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The use of nitrogenous fertilizers in agriculture can cause uncontrolled gas emissions, such as N2O and CO2, leading to global warming and serious climate change. In this study, we evaluated the greenhouse gases emissions (GHGs) that are concomitant with applied different rates of N fertilization, such as 60%, 70%, 80%, 90%, 100%, 110%, and 120% of the recommended dose in green beans grown under three irrigation systems (surface, subsurface, and drip irrigation). The obtained results showed that GHGs were positively correlated with increasing the rate of N fertilization. Meanwhile, the subsurface irrigation system followed by drip irrigation achieved the highest significant (p ≤ 0.05) values regarding the growth and pod yield attributes. Furthermore, N supplements at 90% and/or 100% of the recommended dose under the subsurface irrigation system led to the highest concentration of chlorophyll, vitamin C, total protein, and activities of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and peroxidase (POX). Proline and pod fibers were decreased in parallel with increasing the N rate, while water use efficiency (WUE) was improved with increasing the rate of N supplements up to 100% or 110% of the recommended dose.

Applying nitrogen fertilizers in agriculture can cause uncontrolled gas emissions, such as N2O and CO2, leading to global warming and serious climate changes. In this study, we evaluated the greenhouse gas emissions (GHGs) that are concomitant with applying different rates of N fertilization, i.e., 50, 75, 100, and 125% of the recommended dose (727 kg N ha−1) for two cultivars (Balady and Sids-40) of Allium sativum L. grown under three planting dates (15 September, 1 October, and 15 October). For this purpose, two field experiments were carried out during the two growing seasons of 2020/2021 and 2021/2022. Treatments were arranged in a split–split plot design with three replicates: planting dates were set up in the main plots, nitrogen levels were conducted in the submain plots, and garlic varieties were in the sub-subplots. The obtained results can be summarized as follows: Planting on 15 September significantly increased vegetative growth parameters (i.e., plant height, leaves area, number of leaves plant−1, and leaves dry weight) and total bulb yield, in both seasons. The application of the highest rate of N (125%) gave significantly higher records for vegetative growth parameters, while the 75% nitrogen treatment appeared to give the highest total bulb yield in both seasons. The means of plant growth characteristics and total bulb yield were significantly increased by the cultivation of the Balady cultivar. In addition, the results show that GHGs were positively correlated with increasing the rate of N fertilization. It could be recommended that planting on 15 September and fertilizing with 75% N fertilizer from the recommended dose for Balady cultivar achieve maximum yield and its components.

Temperature rise is one of the most challenging climate change impacts that increase the intensity of heat stress. In this investigated the production of celery (Apium graveolens var. rapaceum F1 hybrid)) was tested during the late season. The experiment was carried out during the two successive summer seasons of 2019 and 2020 in Giza Governorate, Egypt. The experimental design is a split-plot, the main plots consist of three low tunnel cover treatments, and three spray treatments with three replicates in sub-main plots. Results showed that the use of white net cover gave the highest vegetative growth and yield followed by the black net. Values of plant yield were 951, 765, and 660 g/plant for white, black and without cover, respectively, in the first season. The foliar application of 3 mM of potassium silicate produced the highest vegetative growth and yield compared to the control treatment. Referring to the effect of spray foliar application of potassium silicate on yield 1.5 mM (S1), 3 mM (S2), and control were 892, 795, and 689 g/plant in the first season, respectively. The best combination that delivered the highest vegetative growth and yield was a cover low tunnel with a white net combined with S2 foliar application.

Field experiment was conducted, during two successive seasons of 2014- 2015 and 2015- 2016, at Dokki protected agricultural site, Giza Governorate, Egypt, to study the profitability of different applied irrigation levels and polyethylene (PE) mulch on plant growth and yield of sweet pepper, (Capsicum annum L.) cv. Godion F1, under plastic house condition. Three irrigation levels (0.50, 0.75 and 1.00) of crop evapotranspiration (ETc), using drip irrigation system and three PE mulch treatments (transparent, black and control) were applied. Data revealed that black PE recorded the highest values of early and total fruit yield per plant during the two seasons. Increasing water level up to 1.00 (ETc) enhanced yield with different PE mulch treatments, while water use efficiency (WUE) decreased with increasing water level. However, Using 0.50 (ETc), with different PE mulches increased WUE compared to using 0.75 (ETc) or 1.00 (ETc). The economic assessment of costs and returns from different treatments were calculated. It was found that the average yield was higher in 1.00 ETc with black mulch. Gross margin per 540 m2 were analysed using yield data, price structures and production costs. The 1.00 (ETc) with black mulch had the highest gross margin which is USD 416.8 and USD 533 (1 USD= 9 Egyptian pound) for the first and second seasons, respectively. The benefit cost ratios (BCRs) per 540 m2 were analysed, and 1.00 (ETc) with black mulch had the highest BCR with 1.36 in the first season and 1.45 in the second season. JEL Classification: Q 01, Q 12, Q 19