scholarly journals A geospatial variable rate irrigation control scenario evaluation methodology based on mining root zone available water capacity

2017 ◽  
Vol 19 (4) ◽  
pp. 666-683 ◽  
Author(s):  
K. A. Miller ◽  
J. D. Luck ◽  
D. M. Heeren ◽  
T. Lo ◽  
D. L. Martin ◽  
...  
Keyword(s):  
Root Zone ◽  
Evaluation Methodology ◽  
Variable Rate ◽  
Water Capacity ◽  
Available Water ◽  
Scenario Evaluation ◽  
Available Water Capacity ◽  
Irrigation Control ◽  
Variable Rate Irrigation

scholarly journals Field Characterization of Field Capacity and Root Zone Available Water Capacity for Variable Rate Irrigation

2017 ◽  
Vol 33 (4) ◽  
pp. 559-572 ◽  
Author(s):  
Tsz Him Lo ◽  
Derek M. Heeren ◽  
Luciano Mateos ◽  
Joe D. Luck ◽  
Derrel L. Martin ◽  
...  
Keyword(s):  
Root Zone ◽  
Field Capacity ◽  
Variable Rate ◽  
Water Capacity ◽  
Spatial Characterization ◽  
Available Water ◽  
Sampling Locations ◽  
Available Water Capacity ◽  
Variable Rate Irrigation

Abstract. Accurate spatial characterization of field capacity (FC) and root zone available water capacity (R) can enhance site-specific management practices—such as variable rate irrigation—to lower input costs, reduce contaminant leaching, and/or improve crop yield. Measuring the volumetric water content after wet soils drain following substantial precipitation can provide a field estimate of FC. The average FC (FCa) for the managed root zone was determined at thirty-two locations in a topographically variable field in south central Nebraska. The difference between FC and permanent wilting point estimates—computed using a pedotransfer function—yielded values for R for the observation locations. Sampling locations were too sparse for reliable interpolation across the field. Therefore, relationships between a surrogate, or predictor, variable and soil water properties were used to provide spatial distributions of FC and R for the field. Field estimates of FCa and R were more strongly correlated to elevation (correlation coefficient, r = -0.77 and -0.76, respectively) than to deep soil apparent electrical conductivity (r = -0.46 and -0.39, respectively). Comparing maps of FCa and R from gSSURGO to maps from field characterization yielded a root mean squared difference of 0.031 m3 m-3 for FCa and 34 mm for R. Sampling seven locations across the elevation range in this field produced FCa and R prediction functions that achieved 95% and 87%, respectively, of the reduction in the standard error achievable with a larger number of sampling locations. Spatial characterization of FCa and R depends on identifying a suitable predictor variable(s) based on field knowledge and available spatial data. Well-chosen variables may allow satisfactory predictions using several sampling locations that are distributed over the entire field. Ultimately, the costs and benefits of spatial characterization should be considered when evaluating site-specific water management. Keywords: Available water capacity, Electrical conductivity, Field capacity, Permanent wilting point, Spatial variability, Variable rate irrigation.

Deep drainage and soil salt loads in the Queensland Murray - Darling Basin using soil chloride: comparison of land uses

Soil Research ◽  
2011 ◽  
Vol 49 (5) ◽  
pp. 408 ◽  
Author(s):  
P. E. Tolmie ◽  
D. M. Silburn ◽  
A. J. W. Biggs
Keyword(s):  
Root Zone ◽  
Drainage Water ◽  
Native Vegetation ◽  
Deep Drainage ◽  
Water Capacity ◽  
Available Water ◽  
Murray Darling Basin ◽  
Available Water Capacity ◽  
Secondary Salinity ◽  
Soil Chloride

