EFFECT OF DIFFERENT SURFACE AND DRIP IRRIGATION SYSTEMS ON SUGAR BEET YIELD, IRRIGATION PERFORMANCES AND SOIL SALINITY AT NORTH DELTA.

Abstract

A surface drip irrigation(single lateral, SSDI ,or double laterals/plant row, DSDI)) , subsurface drip irrigation (single lateral, SSSDI ,or double laterals/plant row, DSSDI),gated pipes (GP) and traditional surface irrigation(TSI) were applied with sugar beet(variety Raspoly) during the winter season 2007/2008 at Sakha Agricultural Research Station Farm , Kafr El-Sheikh Governorate, Egypt in order to study the effect of these irrigation systems on sugar beet yield , its quality, irrigation performances and soil salinity. Both drip irrigation systems included 16 mm diameter drip-lines, with emitters discharging about 2L/h and spacing 0.5 m. The subsurface drip irrigation system was installed before the crop seeding, where its laterals (16 mm drip-lines) were buried 0.6 m apart at 15cm below soil surface so that they are not affected by the cultivation practices during the current growing season. The aluminum gated pipes (150 mm diameter) were located at the head of the irrigated field and connected directly with the irrigation pump. The design of this experiment was randomized complete blocks(RCB) with six replicates. The following findings could be summarized as follows: The highest root, sugar yield, sucrose percentage and quality of juice were produced when sugar beet plants were irrigated by gated pipes. While the lowest root and sugar yield were achieved with irrigation by double line of subsurface drip irrigation.  The highest content of K % was obtained when sugar beet plants received the lowest amount of irrigation water. While, the lowest one was recorded with plants received the highest amount of irrigation water.  Na % and amino N % in Juice: The different irrigation systems had insignificant effect on Na and amino N % in Juice.  Water applied was obviously affected by irrigation systems. The DSSDI system was more effective since it received the lowest amount of irrigation water (2074.8 m 3 /fed) followed by SSSDI (2230.2 m 3 /fed) DSSDI system (2255.4 m 3 /fed). On the other hand, TSI system received the highest amount of irrigation water (3150 m 3 /fed) followed by GP system (2692.2 m 3 /fed)  The highest values of field water use efficiency are obtained with SSSDI or DSSDI ,respectively. While, the lowest value is given by TSI system. Also, the highest values of crop water use efficiency are achieved with SSSDI, GP and DSSDI system. The lowest values of crop water use efficiency for root are recorded with SSDI, DSDI and TSI system.  The irrigation by GP and SSDI systems achieved the highest values of water distribution efficiency. While, subsurface drip irrigation system (single or double laterals) recorded the lowest distribution efficiency. On the other hand, surface drip irrigation system achieved the highest values of distribution uniformity with single or double laterals/plant row respectively. While, the lowest distribution uniformity value is recorded with single subsurface drip laterals. Sonbol, H.A. et al. 408  The soil salinity values are increased with depth for surface drip irrigation (single or double laterals), gated pipes and traditional surface irrigation. While with subsurface drip irrigation (single or double laterals), the values are decreased with the depth to 60 cm and then increased again in the last deepest layer (60-90 cm).