Silicon (Si) is an element, not essential, but is beneficial for some plants. The Freundlich model was used to describe Si adsorption on soil samples incubated with different Si and phosphorus (P) concentrations. Soil incubated samples were: T1 soil had no Si or P (control); T2, T3 and T4 soils contained 50, 100, and 200 mg Si L-1, respectively. T5 and T6  soils contained 50 mg Si L-1 in combined with either 7 or 10 mg P L-1 along with T7 and T8 soil  contained 100 mg Si L-1 in combined with either  7  or 10 mg P L-1. In final, T9 and T10 soil contained 200 mg Si L-1 in combined with either 7 or 10 mg P L-1. A series of adsorption experiments were performed using sodium metasilicate pentahydrate (Na2O3Si.5H2O) solution prepared to have concentrations representing 0, 14, 28, 42 and 56 mg Si L-1. The supernatant of Si concentration was determined. The amount of element adsorbed was calculated as the difference between applied element concentrations and that remaining in solution after equilibration. Adsorption isotherms were determined at room temperature (25 oC±1).   Results revealed that a positive trend was generally found; increases in amount of adsorption onto soil with increasing Si concentration and equilibrium concentration in concerned solution either applied separately or applied + initial available Si concentration in soil. The Freundlich equation provides a good fit to the sorption data for all incubated soil samples and R2 values were ranged from  0.82 to 0.97. Present study indicated that adsorption capacity value (Kf) decreased from T1 to T3 soil samples then increased at T4 sample, and intensity adsorption values (1/n) gave almost an opposite trend to that of capacity adsorption (Kf) values.   Moreover, adsorption of Si onto soil incubated with different Si concentrations in combined with P2 decreased as compared to P1. Opposite trend was obtained with equilibrium Si concentration in concerned solution. Also, present study showed that the higher values of Kf obtained in P1 soils (T5, T7 and T9), compared to Kf values of P2 soils (T6, T8 and T10), and intensity adsorption values (1/n) gave almost an opposite trend to that of capacity adsorption (Kf) in both P1 and P2 soils. Finally, large Si sorption capacity and low Si affinity for the surface sites were observed in soil incubated with high Si concentration compared to soil incubated with low ones.

This research study was carried out in the open field during the two successive seasons of 2012/2013 and 2013/2014. The aim of this investigation was to study the response of pot marigold (Calendula officinalis L.) to different application methods and concentrations of seaweed extracts applied as a commercial compound. Seven treatments were initiated, i.e. three concentrations of seaweed extracts (500, 1000, 1500) were used either as foliar spray or as soil drench in addition to the control treatment (tap water). Results indicated that foliar spray with 1500 ppm of seaweed extract increased significantly plant height, number of flowers per plant and vase life in the two tested seasons. However, foliar spray with the lowest concentration of seaweed extract (500 ppm) resulted in significant increments in flower stalk length, flower diameter and carbohydrates content. Moreover, the same concentration showed significant increases in total carotenoids, nitrogen, and phosphorus percentage when used as soil drench in the two tested seasons.

Six weeks feeding trial using 210 one-day old unsexed Cobb 500 chicks was carried out to study the effects of addingphytase enzyme on growth performance, blood parametersand bone characteristics in broiler chicks. Three starter diets were used from 1 to 21 days; T100 {100% of Ca & non-phytate phosphorus NPP requirements (1.00% Ca and 0.50% NPP)}; T75{75% of Ca & NPP requirements (0.75% Ca and 0.38% NPP)} and T50 {50% of Ca & NPP requirements (0.51% Ca and 0.25% NPP)}. Three grower diets were used from 22 to 42 days; T100 {100% of Ca & NPP requirements (0.91% Ca and 0.46% NPP)}; T75{75% of Ca & NPP requirements( 0.68% Ca and 0.34% NPP)} and T50{50% of Ca & NPP requirements (0.45% Ca and 0.23% NPP)}. Seven dietary treatments were distributed according to diets fed consecutively during starter and grower phases as; (100/100) fed starter T100 then grower T100; (100/75) fed starter T100 then grower T75; (100/50) fed starter T100 then grower T50; (75/75) fed starter T75 then grower T75; (75/50) fed starter T75 then grower T50 and (50/50) fed starter T50 then grower T50.All diets added phytase enzyme (FTU 10000/Ton). Each treatment comprised of 30 chicks in 3 replicates of 10 chicks each. Results showed that live body weight and weight gain did not significantly affected by restricted Ca and NPP diets at starter period, where weight gain was significantly affected at grower period. Birds group received diet containing 100/75 with phytase (T3) gave the highest significant values for LBW and BWG, then 50/50 with phytase (T7) as compared with the other experimental groups during the grower and overall periods.Feed consumption and conversion ratio values were no significant differences among groups fed different dietary treatments during starter and grower phases. Plasma P concentrations was significantly affected however plasma Ca concentrations, GOT and GPT valueswere not significantly affected by the reduction of dietary Ca and NPPwith adding phytase. Percentages of tibia ash, Ca and P were significantly affected by dietary treatments. Supplementation of phytasehas a significant effect ontibia breaking strength, while supplementation of phytase hasn’t any effect on tibia Seedorindex.It is obvious that, the best performance was seen with (100/75) diet without any adverse effect on productive performance, blood parameters and most of tibia measurements and chemical composition.

Two field experiments were conducted in 2004 and 2005 seasons at El-Bosaily farm located at Beharia Governorate, Egypt, to study the effect of three nitrogen levels 60, 120 and 180 kg/feddan applied into irrigation water "fertigation" with drip irrigation system on vegetative growth, nutrient content (N, P and K) in leaves and grain and yield of three maize (Zea mays L.) hybrids (Single Cross 10, Three Way Cross 310 and Three Way Cross 324). The experiment design was a split plot with three replications where nitrogen fertilizer levels were distributed in the main plots and maize hybrids allocated in sub plots. The obtained results indicate that the increase of nitrogen level up to 180 kg /fed significantly increased plant height, number of leaves per plant, leaf area index, grain yield and straw weight. Single Cross 10 gave the significant highest vegetative growth and grain yield comparing with the other hybrids. The high-est nitrogen level (180 kg /fed) combined with Single Cross 10 gave the significantly highest grain yield and straw weight. On the other hand, 60 kg N / fed gave the highest nitrogen use effi-ciency (NUE) value followed by 120 kg N / fed The regression analysis of nutrition content (N, P, and K %) between leaf and grain was estimated. The highest regression determination coefficient (r2) was found in nitrogen percentage with r2= 0.965 followed by potassium with r2= 0.936. The lowest r2 was found in phosphorus with r2= 0.872.