EVALUATION OF EPIC FOR ASSESSING CROP YIELD, RUNOFF, SEDIMENT AND NUTRIENT LOSSES FROM WATERSHEDS WITH POULTRY LITTER FERTILIZATION

2006 ◽  
Vol 49 (1) ◽  
pp. 47-59 ◽  
Author(s):  
X. Wang ◽  
R. D. Harmel ◽  
J. R. Williams ◽  
W. L. Harman
Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1333 ◽  
Author(s):  
Yuguo Han ◽  
Gary Feng ◽  
Ying Ouyang

Rainfall is a major dynamic source of soil erosion and nutrient loss on slopes. Soil and water conservation practices and agricultural activities can change the soil surface morphology and thus affect erosion and nutrient losses. This study focused on the effects of several typical soil and water conservation practices and agricultural land, for the purpose of: (1) determining how these practices prevent erosion and nutrient loss and identifying the hydrodynamic mechanisms; and (2) determining the application conditions for different practices. Runoff, sediment, total nitrogen (TN) and total phosphorus (TP) in fish-scale pits, agricultural land, narrow terraces, shrub cover and bare land, under rainfall events in rainy seasons (from May to November) during the 2010–2015 period, were monitored. Slope hydrodynamic mechanisms and application conditions of these practices were also investigated. The results showed that compared with bare land, fish-scale pits performed the best in preventing runoff, sediment, TN and TP, followed by 30% shrub coverage, narrow terraces and agricultural land, successively. Total runoff, sediment, TN and TP losses in fish-scale pits site were 19.70%, 2.03%, 10.10% and 35.97% of those in bare land of the same area, respectively. Soil and water conservation practices could change the hydraulic characteristics of slopes, decrease Re (Reynolds) and Fr (Froude) numbers, thereby decreasing runoff, sediment, TN and TP losses. Fish-scale pits were suitable for the areas with small single rainfall and good water permeability. When rainfall was greater than 60 mm, narrow terraces had highest efficiency in reducing sediment loss; therefore, they were suitable for the areas with relatively high rainfall intensity and soils similar to the sandy loams of the study area. As to the practice of covering land with plants, the effect was sustainable due to the plants’ long-term growth. Agricultural land was not recommended since the losses on it were relatively higher due to the impact of human activities. In reality, these practices may be applied in combination so as to effectively control water, soil and nutrient losses.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7093
Author(s):  
Solmaz Rasoulzadeh Gharibdousti ◽  
Gehendra Kharel ◽  
Arthur Stoecker

Best management practices (BMPs) are commonly used to reduce sediment loadings. In this study, we modeled the Fort Cobb Reservoir watershed located in southwestern Oklahoma, USA using the Soil and Water Assessment Tool (SWAT) and evaluated the impacts of five agricultural BMP scenarios on surface runoff, sediment yield, and crop yield. The hydrological model, with 43 sub-basins and 15,217 hydrological response units, was calibrated (1991–2000) and validated (2001–2010) against the monthly observations of streamflow, sediment grab samples, and crop-yields. The coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB) were used to determine model performance with satisfactory values of R2 (0.64 and 0.79) and NS (0.61 and 0.62) in the calibration and validation period respectively for streamflow. We found that contouring practice reduced surface runoff by more than 18% in both conservation tillage and no-till practices for all crops used in this modeling study. In addition, contour farming with either conservation tillage or no-till practice reduced sediment yield by almost half. Compared to the conservation tillage practice, no-till practice decreased sediment yield by 25.3% and 9.0% for cotton and grain sorghum, respectively. Using wheat as cover crop for grain sorghum generated the lowest runoff followed by its rotation with canola and cotton regardless of contouring. Converting all the crops in the watershed into Bermuda grass resulted in significant reduction in sediment yield (72.5–96.3%) and surface runoff (6.8–38.5%). The model can be used to provide useful information for stakeholders to prioritize ecologically sound and feasible BMPs at fields that are capable of reducing sediment yield while increasing crop yield.


2006 ◽  
Vol 49 (2) ◽  
pp. 349-355 ◽  
Author(s):  
J. A. Daniel ◽  
W. A. Phillips ◽  
B. K. Northup

2012 ◽  
Vol 25 (6) ◽  
pp. 554-564 ◽  
Author(s):  
Z. Adimassu ◽  
K. Mekonnen ◽  
C. Yirga ◽  
A. Kessler

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3721-3740
Author(s):  
Laysa Gabryella de Souza Laurentino ◽  
◽  
Lucia Helena Garófalo Chaves ◽  
Antônio Ramos Cavalcante ◽  
Jean Pereira Guimarães ◽  
...  

The choice of a substrate that meets the nutritional and physical demands of papaya seedlings with the use of organic wastes is directly linked to increases in crop yield and is an important environmental and economic alternative. Aiming to produce good-quality papaya seedlings while considering the composition and availability of substrates, this study examined the influence of applying increasing rates of poultry litter biochar as a substrate component in the production of papaya seedlings. The study was developed in a protected environment belonging to the Federal University of Campina Grande (UFCG). The experiment was laid out in a completely randomized design with a 6 × 2 factorial arrangement consisting of six rates of biochar (4, 8, 12, 16 and 20 t ha-1 and the control) and two papaya cultivars (Formosa and Ouro), with four replicates. Plant height, stem diameter, number of leaves and leaf area were evaluated 90 days after sowing. The fresh and dry biomass of shoots and root system and the Dickson Quality Index were also evaluated. In conclusion, the rates that provided good development of papaya seedlings were 8 and 16 t ha-1, and papaya cultivar Ouro showed better growth results.


2008 ◽  
Vol 39 (19-20) ◽  
pp. 3002-3031 ◽  
Author(s):  
H. Allen Torbert ◽  
Thomas J. Gerik ◽  
Wyatte L. Harman ◽  
Jimmy R. Williams ◽  
Melanie Magre

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