玉米秸秆基纤维素保水剂对土壤持水性能及冬小麦根系生长的影响

为探讨自制的玉米秸秆基纤维素保水剂(SAP)在农业生产上的应用潜力,利用扫描电镜表征了SAP吸水前后形貌变化,探究了SAP施用量对土壤持水性能和不同程度水分胁迫下冬小麦根系生长的影响。结果表明：SAP在土壤中吸水膨胀后降低了土壤容重,土壤最大水分含量较不施SAP显著提高19.1%~67.6%,同时降低了前3天土壤水分蒸发速率。轻度（60%~70%田间持水量）和中度（40%~50%田间持水量）水分胁迫下,施用0.4% w/w SAP处理冬小麦总根长提高15.9%和24.7%,根系活力提高29.6%和43.5%,但充足供水（75%~90%田间持水量）时施用SAP对冬小麦根系活力无显著影响。因此,玉米秸秆基纤维素保水剂施入土壤后能够改善土壤持水性能,从而缓解水分胁迫对冬小麦根系生长的抑制效应。

Effects of Maize Straw Cellulose-based Super Absorbent Polymer on Soil Water Retention Capacity and Root Growth of Wheat

To study the utilization potentiality of maize straw cellulose-based super absorbent polymer (SAP) in agricultural production, the structures of SAP before and after water absorption were characterized. Meanwhile, the effects of SAP application on soil water retention capacity and root growth of wheat under water stress was studied. The results showed that the swelling of SAP decreased soil bulk density, increased soil maximum water content by 19.1% to 67.6% compared to the treatment without SAP, while decreased the evaporation rate in the first 3 days. Under mild (60%-70% of soil water retention capacity) and moderate (40%-50% of soil water retention capacity) water stress, the root length with 0.4% w/w SAP application increased by 15.9% and 24.7%, while the root activity increased by 29.6% and 43.5%, respectively, compared with those without SAP. However, no significant difference of root activity and root biomass were observed under well-watered condition (75%-90% of soil water retention capacity). In summary, the SAP with excellent water retention capacity is effective in promoting the root growth of wheat, and could relieve the inhibiting effect of water stress on winter wheat root growth.