EFFECT OF ORGANIC MANURES IN COMBINATION WITH ELEMENTAL SULPHUR ON SOIL PHYSICAL AND CHEMICAL CHARACTERISTICS, YIELD, FRUIT QUALITY, LEAF WATER CONTENTS AND NUTRITIONAL STATUS OF FLAME SEEDLESS GRAPEVINES I- SOIL PHYSICAL AND CHEMICAL CHARACTERISTICS

The present study was carried out during 1998 and 1999 growing seasons of Flame seedless grapevines in the orchard of Experiment Station, Faculty of Agriculture, Saba Bacha, Alexandria University .The aim of the present study was to investigate the combined effects of elemental sulphur and organic manures on physical and chemical characteristics of experimental soil. The experimental Soil has a clay texture. All vines received the same N requirements (60 kg N/fed.), as recommended, but with  replacement of one third and two third of the N requirements by organic manures namely Town refuse (TR1 and TR2), Farmyard manure (FYM1 and FYM2) and Bio Treasure (BT1 amd BT2) according to their N content. Two rates of elemental sulphur (S) were applied i.e., zero and 250 g sulphur/vine.  All vines were received the same recommended practices. The obtained results revealed that  application of organic manures significantly decreases the soil bulk density and medium pores, but increased the total porosity, large and small pores. The same trends were noticed with Sulphur application but without a significant effect. Organic manures significantly increased the soil moisture contents at 0.0, 0.33 and 15.0 bars, but sulphur application has not a significant effect. Mean weight diameter (MWD), optimum size of particles (OP) and Basic infiltration rate or field saturation conductivity were found to be significantly increased as a result of both sulphur and organic ;manures applications. The data indicated that both TR and FYM were more effective than BT in improving soil physical characteristics without significant differences in both seasons. The results also showed that available soil nutrients i.e. N, P, K, Fe, Mn, Cu and Zn were found to be significantly increased due to both sulphur and organic manure applications. Also, the data revealed that both TR and FYM produced more available N than BT as indicated by Apparent Net N Release (ANNR). Both soil organic matter content (OM) and electrical conductivity (EC) were found to be increased, while the soil pH and exchangeable sodium percentage (ESP) decreased as a results of organic manure applications. Sulphur application has a significant effect in decreasing both of soil pH and ESP in both seasons. A general, the; most outcome of the present study is clarifying the important role of organic manures such as Farmyard manure and Town refuse in modifying the soil physical and chemical behaviors that enhancing the plant production (growth, yield and fruit quality) that will be illustrated in the part II of this study.