Wheat is an important Egyptian grain crop. Nitrogen have a major influence on wheat the productivity. The goal of N management program should be supplying enough N to achieve maximum profit from the crop. But any N not used by the wheat crop is potentially subjected to leaching, which pollutes groundwater and decreases the efficiency of N fertilization. The availability of Nitrogen affect by the soil properties, especially soil salinity, soil content of total calcium carbonate and particles size distribution of soil (soil texture). Also, some other important factors as soil-pH, soil organic matter content and cation exchange capacity of soil...etc. The aim of study to nitrogen critical level limitation of wheat crop under loamy soil through each of different nitrogen levels and obtained the maximum yield of production. Field experiment was carried out in El-Gimmiza Agricultural Researches Station Farm during winter season of 2012-2013 in Loamy soil. The experimental design was randomized complete blocks. Grain and straw yield for wheat crop were determined, soil available nitrogen was determined after harvesting. The obtained result observed that wheat grain plus straw yield was low at N 1 -treatment (5586 kg fed -1 ) and the highest one was at N 3 -treatment (7294 kg fed -1 ). Nitrogen critical level for wheat grain yield was N 3 -treatment (60 kg N fed -1 ). So, the nitrogen critical level for what grain yield is N 3 -treatment (60 kg fed -1 ). From the field experiment, the nitrogen critical level limitation for wheat crop yield is 60 kg N fed -1 under Egyptian environmental conditions for El-Gimmaza area such as soil moisture regime, soil temperature, biotic activity and soil pH.

No abstract

Two field experiments were conducted on clay loam soil during the two successive seasons, summer season 2013 using maize plants and winter season 2013/2014 using wheat plants at El-Gemmeiza Agricultural Research Station, El-Gharbia Governorate to evaluate the effect and residual effects of compost rates placed in 20 and 40 cm depths, arranged in parallel orientation with respect to one another and spaced at 3 m apart or placed on the surface soil layer as well as the control on improving some soil chemical properties and availability of some nutrients either macro or micro, and the productivity of yield and yield components of maize and wheat plants. Furthermore, economical analysis was done by calculating the net income and investment ratios to determine the economical treatment. The experiments were conducted in a split plot in a randomized complete block design (RCBD) with three replicates. Results can be summarized as follows:(1)-All treatments slightly decreased the soil reaction (pH). Furthermore, all treatments caused progressive increases in soil salinity (EC) and total soluble salts (TSS) for the two soil depths (0-20 and 20-40cm) in the two growing seasons. Also, soluble cations and anions slightly increased with all treatments. While, SAR values were decreased compared with the control for the two soil depths in the two growing seasons.(2)-Generally the application depth and the addition rates of compost clearly enhanced the nutrient statues of the investigated soil.( 3)-Organic carbon (O.C, %) and C/N ratio were slightly increased in surface and subsurface soil layers as a result of the application depth and the addition rates of compost. (4)-All treatments led to markedly increases in the available macronutrients (N, P and K) and available micronutrients (Fe, Zn, Mn and Cu) of the soil at the two soil depths in the two growing seasons either with mole depth or compost rates.( 5)-The yield and yield components of maize and wheat positively responded to all treatments compared with the control. The highest values of yield and its components for maize and wheat plants were obtained by the addition of 10 ton compost fed -1 in 40 cm mole depth. The highest grain yield of maize plants increased to 68.46 %, also, the highest grain and straw yields of wheat plants increased to 70.27 and 91.67 %, over the control, respectively. ( 6)-According to the economical analysis, the application of 10 ton compost fed -1 in 40 cm mole depth was the best treatment compared with the other treatments, since it gave the highest net income (12346.38 L.E fed -1 .). While, the lowest values were always incorporated with control (10 cm surface depth without any applications of compost). ( 7)-Therefore, it is more useful to use those treatments (compost rates at different depths) to get a markedly improve in both chemical properties and nutrients which reflect on higher yield incorporated with high net income, as well as to substitute a part of chemical fertilizers by using compost to minimize the pollution resulted from the int...

The limited natural resource of water in Sinia is one of the major problems in agriculture sector. To study and evaluate the different water quality of some wells in North Sinia, a field investigation was performed by chosing 20 sites of soils which irrigated from besidly wells for a long time at El-Arish, Rafah and Sheikh Zuwayid. Water and surface soil samples were taken and analyzed. Simple linear regression relationships were conducted between some properties of wells water and soils. The important results could be summarized as follows:Irrigation water of wells at all locations have very and severe hazards of salinity and sodicity and they lie in categories between (C3 -S1) and (C4 -S4). Water content of soluble Fe, Mn, Cd and Pb are higher than the safty limits in all locations. Soluble NH4 + , NO3and NO2in water wells are less than the critical concentration of safe using.Soils which were sandy and loamy sandy were found non-saline in most locations as affected by irrigation water quality. Soil content of available Fe, Mn, B, Pb, Cd, NH4 + , NO3and NO2were low in all locations except NH4 + and NO3in soil around well No. 16.A high negative correlation was found between, soil-pH and both of available Fe and Mn in soil (-0.634** & -0.732**) and between CaCO3 and available soil boron (-0.489*). Also, a high significant postive correlation between water-pH and available soil boron was found (0.656*).Finally, wells water can be used for irrigation purposes in the area of study under control and with good a management(optimum tillage, adding organic matter and amendements and good croping system etc..).