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Soil water budgets are essential in determining the proper timing and amount of irrigation. Organic fertilizers can be substituted for commercial fertilizers; however, information is sparse on the interaction of irrigation management and nutrient source on cucumber (Cucumis sativus L.) production. Th is study evaluated nutrient source and irrigation management on growth and yield of cucumber grown in the arid area of Egypt. A fi eld experiment was conducted using cucumber grown in northern Egypt at Shibin El-Kom in 2006 and 2007 to evaluate water use and fertilizer rate and type. Th ree irrigation defi cits and seven fertilization types were arranged in a randomized split-plot design with irrigation rates as main plots and fertilizer treatments within irrigation rates. Irrigation treatments were a ratio of crop evapotranspiration (ET) as: 1.0 ET, 0.84 ET, and 0.64 ET. Fertilizer treatments were applied at the recommended rate of N either as a commercial fertilizer or with organic manure. Chlorophyll a and b, leaf area index, and yield were greatest with the lowest ratios of male to female fl owers when adequate water and high N were used (1.0 ET with chicken manure at 7 Mg/ha). Seasonal water use was 498 and 471 mm for 1.0 ET in 2006 and 2007 plantings over the 125 d growing season, respectively. Th e yield reduction coeffi cient averaged 0.77. An optimal scheduling was statistically developed based on crop response in defi cit irrigation to achieve maximum yield for diff erent uniformity coeffi cient variation values. Cucumber performance was signifi cantly aff ected by both irrigation and nutrient defi ciencies.

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Precision irrigation requires a method of quantifying the crop water status or root zone depletion of water to determine when and how much water to apply to the soil. Changes in canopy resistance (rc) and canopy temperatures have the potential of being used as a crop water status indicator for irrigation management. A study was conducted on potato (Solanum tuberosum L.) grown in northern Egypt at Shibin El‐Kom on an alluvial loamy soil for winter (20 Sept. 2001 through 20 Jan. 2002) and spring (1 Feb. 2002 through 20 May 2002) seasons to determine if rc derived from energy balance and plant parameters could be used to determine the onset of water stress and the amount of water required to refill the soil profile. Diurnal rc was determined for well‐watered conditions and achieved minimum values of 20 and 10 s m−1 at noontime during winter and spring periods, respectively. A power relationship of −0.86 for well‐watered conditions was developed between rc and net radiation (Rn) at various plant growth stages. In deficit soil water conditions, rc increased linearly with decreasing available soil water (ASW), with a change in potato rc of 0.75 and 0.39 s m−1 per percentage ASW for 1 and 2 MJ m−2 h−1 of Rn at midgrowth, respectively. A ratio of actual/potential canopy resistance (rc/rcp) was derived to normalize the meteorological differences between growing seasons. This ratio was 2.5 when 50% of ASW was removed and can be used as a parameter to determine the need for irrigations using weather factors and canopy temperature. Canopy resistance increased linearly with increasing soil solution salinity, electrical conductivity, when the soil solution was above the threshold soil salinity value. A ratio of rc/rcp was found to normalize the effects of different environments across saline and water deficit conditions.

Water infiltration and storage under surface irrigation are evaluated, based on the initial soil water content and inflow rate as well as on the irrigation parameters and efficiencies. For that purpose, a field experiment was conducted using fruitful grape grown in alluvial clay soil at Shebin El-Kom in 2008 grape season. To evaluate the water storage and distribution under partially wetted furrow irrigation in comparison to the traditional border irrigation as a control method, two irrigation treatments were applied. They are known as wet (WT) and dry (DT) treatments, at which water was applied when the available soil water (ASW) reached 65% and 50%, respectively. The coefficient of variation (CV) was 6.2 and 10.2% for WT and DT respectively under the furrow irrigation system as compared to 8.5% in border. Water was deeply percolated as 11.9 and 18.9% for wet and dry furrow treatments respectively, as compared with 11.1% for control with no deficit. The application efficiency achieved was 86.2% for wet furrow irrigation achieving a high grape yield (30.7 t/ha). The relation between the infiltration (cumulative depth, Z and rate, I) and opportunity time (t₀) in minutes for WT and DT treatments was: Z_WT = 0.528 t₀^0.6, Z_DT = 1.2 t₀^0.501, I_WT = 19 t₀^–0.4, I_DT = 36 t₀^–0.498. Also, empirical power form equations were obtained for the measured advance and recession times along the furrow length during the irrigation stages of advance, storage, depletion, and recession.

