A field experiment was carried out at Ismailia Agric. Res. Station, ARC during the successive winter growing seasons of 2015 and 2016. Wheat crop (Triticum aestivum L,) was cultivated under sprinkler irrigation system to study the effect of soil amendments (bentonite and potassium humate) on soil chemical properties of sandy soil, under different nitrogen doses (100, 75 and 50% N), along with wheat productivity and nutrients uptake. Results revealed no significant effect of mean pH values of different treatments compared to control. Conversely of results indicated increases of OM and CEC under effect of either bentonite or potassium humate; no significant effect was obtained among rates of nitrogen. Results, generally, showed positive responses of available N, P and K compared to control treatments. Finally, results revealed significant positive responses of total yield (straw and grains) along with total content of nutrient elements. From the present study, soil conditioner (combination of bentonite and potassium humate) was favorable for soil parameters of chemical soil properties of sandy soil which reflects on increase soil fertility. Use of 75 or 50 % N rates instead, of 100% N, being suggested whose difference was not significant

A field experiment was carried out in two successive seasons at El-Ismailia Agric. Res. Station, ARC, in El -Ismailia Governorate, Egypt, to study the efficiency use of two different sources of P fertilizer i.e. superphosphate (SP) versus rock phosphate (RP),both of them were used with three levels (0, 22 and 30 Kg P2O5 fed -

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The use of synthetic soil conditioners such as polyvinyl alcohol (PVA), bitumen (Bit.) and polyacrylamide (PAC) can be considered as a specific management to improve the efficiency of the use of nitrogen fertilizers and some chemical properties of calcareous soils that are reflected in crop productivity. Two rates of synthetic soil conditioners (PAV, Bit. and PAC) and three rates of nitrogen fertilizer (50, 75 and 100% N of recommended dose) were included in this study to evaluate their effects on some chemical properties, nutritional status and yield components of both maize and wheat crops along with nitrogen use efficiency. Field experiments were conducted in calcareous soil at Nubaria Agriculture Research Station farm during two successive seasons, summer season cultivated with maize (Zea mays L., cv Giza 10) and winter season cultivated with wheat ( Triticum aestivum L., cv Giza 168). Results showed that the highest significant yield components of maize and wheat crops along with their total content of the indicated macronutrients were observed when applied high rate of polyvinyl alcohol (0.2 %) accompanied with high rate of nitrogen fertilizer (100% N of recommended dose) as compared to other tested treatments. On the contrary, application of high rate polyacrylamide combined with low rate of nitrogen fertilizer generally was inferior for yield components of both maize and wheat plants. Also, data revealed that the nitrogen use efficiency was the highest (65.0 and 42.4) for maize and wheat plant, respectively, receiving 50 % nitrogen fertilizer rate in presence of 0.2 % polyvinyl alcohol. However, applied high rate of polyvinyl alcohol accompanied with low rate of nitrogen fertilizer was superior decreased pH values of soil as compared to either control or other tested treatments. An opposite trend for EC values which were superior increased in presences of all nitrogen fertilizer rates. Also, CaCO 3 values were lower when applied high rate of polyacrylamide in two seasons. The highest values of available nitrate and ammonium in soil were due to applied 0.2 % of polyvinyl alcohol combined with 75 % of nitrogen fertilizer rate compared to the other tested treatments.

Two aerobic trapezoidal heaps of compost were practiced to investigate the value of bio-enrichment of chopped plants residues (cotton stalks and rice straw) through inoculation the mixture of these residues and some organic and mineral amendments with lignocellulytic fungi during the active composting in relation to their capacity to accelerate lignocellulose degradation. Also, some plant growth promoting rhizobactria were applied to the composted materials at maturity stage to study their ability to improve the biological and nutritional quality of the produced compost. Results of monitoring the composting process exerted that the physicochemicals and microbiological properties of the composted materials were developed with progressing of the process until 90 days. However, bio-enriched heap exhibited more acceleration than unenriched one with regard to reduce the organic carbon and C/N ratio. In addition, the maturity indices exerted acceptable values for generation index, CO2evolution, dehydrogenase activity and ratio of NH + 4/NO-3 as an indicator to nitrification process.