Reducing synthetic nitrogen fertilization is an important issue nowadays due to its environmental hazards and raising the soil quality. So a field trial was executed aiming to assess the possibility of using clover residuals and green manure as a partial substitute for mineral nitrogen fertilizer for wheat plants grown on normal and saline soils. The green manure, as the main factor, was Egyptian clover (variety FAHL), split-plot design with three replicates was used were the main treatments were as follows; M1: without green manure (soil without cultivation between rice and wheat), M2: tillage of clover roots alone with soil and M3: tillage the whole plant with soil. While, the sub-main factor consisted of three rates of mineral N fertilizers i.e., 100, 75, and 50 % of nitrogen recommended dose (NRD) for wheat as mineral fertilizer. Regarding the effect of green manure, the M3 treatment was superior compared to others. Concerning N treatments, 100% of NRD as mineral fertilizer was superior compared to other rates. On the other hand, in both soils (normal & saline) the wheat plants which received 75 % of NRD as mineral fertilizer and simultaneously fertilized with Egyptian clover as green manure (M3) realized performance and productivity as similar as the corresponding wheat plants which received 100 % of NRD as mineral fertilizer without green manure (M1) or in other words, there weren't significant between them for the most of studied parameters. The studied green manure increased nutrient uptake and enhanced the synthesis of chlorophyll in the tissues of the wheat plants grown in either non- saline or saline soils and this may be the reason for increasing the ability of wheat to tolerate salinity. Generally, it can be concluded that mineral N fertilizer rates could be reduced after the incorporation of Egyptian clover as green manures having high nutrient contents and increased nitrogen use efficiency in saline soil which increases wheat yield.

There are environmental hazards of synthetic nitrogen fertilizers, however, there is a general tendency to raise the yield and quality of strategic crops in Egypt i.e., onion plant. Also, a little is known about the joint effects of different nitrogen sources as soil addition plus foliar spraying with bio-stimulants on onion plants. Thus, this research paper aims to assess the possibility of using compost as a partial substitute for synthetic nitrogen fertilizer with onion plants sprayed with some bio stimulants. During two successive seasons (2020/2021 and 2021/2022), a field trial was performed aiming to evaluate the effect of nitrogen recommended dose (NRD) via different nitrogen sources i.e., plant compost (2.0 %N), ammonium sulphate (21.0%N), urea (46.5%N) and ammonium nitrate (33.5%N) and some bio stimulates on onion plant and some soil properties. The nitrogen treatments [N1:40% of NRD as plant compost +20% of NRD as ammonium sulphate + 20% of NRD as urea+20% of NRD as ammonium nitrate, N2:100% of NRD as ammonium sulphate, N3:100% of NRD as urea and N4:100% of NRD as ammonium nitrate] represented the main plots, while foliar application of bio-stimulants represented the sub main plots, where the foliar application treatments were F1: without (control), F2: liquorice extract (7.50 gL-1); F3: garlic extract (350.0 ml L-1) and F4: yeast extract (7.5 gL-1).The findings indicate that onion plants grown under N1 treatment had growth, yield and quality traits better than the corresponding onion plants grown under other nitrogen treatments, where N2 treatment came in the second order and N3 treatment came in the third order, while N4 treatment came in the last order. Regarding foliar application, the plants sprayed with garlic extract (F3) had the highest values of studied traits followed by that sprayed with liquorice extract (F2) then that spayed with yeast extract (F4) and lately that grown without bio stimulants (F1). Generally, the best performance of onion plants was recorded under N fertilization of 40% of NRD as plant compost + 20 % of NRD as ammonium sulphate + 20 % of NRD as urea+ 20 % of NRD as ammonium nitrate and spraying, simultaneously, with garlic extract. Also, all studied soil properties like soil EC, pH, Om and available N differed due to all studied treatments. Thus, it can be confirmed the possibility of using plant compost as a partial substitute for mineral N fertilizer with onion plants sprayed with some bio stimulants.

Medicinal and aromatic plants are the forgotten wealth of Egypt, as the importance of expanding their cultivation comes after the increasing demand for them locally and globally, due to their economic importance and export revenue. So, a field experiment was implemented aiming at evaluating different plant residues compost as main plots [Sn-C: Snap bean compost (foliage), So-C: Soya bean compost (stover) and W-C: Wheat compost (straw), at a rate of 25.0 m 3 ha -1 for each source plus control treatment (without compost)] and various amino acids as sub-main plots [control (without), lysine (100 mg L -1 ), arginine (100 mg L -1 ) and proline (100 mg L -1 ) with the volume of 900 L ha -1 for each studied amino acid] on the performance of feverfew plant. The results show that the Sn-C treatment was superior for obtaining the best performance [ i.e., plant height, No. of branches, herb fresh and dry weights, flower fresh and dry weights, No. of flower plant -1 , essential oil, photosynthetic pigments (chlorophyll and carotene) and chemical constituents (N, P, K)] followed by So-C treatment then W-C treatment, whilst control treatment came in the last order. Regarding the amino acids treatments, the results illustrate that the sequence order of amino acids for obtaining the best performance from top to less was proline, arginine, lysine and control treatment, respectively. Generally, it can be concluded that treating the soil with plant residues compost and simultaneously spraying the plants with amino acids will achieve improvement in the performance of medicinal and aromatic plants.

Drought phenomena have been frequenting in Egyptian history. So, the drought in the agricultural sector is a particularly important area to be examined. Therefore, a field experiment was  carried out to  evaluate three irrigation intervals as main factor [irrigation every 7, 9 and 11 days], soil addition of some conditioners [ control ( without),  compost, zeolite and biochar ] as subplots and foliar application of  magnesium silicate (sprayed or not) as sub-subplots on the performance and productivity of soybean plants as well as soil fertility after harvest. The main results showed that the  soybean plants irrigated every 9 & 11 days had a low values of growth and  production criteria compared to the soybean plants irrigated every 7 days which had the highest values of  both growth criteria (e.g., plant height, fresh and dry weights and chlorophyll content) and yield components ( i.e., pod weight plant-1, seed weight plant-1, stover weight plant-1, 1000 seed weight, seed and stover yield). The  addition of all studied soil amendments improved all studied growth and production criteria compared to the corresponding soybean plants grown on  un amending soil, where the superior amendment was  compost followed by zeolite and lately biochar conditioner. On the other hand, foliar application of magnesium silicate improved all studied growth and production criteria compared to the corresponding soybean plants grown without foliar application. Also, all studied soil amendments differed among them in their positive effect on soil fertility as well as their vital role in saving irrigation water.