【作者】 刘刚；

【导师】 李新平；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2008， 硕士

【摘要】 本文以宁夏银川平原北部盐碱土为研究对象,通过盆栽试验和田间试验,系统的从土壤化学性质、物理性质、微生物区系等方面对硫磺改良盐碱土的改良效果进行了研究。研究结果表明:（1）硫磺可以有效降低土壤pH。盆栽试验土样由于碱性较弱以及供水充分的影响,降低效果最不明显且各硫磺表现效果处理之间差异不大;田间试验中,表层（0～20cm）土壤pH降低效果明显,并与硫磺用量的升高表现出明显的正相关。20～40cm土层土壤pH的变化未有明显的规律性。（2）硫磺的氧化影响了土壤中盐分组成。伴随着硫磺的氧化,土壤中SO₄^2-含量剧增。在田间试验中,土壤中SO₄^2-含量与硫磺用量的升高表现出正相关;土壤中CO₃^2-和HCO₃^-含量降低;土壤中Cl^-含量无太大变化;土壤K⁺含量在盆栽试验中有一定的升高,在田间试验中则变化不大;难溶性二价钙盐镁盐溶解度增大,导致了土壤中Ca²⁺+Mg²⁺剧烈增长。在盆栽试验中表现出随硫磺用量增大而增大的趋势;Ca²⁺+Mg²⁺代换出胶体吸附的交换性Na⁺,引起了土壤中Na⁺含量的增高。Na⁺含量的变化在盆栽试验中亦变现为明显的随硫磺用量增大而增大的趋势。（3）土壤中盐分离子的变化,最终引起了土壤盐分总量的变化,其表现就是土壤EC值的变化。在盆栽试验以及小麦田间试验中（0～20cm）,土壤EC值的变化与硫磺用量的升高正相关。玉米田间试验中（0～20cm）,其变化表现为中硫S2增长幅度最大。20～40cm土层由于影响因素较多,其EC值变化情况很复杂,未表现出任何规律性。（4）硫磺处理能够有效降低土壤交换性钠离子含量,并且硫磺用量越高表现效果越明显的趋势。（5）土壤阳离子交换量主要由土壤粘粒多少和粘土矿物种类的决定。由于硫磺并不能在短期内对土壤粘粒多少和粘土矿物种类产生很大的影响,因此土壤阳离子交换量没有明显变化;施用硫磺降低了土壤碱化度（ESP）,在田间试验中,土壤ESP的降低与硫磺用量的多少表现出明显相关性。（6）施用硫磺影响了土壤中速效养分。其中盆栽试验由于较好的土壤肥力特征以及较高的化肥用量,其速效钾的变化并不明显。受盐分等因素的影响,硫磺处理速效氮和速效磷含量低于纯施肥处理。田间试验中,硫磺的施用可以增加土壤中速效磷和速效钾含量。速效氮在小麦田间试验中,表现为升高的变化趋势,玉米田间试验中则表现为降低的现象。（7）硫磺的施用改善了土壤物理性质。田间试验中,土壤容重降低,土壤孔隙度、田间持水量和毛管上升高度均有不同程度的提高。其中,在玉米田间试验中,土壤容重和孔隙度变化与硫磺用量表现出显著相关性。土壤田间持水量和毛管上升高度变化没有表现出明显的规律性。（8）硫磺处理对土壤微生物区系产生了影响。在8月时,硫磺处理微生物多样性与CK2相近,微生物总量却低于纯施肥处理。到了后期,微生物种类更加丰富,硫磺处理其微生物多样性及总量均强于纯施肥处理。总之,硫磺的施用对土壤理化性质有了一定的改善,促使其朝良性的方向发展。更多还原

【Abstract】 Through the pot-culture and field experiment,we discuss the effects of sulfur to the alkali-saline soil in Pingluo,Ningxia hui autonomous region in soil physical and chemical properties and microflora.The results indicated:（1） Using the sulfur to the alkali-saline soil could decrease the soil pH.The effect was not significant because of the low soil alkalinity and abundant soil water in pot -culture experiment.In field experiment,the effect showed positive correlation with amount of sulfur in 0-20cm horizon,But in the 20-40cm horizon,there was not any tendency.（2） Sulfur oxidation lead to the change of soil EC.The content of soil SO₄^2-,Ca²⁺,Mg²⁺ and Na⁺ were increasing,and the content of soil CO₃^2- and HCO₃ were reduced by improved solubility of insoluble calcium and magnesium salt.At the same time,the content of soil Cl^-and K⁺ had little change.（3） The changes of salt ions resulted in the increasing of soil EC.In the pot -culture experiment and wheat field experiment（0-20cm）,with the growing of sulfur amount the effect was more significant.The treatment S2 showed the best effect in maize field experiment（0-20cm）.In 20-40cm horizon,soil EC had a complicated change because of other factors.（4） The use of sulfur reduced the content of soil exchangeable Na⁺,and showed a trend of positive correlation.（5） The CEC is determined by the amount of clay and the kind of clay mineral,the treatments did not change them,so the CEC had no significant difference;with the use of sulfur,soil ESP was decreasing and showed the regulation of positive correlation with amount of sulfur.（6） Soil available nutrients were affected.Because of a better soil fertility treatment,the soil available K had little change,but the available N and available P of sulfur treatment was less than CK2 in pot -culture experiment.In field experiment,available P and available K were increased;available N showed an increasing trend in wheat experiment.（7） The treatments improved the soil physical character,which could be obviously seen from the change of bulk density、soil porosity、soil field capacity and soil capillary height.In maize field experiment,the change of bulk density and soil porosity had close relativity with amount of sulfur.There wasn’t any law between soil field capacity and soil capillary height and amount of sulfur.（8） Effect of soil microflora under sulfur treatments indicated that soil microbial diversity under sulfur treatment was same to control,total number of soil microbial of CK2 was more than sulfur treatment in august.With the passage of time,soil microbial diversity had a remarkable growth;the sulfur treatment had a better effect than CK2.In brief,using of sulfur already have improved the soil physical and chemical property and guided soil to a better status.更多还原