EFFECT OF DEFICIT IRRIGATION, NITROGEN AND POTASSIUM FERTILIZATION ON SUGAR BEET PRODUCTIVITY IN SANDY SOILS

B.S.I. Makhlouf, A.E.A. Abd El- All
2017 Menoufia Journal of Plant Production  
Two field experiments were carried out in a sandy soil in El-Bostan area, Aly Mubark Experimental Farm, Southern El-Tahrir region, (latitude of 30.57 0 N and longitude of 30.71 0 E), El-Buhira Governorate, Egypt, during the two successive seasons of 2013/2014 and 2014/2015 to find out sufficient amount of irrigation water and the optimal levels of nitrogen and potassium fertilizers to get the highest yield and quality of sugar beet grown in a sandy soil under drip irrigation system conditions.
more » ... split plot design with three replications was used to lay out eighteen treatments, represented the combinations of three deficit irrigation regimes (applying irrigation water at 60%, 80% and 100% of the actual crop evapotranspiration "ET c "), which occupied the main plots, whereas six combinations among three nitrogen fertilization levels (80, 100 and 120 kg N/fed "0.42 ha -1 ") and two potassium levels (24 and 48 kg K 2 O/fed) were distributed randomly in the sub-plots. Sugar beet Sara multi-germ variety was sown in both seasons. Results revealed that irrigating sugar beet at 80% ET c significantly increased root length and diameter, sucrose%, extractable sugar% (ES) and purity% in both seasons. However, applying water at 100% ET c significantly increased leaf area index (LAI), K and α-amino N contents in root as well as top, root and sugar yields/fed in both seasons. Increasing potassium fertilizer level to 48 kg K 2 O/fed significantly increased all traits under study, except purity% significantly decreased, in both seasons, meanwhile the increment in ES% did not reach to the significant level in the 1 st season. Root length and diameter, Na, K and α-amino N contents, LAI, top, root and sugar yields/fed were significantly increased by increasing nitrogen levels from 80 to 120 kg N/fed, whereas adding 100 kg N/fed gave the highest significant values of sucrose% and ES%, in both seasons. The combination between water regime at 80% ET c and 48 kg K 2 O/fed gave the highest averages of root length, sucrose% and ES%, in both seasons. The combination between water regime at 100% ET c and 48 kg K 2 O/fed significantly increased root yields/fed in both seasons, as well as sugar yield/fed in the 1 st one. The addition of water at 100% ET c with 120 kg N/fed significantly increased root diameter, LAI and yields of top, root and sugar/fed in both seasons. Sucrose%, ES% and purity% significantly increased by the application of water at 80% ET c and 100 kg N/fed in both seasons. The combination between 48 kg K 2 O/fed and 100 kg N/fed produced the highest significant values of sucrose% and ES%, in the 1 st season. Water use efficiency (WUE) calculated on root and/or suger yield basis increased with decreasing the amount of applied irrigation water indicating that deficit irrigation regime is a good tool to increase WUE for sugar beet under drip irrigation condition in sandy soil. Based on the previous results, the application of irrigation water at 80% ET c with the addition of 48 kg K 2 O/fed and 100 kg N/fed could be recommended to get the best quality, while the combination of 100% ET c , 48 kg K 2 O/fed and 120 kg N/fed is recommended to get the highest yields of sugar beet grown in a sandy soil under drip irrigation at El-Bostan, El-Buhira Governorate.
doi:10.21608/mjppf.2017.125867 fatcat:6tq54brlmzfylmluhycd6b25gu