Search Results

You are looking at 41 - 50 of 418 items for :

  • "water management" x
Clear All
Full access

Gary A. Clark and Allen G. Smajstrla

Proper design and installation are essential to provide a drip irrigation system that can be managed with minimal inputs and maximum profit. Because drip irrigation can apply precise amounts of water and chemicals, constraints associated with the plants, soil, water supply, and management must be considered in the design, installation, and management processes.

Free access

R.C. Beeson Jr.

This research was partially supported by a grant from the Southwest Florida Water Management District. This work supported by the Florida Agricultural Experiment Station, and approved for publication as journal series R-10969.

Free access

Nicholaus D. VanWoert, D. Bradley Rowe, Jeffrey A. Andresen, Clayton L. Rugh and Lan Xiao

Green roofs are an increasingly common, environmentally responsible building practice in the United States and abroad. They represent a new and growing market for the horticulture field, but require vegetation tolerant of harsh environmental conditions. Historically, Sedum species have been the most commonly used plants because, with proper species selection, they are tolerant of extreme temperatures, high winds, low fertility, and a limited water supply. A greenhouse study was conducted to determine how water availability influences growth and survival of a mixture of Sedum spp. on a green roof drainage system. Results indicate that substrate volumetric moisture content can be reduced to 0 m3·m–3 within 1 day after watering depending on substrate depth and composition. Deeper substrates provided additional growth with sufficient water, but also required additional irrigation because of the higher evapotranspiration rates resulting from the greater biomass. Over the 88 day study, water was required at least once every 14 days to support growth in green roof substrates with a 2-cm media depth. However, substrates with a 6-cm media depth could do so with a watering only once every 28 days. Although vegetation was still viable after 88 days of drought, water should be applied at least once every 28 days for typical green roof substrates and more frequently for shallower substrates to sustain growth. The ability of Sedum to withstand extended drought conditions makes it ideal for shallow green roof systems.

Free access

George Hochmuth

Responses to a 1993 survey showed that drip irrigation was used on 36,400 ha of commercial vegetables in the southeastern and mid-Atlantic United States. Florida led with 44% of total drip-irrigated vegetable area, followed by Georgia, North Carolina, and Pennsylvania, with about 10% each. Drip irrigation was used most commonly on tomato, pepper, and watermelon crops. The most-important benefits of drip irrigation were improved water and fertilizer delivery efficiencies compared to other irrigation systems, such as overhead sprinklers and subirrigation. Challenges with drip irrigation included high installation cost, emitter clogging problems, need for filtration, overirrigation problems, disposal of tubing, and lack of readily available expertise. Most drip irrigation was used with polyethylene mulch and most tubing was thin-wall disposable rather than thick-wall reusable. Eighty-one percent of the drip-irrigated vegetable acreage was fertigated with N and K. Survey responses indicated that drip irrigation use for vegetables is increasing.

Full access

S.M. Scheiber, E.F. Gilman, D.R. Sandrock, M. Paz, C. Wiese and Meghan M. Brennan

Concern among water management officials, researchers, and the public regarding landscape water consumption has escalated as demands on potable water supplies increase in Florida and other populated regions ( Archer, 2002 ; Beeson and Gilman, 1992

Free access

Nicholas A. Pershey, Bert M. Cregg, Jeffrey A. Andresen and R. Thomas Fernandez

The objectives of this study were to quantify irrigation volume, runoff volume and nutrient content, and plant growth of container-grown conifers when irrigated based on plant daily water use (DWU) vs. a standard irrigation rate. Four conifer taxa were grown in 10.2-L (no. 3) containers subjected to four irrigation treatments from 23 June to 16 Oct. 2009 and 6 June to 31 Oct. 2010. The taxa were: 1) Chamaecyparis obtusa Sieb. & Zucc. ‘Filicoides’, 2) Chamaecyparis pisifera (Sieb. & Zucc.) Endl. ‘Sungold’, 3) Thuja occidentalis L. ‘Holmstrup’, and 4) Thuja plicata D. Donn ‘Zebrina’. The four irrigation treatments were: 1) control application of 19 mm·d−1, 2) irrigation applied to replace 100% DWU (100 DWU) per day, 3) applications alternating 100% with 75% DWU in a 2-day cycle (100–75 DWU), and 4) a 3-day application cycle replacing 100% DWU the first day and 75% DWU on the second and third days (100–75–75 DWU). Irrigation treatments did not affect plant growth index {GI= [(H + WNS + WEW)/3]} in 2009. In 2010, GI of C. obtusa ‘Filicoides’ was greater for 100 DWU than the control plants. Seasonal total water applied for 100, 100–75, and 100–75–75 DWU was 22%, 32%, and 56% less, respectively, than the control amount of 117 L per container in 2009 (114 days) and 24%, 18%, and 24% less than the control amount of 165 L per container in 2010 (147 days). Scheduling irrigation based on DWU reduced runoff volumes and (nitrate-nitrogen) NO3 -N and (phosphate-phosphorous) PO4 3−-P load compared with the control. Irrigating based on DWU reduced water application and runoff volumes and NO3 -N and PO4 3−-P load while producing plants of equal or greater size than control plants.

