重度盐碱地改良措施对土壤特性和不同植物光合、生长的影响

Influence on Soil Properties and Different Plant Photosynthesis,Growth by Different Amelioration Methods

研究了重度盐碱地改良对土壤特征及不同植物光合生长的影响,结果发现:实施不同改良措施后,土壤特性方面发生了显著变化,土壤总孔隙度比对照(盐碱裸地)提高5%～20%;田间持水量比对照提高3%～13%;土壤容重由对照的1.2～1.4g.cm-3降到0.7～1.0g.cm-3;土壤紧实度由对照的2000～2500kPa降低到500～1000kPa;土壤毛细管上升高度和土壤透水速率也高于对照;土壤电导率平均降低了1288μs.cm-1;土壤pH值平均降低1.5左右;浅槽改良和深槽改良后碱解氮分别提高了50%和100%;浅槽改良和深槽改良后土壤CO2浓度达到2500～3500和3000～3500μL.L-1;深槽改良使得土壤深层氧气浓度下降到17%左右。改良后种植的植物光合能力方面也有不同提高,其中甘草、甜玉米和偃柏等经深槽改良处理后比对照提高2.5～12μmol.m-2.s-1。不同植物经过处理后在生物量方面明显提高,其中甜玉米、白菜、萝卜和偃柏等深槽改良处理明显高于其客土覆盖处理,我们的研究表明大规模盐碱地改良后种植品种选择应该因地制宜,综合考虑其土壤特性和植物适应性。

Though studying the ameliorated influence of Saline-alkali soil＇s soil properties,photosynthesis and growth of different plants,we found that,after Saline-alkali ameliorations,soil properties significantly changed. The soil total porosity was 5% to 20% higher than control （bare land）; field capacity was increased by 3%-13%; soil bulk density from the control of 1.2-1.4g·cm^-3down to 0.7-1.0g·cm^-3 soil compaction in control 2000-2500kPa reduced to 500-1000kPa; soil capillary rise height and soil permeability rate were also higher than control; soil conductivity reduced by an average 1288μs·cm^-1; soil pH value averagely decreased 1.5; shallow groove and deep groove treatments respectively improved nitrogen by 50% and 100%; shallow groove and deep-groove treatments improved soil CO2 concentrations 2500-3500μL·L^-1and 3000-3500μL·L^-1 Deep-groove treatment dropped the soil oxygen concentration to about 17%. The photosynthetic capacity of plants had been increased; Glycyrrhiza uralensis,Zea mays and Sabina chinensis var. sargentu in the deep-groove treatment were increased by 2.5-12μmol·m^-2·s^-1. There were obviously improvements in biomass,including Z.mays,Brassica oleracea,Raphanus sativus,and S.chinensis var. sargentu,etc. The deep groove treatment was much higher than the others. It was proved the requirement of these plants to high soil organic matter. The biomass differences of Medicago sativa,G.uralensis,Beta vulgaris var. saccharifera and Iva xanthifolia in different ameliorations were not obvious. Our finding indicted the ideal plants for large-scale Saline-alkali soil amelioration should fully consider soil condition and plant adaptability.