摘要
针对我国土壤酸化普遍、华南土壤酸性较强的问题,研究华南荔枝园土壤p H状况,并进一步探讨荔枝生长最适pH,为荔枝园土壤p H改良的程度和范围提供理论依据和数据支持。采集华南荔枝主产区458个荔枝园土壤样本,研究比较主产区土壤p H状况。另外,采集华南典型荔枝园赤红壤(pH 4.20),以不添加改良剂为对照,添加硫磺(0.5 g·kg^(-1))和不同用量石灰(0.5、1、2、4 g·kg^(-1))调节土壤p H,形成6个土壤pH处理,进行120 d土壤培养和300 d荔枝盆栽试验,研究土壤pH对土壤性质及荔枝生长的影响。华南荔枝园土壤pH在3.85~7.82之间,平均为4.64,整体为酸性,其中以广西荔枝园土壤总体酸性最强。强酸性、酸性、弱酸性、中性和弱碱性荔枝园分别占45.7%、48.0%、5.0%、1.1%和0.2%。培养试验表明,土壤p H在3.84~8.03范围内,碱解氮、速效钾、有效镁含量及脲酶、酸性磷酸酶活性与土壤p H呈显著负相关,有效磷、钙和铜与p H为显著正相关,有效锌、铁和锰与p H关系不密切。盆栽试验显示,施用1 g·kg^(-1)石灰处理荔枝叶片光合作用强,不同时期叶片数、叶面积、茎粗均不同程度高于其他处理,收获时生物量增量及增幅也显著高于其他处理。初步认为荔枝生长适宜的土壤pH为5.03。如土壤p H≤4.64或≥6.46,荔枝生长显著变差。如以pH为5.03作为最适宜的土壤pH来初步衡量,则华南有62.0%的荔枝园土壤pH可能显著抑制荔枝生长,pH需提高平均0.68个单位。这表明华南荔枝园土壤pH改良任务十分迫切。
Soil acidification commonly occurs in China and soils are particularly in high acidity in South China.The present study aims to elucidate soil pH status in litchi orchards in South China and identify the suitable soil pH for litchi growth,providing support for soil pH amelioration in litchi orchards of China.458 soil samples were collected in litchi orchards from litchi main producing areas including Guangdong,Guangxi,Fujian,Hainan and Yunnan provinces.The pH values of these soil samples were determined in solutions(soil∶water=1∶2.5)and then evaluated.A typical latosolic red soil(pH 4.20)from a commercial litchi orchard in Guangdong province was used to simultaneously carry out a 120 d soil incubation and a 300 d litchi culture experiment,respectively.Six soil pH treatments were assigned by addition of 0.5 g·kg-1 sulfur and 0.5,1,2 and 4 g·kg-1 of lime,respectively.The soil without any amendment was included as the control.Effects of soil pH on soil fertility,enzyme activity and growth of litchi seedling were investigated.Soil pH in 458 litchi orchards varied from 3.85 to 7.82,with the average value of 4.64.Litchi orchards,with soil pH<4.5,4.5~5.5,5.5~6.5,6.5~7.5 and>7.5,accounted for 45.7%,48.0%,5.0%,1.1%and 0.2%of the total sampled orchards,respectively.Litchi orchards in Guangxi province had the lowest average soil pH.During the incubation,soil pH in the control,sulfur and 0.5,1,2 and 4 g·kg-1 lime treatments averaged as 4.64,4.25,4.68,5.03,6.46 and 7.58,respectively.Sulfur application increased soil available P,Ca,Mg,Cu and Zn contents,however,reduced acid phosphatase activity(APA)and did not affect urease activity(UA).Liming decreased soil alkali-hydrolyzable N,available K,Zn and the activities of both soil enzymes,but enhanced soil available P,Ca and Cu.Totally,soil alkali-hydrolyzable N,available K,Mg,UA and APA significantly and negatively correlated to soil pH within the pH range of 3.84~8.03 during the incubation,with the Pearson coefficients of-0.529**,-0.850**,-0.579**,-0.458**and-0.872**,respe
作者
邱全敏
王伟
吴雪华
周昌敏
白翠华
姚丽贤
QIU Quan-min;WANG Wei;WU Xue-hua;ZHOU Chang-min;BAI Cui-hua;YAO Li-xian(College of Natural Resources and Environment,South China Agricultural Sciences,Guangzhou Guangdong 510640)
出处
《中国土壤与肥料》
CAS
CSCD
北大核心
2020年第6期89-99,共11页
Soil and Fertilizer Sciences in China
基金
国家现代农业产业技术体系建设专项(CARS-32)。
