With rising concern about current irrigation and fertilizer NPk management, the present study was conducted to evaluate the effect of sources and methods of fertilizer application on nutrient distribution, uptake, recovery and fruit yield of tomato grown in a sandy soil. equal amounts of NPk were applied in solid form or through fertigation at levels of 0%, 50%, 75% and 100% with the remainder 100%, 50% and 25% applied as solid fertilizers to the soil. available NO 3 − -N and K were confined to the root zone of tomato in 75% and 100% NPk fertigation levels, while they moved beyond the root zone when they applied in two equal splits as solid fertilizers with drip (0% fertigation) and furrow irrigation. the mobility of P was greater in the root zone following its application through fertigation compared to a solid application as super phosphate. Drip irrigation showed significantly higher absolute growth rate (aGr), total dry weight (tDW) and leaf area index (lai) of tomato over furrow irrigation. Moreover, tomato plants were able to utilize applied nutrients more efficiently in fertigation system than with conventional solid fertilizer application. highest aGr, tDW and lai were recorded when nutrients were applied to 100% by drip fertigation. the fruit yield of tomato was higher with drip irrigation (58.62 t ha −1 ) than with furrow irrigation, (47.37 t ha −1 ). Maximum fruit yield was recorded with 100% NPk fertigation (74.87 t ha −1 ) and was associated with a higher number of fruits per plant and a bigger fruit size than the solid applied fertilizers under both drip and furrow irrigation. On average, tomato accumulated more NPk across the fertigation levels than with drip and furrow irrigation. similarly, the more controlled application of nutrients in fertigation treatments improved NPk recovery and fertilizer use efficiency (FUE) and resulted in lesser leaching of NO 3 − -N and k to deeper soil layers.Keywords Drip irrigation · Growth rate · NPk distribution · Nutrient uptake · sandy soil Nährstoffaufnahme und Ertrag von Tomaten bei unterschiedlichen Düngungsanwendungsmethoden und Bewässerungsdüngungsstufen in TrockengebietenZusammenfassung Die bedeutung des bewässerungsma-nagements und der NPk-Düngüng steigt stetig an. in einer studie wurde die Wirkung der Düngerformen und der anwendungsmethoden auf Nährstoff- Verteilung, -aufnahme, und -Verwertung untersucht. Weiterhin wurde der ertrag von tomaten, die auf sandigem boden angebaut wurden, untersucht.es wurden gleiche Mengen an NPk-Düngemittel ausgebracht (Fertigation* in Stufen von 0%, 50%, 75% und 100% und der rest von 100%, 50%, 25% und 0% als feste Form). Verfügbares NO 3 − -N und k wurde in der Wurzelzone von Tomaten bei einer Fertigationsstufe von 75% und 100% NPk gefunden, während bei einer anwendung mit festem Düngemittel (0% Fertigation) und Furchenbewäs-Gesunde Pflanzen (1 3 12 M. a. badr et al. serung sich NO 3 − -N und k über die Wurzelzone hinaus bewegten.Die Mobilität von P war größer bei einer ausbringung durch bewässerungsdüngung als bei einer...

Efficient water delivery systems such as drip irrigation can contribute towards increasing crop yield potential, improving crop water and fertilizer use efficiency. However, critical management considerations such as subsurface drip irrigation are necessary to attain improved irrigation efficiencies and production benefits particularly under arid regions. The objective of this study was to determine the effect of two irrigation methods, surface and subsurface drip irrigation combined with four irrigation levels, 100, 80, 60 and 40% of crop evapotranspiration on yield and yield components of potato grown on sandy soil. The field experiments were conducted in the years 2008 and 2009. In terms of soil water availability to plants, subsurface drip provided more favorable growth conditions for plant growth and maintained higher soil water content at the root zone, which resulted in a significant higher potato yield compared to surface drip irrigation. The difference between the two irrigation methods on yield components was concentrated on the mean tuber weight per plant, while no significant difference was found on the tuber number per plant. Reducing the amounts of applied water significantly decreased total potato yield and its components. Under subsurface drip irrigation, reducing amounts of applied water to 80% ETc gave comparable yield and yield components to surface drip at full irrigation supply, indicating that 20% irrigation water can be saved without affecting the potato yield. At all irrigation levels, subsurface drip recorded higher water use efficiency (WUE) over surface drip. Maximum value was observed at 40% ETc. Fertilizer use efficiency (FUE) was also higher under subsurface drip and reduced significantly under both irrigation methods with increasing water deficit. These results suggested that subsurface drip offers the potential of better water management with respect to saving and distribution of water in the root zone and to obtain maximum yield accompanied by highest water and FUE.Keywords Subsurface drip irrigation · Dry stress · Potato · Water use efficiency · Fertilizer use efficiency Die Effizienz der Unterflur-Tropfbewässerung im Kartoffelanbau unter verschiedenen TrockenstressbedingungenZusammenfassung Effiziente Bewässerungssysteme, wie Tröpfchenbewässerung können zur Steigerung des Ertragspotenzials, sowie zur Verbesserung der Wasser-und Dün-gernutzungseffizienz beitragen. Allerdings sind kritische Erwägungen des Unterflur-Tröpfchenbewässerungs-Managements notwendig, um eine verbesserte Effizienz der Bewässerung und Produktionsvorteile, vor allem in ariden Regionen, zu erreichen. Ziel dieser Studie war es, die Wirkung von zwei Bewässerungsmethoden, eine oberflächliche und eine unterirdische Tropfbewässerung, kombiniert mit vier Bewässerungsstufen 100, 80, 60 und 40 % der Evapotranspiration, auf Ertrag und Ertragskomponenten der Kartoffel auf sandigen Böden zu untersuchen.