Squash yield and quality under furrow and trickle irrigation methods and their responses to different irrigation quantities were evaluated in 2010 spring and fall seasons. A field experiment was conducted using squash (Cucurbita pepo L.) grown in northern Egypt at Shibin El Kom, Menofia. A Randomized Split-Plot Design was projected with irrigation methods as main plots and different irrigation quantities randomly distributed within either furrow or trickle irrigation methods. Irrigation quantity was a ratio of crop evapotranspiration (ET c) as: 0.5, 0.75, 1.0, 1.25, and 1.5 ET c. Each treatment was repeated three times, two planting rows from five rows were left for squash seed production. In well-watered conditions (1.0ET c), seasonal water usable by squash was 304 and 344 mm over 93 days in spring and 238 and 272 mm over 101 days in fall under trickle and furrow irrigation methods, respectively. Squash fruit yield and quality were significantly affected by season and both irrigation method and quantity, except fruit number wasn't by irrigation method and its length wasn't affected by season. Interaction between season and irrigation quantity significantly affected leaf area index, TSS, and fruit weight. Moreover, seed yield and quality were significantly changed by season and both irrigation method and quantity, except harvest index wasn't affected by irrigation method. Only a significant interaction between season and irrigation method was for seed yield and 100 seeds weight. Interaction between season and irrigation quantity insignificantly affected seed yield and quality except harvest index. Both fruit and seed yields were significantly affected in a linear relationship (r 2 ≥0.91) by either deficit or surplus irrigation quantities under both irrigation methods. Adequate irrigation quantity under trickle irrigation, relative to that of furrow, enhanced squash yield and improved its quality in both growing seasons.

Potato growth, yield, and quality under improved irrigation methods and non-uniformity of their irrigation applications are important to enhance water management in arid regions. A field experiment was conducted in 2014 spring and fall growing seasons using potato (Solanum tuberosum) grown in northern Egypt at Shibin El Kom, Menofia, Egypt to evaluate potato response to furrow or trickle irrigation. A Randomized Split-Plot Design with irrigation method randomly distributed and non-uniformity of irrigation applications evaluated along either irrigation furrow or trickle lateral as dependent variables measured at the 3 rd , 13 th , 23 rd , 33 rd , 43 rd and 53 rd m along the 55 m irrigation line. Traditional (TF) and partial (PF) furrows as well as trickle point (TP) and line (TL) sources were used as irrigation methods. Each treatment was repeated three times. For a 33 rd m treatment, seasonal optimum water use by potato was 328, 234, 269 and 292 mm over 118 days in spring and 200, 164, 178 and 186 mm over 122 days in fall under TF, PF, TP and TL irrigation methods, respectively. Potato tuber yield and quality were significantly affected by growing season (S), irrigation method (I) and non-uniformity of irrigation application (U). Tuber yield, total soluble solid (TSS) and leaf area index (LAI) were significantly affected by I and U, and their interaction I * U; harvest index (HI) was not affected by I but U. Except for TSS by S * I and HI by U * I and S * I, results showed no significant differences. Moreover, tuber weight, number and marketable yield were significantly affected by S, I, U and I * U interaction, except medium tuber size and culls by S. A given 33 rd treatment under partial furrow and trickle irrigation, relative to that of traditional furrow, enhanced tuber yield and improved quality in both growing seasons. In non-uniform irrigation application over two growing seasons, potato crop response was developed under varied irrigation methods. Tuber yields were significantly affected in a linear relationship (r 2 ≥ 0.75) by either water deficit or excessive water under irrigation methods.

Wetted soil shape under trickle irrigation is an important parameter in irrigation scheduling and design in agricultural farms. Irrigation water should not be beyond crop root zone to avoid deep percolation. Moreover, irrigation water applied should adequate crop water use in irrigation interval. The purpose of this work is to figure out the suitable shape of wetted soil based on soil type, flow rate, and crop water use. A field experiment was conducted in sand, silt and clay soils under trickle source with varying flow rates as 2, 4, 8, 16, and 24 liter/h. Squash, corn, and grape crops were selected to represent different root zones for irrigation scheduling. Field results showed that horizontal and vertical water movements were related to both emitter flow rate and soil intake rates. Suitable flow rate and irrigation interval were found for selected soil and crop types. Soil moisture content was contoured directly after irrigation and soil-water redistribution. Optimal flow rates were 2 and 4 liter/h in clay soil, 8 and 16 liter/h in loam, 16 and 24 liter/h in sand. Adjusted method was recommended to calculate irrigation interval by revising wetted root zone volume, taking into account different soil, crops, crop stages, and seasons.