Study On The Response Of Soil To The Land Application With Sugar Beet Rinse Water

Heilongjiang, as a major agricultural province, due to the unique geography location and climate condition, is very suitable for sugar beet planting. The rinse processing of sugar production pretreatment has discharged abundant wastewater because of vast water washing root tuber of sugar beet. If the water is treated by traditional biochemistry degradation technology, long period and high cost about treatment are problems. Sugar beet rinse water (SBRW) is safe because it contains amounts of nutrients, and does not contain heavy metals and pathogens for the safety of sugar processing. Land application with SBRW can not only save irrigation water and reduce the treatment cost, but also ease the loading of environment. However, it is uncertain to know the response of soil to the land application with SBRW. Therefore, the study mainly focused on the response, by taking the typical crop (corn and soybean) soil irrigated with SBRW as research objetive, and sampling as well as measuring soil pH, available nutrients, EC, exchangeable sodium, cation exchange capacity (CEC), soil salinity (EC) and ion contents. Samples were also collected in other plot:pre-irrigation (provided reference "background" values), well water (WW) irrigation (served as the control) site. Correlation analysis and principal component analysis (PCA) were used to evaluate impact of SBRW irrigation on safety effect of the whole soil profile. Meanwhile, the study also analyzed the impact on yield and groundwater with SBRW irrigation. The main results were listed as follows:1. Compared with WW irrigation site and pre-irrigation, the pH decreased at SBRW irrigation site both in corn and soybean soil at the depth of0-20cm and the contents of available nutrients also improved in the soil layer (0-20cm). SBRW would improve the soil quality and boost the growth of crop.2. SBRW, characterized by high salinity, did not cause salt accumulation of soil, and the exchangeable sodium percentage (ESP) in each soil layer was far below the critical value (5%). SBRW did not cause the risk of soil secondary salinization in a short term. Further researches are requested to monitor long-term soil salinity.3. The results of PCA showed that soil available nutrients and CEC changed more remarkably than ESP in both the two crop soil. The results indicated that SBRW irrigation made positive effects on soil nutrients and fertilizer-conserving capacity while it had little influence on ESP.4. SBRW irrigation had no obvious impact on the original balanced condition of soil colloid and the distribution law of ion, and had low risk of negative effect on stability of soil structure.5. Correlation analysis results between EC and soil salt ions in both the two crop soils irrigated with SBRW indicated that EC had showed positive relationship with contents of HCO3-and SO42-. In the long term, as long as maintaining the concentrations of SO42-and HCO3-in a suitable level, just as in the study, SBRW irrigation would have little risk of secondary salinization of soil and mineralization of groundwater.6. Compared with WW irrigation, SBRW irrigation could effectively enhance the yield of crop. Yields of corn and soybean had improved7.79%and4.94%, respectively.7. Compared with WW irrigation and pre-irrigation, SBRW irrigation did not have negative effect on characteristics of groundwater in a short time. Considering the irrigation loading, rainfall washing, soil texture, soil’s hydraulic conductivity (0.23mm/min) and specific retention (35.40%), SBRW irrigation would have little effect on groundwater in a long term.By researching on the response of soil to the land application with SBRW, results confirmed that besides as irrigant, SBRW was also as a "liquid fertilizer" for improvement of soil fertility and crop yield. The study played an important role in guiding and utilizing SBRW as irrigant.