Oussama Mounzer

Influence of irrigation with saline reclaimed water on young grapefruits

ABSTRACT The use of non conventional water resources, as strategy to an efficient water management, is receiving greater attention. We have designed an experiment, during four year under field conditions in a commercial grapefruit orchard located in Campotejar (Murcia, Spain). The main objective was to evaluate the effects of irrigation with saline reclaimed water compared with traditional irrigation water (Tajo-Segura water transfer) on growth, leaf mineral content, plant and soil water status, yield, and fruit quality. Na, B and Cl concentrations exceeded the recommended level in reclaimed water, for this reason, soil salts accumulation and infiltration problems were observed during last season in this treatment. Leaf B concentration was over the phytotoxic limit in reclaimed water plants, although no visual toxicity symptoms were observed. No differences were observed concerning to leaf Cl and Na concentration. The canopy volume, the number of fruits per trees, and the total yield were reduced by the e...

Growth, heavy metal status and yield of salt-stressed wheat ( Triticum aestivum L.) plants as affected by the integrated application of bio-, organic and inorganic nitrogen-fertilizers

Efforts have been made to use the integrated application of bio-, organic and inorganic nitrogen (N)-fertilizers to decrease waste accumulation, and to minimize nutrient losses and yield contamination with heavy metals for human nutrition and health. Therefore, a field experiment was conducted to assess the effect of integrated applications of organic manures, bio-fertilizer and/or mineral-N fertilizers on growth, yield, some chemical constituents and shoot and yielded grain heavy metal contents of wheat ( Triticum aestivum L. cv. Sakha 93) plants grown under salinity stress (ECe = 7.84 dS m -1 ). Results showed that, the treatment comprised of ⅓NH 4 NO 3 (55 kg N ha -1 ) + Cerealine (bio-fertilizer; 4 Kg ha -1 ) + cattle manure (10 t ha -1 ) was found to be most effective, producing the best status of growth characteristics, osmoprotectants concentrations, essential nutrient contents, shoot heavy metal concentrations, and grain yield and its content of heavy metals compared to the all other treatments. The treatment comprised of Cerealine (4 Kg ha -1 ) + cattle manure (20 t ha -1 ) was occupied the second order. We can recommend to use the integrated treatment of ⅓NH 4 NO 3 (55 kg N ha -1 ) + Cerealine (bio-fertilizer; 4 Kg ha -1 ) + cattle manure (10 t ha -1 ) effectively in saline soils to improve wheat growth and yield with minimum contents of heavy metals for human health and nutrition.

CropSyst model for wheat irrigation water management with fresh and poor quality water

Abstract CropSyst model can be used as irrigation water management tool to increase wheat productivity with poor quality water. The objective of this study was to calibrate CropSyst model for wheat irrigated with fresh and agricultural drainage water. To do so, three field experiments were conducted during three successive seasons in Nubaria Agricultural Research Station, Egypt representing the newly reclaimed calcareous soils. In the first season the treatments were 100% crop evapotranspiration (ETc) of fresh water (FW) and 100% ETc of agricultural drainage water (DW), while in the second and the third seasons, the treatments were 100% ETc of FW, 100% ETc of DW, 120% ETc of DW and 130% ETc of DW. From these results one can concluded that deducting 5% of the applied water to all treatments reduced yield by 3, 5 and 7% in the first, second and third growing season, respectively as a result of heat stress existed in the 2nd and 3rd seasons during reproductive phase. Furthermore, deducting 5% of the applied water from all treatments in the vegetative phase only resulted in lower yield losses. Thus, using CropSyst model could guide us to when we could reduce the applied irrigation water to wheat to avoid high yield losses.

CropSyst model for wheat under deficit irrigation using sprinkler and drip irrigation in sandy soil

Abstract CropSyst (Cropping Systems Simulation) is used as an analytic tool for studying irrigation water management to increase wheat productivity. Therefore, two field experiments were conducted to 1) calibrate CropSyst model for wheat grown under sprinkler and drip irrigation systems, 2) to use the simulation results to analyse the relationship between applied irrigation amount and the resulted yield and 3) to simulate the effect of saving irrigation water on wheat yield. Drip irrigation system in three treatments (100%, 75% and 50% of crop evapotranspiration – ETc) and under sprinkler irrigation system in five treatments (100%, 80%, 60%, 40%, and 20% of ETc) were imposed on these experiments. Results using CropSyst calibration revealed-that results of using CropSyst calibration revealed that the model was able to predict wheat grain and biological yield, with high degree of accuracy. Using 100% ETc under drip system resulted in very low water stress index (WSI = 0.008), whereas using 100% ETc sprinkler system resulted in WSI = 0.1, which proved that application of 100% ETc enough to ensure high yield. The rest of deficit irrigation treatments resulted in high yield losses. Simulation of application of 90% ETc not only reduced yield losses to either irrigation system, but also increased land and water productivity. Thus, it can be recommended to apply irrigation water to wheat equal to 90% ETc to save on the applied water and increase water productivity.

Response Of Wheat (Triticum aestivum L.) Crop And Broad-Leaved Weeds To Different Water Requirements And Weed Management In Sandy Soils

Abstract Water scarcity is a major cause of crops yield reduction in many parts of the world. So, a more rational use of irrigation water should be adapted and deficit irrigation principles should be accepted with a certain level of reduction in yield level. To study the efficiency of four water requirements (100% whole season, 75% whole season, 50% whole season and 100% whole season while 50% at grain-filling stage) and five weed-control treatments (three postemergence herbicides i.e., metosulam, tribenuron-methyl, and bromoxynil), hand weeding and unweeded check, and their interactive effects, two field experiments on wheat crop were conducted in two successive seasons at the agricultural experimental station of the National Research Centre, Nubaria, Egypt. Bromoxynil, tribenuron-methyl came in the first order for controlling total broad-leaved weeds. Application of 100% water requirement recorded the highest values compared to all other irrigation water treatments in term of flag-leaf area, chlorophyll content, plant height, number of spike/m2, spike weight, grains number/spike, weight of 1,000 grains, yield and yield attributes of wheat. Metosulam followed by bromoxynil, tribenuron-methyl and hand-weeding treatments gave higher values of grain yield/ha. The highest grain yield, protein and carbohydrates percentages of wheat grains were obtained from addition of 100% water requirement with metosulam treatment was used followed by 75% of water requirement combined with metosulam treatment without significant difference among these treatments.