Effects of Sugar Beet Factory Lime, Vinasse, and Compost Mixed with Vinasse Application on Sandy Soil Properties and Canola Productivity

Abstract

Large amounts of sugar industrial wastes such as sugar beet factory lime (SBFL) and vinasse (V) are producing annually causing some problems to the environment if not exploited or recycled. Sandy soils and new reclaimed soils are suffering from lack of water retention, low fertility and thus low productivity, requiring more attention to maximize their water and nutrients supply potentials using new and low-cost soil conditioners. Therefore, it was though useful to use sugar factory by products in solving such problems in sandy soils. For this purpose, a field experiment in a completely randomized experimental design with three replicates was conducted through two successive growing seasons (2016/2017 and 2017/2018) in sandy soil, to study the effect of SBFL at a rate of 10 t/ha, V in irrigation water (5 ml/L) and compost mixed with vinasse, CMV at 1:1 rate on some selected soil physico-chemical properties and canola productivity. Results showed that, application of CMV followed by V and SBFL significantly increased soil organic matter, soil available macro-nutrients (N, P and K) and water holding capacity. Meanwhile, soil bulk density and hydraulic conductivity values were decreased subjected to conditioners application, confirming their suitability in improving sandy soil properties for sustainable agriculture. Consequently, canola seed yield, oil and protein content increased significantly due to CMV, V and SBFL application. From view point of water, the highest values of canola water productivity were obtained under CMV application followed by V and SBFL compared with control, favoring their suitable use to get more crop with less drop in sandy soils. Economically, application of SBFL achieved the higher seasonal net return and benefit cost ratio with lower specific cost followed by V and CMV respectively. The study, therefore recommends using CMV to improve the sandy soil properties and its productivity, despite its relatively low economic return compared to other conditioners, given the high-water productivity of CMV application and alleviating the high salinity of V application.