Glyphosate (GLY) and glufosinate-ammonium (GLUA) are broad-spectrum, non-selective, contact herbicides that are commonly used in fruit farms Achieving the separation and detection of glyphosate and glufosinate from soil samples by chromatography is a challenging task as they are ionic and highly water-soluble compounds. The aim of this study is conducted to determine the dissipation of GLY and GLUA applied at two dose levels in three-depth soils of orange orchards. The residues of GLY and GLUA were determined by the HPLC-UV detector. The residual detection limits of GLY and GLUA of the method were 0.03 and 0.05 ng/g in soil respectively. The obtained data indicated that GLY persistent in the soil is very short, only for 7 days, following applications of 1 to 2 kg/fed in the orange crop. GLUA dissipated in soil within 14 days of application, regardless of dose. The half-life (T/2) of GLY and GLUA were 1.68 and 1.42 days at 0 cm depth, respectively. There was no significant difference between the half-life of the two herbicides in soil at three depths. These results showed that GLY dissipation occurs rapidly in soil. However, GLUA was moderately persistent in soil. The two compounds tested showed a reduction of dry weight for four types of weeds after 14 days of recommended and double-rate application.

The pesticide residues in drinking water, irrigation water, sediment and soil sam-ples collected from three villages, i.e. Samadon, Ashmon and El-Ramla, located at Menofia Governorate, Egypt were monitored during the period of Septemper 2002 to February 2003. The obtained results showed that the detected pesticide residues were varied in their types and structures in the investigated villages during period of study. It is clear that residues of organochlorine insecticide and the herbicide, atra-zine, were the most frequently detected in both of drinking and irrigation water sam-ples. According to the detected amounts and numbers of pesticide residues in all the collected samples, the soil samples contained higher pesticide residues (average of 0.07 ppm)  sediment (average of 0.05 ppm)  irrigation water (average of 0.04 ppm)  drinking water (0.01-0.02 ppm). Comparing between the selected sites, Sa-madon was the highest site contained pesticide residues more than Ashmon and El-Ramla.

Persistence Vs degradation behavior of insecticide imidacloprid (35% SC) and fungicide myclobutanil (24% EC) in/on grape (leaves and fruits) and surrounding soil under canopy were investigated under field conditions. Leaves, fruits and soil samples were collected at 2 hours to 21 days after application at the recommended rate. QuEChERS method was used for extraction and clean-up and analyzed using HPLC and GC for imidacloprid and myclobutanil, respectively .The initial residue deposits, degradation percentages and/or, the parameters (RL50 and RL90) and Pre Harvest Intervals (PHIs) of the targeted pesticides were the criteria of concern. Results revealed that, grape leaves retained higher initial amounts than fruits by about 5.0 7 and 1.34 times for imidacloprid and myclobutanil, respectively. As for RL50, RL90 and PHIs values, imidacloprid showed 4.12 ,13.42 and 21.95 days and 5.13 ,13.41 and 11.96 days on grape leaves and fruit, respectively. The corresponding calculated values were 4.71, 9.38 and 16.31days and 1.97, 9.14 and 14.90 days for myclobutanil on the same targeted samples, respectively. In addition, the grape fruits could be consumed safely after 12 and 15 days of treatment with imidacloprid and myclobutanil, respectively. On the other hand , results indicated that the residue half life (RL50) values for the same targeted pesticides in soil  were 11.56 and 15.74 days, respectively. In general, myclobutanil residues in soil recorded higher persistence levels than higher imidacloprid and on the contrary it showed less persistence in/on grape leaves and fruits.

Three irrigation water resources were chosen at Kafr-Saqr district, El-Sharkia Governorate to assess their qualities and their impact on soil properties. The chosen irrigation water were fresh, mixed, and drainage water applied during the two successive seasons of winter-summer of (2013 and 2014). Soil samples were collected from each location at four depths (0-20, 20-40, 40-60 and 60-100 cm). Results showed EC values of mixed and drainage water were above the normal range (which should be < 0.7 dS.m-1)). Also, the mixed and drainage irrigation waters had approximately 3.5 and 5.6 folds the salinity of the fresh water. Mean pH values of the collected irrigation water samples were within the permissible limits (6.5 to 8.4). TDS values of the fresh water were within the normal range (< 450 mg.L-1). Meanwhile, mixed and drainage water were classified as of slightly and moderately salinity hazards. The highest values of turbidity were found in the drainage water, then mixed and fresh water. SAR values of fresh water were < 1.0.  The SAR values for mixed and drainage waters ranged from 2.62 to 2.69 and from 3.68 to 3.76, respectively. BOD and COD values violated the standard limits of law 48/1982 (10 mg.L-1 for drainage water and 6 mg.L-1 for fresh water) except for the BOD values of fresh water. The increase in pH values for the soil irrigated with the mixed and drainage. The continuous irrigation of soil by wastewater resulted in continuous increase in EC values. As well as, increase the amount of total soluble salts in all layers. The application of the different irrigation waters led to increase in soluble ion.