摘要
【目的】研究基于长期定位试验,探索长期不同施肥下红壤性水稻土不同土层活性有机质(labile organic matter(LOM))和碳库管理指数(carbon pool management index,CPMI)变化特征,为红壤性水稻土碳库的合理管理提供依据。【方法】选取进贤红壤长期定位试验站4个典型施肥处理:(1)不施肥(CK);(2)单施化肥(NPK);(3)在NPK的基础上早稻施绿肥,晚稻施猪粪和稻草冬季还田(NPKSM);(4)在NPK的基础上早稻施绿肥,稻草冬季还田(NPKS),测定并分析0-10、10-20、20-40及40-60 cm土层土壤高活性有机质(HLOM)、中活性有机质(MLOM)、低活性有机质(LLOM)、非活性有机质(NLOM)含量以及CPMI变化特征。【结果】不同处理土壤有机质(SOM)含量均随土层加深而降低,施肥处理相对CK均明显提高了不同土层的SOM;在0-20 cm土层,SOM含量表现为NPKSM>NPKS>NPK>CK,且均以NPKSM处理最高,达到43.47 g·kg^-1(10-20 cm)和45.09 g·kg^-1(0-10 cm);在20-60 cm土层,NPKSM和NPKS处理相较于CK显著提高了土壤有机质含量,但两者之间差异不显著。除NPK处理外,各处理土壤可溶性有机碳(DOC)含量随土层的加深显著降低。NPKSM和NPKS处理相较于NPK和CK,显著提高了耕层(0-20 cm)土壤DOC的含量,其中NPKSM处理最高,为35.93 mg·kg^-1。施肥处理比CK处理提高了土壤HLOM、MLOM、LLOM含量,相同处理相同土层表现为LLOM>MLOM>HLOM,其中NPKSM和NPKS显著提高了各LOM组分含量,且随土层的加深无明显犁底层效应,这可能与活性有机质随水分下渗相关。其中,各施肥处理土壤HLOM、MLOM均随土层加深呈先升高后下降趋势,NPKSM和NPKS处理HLOM含量在20-40 cm土层中达到最高,分别为5.31和5.49 g·kg^-1;各处理MLOM均在10-20 cm土层中达到最高,以NPKSM处理含量最高,为10.62 g·kg^-1;而土壤LLOM含量随土层的加深而逐渐降低,在0-20 cm土层中以NPKSM处理含量最高,达到18.52 g·kg^-1(0-10 cm)和15.93 g·kg^-1(10-20 cm)。不同长期施肥处理提高了土壤各LOM组分的比例及碳库管理指数,在0-10 cm表层土中,NPKS和NPKSM处理相较于CK,总活性有机质比例分别提高了27.9%和29.48%,MLOM占比分别提高了7.21%和7.72%,HLOM占比分别提高了5.10%和4.96%。以不施肥处理为参照,各施肥处理碳库管理指数均大于100,且以NPKSM和NPKS处理提高效果最好,有助于提高红壤性水稻土肥力。相较于CK,单施化肥一定程度上提高了表层土壤有机质、活性有机质、可溶性有机碳及碳库管理指数。耕层(0-20 cm)土壤中3种活性有机质两两之间呈极显著正相关关系(P≤0.01),且与总有机质、全氮、可溶性有机碳及水稻产量均呈现显著正相关(P≤0.05)。【结论】不同施肥处理土壤有机质和低活性有机质均随土层加深而降低。NPKSM处理提高土壤有机质及活性有机质含量的效果最佳,并能显著提高0-20 cm土层土壤高活性有机质和碳库管理指数,NPKS次之;而在20-60 cm土层中,NPKS处理对提高中活性有机质和碳库管理指数效果最明显。
【Objective】This study was aimed to explore the characteristics of the labile organic matter(LOM)and carbon pool management index(CPMI)under different fertilization in different soil layers in red soil,so as to provide a theoretical basis for carbon pool management in red soil.【Method】Based on the long-term experiment site located at Jinxian,Jiangxi province,four typical treatments were chosen as:(1)no fertilization(CK);(2)mineral nitrogen,phosphorus,potassium(NPK);(3)NPK combined with pig manure and straw(NPKSM);(4)NPK combined with straw(NPKS).The highly LOM(HLOM),moderately LOM(MLOM),lowly LOM(LLOM),non-LOM(NLOM)and CPMI in four soil depths(i.e.0-10 cm,10-20 cm,20-40 cm and 40-60 cm)were measured and analyzed.【Result】The results showed that the soil organic matter(SOM)content under each treatment was decreased with increasing of soil depths.Compared with CK treatment,the SOM was increased under the fertilization treatments.In 0-20 cm,the SOM content was ordered as NPKSM>NPKS>NPK>CK,with the highest value as 43.47 g·kg^-1(10-20 cm)and 45.09 g·kg^-1(0-10 cm)under NPKSM treatment.In 20-60 cm,the SOM content under NPKSM and NPKS was significantly higher than that under CK,while there was