Gary A. Clark Research Agricultural Engineer Subsurface drip irrigation (SDI) systems deliver water to the root zone of crops using polyethylene drip tubing that is permanently buried below the soil surface. In properly designed and operated systems, little or no wetting of the soil surface occurs, nor is there visual evidence of the system performance. Because SDI systems apply water different...

tion of salt in the soil, salt leaching from the root zone should be conducted. In regions where the rainfall is Development of an impermeable layer at some depth beneath the low, a leaching fraction (the fraction of applied water soil surface and the presence of a high groundwater level are common that appears as drainage water) is added to the irrigation phenomena in the Yizre’el Valley, Isra...

Vertical soil moisture profiles based on the principle of maximum entropy (POME) were validated using field and model data and applied to guide an irrigation cycle over a maize field in north central Alabama (USA). The results demonstrate that a simple two-constraint entropy model under the assumption of a uniform initial soil moisture distribution can simulate most soil moisture profiles that ...

Spring and summer tillage are usually followed by irrigation before planting crops in California's summer-dry Mediterranean-type climate. Tillage treatments such as rototillage or disking are known to disturb the soil structure to different extents, but little is known about how the intensity of a tillage event and subsequent irrigation affect the microbial biomass, respiration, CO2 efflux, and...

Sub-surface irrigation (SUI) is a new water-saving irrigation technology. To explore the influence of SUI on soil conditions in a cherry orchard and its water-saving efficiency, experiments were conducted from 2009 to 2010 using both SUI and flood irrigation (FLI) and different SUI quotas in hilly semi-arid area of northern China. The results demonstrated the following: 1) The bulk density of t...

Soil salinization is a global problem that limits agricultural development and impacts human life. This study aimed to understand the dynamic changes in water and salinity in saline-alkali soil based on an indoor soil column simulation. We studied the changes in the water and salt contents of soils with different degrees of salinization under various irrigation conditions. The results showed th...

in order to investigate the effects of super absorbent polymer application on reduction of drought stress to corn, a split plot arrangement based on randomized complete block design with three replications was conducted at research field of agriculture faculty of ferdowsi university of mashhad during growing season of 2010-11. the main plot treatments were 1) application of 40 kg.ha-1 super abs...

Research to date has confirmed 2,4-D residues may dislodge from turfgrass; however, experiments have not been conducted on hybrid bermudagrass (Cynodon dactylon L. x C. transvaalensis), the most common athletic field turfgrass in subtropical climates. More specifically, previous research has not investigated the effect of post-application irrigation on dislodgeable 2,4-D residues from hybrid be...

With 110-d incubation experiment in laboratory, the responses of microbial quantity, soil enzymatic activity, and bacterial community structure to different amounts of diesel fuel amendments were studied to reveal whether certain biological and biochemical characteristics could serve as reliable indicators of petroleum hydrocarbon contamination in meadow-brown soil, and use these indicators to ...

Drip irrigation systems offer the potential for efficient irrigation of high value crops and have proven feasible from engineering and agronomic standpoints in the northern Great Plains. However, little information is available in this region regarding the optimum design and economics of these systems. The objective of this study was to develop a computerized model for design and economic optim...