不同改良剂对河套灌区盐渍化土壤性状和葵花生长特性的影响

为了评价不同改良剂对盐渍化土壤的改良效果,以葵花为研究对象,采用大田裂区试验方法,设置生物炭(DC,22.5 t/hm~2)、脱硫石膏(DS,37.5 t/hm~2)、脱硫石膏加有机肥(DSF,各37.5 t/hm~2)、对照(DCK)4种处理。结果表明:施加改良剂均降低了土壤容重,增加了土壤孔隙度,生物炭效果最明显,在耕层(0—20 cm)收获后较播种前土壤容重降低6.11%,是DCK的4倍,孔隙度增加12.89%,是DCK的5倍;脱硫石膏降低土壤pH和电导率效果最优,最大降幅分别为10.09%和28.51%;3种改良剂对盐渍化土壤的肥力效应不同,与对照相比,在收获后生物炭处理显著提高土壤耕层有机质、碱解氮、速效磷含量,脱硫石膏显著提高速效钾含量;各改良剂处理能显著增加葵花株高、茎粗、干物质积累量和百粒重,且生物炭处理的葵花产量最高,为4 539.60 kg/hm~2,较对照增产32.28%。综上所述,在河套灌区盐渍化土壤中施入不同改良剂后,土壤性状得到明显改善,促进葵花的正常生长,提高了产量。其中施入生物炭22.5 t/hm~2对盐渍土壤改良效果最佳,其次是施入脱硫石膏37.5 t/hm~2,能有效地提高土壤肥力和葵花产量。

Effects of Different Amendments on the Properties of Salinized Soil and Sunflower Growth in Hetao Irrigation District

In order to evaluate the improvement effect of different amendments on salinized soil, this study took sunflower as the research object. A field split plot experiment was conducted with 4 treatments:the biochar (DC, 22.5 t/hm²),desulfurization gypsum (DS, 37.5 t/hm²),desulfurization gypsum and organic fertilizer (DSF, 37.5 t/hm²) and the control (DCK). The results showed that the soil bulk density were reduced, and soil porosity was increased by adding amendments, among which the biochar gave the best effect. For the plough layer (0-20 cm), the soil bulk density was decreased by 6.11% after harvest, which was 4 times of the control. Soil porosity was increased by 12.89%, which was 5 times of the control. The desulfurization gypsum had the best effect in reducing soil pH value and electrical conductivity, with the biggest drop of 10.09% and 28.51%, respectively. Different amendments had different effects on soil fertility. Compared with the control, the biochar treatment significantly increased the contents of organic matter, available nitrogen and available phosphorus in surface soil after harvest. The desulfurization gypsum significantly increased the contents of available potassium. The sunflower plant height, stem diameter, dry matter accumulation and 100-grain weight were significantly increased by the different amendments. The highest sunflower yield was observed under the biochar treatment, which was 4 539.60 kg/hm², 32.28% higher than the control. In summary, the soil properties were significantly improved after adding different amendments in the salinized soil of Hetao Irrigation District, leading to the increased sunflower growth and yield. The application of biochar with 22.5 t/hm² had the best effect on the improvement of saline soil, followed by desulfurization gypsum of 37.5 t/hm², both of which could effectively improve soil fertility and sunflower yield.