Increases in deep drainage below the root-zone can lead to secondary salinity. Few data were available for drainage under dryland cropping and pastures in the Queensland Murray–Darling Basin (QMDB) before this study. Modelled estimates were available; however, without measured drainage these could not be validated. Soil chloride (Cl) mass-balance was used to provide an extensive survey of deep drainage. The method is ‘backward-looking’ and can detect low rates of drainage over longer times. Soil Cl and other soil properties were collated for a number of soils, mostly Vertosols and Sodosols, for paired native vegetation, cropped and sometimes pasture sites, from historical data and new soil sampling. Large amounts of salt and Cl had accumulated under native vegetation (Cl mean 25 t/ha, range 6–54, in 2.4 m depth), due to low rates of drainage. Steady-state Cl balances for native vegetation gave average drainage of 1.2 mm/year at wetter, eastern sites and 0.3 mm/year for Sodosols and Grey Vertosols in drier, western areas. Chloride profiles were mostly of a shape indicating matrix/piston flow. One site (Hermitage fallow trial) appeared to be affected by diffusion of Cl to a watertable. The Cl profiles from 14 longer term cropping sites (18–70 years), mainly used for winter cropping/summer fallow, indicate: (i) large losses of Cl since clearing (mean 50%, range 13-85% for 0–1.5 m soil); and (ii) drainage rates from transient Cl balance are a relatively low percentage of rainfall but are considerably higher than under native vegetation. Drainage averaged 8 mm/year and ranged from 2 to 18 mm/year. This variation is partly explained by rainfall (R2 = 0.63) (500–730 mm/year) and soil plant-available water capacity (R2 = 0.77) (80–300 mm). Deep drainage increases with increasing rainfall and with decreasing available water capacity. Drainage under pasture was less than under cropping but greater than under native vegetation. The deep drainage water (leachate) was of poor quality and will increase salinity if added to good quality groundwater. Leachate at nine sites was too saline to be used (undiluted) for irrigation (>2500 mg Cl/L) and was marginal at the remainder of sites (~800 mg Cl/L). Cropping areas in the QMDB have the precursors for secondary salinity development—high salt loads and an increase in drainage after clearing. The Vertosols and Sodosols studied occur in 90% of croplands in the QMDB. Salinisation will depend on the properties of the underlying regolith and groundwater systems.

scholarly journals Determination of the effects of tillage on the productivity of a sandy loam soil using soil productivity models

2021 ◽  
Vol 67 (No. 3) ◽  
pp. 108-115
Author(s):  
Tanko Bako ◽  
Ezekiel Ambo Mamai ◽  
Istifanus Akila Bardey
Keyword(s):  
Organic Matter ◽  
Iron Oxide ◽  
Bulk Density ◽  
Aluminium Oxide ◽  
Available Phosphorus ◽  
Soil Productivity ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Tillage Methods

Based on the hypothesis that soil properties and productivity components should be affected by different tillage methods, field and laboratory experiments were conducted to study the effects of zero tillage (ZT), one pass of disc plough tillage (P), one pass of disc plough plus one pass of disc harrow tillage (PH) and one pass of disc plough plus two passes of disc harrow tillage (PHH) on the distribution of the bulk density, available water capacity, pH, organic matter, available phosphorus, iron oxide and aluminium oxide at different soil depths, and their effects on the soil productivity. The available water capacity, pH, organic matter and available phosphorus were found to increase with the degree of tillage, while the bulk density, iron oxide and aluminium oxide were found to decrease with the degree of tillage. The results show that the soil productivity index was significantly (P ≤ 0.05) affected by the tillage methods and found to increase with the degree of tillage.

scholarly journals Improvement of soil available water capacity using biopore infiltration hole with compost in a coffee plantation

2021 ◽  
Vol 8 (3) ◽  
pp. 2791-2799
Author(s):  
Atiqah Aulia Hanuf ◽  
Sugeng Prijono ◽  
S Soemarno
Keyword(s):  
Chlorophyll Content ◽  
Soil Depth ◽  
Block Design ◽  
Control Treatment ◽  
Coffee Plantation ◽  
Coffee Tree ◽  
Coffee Pulp ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity

Coffee plantation management has an important role in soil quality in order to increase coffee production. Biopore Infiltration Hole with Compost (BIHC) can increase soil available water capacity. In this study, the goal was to improve soil available water capacity in a coffee plantation with the implementation of the BIHC. This study was conducted at PTPN XII Bangelan, Malang, on March - August 2020. A randomized block design with seven treatments and four replications was used. The BIHC consisted of two-hole depths (30 cm and 60 cm) and two types of compost (goat manure and coffee pulp compost). The soil characteristics observed were water retention (pF) and C-organic at soil depths of 0-20, 20-40, and 40-60 cm. The coffee tree observed were number of leaves and chlorophyll content. Data obtained were subjected to analysis of variance (ANOVA) by the F test and Duncan's Multiple Distance Rate Test (DMRT) at 5% probability, using SPSS program. Results of the study showed that BIHC was able to increase the content of soil C-organic and the available water capacity significantly compared with control treatment. The BIHC implementation could increase soil available water capacity up to 65% at a soil depth of 0-20 cm, up to 60% at a soil depth of 20-40 cm, and up to 51% at a soil depth of 40-60 cm more than the control treatment. The soil available water capacity suggested a significant positive correlation (p≤0.05) with the leaves number of coffee tree and chlorophyll content of leaves.

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