Field studies on effect of soil conditioners and mulch on runoff lrom kaolinitic and illitic soils

Soil Research ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 249 ◽  
Author(s):  
R Stern ◽  
MC Laker ◽  
AJ Vandermerwe
Keyword(s):  
Beneficial Effect ◽  
Hydraulic Properties ◽  
Field Studies ◽  
Annual Runoff ◽  
Control Treatment ◽  
Water Penetration ◽  
Consecutive Season ◽  
Mulch Cover ◽  
Runoff Plots ◽  
Effect Of Surface

Runoff plots (1 - 5 m2) were constructed at three sites where crusting, runoff and erosion are severe problems. The effect of surface application of phosphogypsum (PG), polyacrylamide (PAM) and mulch cover on runoff during natural rainstorms were studied. Runoff percentage from control (bare) plots in some rainstorms exceeded 90% of the rainfall. The annual runoff from control plots ranged between 33 and 73% of the annual rain. Mulch was highly beneficial in reducing runoff, indicating that seal formation restricted water penetration rather than hydraulic properties of the profile. PG reduced runoff to 0.15-0.82 of the untreated plots. The efficiency of PG in reducing runoff was inversely correlated with rainstorm intensity. The beneficial effect of PC in reducing runoff lasted throughout the rainy season. Its beneficial effect terminated during the consecutive season in the Irene site when the cumulative rain depth exceeded 700 mm. PAM treatment reduced annual runoff by two to three fold in comparison with the control treatment. The effect of PAM on diminishing runoff in the rainfall simulator studies was more pronounced than in the field conditions.

ESTIMATION OF SOIL HYDRAULIC PROPERTIES WITH THE CONE PERMEAMETER: FIELD STUDIES

Soil Science ◽  
1999 ◽  
Vol 164 (8) ◽  
pp. 527-541 ◽  
Author(s):  
Radka Kodešová ◽  
Sondra E. Ordway ◽  
Molly M. Gribb ◽  
Jiří Šimůnek
Keyword(s):  
Hydraulic Properties ◽  
Field Studies ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

scholarly journals Reducing Sprinkler Irrigation Volumes for Strawberry Transplant Establishment in Florida

2012 ◽  
Vol 22 (2) ◽  
pp. 224-227 ◽  
Author(s):  
Bielinski M. Santos ◽  
Teresa P. Salame-Donoso ◽  
Alicia J. Whidden
Keyword(s):  
Foliar Application ◽  
Sprinkler Irrigation ◽  
Field Studies ◽  
Early Morning ◽  
Fruit Weight ◽  
Control Treatment ◽  
Water Volume ◽  
Kaolin Clay ◽  
Irrigation Control ◽  
Water Volumes

Two field studies were conducted to determine whether foliar kaolin clay applications would reduce water volumes during the establishment of bare-root strawberry (Fragaria ×ananassa) transplants. Transplant establishment treatments resulted from combinations of duration of sprinkler irrigation and foliar application of kaolin clay were: a) 4 days of sprinkler irrigation, b) 4 days of sprinkler irrigation plus kaolin clay on day 5, c) 6 days of sprinkler irrigation, d) 6 days of sprinkler irrigation plus kaolin clay on day 7, e) 8 days of sprinkler irrigation, f) 8 days of sprinkler irrigation plus kaolin clay on day 9, and g) 10 days of sprinkler irrigation (control). One day of sprinkler irrigation was defined as the application of 8 hours per day of irrigation to ensure plant establishment, using ≈6000 gal/acre per hour of water. Kaolin clay treatments were applied using a rate of 25 lb/acre and on the early morning of the following day after sprinkler irrigation was suspended. Treatments influenced the number of established plants and diameter at 4 and 8 weeks after transplanting (WAT), leaf greenness at 8 WAT, and early and total fruit weight. There were no differences in the number of established plants among treatments that received 10 days of sprinkler irrigation (control), 8 days of sprinkler irrigation followed by kaolin clay on day 9, and 6 days of sprinkler irrigation followed by kaolin clay on day 7, ranged between 97% and 98% plant survival. The highest strawberry early and total fruit weights (3.6 and 15.7 tons/acre, respectively) occurred in plots transplanted with either 6 days of sprinkler irrigation plus kaolin clay on day 7, 8 days of sprinkler irrigation plus kaolin clay on day 9, or 10 days of sprinkler irrigation. These data indicated that the addition to kaolin clay after 6 or 8 days of sprinkler irrigation improved strawberry establishment, growth, and yields to the same levels as the control treatment, while saving at least 20% of the water volume needed for establishment.

scholarly journals Runoff Losses on Urban Surfaces during Frequent Rainfall Events: A Review of Observations and Modeling Attempts

