الفهرس 
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Abstract
This investigation was carried out in Soil Sci. Dept, Faculty of Agric., Al-Azher Univ, Assuit Egypt. To study the effect of some organic materials on some soil physical and chemical properties, as well as growth parameters (dry weight, nutrient content and uptake) of maize and wheat plants cultivated as test crops. To achieve the above purposes, laboratory and pot experiments were conducted during the two successive seasons 2003/2004 and 2004/2005.
The soil sample used for the study was collected from the surface layer (0–30 cm) depth, of the Agricultural Experiment Station Farm (located in Assiut Valley), Faculty of Agriculture, Assiut University which representing the newly reclaimed calcareous soil. The obtained results are summarized in the followings:
5.1- Laboratory Experiments:
5.1.1- Columns experiment:
This experiment was carried out to elucidate the effect of three kinds of organic materials on improving soil physical and Hydro-physical properties (soil bulk density, hydraulic conductivity and advanced wetting front) after different incubation periods i.e. 30, 60, and 90 days at rates 0, 3, 6 and 9 ton/fed. of both types of compost with 0, 3 and 6 Kg/fed. of K-Humate.
The results obtained could be summarized as follows:
5.1.1.1-Bulk density:
The results indicated that the organic materials led to decreasing the soil bulk density. The lower value of soil bulk density was observed with the untreated compost (UC) at the application rate 9 ton/fed. with 6 Kg/fed. of K-Humate (KH) at the end of incubation period (90 days) compared to the control. Organic materials decreased soil bulk density from 1.67(control) to 1.52 g/cm3.
5.1.1.2-Hydraulic conductivity:
Treating soil with organic materials significantly decreased hydraulic conductivity values through their effect on improving macro-pores and aggregation, while decreased it in the soil by binding soil particles and thus decreasing its macro-pores. The highest decrease of hydraulic conductivity was obtained by using the highest rate of TC( 9 ton/fed.) plus 6 Kg KH/fed. after 30, 60 and 90 days. Organic materials decreased H.C from 0.33 (control) to 0.14 m/day at 90 days.
5.1.1.3-Advanced wetting front:
The results indicated that, the advanced wetting front through the soil columns significantly decreased by increasing the application rates of organic materials. The highest decrease of advancing of wetting front values were observed with 9 ton/fed. of treated compost (TC) + 6 Kg/fed. of K-Humate (KH).
The first drop of water in this treatment reached the bottom or at the end of soil column depth (35 cm) at the total time of 570 min. However it reached the bottom of soil column in untreated soil (control) at 330 min.
5.1.2- Incubation experiment:
This experiment was carried out to study the effect of different incubation periods (0, 30, 60 and 90 days) of three kinds of organic materials on the results obtained could be summarized as follows:
5.1.2.1-Electrical Conductivity (E.C):
The initial value of electrical conductivity (E.C) for soil was (1.01 dSm-1), the all treatments of organic materials, showed gradual increases during periods of incubation. The soil E.C increased by increasing the rates of organic materials especially with applied of 9 ton TC/fed plus 6 Kg/fed. K-Humate after 60 days from organic materials application. The values of E.C were increased up to 1.88 dSm-1.
5.1.2.2-Soil reaction (pH):
The results indicated that the treating soil with organic materials at the first time of incubation significantly decreased soil pH by increasing the rates of composts kinds and K-Humate during incubation periods. With applied of 9 ton TC/fed. and 6 Kg/fed. K-Humate, after 60 days of incubation the values of pH were decreased from 8.60 to 7.41pH unit.
5.1.2.3- Soil organic matter (O.M):
The results indicated that the all treatments of organic materials significantly increased O.M content with increasing the rate of compost kinds and K-Humate. The values of O.M% increased from 0.01% in untreated soil (control) to the maximum value of 0.86% for the soil treated with a rate 9 ton UC/fed. and 6 Kg/fed. K-Humate after 90 days of incubation.
5.1.2.4-Macro-nutrients availability:
1-Available Nitrogen
The results indicated that the soil available nitrogen, significantly increased with increasing the application rates of organic materials. The maximum values of available soil-N during the incubation periods were obtained after 30 and 90 days of incubation. This was clear in all organic materials treatments and the higher N availability was found in the case of treated compost (TC) than (UC). The highest amount of available soil-N was observed with a rate 9 ton/fed. of compost (TC) and 3 Kg/fed. of K-Humate in the period of 30 and 90 days. The values of available soil-N increased from 8.87 ppm at the control to 74.42 ppm. Organic materials significantly increased soil available nitrogen than the control, proceeding in the order: Control < TC < UC < KH, with significant differences between the treatments.
2- Available phosphorus
The results of the soil available phosphorus were significantly increased by increasing the rates of organic materials applied and the maximum values of available soil-P during the incubation periods were occurred after 30 and 90 days of incubation. The values of the available soil-P were higher in the case of treated compost (TC) and (UC) than (KH). The rate of 9 ton/fed. of compost (TC) and 3 Kg/fed. of K-Humate in the period of 30 and 90 days gave the highest amount of the available P. These values increased from 5.23 ppm at the control to 15.07 ppm. Organic materials significantly increased soil available phosphorus than control, proceeding in the order: Control < TC < UC < KH, with significant differences between the treatments.
3- Available potassium.
The results indicated that the soil available potassium, significantly increased with increasing the application of organic materials rates. The maximum values of available soil-K during the incubation periods were occurred after 30 and 60 days of incubation. The values of the available soil-K reported in the case of treated compost (TC) and (UC) were higher than (KH). The highest amount of the available soil-K was observed with a rate of 9 ton TC/fed. plus 3 Kg KH/fed. in the period of 30 and 60 days. These values increased from 157.72 ppm at the control to 425.97 ppm. Organic materials significantly increased the soil available potassium than control, proceeding in the order:
Control < TC < UC < KH
With significant differences between the treatments.
