运东近滨海地区燕麦秸秆盐分积累与改良盐碱地潜力分析

为探明燕麦在运东滨海盐碱地区秸秆盐分积累特点以及改良盐碱地的潜力,选用"坝莜1号"、"白燕2号"和"花早2号"燕麦,采用单因素随机区组试验,以品种和土壤含盐量作为因素,进行了2组田间试验,测得燕麦的生物量、秸秆离子浓度和积累量及秸秆与土壤离子浓度比值。研究结果显示,"坝莜1号"燕麦开花-灌浆至成熟期整株生物量从2.9 t·hm-2增加至3.8 t·hm-2,延迟20 d收获则减少至2.5 t·hm-2。"白燕2号"在低土壤盐分浓度(1.0 g·kg-1左右)下的生物量(3.1 t·hm-2)显著大于中浓度(2.0 g·kg-1左右,1.7 t·hm-2)和高浓度(3.0 g·kg-1左右,0.4 t·hm-2)下的生物量。中等土壤盐分浓度下"坝莜1号"的生物量(3.8 t·hm-2)显著高于"白燕2号"(3.1t·hm-2)和"花早2号"(2.2 t·hm-2)。"坝莜1号"秸秆中Na+、K+浓度从开花到成熟均显著增加,而Mg2+、Ca2+和Cl-则显著降低。延迟20 d收获,除Ca2+外,其他离子浓度均显著降低。随着土壤盐分的升高,"白燕2号"秸秆Na+、Mg2+、Ca2+和Cl-浓度显著升高,而K+显著下降。3个品种的Na+、K+和Mg2+之间存在显著差异,而Cl-和Ca2+浓度无显著差异。燕麦秸秆中Cl-浓度最高,K+和Na+基本相当,均高于Mg2+和Ca2+。"坝莜1号"秸秆中Na+、K+、Mg2+、Cl-积累量成熟期最高,延迟收获20 d后积累量均显著降低。"白燕2号"秸秆Na+、K+、Mg2+、Ca2+、Cl-积累量随土壤盐分升高显著下降。除Ca2+外,Na+、K+、Mg2+、Cl-积累量品种之间差异显著。"坝莜1号"秸秆与土壤离子浓度比值中,Na++K+最大(46~63),其次是Cl-(30~46)、Mg2+(24~30)和Ca2+(3~15);延迟收获后Na++K+和Cl-秸秆与土壤浓度比值显著下降,Mg2+比值无显著变化,Ca2+比值显著升高。随着土壤盐分升高"白燕2号"秸秆与土壤Na++K+和Cl-浓度比值显著下降,Ca2+无显著变化。秸秆与土壤离子浓度比值在品种之间存在显著差异。燕麦理论上具有改良盐碱地的潜力,但收获时间和土壤盐分均会显著地影响燕麦生物量、离子浓度和积累量,从而影响燕麦改良盐碱地的效果。

Analysis of oat-straw salt ion accumulation and the potential for improvingsaline-alkali soils in coastal Hebei Province

Because oat is highly nutritious and resistant to drought, barren and saline conditions, it is extensively cultivated around world. However, there is less oat cultivation in low-latitude coastal saline areas. Therefore the absorption of soil salt ions and the potential for improvement of saline-alkali soils via oat cultivation has been rarely researched. To investigate the characteristics of straw salt accumulation and the potential for improving saline-alkali soils via oat cultivation in coastal Hebei Province, the single factor randomized block design experiments of two factors (variety and soil salinity) was analyzed for oat biomass, straw ion concentration and accumulation, and straw-soil ion concentration ratio. The results showed that variety "Bayou1" oat biomass was 2.9 t·hm^-2 at flowering-filling stage, which increased to 3.8 t·hm ^-2 at maturity. When "Bayou1" oat harvest was delayed for 20 days, biomass yield decreased to 2.5 t·hm ^-2. "Baiyan2" oat biomass was 3.1 t·hm ^-2 in low saline soils (containing 1.0 g·kg ^-1 salt), which was significantly greater than in medium (1.7 t·hm^-2) and high (0.4 t·hm^-2) saline soils (containing 2.0 g·kg^-1 and 3.0 g·kg^-1 salt, re-spectively). Under the medium salinity conditions, "Bayou1" biomass (3.8 t·hm^-2) was significantly higher than "Baiyan2" (3.1 t·hm^-2) and "Huazao2" (2.2 t·hm ^-2) biomass. Na⁺ and K⁺concentrations in "Bayou1" straw from flowering to maturity stage significantly increased, while Mg²⁺, Ca²⁺ and Cl decreased. When oat harvest was delayed, straw ion concentration (with the excepting of Ca²⁺) significantly dropped. Na+, Mg²⁺, Ca²⁺ and Cl in "Baiyan2" straw significantly increased with increasing soil salinity, whild K⁺ significantly decreased. There were significant differences in Na⁺, K⁺ and Mg²⁺ concentrations among the three oat varieties, but no notable differences in Ca²⁺ and Cl . Cl concentration was highest in the oat straws, followed by K⁺+Na⁺, Mg²⁺, Ca²⁺, Na⁺, K⁺, Mg²⁺and Cl accumulations in "Bayou1" straw were highest at maturity, which significantly dropped under delayed harvest. Na+, K+, Mg2+, Ca²⁺ and Cl accumulations in "Baiyan2" dropped with soil salinity increasing. With the exception of Ca²⁺, there were significant differences in straws Na⁺, K⁺, Mg²⁺ and Cl accumulations among the three oat varieties. For "Bayou1" straw-soil ion concentration ratio, Na⁺+K⁺ was highest (with ratio of 46~63), followed by Cl (30~46), Mg²⁺ (24~30) and Ca²⁺ (3~15). With the exception of Mg²⁺ and Ca²⁺, the ratios dropped significantly when oat harvests were delayed. With soil salinity increasing, Na⁺+K⁺ and Cl ratios of oat-straw to soil significantly dropped, Ca²⁺ ratio changed unsignificantly. There were significant differences in straw-soil ion ratios among the oat varieties. The oat had the potential for improving saline-alkali soils in theory, but harvest time and soil salinity significantly affected oat biomass, ion concentration and accumulation. Furtherly, the influences of application of subsurface drainage system on topsoil salt balance and the effect of drought on oat salt accumulation during the oat growth season needed further research.