Effects of Residual Wheat Straw and Nitrogen Fertilizer on Yield and Quality of Sugar Beet in a Semi-Arid Region

The effect of wheat residue and nitrogen fertilizer on the following sugar beet crop was investigated in two successive experiment years. Significant differences were observed in beet and sugar yield by elevating levels of nitrogen application in both experiment years. Different values of straw incorporation had no effect on beet and sugar yield compared to nitrogen-straw interaction treatments. Elevating nitrogen application resulted in significant white sugar yield in both the experiment years. The values of white sugar yields were greatly affected by nitrogen-straw interactions compared to corresponding pure straw treatments, while no significant differences were observed between nitrogen-straw interaction treatments and the corresponding nitrogen application treatments. The polarized sugar per cent and white sugar content were not significantly affected by different levels of straw incorporation, fertilizer N application and nitrogen-straw interaction treatments in both experiment years. The Elevating nitrogen applications resulted in significant increase of molasses sugar. The sugar losses in molasses were not compensated by straw-nitrogen interaction compared to corresponding pure nitrogen application treatments. The α-amino N values in beets were statistically increased by elevating levels of nitrogen fertilizer application, while no significant variations were observed between the straw-nitrogen interaction and the corresponding nitrogen application treatments. The values of Na and K impurities were not increased significantly by elevating applications of nitrogen fertilizer; also straw-nitrogen interaction did not greatly influence the Na and K values compared to corresponding nitrogen fertilizer application.