Soil-transmitted helminths are mainly a group of parasitic nematodes causing human infection through contact with parasite eggs or larvae; they survive in the warm and moist soil of the tropical and subtropical countries. This study was carried out in Sharkyia governorate from October, 2011 to October, 2013, to correlate between the prevalence and distribution of these parasites in the soil and the physicochemical factors affecting the examined samples of the soil. One hundred and twenty samples of different types of soil (clay, silt, sand) from different localities were collected and examined. Diagnosis of geohelminths was confirmed by the recovery of their eggs and larvae with other protozoa by different parasitological methods. The modified baermann method was found to be more efficient in detection of geohelminths larvae than charcoal culture method. Among the examined sites geohelminths were much more numerous in the soil of rural areas especially in the spring and summer seasons, while the contamination of canal banks by geohelminths was the worst (80 %). An insignificant correlation was reported between the soil texture and the number of positive samples in the examined areas while the relationship was directly proportional among (moisture, PH, organic). It appeared that the most common geohelminthic stage was Toxocara spp. eggs besides other types of protozoa especially Balantidium coli cysts. This suggests that factors other than soil texture are important in the prevalence of geohelminths in the soil e.g. temperature, moisture, PH and organic matter. So, to change some of these factors in a trial to control geoparasites transmission but with keeping the environment should be tried. These results also open the way to further studies to highlight the mutual affection between inhabitants of these sites and the prevalence of these geoparasites.

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G ROWING maize in calcareous soils requires adequate supply of phosphorus inputs, yet excessive P-applications may affect negatively micronutrients availability in soil, including Zn. Thus, the current study evaluates the ability of humic acid (HA) to counteract the negative effects of applied P on Zn-uptake by maize plants. To achieve this aim, a field experiment was conducted in a calcareous soil (CaCO 3 =268.91 g kg-1) following a split plot design to study the interactions between different P-inputs (100, 125 and 150% of the recommended dose, applied in main plots) and available-Zn in presence and absence of HA (applied in sub-plots at either 2 or 4 kg HA ha-1). Results revealed that increasing the level of P-application raised significantly P availability and consequently its uptake by maize plants; thus, enhanced significantly plant growth parameters and grain yield. In this concern, 125% of the recommended P-dose recorded the highest partial factor productivity values. Likewise, application of HA raised significantly available-P content and improved considerably plant growth and grain yield, especially with increasing the rate of its application. On the other hand, increasing the level of P-fertilizers decreased significantly Zn-availability and uptake by plants; however, in presence of HA, this effect was counteracted. Although, this amendment recorded no significant effect on soil-Zn availability; however, it raised significantly its content in shoots but not in grains. In conclusion, HA improved significantly the productivity of maize grown on a calcareous soil. This amendment not only improved the partial factor productivity of P-fertilizer, but also increased Zn-uptake by maize plants.

Two factorial field experiments on wheat (Var. Msr 2) have been carried out during two successive seasons of (2015 / 2016 and 2016/2017), at Sakha Agric. Res. Station. The factors comprised organic fertilizer rates (0, 10 and 20 m 3 fed-1) and phosphorus fertilizer rates (0, 30 and 45 kg P 2 O 5 fed-1) in four replicates. The soils of the experimental locations is a clay loam in texture and have mean values of EC e = 6.1dS.m-1 , ESP = 8.4 % and pH = 8.15; which indicated moderate effects with salinity and sodicity.The important results could be summarized as follows:(1) organic manuring (as compost) with rates of 10(OM 10) or 20(OM 20) m 3 fed-1 led to higher values of wheat grain and straw yields ,as well as grains-protein content relative to the nonemanured treatment.(2) Phosphorusfertilizationwithrates of 30 and / or 45 kg P 2 O 5 fed-1 have been resulted in better grain and straw yields beside higher values of wheat grains-protein content as compared to the controltreatment (P 0).(3) The interaction treatment of (20 m 3 compost x 45 kg P 2 O 5 fed-1) was the best onewhich recorded the maximum values for the previous studied parameterswith increments of[(79.8 %) S1 , (78.6 %) S2 ] N ; [(69.2 %) S1 ,(100 %) S2 ] P and [(79.9 %) S1 , (78.6 %) S2 ] prot over control treatments (OM 0.0 × P 0.0) and for the two seasons, respectively.(4) The co-fertilization of organic manure along with Pfertilization enhanced many biochemical reactions which have beenincreased the availability of phosphate ions and subsequent increment in P-relative efficiencies of P-fertilizer, which have been led to higher wheat yields.

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