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M.T.: Response of wheat (Triticum aestivum L.) crop and broad-leaved weeds to different water requirements and weed management in sandy soil.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/m 2 , 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.

This research aimed at investigating the impact of irrigation systems, a deficit irrigation strategy and organic mulching using rice straw on maize water productivity in Egypt's arid conditions. The field experiment included 16 treatments over 2 seasons, 2015 and 2016. Irrigation systems were a drip irrigation system (DIS) and a furrow irrigation system (FIS), while the irrigation strategies were 100% full irrigation (FI), 75% FI, 50% FI and partial root drying (PRD). Organic mulching using rice straw (OMRS) was also investigated. The experimental results indicated that there was a positive impact of applying a PRD strategy by drip irrigation in the presence of organic mulching on the yield (12.6 t ha -1 for 2015 and 12 t ha -1 for 2016) and on the water productivity of maize (4.81 kg m -3 for 2015 and 4.58 kg m -3 for 2016), but under the control treatment (FIS with 100% full irrigation and without organic mulching) yield was 7.22 t ha -1 for 2015 and 7.34 t ha -1 for 2016 and water productivity of maize was 0.64 kg m -3 for 2015 and 0.62 kg m -3 for 2016. The SALTMED model simulated reasonably well the soil moisture and salinity distribution as well as maize dry matter, yield and water productivity for all treatments, with R 2 of 0.998, 0.997 and 0.996, respectively. The results support the use of a PRD strategy by a drip irrigation system accompanied by an organic mulch of rice straw instead of the commonly used furrow irrigation. The PRD would save more fresh water, achieve higher yields and water productivity. In addition, mulching would reduce evaporation losses, retain soil moisture and increase organic matter content. RÉSUMÉCette recherche visait à étudier l'impact des systèmes d'irrigation, la stratégie d'irrigation déficitaire et le paillage organique en utilisant la paille de riz sur la productivité de l'eau du maïs dans les conditions arides de l'Egypte. L'expérience de terrain comprenait seize traitements pendant deux saisons, 2015 et 2016. Les systèmes d'irrigation étaient un système d'irrigation goutte à goutte (DIS) et un système d'irrigation par rigoles (FIS), alors que les stratégies d'irrigation étaient irrigation complète à 100% (FI), 50% de FI et séchage partiel des racines (PRD). Le paillage organique utilisant de la paille de riz (OMRS) a également été étudié. Les résultats expérimentaux ont montré qu'il y avait un impact positif de l'application de la stratégie PRD par goutte à goutte en présence de paillage organique sur le rendement (12.6 t ha -1 pour 2015 et 12 t ha -1 pour 2016) et la productivité de l'eau du maïs (4.81 kg m -3 pour 2015 et 4.58 kg m -3 pour 2016) mais sous contrôle (FIS avec 100% d'irrigation totale et sans paillage organique) étaient (7.22 t ha -1 pour 2015 et 7.34 t ha -1 pour 2016) et la productivité de l'eau du maïs (0.64 kg m -3 pour 2015 et 0.62 kg m -3 pour 2016). Le modèle SALTMED a raisonnablement simulé la distribution de l'humidité et de la salinité du sol ainsi que la matière sèche du maïs, le rendement et la productivité de l'eau pour tous les traitements...

This study investigated the suitability and benefits of using drainage water of fish farms (DWFF), instead of canal fresh water (IW), for wheat irrigation. Two water qualities, DWFF and IW, and four levels of N‐fertigation rates [100% N (192 kg N ha−1 season−1), 80% N, 60% N and 40% N] were tested. The results showed a positive impact when increasing N‐fertigation rate on the yield using both DWFF and IW. However, the yield under DWFF was higher than the yield under the IW treatment by between 11 and 51% in 2014 and between 8 and 38% in 2015. This is due to the additional amount of dissolved biological nitrogen and other nutrients inherent in DWFF. The SALTMED model simulated reasonably well the soil moisture and nitrogen content of all soil layers as well as wheat dry matter, yield and water productivity for all treatments, with R2 of 0.99, 0.97 and 0.96, respectively. It was concluded that the use of drainage water of fish farms instead of fresh water for irrigation of wheat could help to achieve higher yields while using less irrigation water and less chemical fertilizers. Additional benefits are less drainage to the drainage network and higher income for farmers. Copyright © 2017 John Wiley & Sons, Ltd.