为揭示不同高分子材料对土壤-小麦氮磷的互作效应,在滴灌土壤中添加腐植酸、改性高分子和复合高分子3种材料,研究其对不同粒级土壤氮磷含量和储量的变化特征,以及对春小麦各器官氮磷积累及产量的影响.结果表明,高分子材料对不同粒级全氮含量影响较大.与对照(CK)相比,腐殖酸处理(H)显著增加了>20～40 cm土层中>2、>1～2、>0.25～1和≤0.053 mm粒级范围的全氮含量;改性高分子材料(P)和复合高分子材料(HP)处理分别显著提高了表层土壤(0～20 cm)中>2、>1～2和≤0.053 mm粒级范围和>2、>0.25～1和≤0.053 mm粒级范围的全氮含量.对不同粒级全磷含量的研究发现,H和P处理分别显著提高了表层土壤中>0.25～1和>2 mm粒级范围内的全磷含量,同时在>20～40 cm土层中,H和P处理均在>1～2、>0.053～0.25 mm粒级范围内的全磷含量与CK处理存在显著差异.进一步对不同粒级氮磷储量的研究表明,H处理主要增加了>0.25～1 mm粒级范围内的氮磷储量;P处理有利于提高>1～2、>0.25～1、>0.053～0.25和≤0.053 mm粒级范围内的全磷储量.高分子材料尽管不利于春小麦茎的氮磷积累量及干物质量的增加,却提高了其他器官氮磷积累量及干物质量,特别是在成熟期的籽粒中这种增加幅度更大.其中H和P处理中籽粒的氮磷积累量较CK分别增加了25.6％、24.9％和40.9％、26.7％(P<0.05),同时籽粒产量提高了19.7％和12.6％(P<0.05).冗余分析表明,>1～2和>0.25～1 mm粒级范围内的氮磷储量是春小麦增产的主要驱动因子之一.该研究结果明确了高分子材料对土壤氮磷养分的作用机制,为当地的应用和推广提供更为深入的理论基础.

The effects of four liquid modifiers (organic–inorganic composite modifier, inorganic polymer compound modifier, polyacrylate compound modifier, and organic polymer compound modifier) on plant growth, cadmium (Cd) content, photosynthetic parameters and antioxidant enzymes were studied in cotton (Xinluzao) under Cd stress (5 mg kg−1) in a barrel experiment. The results showed that the Cd treatment of soil increased Cd content in cotton and reduced plant height, net photosynthesis rate (Pn), chlorophyll fluorescence parameters, antioxidant enzyme activity, and biomass. However, the application of liquid modifiers alleviated Cd stress, increased plant biomass, and decreased Cd content in plant organs as well as Cd transport coefficients of the stem and cottonseed. At the same time, there was an increase in gas exchange, photosynthetic pigment content, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity in cotton leaves, whereas malondialdehyde content (MDA) decreased. These results suggest a positive role of liquid modifiers in alleviating Cd stress in cotton, which was due to (1) significant reduction in Cd uptake of roots and Cd-transportation to leaves and (2) improvement in the antioxidant activity, which regulated the oxidants to a level under control, minimizing the oxidative damage in cotton.

为探讨重金属铅(Pb)、镉(Cd)污染下棉粕腐植酸和聚丙烯酸钾修复剂对土壤微生物多样性的影响,采用田间桶栽试验,进行了棉粕腐植酸、聚丙烯酸钾以及两者复合施用修复污染棉田土壤的研究,通过高通量测序分析了土壤微生物多样性的变化,并利用傅里叶红外光谱进行了土壤化学结构的修复响应分析.结果表明:与未施用修复剂处理相比,施用棉粕腐植酸和聚丙烯酸钾减少了表层土壤Pb、Cd含量,其中两者复合处理可分别减少62.6％ 和52.3％;改变了土壤微环境进而影响了土壤微生物多样性,不同处理共发现土壤细菌25个门,69个纲,149个目,273个科,442个属,其中优势菌门主要为变形菌门、酸杆菌门、芽单胞菌门和放线菌门.聚丙烯酸钾处理增加了土壤中变形菌门的相对丰度,棉粕腐植酸和复合修复处理增加了酸杆菌门和芽单胞菌门的相对丰度.由此可见,铅镉复合污染土壤中微生物多样性丰富,优势菌群相对稳定,聚丙烯酸钾和棉粕腐植酸通过改变土壤微环境进而影响菌群丰度.

通过田间桶栽试验研究了高浓度镉（40mg/kg）条件下,4种改良剂（有机—无机复合稳定剂、无机高分子复配材料、聚丙烯酸盐复配材料、有机高分子复配材料）对棉田土壤剖面中土壤pH、阳离子交换量（CEC）、镉含量及其形态分布迁移的影响。结果表明:（1）4种改良剂均显著提高了棉田土壤剖面各层的pH和CEC,无机高分子复配材料在0—20cm土层效果最好,分别增加了0.43个单位和4.43cmol/kg;（2）改良剂促进土壤可交换态镉向其余4种形态的转化,相关分析表明碳酸盐结合态与可交换态镉含量呈极显著负相关（P＜0.01）,在0—20cm和20—40cm土层中效果尤为突出,以无机高分子复配材料对土壤可交换态镉的降低效果最好,降低了3.61mg/kg;（3）各土层中的pH和CEC均与可交换态镉呈负相关,与其他形态呈正相关。即改良剂通过改变土壤pH和CEC,影响土壤镉的分布及迁移,从而降低镉的有效性,达到改善土壤环境的目的。

为了探究PPMn型水溶肥混合棉粕腐植酸肥施用对棉田土壤和棉花产量的影响,通过红外光谱和扫描电镜分析两种新型水溶肥的官能团特征和外观特征,并利用田间小区试验研究了两种新型水溶肥对棉田土壤物理性质及团聚体、棉花产量和肥料利用率的影响。结果表明:施用棉粕腐植酸肥（H）、PPMn型水溶肥（P）和两种新型水溶肥混合（HP）对改善土壤物化结构和提升棉花产量均优于常规水溶肥（S）和不施肥（CK）,其中HP处理效果最好。HP处理使土壤容重降低8.15%,土壤孔隙度增加7.49%,有效降低了＜0.25mm土壤团聚体所占比例,显著提升氮磷钾的农学利用效率,棉花产量相对于其他处理增加7.5%~41.0%。

[Objective] The objective of this experiment was to compare the effects of three polymer compounds on the properties of salinized soil.[Method] The experiment took place in Shihezi 146 state farms.This study to the severe salinization soil through field experiment with polyacrylate (PAAS),polyacrylamide (PAM) and cellulose (HEC),the determination of the change of soil electrical conductivity,pH,salt ion content.[Result] There linds of polymer compounds could decrease soil EC and content of water-soluble Na +,Ca2 +,SO42-,Mg2 +,Cl-,HCO3-,especially water-soluble Na +.[Conclusion] Therefore,polyacrylate (PAAS),polyacrylamide (PAM) and cellulose (HEC) were the best compounds in improving salinization soil,and provide a reference for salt reducing.