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2777
Author(s):  
Mohamad Rammal ◽  
Emmanuel Berthier
Keyword(s):  
Urban Areas ◽  
Field Studies ◽  
Annual Runoff ◽  
Urban Drainage ◽  
Infiltration Process ◽  
Rainfall Events ◽  
Fully Integrated ◽  
Wide Range ◽  
Runoff Losses ◽  
Preferential Pathways

Quantifying urban runoff during frequent rainfall events is a key element in quality management of urban water due to their high contribution to the annual runoff flow. This explains the growing interest among hydrologists in studying runoff flow on urban surfaces. In this paper, we review most of the experimental approaches as well as the modeling ones conducted in the literature to understand and estimate runoff flow on urban areas. This review highlights the incoherence between our current understanding of the hydrological behavior of urban areas during frequent events and our conception of the loss functions in the urban drainage models. Field studies provided more insight into the determinant processes occurring on the different surface types during frequent events with depression storage being a fundamental element varying between surface types and for the same surface type and infiltration process being relatively important on paved areas especially in their cracks that constitute preferential pathways for rainwater. Analyzing a wide range of urban drainage models showed that these elements along with the temporal evolution of the hydrological behavior of urban surfaces due to seasonal and state conditions are not fully integrated in the models’ structures, which were initially developed for heavy rainfall events. Adapting the assumptions of urban drainage models based on these new factors must improve the performance of hydrological models for frequent rainfall events.

scholarly journals Soil chemical properties and nutrients in maize fertilized with urban waste compost1

2017 ◽  
Vol 47 (2) ◽  
pp. 186-194 ◽  
Author(s):  
José Ricardo Mantovani ◽  
Fernando Spadon
Keyword(s):  
Block Design ◽  
Organic Fertilizer ◽  
Chemical Properties ◽  
Leaf Tissue ◽  
Field Studies ◽  
Soil Chemical Properties ◽  
Control Treatment ◽  
Mineral Fertilization ◽  
Urban Waste ◽  
Compost Application

ABSTRACT Urban waste compost has a potential to be used as an organic fertilizer in agriculture, but field studies are required to define the recommendable rates for crops. This study aimed at evaluating the effect of fertilization with urban waste compost on the soil chemical properties, yield, nutrient and heavy metal contents, in maize leaves and grains. The field experiment was carried out in a randomized complete block design, with seven treatments and four replications. The treatments consisted of six urban waste compost doses (0 Mg ha-1, 5 Mg ha-1, 10 Mg ha-1, 20 Mg ha-1, 30 Mg ha-1 and 40 Mg ha-1), applied in the planting furrow, plus an additional control treatment, with NPK mineral fertilization and no waste compost application. Fertilization with up to 40 Mg ha-1 of urban waste compost improves soil fertility. Fertilization with urban waste compost increases grain yield and the N, P and K contents in leaf tissue and maize grains, without inducing plant contamination with heavy metals. The application of 30 Mg ha-1 of urban waste compost can replace mineral fertilization in maize cultivation.

A comparative assessment of the response of three fruit fly species (Diptera: Tephritidae) to a spinosad-based bait: effect of ammonium acetate, female age, and protein hunger

2010 ◽  
Vol 101 (4) ◽  
pp. 373-381 ◽  
Author(s):  
J.C. Piñero ◽  
R.F.L. Mau ◽  
R.I. Vargas
Keyword(s):  
Ammonium Acetate ◽  
Fruit Fly ◽  
Field Studies ◽  
Bactrocera Dorsalis ◽  
Food Sources ◽  
Control Treatment ◽  
Field Cage ◽  
Wild Female ◽  
Female Age ◽  
Protein Starvation

AbstractAmmonia-releasing substances are known to play an important role in fruit fly (Diptera: Tephritidae) attraction to food sources, and this information has been exploited for the development of effective synthetic food-based lures and insecticidal baits. In field studies conducted in Hawaii, we examined the behavioural response of wild female oriental fruit fly (Bactrocera dorsalis (Hendel)), melon fly (B. cucurbitae (Coquillett)), and Mediterranean fruit fly (Ceratitis capitata (Wiedemann)) to spinosad-based GF-120 NF Naturalyte Fruit Fly Bait© formulated to contain either 0, 1 or 2% ammonium acetate. Use of visually-attractive yellow bait stations for bait application in the field allowed for proper comparisons among bait formulations. Field cage tests were also conducted to investigate, using a comparative behavioural approach, the effects of female age and protein starvation on the subsequent response of F1 generation B. cucurbitae and B. dorsalis to the same three bait formulations that were evaluated in the field. Our field results indicate a significant positive effect of the presence, regardless of amount, of AA in GF-120 for B. dorsalis and B. cucurbitae. For C. capitata, there was a significant positive linear relationship between the relative amounts of AA in bait and female response. GF-120 with no AA was significantly more attractive to female C. capitata, but not to female B. dorsalis or B. cucurbitae, than the control treatment. Our field cage results indicate that the effects of varying amounts of AA present in GF-120 can be modulated by the physiological stage of the female flies and that the response of female B. cucurbitae to GF-120 was consistently greater than that of B. dorsalis over the various ages and levels of protein starvation regimes evaluated. Results are discussed in light of their applications for effective fruit fly suppression.

