4-amino-3,5,6-trichloropicolinic acid (picloram) in an Osborne clay soil was determined over a 4-year period. Picloram concentrations were determined with soybean(Glycine max(L.) Merr. ‘Altona’) as the bioassay plant. Application rates ranged from 35 to 700 g/ha. Movement and dissipation of picloram were neglible under low soil moisture conditions, but under high rainfall conditions picloram was leached into the 30 to 60-cm depth. A greater percent of the picloram was leached at the higher application rates. Dissipation increased with temperature (days over 27 C) and decreased with increasing depth in the soil profile. Two applications of picloram at 70 g/ha applied in 2 successive years showed no detectable accumulation, but accumulation occurred from two applications of 350 g/ha; 32% of the activity remained after approximately 2 years.


1994 ◽  
Vol 19 (1) ◽  
pp. 313-314
Author(s):  
Stanley R. Swier

Abstract Two formulations of Merit were compared for efficacy against Japanese beetle grubs on a golf course fairway in Amherst, NH. Plots were 10 × 10 ft, replicated 4 times in an RCB design. Treatments were applied 26 Apr and rated 24 Sep. The granular formulation was applied with a homemade salt shaker. The wettable powder was applied in a watering can at a volume of 5 gal water/1000 ft2. After application, plots were irrigated with 0.5 inches water. Plots were rated by counting the number of live grubs in a 3 ft2 sample. Conditions at the time of treatment were: air temperature, 53.3°F; soil temperature, 2 inches, 50.8°F; thatch depth, 0.5 inch; soil pH, 5.8; slope, 1%; soil texture, sandy loam, 53% sand, 43% silt, 4% clay; soil organic matter, 6.5% soil moisture, 19.4%.


2021 ◽  
Author(s):  
Chang-Hwan Park ◽  
Aaron Berg ◽  
Michael H. Cosh ◽  
Andreas Colliander ◽  
Andreas Behrendt ◽  
...  

Abstract. The prevalent soil moisture probe algorithms are based on a polynomial function that does not account for the variability in soil organic matter. Users are expected to choose a model before application: either a model for mineral soil or a model for organic soil. Both approaches inevitably suffer from limitations with respect to estimating the volumetric soil water content in soils having a wide range of organic matter content. In this study, we propose a new algorithm based on the idea that the amount of soil organic matter (SOM) is related to major uncertainties in the in-situ soil moisture data obtained using soil probe instruments. To test this theory, we derived a multiphase inversion algorithm from a physically based dielectric mixing model capable of using the SOM amount, performed a selection process from the multiphase model outcomes, and tested whether this new approach improves the accuracy of soil moisture (SM) data probes. The validation of the proposed new soil probe algorithm was performed using both gravimetric and dielectric data from the Soil Moisture Active Passive Validation Experiment in 2012 (SMAPVEX12). The new algorithm is more accurate than the previous soil-probe algorithm, resulting in a slightly improved correlation (0.824 0.848), 12 % lower root mean square error (RMSE; 0.0824 0.0725 cm3·cm−3), and 90 % less bias (−0.0042 0.0004 cm3·cm−3). These results suggest that applying the new dielectric mixing model together with global SOM estimates will result in more reliable soil moisture reference data for weather and climate models and satellite validation.


2008 ◽  
Vol 88 (6) ◽  
pp. 1073-1086 ◽  
Author(s):  
R. E. Karamanos ◽  
J. T. Harapiak ◽  
N. A. Flore

The rates of nitrogen (N) that can be safely placed with the seed remains a frequent question of producers, especially as direct seeding continues to increase as a practice in western Canada. Guidelines have been in place since the mid-1990s; however, they address only "favourable conditions" and experimentation relating to their derivation has not been formally published. This study attempted to quantify "favourable conditions" as well as supplement existing guidelines with information under non-favourable or ideal conditions so that producers may assess the risk of applying N with the seed. To this end, the results from 32 experiments with CWRS wheat and 10 with barley conducted in early to mid-1990s were compiled. The experimental design included three seedbed utilization (SBU) rates (10, 20, and 40%) and five N rates (0, 20, 40, 60, and 80 kg N ha-1) with four replications. Grain yield, relative plant stands (calculated as a percentage of the unfertilized control) and days to maturity (DTM) were determined in all experiments. Three types of responses to seedrow N application occurred. Type A had no impact of fertilizer N rate on the yield of CWRS wheat at wide (40%) SBU, but grain yield decreased at narrower SBU (10 and 20%). Type B had no impact of fertilizer N rate on the yield of CWRS wheat at narrow (10%) SBU but grain yield increased at wide SBU (20 and 40%). Type C had grain yield increases due to fertilizer N independent of SBU. Type A was characterized by dry soil moisture conditions and relatively high residual NO3−-N levels, whereas Types B and C were characterized by normal and very moist soil conditions and low to medium residual NO3−-N levels. The results within each response type were modified by soil organic matter (SOM) and texture. Grain yield losses generally occurred when relative plants stands were below 85% of those of unfertilized plots. In addition, conditions that led to a decrease in relative plant stands and grain yield also resulted in delayed maturity. Accounting for all the above factors enabled us to expand current guidelines under normal conditions to a range of agroecological conditions. Key words: Guideline, texture, soil organic matter, residual NO3−-N, soil moisture


Sign in / Sign up

Export Citation Format

Share Document