no different between NPKSM and NPKS.The dissolved organic carbon(DOC)content was decreased with soil depth under all treatments except NPK.The DOC content under NPKSM and NPKS was significantly higher than that under NPK and CK,and the highest value was 35.93 mg·kg^-1 under NPKSM treatment.The HLOM,MLOM,and LLOM content were increased under fertilization treatments compared with CK treatment.The LOM content was ordered as LLOM>MLOM>HLOM under the same treatment in same soil layer.All the LOM components content was significantly higher under NPKSM and NPKS treatments in all soil layers.The HLOM and MLOM content under all treatments were trended as first increased and then decreased with increasing of soil depth.The HLOM content was reached to peak in 20-40 cm under NPKSM(5.31 g·kg^-1)and NPKS(5.49 g·kg^-1).The highest MLOM content appeared in 10-20 cm under NPKSM treatment with 10.62 g·kg^-1.The LLOM content under all treatments was decreased with soil depth.In 0-20 cm,the LLOM content was highest under NPKSM treatment with 18.52 g·kg^-1(0-10 cm)and 15.93 g·kg^-1(10-20 cm),respectively.The proportion of different LOM components and CPMI were increased under the fertilizer treatments.In 0-10 cm,compared with CK,the LOM content under NPKS and NPKSM was increased by 27.9%and 29.48%,respectively,MLOM proportion was increased by 7.21%and 7.72%,respectively,HLOM proportion was increased by 5.10%and 4.96%,respectively.The CPMI under fertilization treatment was higher than 100,and which was obviously higher under NPKSM and NPKS.In 0-20 cm,the different LOM components were extremely significantly positive correlation(P≤0.01),and they were significantly positive correlated with total SOM,total nitrogen,dissolved SOM and rice yield(P≤0.05).【Conclusion】The SOM and LLOM content under all treatments were decreased with the increasing of soil depth.The SOM and all LOM components were significantly improved under NPKSM treatment,and HLOM and CPMI under NPKSM were the highest,followed by NPKS in 0-20 cm,while,which was the highest under NPKS in 20-60 cm.
作者
李小磊
张玉军
申凤敏
姜桂英
刘芳
柳开楼
刘世亮
LI XiaoLei;ZHANG YuJun;SHEN FengMin;JIANG GuiYing;LIU Fang;LIU KaiLou;LIU ShiLiang(College of Resources and Environmental Sciences,Henan Agricultural University,Zhengzhou 450002;Zhengzhou Institute of Urban Landscape and Architecture,Zhengzhou 450051;Jiangxi Institute of Red Soil,Jinxian 331717,Jiangxi)
出处
《中国农业科学》
CAS
CSCD
北大核心
2020年第6期1189-1201,共13页
Scientia Agricultura Sinica
基金
国家重点研发计划重点专项项目(2016YFD0300803)
国家自然科学基金(41401327)
河南省科技厅基金(192102110161)。
关键词
长期施肥
活性有机质
碳库管理指数
土层
红壤性水稻土
long-term fertilization
labile organic matter
carbon pool management index
soil depth
red soil