不同耕作方式与有机肥施用对旱地麦田土壤磷组分的影响

Effects of different tillage measures and organic manure application amount on soil phosphorus fractions in dry-land wheat fields

为探讨耕作措施和有机肥施用对旱地麦田土壤磷组分的影响,本研究依托2007年布设的黄土高原旱地小麦耕作与施肥长期定位试验,采用Tiessen磷素分级方法,系统研究了深翻+化肥(T)、深翻+鸡粪+化肥(TM)、免耕+化肥(NT)和免耕+鸡粪+化肥(NTM) 4种农艺措施下麦田0~20 cm土层有效磷、全磷和磷组分分布特征。结果表明:1) NT处理有效磷含量较T处理提高58.37%,有机肥处理(NTM和TM)有效磷和全磷含量均显著高于不施有机肥处理(NT和T),NTM处理的有效磷和全磷含量较TM处理分别显著提高11.43%和43.41%。2)与T处理相比,NT、NTM和TM处理可不同程度提高0~20 cm土层活性无机磷组分NaHCO_(3)-Pi以及中活性无机磷组分NaOH-Pi含量,尤其以NTM和TM处理效果最好。3) NT处理的NaHCO_(3)-Po和NaOH-Po较T处理分别显著提高53.07%和55.56%,NTM处理的这2种组分含量较TM处理分别显著提高90.84%和60.31%,Residual-P NT处理较T以及NTM处理较TM分别提高12.90%和36.60%。4)长期定位试验地每年施入的磷肥在土壤中有盈余,残留的磷主要以NaHCO_(3)-Pi、D.HCl-Pi、NaHCO_(3)-Po和C.HCl-Po形态存在,免耕增施有机肥促进了稳定性磷(C.HClPo)向活性磷(NaHCO_(3)-P)和潜在活性磷(NaOH-P)的转化;偏最小二乘(PLS)回归分析结果表明,NaHCO_(3)-Pi和NaOH-Pi是最有效的磷源,对小麦产量的提升贡献较大,NTM处理对这2种磷组分积累的促进效果最明显。综上免耕增施有机肥是发展黄土高原旱作农业值得推广的农艺措施,同时在推广应用时需要考虑减少化学磷肥用量。

To explore the effects of tillage measures and organic manure application on soil phosphorus fractions in dry-land wheat fields,based on a long-term positioning experiment of tillage and fertilizer(since 2007)in the Loess Plateau,through using the soil phosphorus classification method of Tiessen,we have systematically studied the distribution characteristics of soil available phosphorus,total phosphorus and phosphorus fractions in 0−20 cm soil layer under four agronomic measures:deep tillage+chemical fertilizer(T),deep tillage+chicken manure+chemical fertilizer(TM),no tillage+chemical fertilizer(NT),and no tillage+chicken manure+chemical fertilizer(NTM).The results showed that:1)compared to T treatment,the soil available phosphorus content under NT treatment was increased by 58.37%,the available phosphorus and total phosphorus contents under organic fertilizer treatments(i.e.,NTM and TM treatments)were higher than those under no organic fertilizer treatments(i.e.,NT and T treatments).Compared with those under TM treatment,the available phosphorus and total phosphorus contents under NTM treatment were significantly increased by 11.43%and 43.41%,respectively.2)Compared to T treatment,NT,NTM,and TM treatments improved the content of the active inorganic phosphorus fractions of NaHCO_(3)-Pi and moderate active inorganic phosphorus fractions of NaOH-Pi,especially under NTM and TM treatments.3)Compared to T treatment,the contents of NaHCO_(3)-Po and NaOH-Po under NT treatment were increased by 53.07%and 55.56%,respectively.Compared to that of TM treatment,the above two fractions under NTM treatment were significantly increased by 90.84%and 60.31%,respectively.Compared to T treatment,the residual-P content under NT treatment was increased by 12.90%,and the Residual-P content under NTM treatment was increased by 36.60%compared to that of TM treatment.4)A surplus of phosphorus fertilizer was applied each year in the 17 a long-term positioning test base,and the residual phosphorus mainly existed in the form of NaHCO_(3)-Pi,D.HCl-Pi,NaHCO_(3)-Po,and C.HCl-Po.No tillage and organic manure could promote the translation from stable phosphorus(C.HCl-Po)to active phosphorus(NaHCO_(3)-P)and potentially mobile phosphorus(NaOH-P).Partial least square(PLS)regression analysis indicated that NaHCO_(3)-Pi and NaOH-Pi were the most effective phosphorus sources and their contributions to wheat yield were high.The NTM treatment showed the most apparent effect in promoting the accumulation of the two phosphorus fractions.Therefore,no tillage and organic manure application is an agronomic practice worth promoting in dry-land wheat fields in this area;however,reduction of chemical phosphate fertilizer application should be considered in the popularization and application.