Nitrogen and Water Rates for Subsurface Trickle-irrigated Collard, Mustard, and Spinach

Abstract

<jats:p>Three field experiments using subsurface trickle irrigation with various rates of target soil water tension (SWT) and N rates were conducted in southern Arizona during 1990–93. The experiments were conducted with collard (<jats:italic>Brassica oleracea</jats:italic> L. Acephela Group cv. Vates), mustard [<jats:italic>Brassica juncea</jats:italic> (L.) Czerniak cv. Southern Giant], and spinach (<jats:italic>Spinacea oleracea</jats:italic> L. cv. Indian Summer). The interactive effects of water and N treatments on crop yield, N uptake, and unutilized fertilizer N were studied. In general, excessive irrigation (SWT &lt;5.6 kPa) resulted in lower yield and N uptake and higher unutilized fertilizer N. Optimum SWTs were 9 kPa for collard, 8 kPa for spinach, and 6 to 10 kPa for mustard.</jats:p>

Yield and Quality of Two Sugar Beet Varieties as Influenced by Nitrogen Fertigation Regimes Under Drip – Irrigation System

“…Similar trends were observed on root length, root diameter and root yield. Similar results were recorded by Feigin et al (1982), Thompson and Doerge, (1995), Zebarth et al (1995), Thompson et al (2000), Ghali et al (2004) and Ouda,soheir (2006).…”

“…Regarding the effect of N fertilizers application and water supply methods (fertigation), Feigin et al (1982) and Thompson and Doerge (1995) reported that three qualities are necessary for efficient fertilization through irrigation, they are: (1) irrigation water must contain the needed nutrients in forms available to plants or in forms readily converted to available, forms; (2) water must be uniformly distributed and (3) application of water must be done so that plants are not burned and irrigation lines, emitters or orifices are not plugged. Cortez et al (2000) stated that this method (fertigation) produces good results, including higher overall agricultural yield.…”

Soil Water Tension, a Powerful Measurement for Productivity and Stewardship

“…Cole crops grown under arid conditions in Arizona with little rainfall respond to low SWT criteria. Irrigation criteria as wet as 6 to 12 kPa are recommended for production on sandy loam in fall-winter in Arizona (Thompson and Doerge, 1995;Thompson et al, 2000aThompson et al, , 2000bThompson et al, , 2002aThompson et al, , 2002b. Broccoli grown in the spring at Agassiz, British Columbia, Canada, showed little difference in yields when grown at 20 or 30 kPa all season compared with 50 kPa during plant development followed by 20 kPa during head formation (Maurer, 1976).…”

Effect of Irrigation Intervals, Nitrogen Sources and Nitrogen Levels on Some Characters of Parsley (Petroselinum crispum Mill )

“…Generally, they found that spinach yield and its components were higher at either 100% or 75% Etc rates of irrigation. On the other hand, Thompson and Doerge (1995) found that excessive irrigation resulted in lower yield of spinach. Also, Sanchez (2000) and Karam et al (2002) stated that water deficit reduced leaves number, leaf area and dry matter content characters in spinach plants.…”