Field studies of the effects of pre-sowing weed control and time of sowing on tropical perennial grass establishment, North-West Slopes, New South Wales

2010 ◽  
Vol 61 (2) ◽  
pp. 182 ◽  
Author(s):  
G. M. Lodge ◽  
M. A. Brennan ◽  
S. Harden
Keyword(s):  
Weed Control ◽  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Field Studies ◽  
Perennial Grasses ◽  
Control Treatment ◽  
North West ◽  
South Wales ◽  
Plant Frequency

Two separate experiments on the North-West Slopes of New South Wales investigated: (1) the effects of differing lengths of pre-sowing weed control (2 years, 1 year, and 3–4 months in the spring immediately before sowing) on the soil seed density of liverseed grass (Urochloa panicoides) from November 2005 to November 2007 and its seedling density at establishment (December 2007), as well as on subsequent herbage mass and plant frequency of this species and Panicum coloratum var. makarikariense cv. Bambatsi (Expt 1); and (2) the effects of cultivar, time of sowing (November 2006, January 2007, and March 2007), and defoliation in the autumn after sowing, on the over-wintering ability of 5 tropical perennial grasses (Expt 2). The cultivars sown in Expt 2 were Bambatsi, Dichanthium aristatum cv. Floren, Chloris gayana cv. Katambora, Digitaria eriantha var. eriantha cv. Premier, and Bothriochloa bladhii var. glabra cv. Swann. At sowing (November 2007), liverseed grass seed and seedling densities in Expt 1 were lowest (P < 0.05) in the 2-year pre-sowing weed control treatment (15 and 13/m2, respectively), and the subsequent herbage mass of Bambatsi (January and October 2008) was highest (P < 0.05) in this treatment. In Expt 2, 59 frosts occurred in 2007, and Floren, Bambatsi, and Swann sown in March of that year over-wintered poorly and had lower (P < 0.05) herbage mass and plant frequency in the following spring compared with the other sowing times. These differences were also evident in autumn and spring 2008, up to 23 months after sowing.

scholarly journals A review of the effectiveness of operational curtailment for reducing bat fatalities at terrestrial wind farms in North America

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0256382
Author(s):  
Evan M. Adams ◽  
Julia Gulka ◽  
Kathryn A. Williams
Keyword(s):  
Linear Model ◽  
Meta Analysis ◽  
Wind Farms ◽  
Field Studies ◽  
The United States ◽  
Continuous Variable ◽  
Control Treatment ◽  
Exact Nature ◽  
Non Linear ◽  
The Relationship

Curtailment of turbine operations during low wind conditions has become an operational minimization tactic to reduce bat mortality at terrestrial wind energy facilities. Site-specific studies have demonstrated that bat activity is higher during lower wind speeds and that operational curtailment can effectively reduce fatalities. However, the exact nature of the relationship between curtailment cut-in speed and bat fatality reduction remains unclear. To evaluate the efficacy of differing curtailment regimes in reducing bat fatalities, we examined data from turbine curtailment experiments in the United States and Canada in a meta-analysis framework. We used multiple statistical models to explore possible linear and non-linear relationships between turbine cut-in speed and bat fatality. Because the overall sample size for this meta-analysis was small (n = 36 control-treatment studies from 17 wind farms), we conducted a power analysis to assess the number of control-treatment curtailment studies needed to understand the relationship between fatality reduction and change in cut-in speed. We also identified the characteristics of individual curtailment field studies that may influence their power to detect fatality reductions, and in turn, contribute to future meta-analyses. We found strong evidence that implementing turbine curtailment reduces fatality rates of bats at wind farms; the estimated fatality ratio across all studies was 0.37 (p < 0.001), or a 63% decrease in fatalities. However, the nature of the relationship between the magnitude of treatment and reduction in fatalities was more difficult to assess. Models that represented the response ratio as a continuous variable (e.g., with a linear relationship between the change in cut-in speed and fatalities) and a categorical variable (to allow for possible non-linearity in this relationship) both had substantial support when compared using AICc. The linear model represented the best fit, likely due to model simplicity, but the non-linear model was the most likely without accounting for parsimony and suggested fatality rates decreased when the difference in curtailment cut-in speeds was 2m/s or larger. The power analyses showed that the power to detect effects in the meta-analysis was low if fatality reductions were less than 50%, which suggests that smaller increases in cut-in speed (i.e., between different treatment categories) may not be easily detectable with the current dataset. While curtailment is an effective operational mitigation measure overall, additional well-designed curtailment studies are needed to determine precisely whether higher cut-in speeds can further reduce bat fatalities.

Sign in / Sign up

Export Citation Format

Share Document