摘要
【目的】研究长期不同施肥条件下褐土养分含量和与土壤有机质水解、碳氮磷有效性相关的酶活性及其化学计量变化特征,以深刻认识农田土壤元素循环的生物地球化学特征。【方法】依托1992年开始的山西寿阳旱地农田生态系统野外长期定位试验,选取其中不施肥对照(CK),4个单施无机肥处理(N_(1)P_(1)、N_(2)P_(2)、N_(3)P_(3)、N_(4)P_(4)),3个无机肥和有机肥配施处理(N_(2)P_(1)M_(1)、N_(3)P_(2)M_(3)、N_(4)P_(2)M_(2))和1个单施有机肥处理(M_(6))进行研究。于1992、2001、2006和2016年,分析了表层土壤(0—20 cm)中有机碳(C)、全氮(TN)、全磷(TP)、有效氮(AN)和有效磷(AP)含量及与碳氮磷循环相关的β-1,4-葡萄糖苷酶(β-1,4-glucosidase,BG)、β-1,4-N-乙酰氨基葡萄糖苷酶(β-1,4-N-acetylglucosidase,NAG)和碱性磷酸酶(alkaline phosphatase,ALP)活性。计算土壤养分之间和酶之间的化学计量比(C∶TN、C∶TP、TN∶TP和lnBG/lnNAG、lnBG/lnALP、lnNAG/lnALP)。计算酶向量角度(vector angle)和向量长度(vector length)。以向量角>45°或者<45°的多少来评价微生物受磷、氮限制的程度,向量角>45°越多表示微生物受磷限制越强,向量角<45°越多表示微生物受氮限制越强。以向量长度评价微生物受碳限制的程度,向量长度越长表示微生物受碳限制越强。【结果】1)除N4P4处理土壤C:TN显著高于M_(6)处理外,其他化肥和有机肥处理之间C:TN和C:TP不存在显著差异,而土壤TN:TP在各施肥处理下显著低于M_(6)处理(P<0.05)。与CK相比,M_(6)处理C∶TN显著降低了30.2%,TN∶TP显著升高了41.0%;N_(4)P_(4)处理C∶TP显著降低了23.3%,TN∶TP降低了17.6%(P>0.05)。土壤C∶AN平均为2.11~2.29,处理之间无显著差异;土壤C∶AP和AN∶AP随化肥和有机肥投入量增加而降低,4个有机肥处理的土壤C∶AP和AN∶AP降幅大于4个化肥处理。2)长期N_(2)P_(2)、N_(3)P_(3)和N_(4)P_(4)处理下,土壤lnBG/lnNAG、酶向量角
【Objectives】We studied soil element content,the enzyme activity related to C,N and P availability and their stoichiometric changes to understand the effects of long-term fertilization on the biogeochemical characteristics and nutrients cycling of farmland.【Methods】The long-term field experiment was conducted in Shouyang County of Shanxi Province,and started in 1992.The study had nine fertilization treatments:no fertilizer control(CK),four chemical fertilizer treatments(N_(1)P_(1)、N_(2)P_(2)、N_(3)P_(3)、N_(4)P_(4)),three chemical fertilizer combined with manure treatments(N_(2)P_(1)M_(1)、N_(3)P_(2)M_(3)、N_(4)P_(2)M_(2)),and one manure treatment(M_(6)).Among these fertilization treatments,N_(1),N_(2),N_(3) and N_(4) represent urea N input rates of 60,120,180 and 240 kg/hm^(2);P_(1),P_(2),P_(3) and P_(4)represent super calciumphosphate input rates of 37.5,75.0,112.5 and 150.0 kg/hm^(2);M_(1),M_(2),M_(3) and M_(6) represent manure application rates of 22500,45000,67500 and 135000 kg/hm^(2),respectively.In 1992,2001,2006 and2016,soil samples were collected within 0–20 cm layer in all the nine treatments for the determination of soil organic carbon(C),total N(TN),total P(TP),available N(AN),available P(AP) content,and the activity of C-acquiring enzyme(β-1,4-glucosidase,BG),N-acquiring enzyme(β-1,4-N-acetylglucosidase,NAG) and Pacquiring enzyme(alkaline phosphatase,ALP).The soil elements stoichiometric ratios(C∶TN,C∶TP,TN∶TP) and enzyme C∶N(lnBG/lnNAG),enzyme C∶P(lnBG/lnALP) and enzyme N∶P(lnNAG/lnALP)ratios were analyzed.The enzyme vector angles > 45° and 0.05) and lnNAG/lnALP ratios were slightly lower(P>0.05) than the manure treatments under long-term N_(2)P_(2),N_(3)P_(3) and N_(4)P_(4) treatments.The lnBG/lnNAG was all higher but the lnNAG/lnALP was lower than their initials in 1992.The calculated vector angle was higher than45° for all fertilization treatments,and the vector length was 11.1%–52.4% higher than those in 1992.3)Significant correlations were found between AN and t
作者
陈浩宁
周怀平
文永莉
向云
程曼
CHEN Hao-ning;ZHOU Huai-ping;WEN Yong-li;XIANG Yun;CHENG Man(Institute of Loess Plateau,Shanxi University,Taiyuan,Shanxi 030006,China;College of Resources and Environment,Shanxi Agricultural University,Jinzhong,Shanxi 030031,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2022年第6期972-983,共12页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金青年科学基金项目(41807072,41807025)
山西省高等学校科技创新项目(2020L0037)。
关键词
长期施肥
褐土
生态化学计量
资源限制
long-term fertilization
cinnamon soil
ecological stoichiometry
resource constraints