5.1.2.5- Micronutrients availability
1- Available Fe
The results indicated that the application of organic materials increased available–Fe in studied soil and the maximum values of available–Fe during the incubation periods was occurred after 30 and 90 days of incubation. The amount of available–Fe obtained with 9 ton TC/fed. plus 3 Kg KH/fed. after 30 days was higher than 90 days of incubation. Application KH or both UC and TC at different levels, significantly increased soil available–Fe than the control, proceeding in the order: TC+ KH > UC+KH > TC > UC > KH > Control
2- Available Mn
The results indicated that the application of organic materials increased available–Mn in studied soil. The maximum values of available–Mn during the incubation periods were occurred after zero time and 90 days of incubation. The amount of available–Mn obtained with 9 ton TC/fed. plus 3 Kg KH/fed. after 0 days was higher than 90 days of incubation. Application KH or both UC and TC at different levels, significantly increased soil available–Mn than the control, proceeding in the order:- TC+ KH > UC+KH > TC > UC > KH > Control
3- Available Zn
The results indicated that the application of organic materials increased available–Zn in studied soil. The maximum values of available–Zn during the incubation periods were occurred after zero time and 60 days of incubation. The amount of available–Zn obtained with 9 ton UC/fed. plus 3 Kg KH/fed. after 0 days was higher than 60 days of incubation. Application KH or both UC and TC at different levels, significantly increased soil available–Zn than the control, proceeding in the order:- UC+KH > TC+ KH > KH > UC > TC > Control
4- Available Cu
The application of organic materials increased available–Cu in studied soil and the maximum values of available–Cu during the incubation periods were occurred after 30 and 90 days of incubation. The amount of available–Zn obtained with 9 ton UC/fed. plus 3 Kg KH/fed. after 30 days was higher than 90 days of incubation. Application KH or both UC and TC at different levels, significantly increased soil available–Cu than the control, proceeding in the order:-
UC+KH > TC+ KH > UC > TC > KH >Control
5.2- Greenhouse Experiments:
Two greenhouse experiments were conducted to study the effect of organic material on crop yield, content and uptake of the same nutrients studied in incubation experiment (N, P, K, Fe, Mn, Zn and Cu). Maize crop was used as a test crop with different rates of organic materials; wheat crop was planted after maize in order to evaluate the residual effect of previous treatments under the greenhouse condition.
5.2.1-Effect experiment:
The obtained results could be summarized as follows:
5.2.1.1- Dry weight yield:
Results of greenhouse experiment revealed that the organic materials significantly increased the dry weight yield of maize plants grown in the treated soil over control.
Generally the dry weight yield of maize was greatly affected by the organic materials. The highest amount of dry weight yield of maize obtained by the application of TC combined with K-Humate ( 9 ton/fed. plus 3 Kg/fed.). The organic materials increased the dry weight yield in the order: TC+ KH > UC+KH > TC > UC > KH > Control
5.2.1.2- Macronutrients content and uptake:
The results indicated that the application of organic materials, significantly increased NPK content (ppm) and uptake (mg/pot) by the maize plants. Also, nitrogen content and uptake by maize plants was greatly affected by the different organic materials increased in order of: TC > KH > UC
Also, P and K content and uptake by maize plants increased significantly by different organic materials. The highly values occurred with 9 ton TC/fed. plus 3 Kg KH/fed. Phosphorus and potassium content and uptake by maize plants was greatly affected by the different organic materials in order of: TC > UC > KH
5.2.1.3- Micronutrients content and uptake.
Treating soil with different application rates of organic materials significantly increased micronutrients Fe, Mn, Zn and Cu content and uptake by maize plant.
The highest values of Fe and Mn content and uptake occurred with 9 ton TC/fed. plus 3 Kg KH/fed. while the highest values of Cu and Zn content and uptake occurred with 9 ton UC/fed. plus 3 Kg KH/fed.
5.2.2- Residual effect experiment:
The results of residual effect after the application of organic materials could be summarized as under.
5.2.2.1- Dry weight yield:
The residual effect of organic materials application after maize has benefited the growth of wheat plant (second crop) the rate of treated compost (TC) at 9 ton/fed. with 3 Kg/fed. of K-Humate recorded the maximum increase in dry weight yield.
5.2.2.2- Macronutrients content and uptake by wheat plant
The results indicated that the residual effect of application of organic materials significantly increased NPK content and uptake by the wheat plants. The NPK content and uptake by wheat plants was greatly affected by the residual effect of different organic materials increased in order of: TC > TC + KH > UC > UC + KH > KH > control
5.2.2.3- Micronutrients content and uptake by wheat plants:
Generally, the residual effect of organic materials significantly increased the micronutrients of Fe, Mn, Zn and Cu content and uptake by wheat plants. The rate of treated compost at 9 ton/fed. plus 3 Kg/fed. K-Humate recorded the maximum increase in the Fe, Mn, Zn and Cu content and uptake by wheat plant
Finally and according to the obtained results, the following conclusion and recommendations could be made.
1– Using compost and K-Humate had positive impact in improving soil physical and chemical properties and crop preface in calcareous soil.
2– The integrated use of organic and inorganic fertilizers is recommended in such poor soil.
3– The calcareous soil still have a significant response to high rates of treated compost for K-Humate application. From the obtained results, 9 ton/fed and 3 Kg/fed is recommended particularly in the newly reclaimed soils.
4– Also, concluding from the results of this study, addition of organic materials followed by good soil management could be recommended, especially in the newly reclaimed areas of sandy and calcareous soils.