Free access

Juan Carlos Díaz-Pérez and James E. Hook

Bell pepper (Capsicum annuum L.) plants have a high demand for water and nutrients. Water stress on bell pepper is associated with reduced yields and incidence of blossom-end rot (BER). High irrigation rates are commonly applied to maximize yields. Excessive irrigation rates, however, may negatively affect bell pepper plants. The objective of this study was to evaluate the effects of irrigation rates and calcium fertilization on plant growth and fruit yield and quality. Trials were conducted in the spring of 2001, 2003, and 2005 at the University of Georgia, Tifton Campus. Drip-irrigated bell pepper (‘Camelot’ or ‘Stiletto’) plants were grown on black plastic mulch. Plants were irrigated with rates that ranged from 33% to 167% of the rate of crop evapotranspiration (ETc). Results showed that irrigation at 70% ETc (2001), 67% ETc (2003), and 50% ETc (2003) were sufficient to maximize vegetative growth and fruit yield and provided yields similar to those at 100% ETc. Leaf net photosynthesis and stomatal conductance (g S) were reduced, and incidence of BER was increased with reduced irrigation rates (33% and 67% ETc). Incidences of soilborne diseases (Pythium spp. and Phytophtora capsici) tended to increase in plants receiving excessive irrigation rates (167% ETc). Irrigation rate also affected fruit quality; incidence of BER and fruit soluble solids were both increased at 33% ETc. Calcium fertilization had no effect on soil water content (SWC), plant growth, and incidence of soilborne diseases, and an inconsistent effect on fruit yield and incidence of BER. In conclusion, there is potential for use of irrigation at rates below 100% ETc. Reduced irrigation diminished the volumes of water applied and provided fruit yields similar to those at 100% ETc. Excessive irrigation rates (167% ETc or above) wasted water and resulted in both higher incidences of soilborne diseases and reduced bell pepper yields.

Free access

Matthew W. Kent and David Wm. Reed

Greenhouse cultural methods must minimize runoff to keep pace with environmental regulation aimed at protecting water resources. Two experiments were designed to investigate the effect of N fertilization rate on New Guinea impatiens (Impatiens ×hawkeri) and peace lily (Spathiphyllum Schott) in an ebb-and-flow subirrigation system. Maximum growth response for impatiens was centered around 8 mm N levels as measured by root and shoot fresh and dry weight, height, leaf number, leaf area, and chlorophyll concentration. For peace lily, growth peaked at about 10 mm N. Growing medium was divided into three equal layers: top, middle, and bottom. Root distribution favored the middle and bottom layers, and the relative distribution of roots was consistent as N level increased. EC remained low in middle and bottom layers at N concentrations below 10 mm, but increased significantly for all layers at levels above 10 mm. The EC for the top layer was 2 to 5 times higher than in the middle or bottom layers at all N levels. Increased nitrate concentration paralleled increased EC, while pH decreased as N concentration increased for impatiens and peace lily.

Free access

Michael P. O'Neill and James P. Dobrowolski

services create a “perfect storm” for agricultural water management. Now, more than ever, agricultural water managers and producers are being called on to reduce consumptive water use and expand production. However, it is not clear that the necessary

Full access

Carolyn DeMoranville

consideration of environmental protection and the potential of water management practices to move nutrients off the farm. The purpose of this article is to review recent information regarding nutrient requirements of cranberry and recommendations for the use of