No abstract

No abstract

No abstract

The effect of different nitrogen (N) levels on growth and productivity of Cape gooseberry, cultivated in new reclaimed lands (sandy soil) at Nubaria region in Egypt, was investigated. Nitrogen levels were applied at rates of 50, 100, 150 and 200 kg N ha -1 as ammonium sulfate. The amount of N for each treatment was divided into five applications (after transplanting, seven days later, at the beginning of flowering, during fruit set and after the first harvest). Several growth parameters and yield were recorded in addition to nitrogen content in leaves. The results revealed that Cape gooseberry plants responded positively to nitrogen levels in sandy soils. Yield, number of fruits, and diameter of fruits increased significantly by increasing the nitrogen level up to 200 kg N ha -1 . Moreover, plant height, number of leaves, N-content in leaves and N-uptake shows a positive reaction to increased nitrogen supply. The quantitative effects of nitrogen on Cape gooseberry plants and the possible explanations of plant responses are discussed.

Crop production in arid regions requires continuous irrigation to fulfill water demand throughout the growing season. Agronomic measures, such as roots-soil microorganisms, including arbuscular mycorrhizal (AM) fungi, have emerged in recent years to overcome soil constraints and improve water use efficiency (WUE). Eggplant plants were exposed to varying water stress under inoculated (AM+) and non-inoculated (AM−) to evaluate yield performance along with plant physiological status. Plants grown under full irrigation resulted in the highest fruit yield, and there were significant reductions in total yield and yield components when applying less water. The decline in fruit yield was due to the reduction in the number of fruits rather than the weight of the fruit per plant. AM+ plants showed more favorable growth conditions, which translated into better crop yield, total dry biomass, and number of fruits under all irrigation treatments. The fruit yield did not differ between full irrigation and 80% evapotranspiration (ET) restoration with AM+, but a 20% reduction in irrigation water was achieved. Water use efficiency (WUE) was negatively affected by deficit irrigation, particularly at 40% ET, when the water deficit severely depressed fruit yield. Yield response factor (Ky) showed a lower tolerance with a value higher than 1, with a persistent drop in WUE suggesting a lower tolerance to water deficits. The (Ky) factor was relatively lower with AM+ than with AM− for the total fruit yield and dry biomass (Kss), indicating that AM may enhance the drought tolerance of the crop. Plants with AM+ had a higher uptake of N and P in shoots and fruits, higher stomatal conductance (gs), and higher photosynthetic rates (Pn), regardless of drought severity. Soil with AM+ had higher extractable N, P, and organic carbon (OC), indicating an improvement of the fertility status in coping with a limited water supply.

This study was conducted on a sandy loamy soil at Giza, Egypt, in December 2002 and 2003 to investigate the interactive effect of Zn and different nitrogen sources, i.e., mineral nitrogen (ammonium sulfate) and organic nitrogen (poultry manure) on the growth and productivity of onion (Allium cepa) cv. Giza 20. Four levels of Zn application (0, 1, 2 and 3 ppm) in a sulfate form were foliar sprayed at 30 and 60 days after planting. Within each Zn application, three treatments of nitrogen dose were applied in different combination forms (mineral and organic sources). Nitrogen treatments were 100% mineral N; 75% mineral + 25% organic and 50% mineral + 50% organic. Organic-N source was poultry manure. All poultry manure treatments were applied during soil preparation. Data showed that all growth parameters of onion plants increased as the fraction of poultry manure increased. Zn had also a positive effect on all plant parameters except of plant length, and leaf dry weight. The interactive effect of Zn and poultry manure increased yield and quality of onion bulbs. The most effective treatments on bulb fresh weight, total yield and quality were the spraying with 1 or 2 ppm zinc and the application of N as 75% mineral and 25% organic, in both seasons.